Carnivores Table Of Contents - Internet Center for Wildlife Damage

CARNIVORES
C-1
Badgers
Fred C. Lindzey
C-5
Bears, Black
Scott E. Hygnstrom
C-17
Bears, Grizzly/Brown
Charles J. Jonkel
C-25
Bears, Polar
Peter L. Clarkson and Ian Stirling
C-35
Bobcats
Dallas R. Virchow and Denny Hogeland
C-45
Cats, Feral House
William D. Fitzwater
C-51
Coyotes
Jeffrey S. Green, F. Robert Henderson, and
Mark D. Collinge
C-77
Dogs, Feral
Jeffrey S. Green and Philip S. Gipson
C-83
Foxes
Robert L. Phillips and Robert H. Schmidt
C-89
Mink
Edward K. Boggess
C-93
Mountain Lions
James E. Knight
C-101
Raccoons
Edward K. Boggess
C-109
River Otters
Edward P. Hill
C-113
Skunks
James E. Knight
C-119
Weasels
F. Robert Henderson
C-123
Wolves
William J. Paul and Philip S. Gipson
Fred Lindzey
Assistant Unit Leader
Wyoming Cooperative Fish and
Wildlife Research Unit
US Fish and Wildlife Service
University of Wyoming
Laramie, Wyoming 82071
BADGERS
Fig. 1. Badger, Taxidea taxus
Damage Prevention and
Control Methods
Exclusion
Generally not practical.
Habitat Modification
Controlling rodent populations may
make habitats less suitable for
badgers.
Frightening
Bright lights.
Toxicants
Identification
None are registered.
Fumigants
None are registered.
Trapping
Steel leghold traps.
Live traps.
Shooting
Where permitted, shooting with a rifle,
handgun, or shotgun is effective.
Repellents
None are registered.
The badger (Taxidea taxus) is a stocky,
medium-sized mammal with a broad
head, a short, thick neck, short legs,
and a short, bushy tail. Its front legs
are stout and muscular, and its front
claws are long. It is silver-gray, has
long guard hairs, a black patch on each
cheek, black feet, and a characteristic
white stripe extending from its nose
over the top of its head. The length of
this stripe down the back varies. Badgers may weigh up to 30 pounds (13.5
kg), but average about 19 pounds (8.6
kg) for males and 14 pounds (6.3 kg)
for females. Eyeshine at night is green.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-1
General Biology,
Reproduction, and
Behavior
Fig. 2. Range of the badger in North America.
Range
The badger is widely distributed in the
contiguous United States. Its range
extends southward from the Great
Lakes states to the Ohio Valley and
westward through the Great Plains to
the Pacific Coast, though not west of
the Cascade mountain range in the
Northwest (Fig. 2). Badgers are found
at elevations of up to 12,000 feet
(3,600 m).
Habitat
Badgers prefer open country with light
to moderate cover, such as pastures
and rangelands inhabited by burrowing rodents. They are seldom found in
areas that have many trees.
Food Habits
Badgers are opportunists, preying on
ground-nesting birds and their eggs,
mammals, reptiles, amphibians, and
insects. Common dietary items are
ground squirrels, pocket gophers,
prairie dogs, and other smaller rodents. Occasionally they eat vegetable
matter. Metabolism studies indicate
that an average badger must eat about
two ground squirrels or pocket
gophers daily to maintain its weight.
Badgers may occasionally kill small
lambs and young domestic turkeys,
parts of which they often will bury.
C-2
Badgers are members of the weasel
family and have the musky odor characteristic of this family. They are especially adapted for burrowing, with
strong front legs equipped with long,
well-developed claws. Their digging
capability is used to pursue and capture ground-dwelling prey. Typical
burrows dug in pursuit of prey are
shallow and about 1 foot (30 cm) in
diameter. A female badger will dig a
deeper burrow (5 to 30 feet long [1.5 to
9 m]) with an enlarged chamber 2 to 3
feet (0.6 to 0.9 m) below the surface in
which to give birth. Dens usually have
a single, often elliptical entrance, typically marked by a mound of soil in the
front.
Badgers have a rather ferocious
appearance when confronted, and
often make short charges at an
intruder. They may hiss, growl, or
snarl when fighting or cornered. Their
quick movements, loose hide, muscular body, and tendency to retreat
quickly into a den provide protection
from most predators. Larger predators
such as mountain lions, bears, and
wolves will kill adult badgers. Coyotes
and eagles will take young badgers.
Badgers are active at night, remaining
in dens during daylight hours, but are
often seen at dawn or dusk. During
winter they may remain inactive in
their burrows for up to a month,
although they are not true hibernators.
Male badgers are solitary except during the mating season, and females are
solitary except when mating or rearing
young. Densities of badgers are
reported to be about 1 per square mile
(0.4/km2) although densities as high as
5 to 15 badgers per square mile (1.9 to
5.8/km2) have been reported. An adult
male’s home range may be as large as
2.5 square miles (6.5 km2); the home
range of adult females is typically
about half that size. Badgers may use
as little as 10% of their range during
the winter.
Badgers breed in summer and early
fall, but have delayed implantation,
with active gestation beginning around
February. Some yearling females may
breed, but yearling males do not. As
many as 5 young, but usually 2 or 3,
are born in early spring. Young nurse
for 5 to 6 weeks, and they may remain
with the female until midsummer.
Most young disperse from their
mother’s range and may move up to
32 miles (52 km). Badgers may live up
to 14 years in the wild; a badger in a
zoo lived to be 15 1/2 years of age.
Damage and Damage
Identification
Most damage caused by badgers
results from their digging in pursuit of
prey. Open burrows create a hazard to
livestock and horseback riders. Badger
diggings in crop fields may slow harvesting or cause damage to machinery.
Digging can also damage earthen
dams or dikes and irrigation canals,
resulting in flooding and the loss of
irrigation water. Diggings on the
shoulders of roads can lead to erosion
and the collapse of road surfaces. In
late summer and fall, watch for signs
of digging that indicate that young
badgers have moved into the area.
Badgers will occasionally prey on livestock or poultry, gaining access to protected animals by digging under fences
or through the floor of a poultry
house. Tracks can indicate the presence of badgers, but to the novice, badger tracks may appear similar to
coyote tracks (see Coyotes). Claw
marks are farther from the toe pad in
badger tracks, however, and the front
tracks have a pigeon-toed appearance
(Fig. 3).
Badgers usually consume all of a prairie dog except the head and the fur
along the back. This characteristic
probably holds true for much of their
prey; however, signs of digging near
the remains of prey are the best evidence of predation by a badger.
Because badgers will kill black-footed
ferrets, their presence is of concern in
reintroduction programs for this
endangered species.
For Additional
Information
Hawthorne, D. W. 1980. Wildlife damage and
control techniques. Pages 411-439 in S. D.
Schemnitz, ed. Wildlife management
techniques manual. The Wildl. Soc.,
Washington, DC.
H
F
F
Badger
H
Coyote
Long, C. A. 1973. Taxidea taxus. Mammal. Spec.
26:1-4.
Fig. 3. Badger tracks compared to coyote tracks.
Legal Status
In some states, badgers are classified
as furbearers and protected by regulated trapping seasons, while in other
states they receive no legal protection.
Contact your state wildlife agency
before conducting lethal control of
badgers.
Damage Prevention and
Control Methods
Exclusion
Mesh fencing buried to a depth of 12
to 18 inches (30 to 46 cm) can exclude
most badgers. The cost and effort to
construct such fences, however, preclude their use for large areas.
Habitat Modification
Control of rodents, particularly burrowing rodents, offers the greatest
potential for alleviating problems
resulting from badger diggings. For
example, controlling ground squirrels
or pocket gophers in alfalfa fields will
likely result in badgers hunting elsewhere.
Frightening
Badgers may be discouraged from a
problem area by the use of bright
lights at night. High-intensity lamps
used to light up a farmyard may discourage badger predation on poultry.
Lindzey, F. C. 1982. Badger. Pages 653-663 in
J. A. Chapman and G. A. Feldhamer, eds.
Wild mammals of North America: biology,
management, and economics. The Johns
Hopkins Univ. Press, Baltimore, Maryland.
Trapping
Badgers can be removed by using live
traps and/or leghold traps set like
those for coyotes (see Coyotes). Snares
have been used with mixed success.
Badgers often return to old diggings.
A good bait for badgers is a dead
chicken placed within a recently dug
burrow. Fur trapping may reduce badger populations locally, but badger
pelts are generally of little value and
most badgers are caught incidentally.
Leghold traps (No. 3 or 4) are adequate to hold a badger. Rather than
staking the trap to the ground, it is better to attach it to a drag such as a
strong limb or similar object that the
badger cannot pull down into its burrow. Badgers will often dig in a circle
around a stake, sometimes enough to
loosen the stake and drag the trap
away.
Shooting
Messick, J. P. 1987. North American badger.
Pages 584-597 in M. Novak, J. A. Baker, M. E.
Obbard, and B. Malloch, eds. Wild furbearer
management and conservation in North
America. Ontario Ministry of Nat. Resour.
Minta, S. C., and R. E. Marsh. 1988. Badgers
(Taxidea taxus) as occasional pests in
agriculture. Proc. Vertebr. Pest. Conf. 13:199208.
Sargeant, A. B., and D. W. Warner. 1972.
Movements and denning habits of a badger,
J. Mammal. 53:207-210.
Schwartz, C. W., and E. R. Schwartz. 1981. The
wild mammals of Missouri, rev. ed. Univ.
Missouri Press, Columbia. 356 pp.
Wade, D. A. 1973. Control of damage by coyotes
and some other carnivores. Coop. Ext. Serv.
Pub. WR P-11, Colorado State Univ., Fort
Collins. 29 pp.
Wade, D. A., and J. E. Bowns. 1982. Procedures
for evaluating predation on livestock and
wildlife. Bull. B-1429, Texas A & M Univ.
System, College Sta., and the US Fish Wildl.
Serv. 42 pp.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
Badgers can be controlled by shooting.
Spotlighting, if legal, can be effective.
Incidental shooting has contributed to
reducing their numbers in some areas.
Acknowledgments
This chapter is a revision of the chapter on
badgers by Norman C. Johnson in the 1983
edition of Prevention and Control of Wildlife
Damage. F. Robert Henderson and Steve Minta
provided information included in this chapter.
Figures 1 and 2 from Schwartz and Schwartz
(1981).
Figure 3 from Wade (1973).
C-3
C-4
Scott E. Hygnstrom
Extension Wildlife Damage Specialist
Department of Forestry, Fisheries
and Wildlife
University of Nebraska
Lincoln, NE 68583-0819
BLACK BEARS
Fig. 1. Black bear, Ursus americanus
Damage Prevention and
Control Methods
Exclusion
Use heavy woven-wire or electric
fences to exclude bears from
apiaries, cabins, landfills, and other
high-value properties.
Store food in bear-proof structures or
containers, or on elevated
platforms.
Cultural Methods
Use proper sanitation and solid-waste
management techniques.
Remove brush and cover around
farmsteads, corrals, and residences.
Frightening
Shooting
Install night lights and human effigies.
Baiting and predator calling—bears
lured within range can be shot with
firearms of .30 caliber or larger.
Blaring music, pyrotechnics, and
guarding dogs may provide
temporary relief from damage.
Tracking with dogs.
Repellents
Avoiding Human-Bear Conflicts
Capsaicin spray.
Be familiar with several safety
precautions when camping or
traveling in bear country. In
general, never feed black bears and
avoid close encounters with them.
Toxicants
None are registered.
Fumigants
None are registered.
Trapping
Culvert and barrel live traps.
Foot snares.
Confine livestock and remove
carcasses.
Locate camp sites and hiking trails in
areas of low bear activity.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-5
Habitat
No prominent
shoulder hump
Less robust build
Adult male
250 pounds
Straight muzzle
Adult female
150 pounds
Short curved claws
Black bear
Prominent shoulder hump
Massive head
Chunky build
Dishface (long
upturned muzzle)
Adult male
450 pounds
Adult female
250 pounds
Long claws
Grizzly/Brown bear
Fig. 2. Characteristics of black bears and grizzly/brown bears.
Identification
The black bear (Ursus americanus, Fig.
1) is the smallest and most widely distributed of the North American bears.
Adults typically weigh 100 to 400
pounds (45 to 182 kg) and measure
from 4 to 6 feet (120 to 180 cm) long.
Some adult males attain weights of
over 600 pounds (270 kg). They are
massive and strongly built animals.
Black bears east of the Mississippi are
predominantly black, but in the Rocky
Mountains and westward various
shades of brown, cinnamon, and even
blond are common. The head is moderately sized with a straight profile
and tapering nose. The ears are relatively small, rounded, and erect. The
tail is short (3 to 6 inches [8 to 15 cm])
and inconspicuous. Each foot has five
curved claws about 1 inch (2.5 cm)
long that are non-retractable. Bears
walk with a shuffling gait, but can be
quite agile and quick when necessary.
For short distances, they can run up to
35 miles per hour (56 km/hr). They are
quite adept at climbing trees and are
good swimmers.
C-6
Black bears frequent heavily forested
areas, including large swamps and
mountainous regions. Mixed hardwood forests interspersed with
streams and swamps are typical habitats. Highest growth rates are achieved
in eastern deciduous forests where
there is an abundance and variety of
foods. Black bears depend on forests
for their seasonal and yearly requirements of food, water, cover, and space.
It is important to be able to distinguish
between black bears and grizzly/
brown bears (Ursus arctos). The grizzly/brown bear is typically much
larger than the black bear, ranging
from 400 to 1,300 pounds (180 to 585
kg). Its guard hairs have whitish or
silvery tips, giving it a frosted or “grizzly” appearance. Grizzly/brown bears
have a pronounced hump over the
shoulder; a shortened, often dished
face; relatively small ears; and long
claws (Fig. 2).
Food Habits
Black bears are omnivorous, foraging
on a wide variety of plants and animals. Their diet is typically determined by the seasonal availability of
food. Typical foods include grasses,
berries, nuts, tubers, wood fiber,
insects, small mammals, eggs, carrion,
and garbage. Food shortages occur
occasionally in northern bear ranges
when summer and fall mast crops
(berries and nuts) fail. During such
years, bears become bolder and travel
more widely in their search for food.
Human encounters with bears are
more frequent during such years, as
are complaints of crop damage and
livestock losses.
Range
Black bears historically ranged
throughout most of North America
except for the desert southwest and
the treeless barrens of northern
Canada. They still occupy much of
their original range with the exception
of the Great Plains, the midwestern
states, and parts of the eastern and
southern coastal states (Fig. 3). Black
bear and grizzly/brown bear distributions overlap in the Rocky Mountains,
Western Canada, and Alaska.
Fig. 3. Range of the black bear in North America.
General Biology,
Reproduction, and
Behavior
Black bears typically are nocturnal,
although occasionally they are active
during the day. In the South, black
bears tend to be active year-round; but
in northern areas, black bears undergo
a period of semihibernation during
winter. Bears spend this period of dormancy in dens, such as hollow logs,
windfalls, brush piles, caves, and holes
dug into the ground. Bears in northern
areas may remain in their dens for 5 to
7 months, foregoing food, water, and
elimination. Most cubs are born
between late December and early February, while the female is still denning.
Black bears breed during the summer
months, usually in late June or early
July. Males travel extensively in search
of receptive females. Both sexes are
promiscuous. Fighting occurs between
rival males as well as between males
and unreceptive females. Dominant
females may suppress the breeding
activities of subordinate females. After
mating, the fertilized egg does not
implant immediately, but remains
unattached in the uterus until fall.
Females in good condition will usually
produce 2 or 3 cubs that weigh 7 to 12
ounces (198 to 340 g) at birth.
After giving birth, the sow may continue her winter sleep while the cubs
are awake and nursing. Lactating
females do not come into estrus, so
females generally breed only every
other year. Parental care is solely the
female’s responsibility. Males will kill
and eat cubs if they have the opportunity. Cubs are weaned in late summer
but usually remain close to the female
throughout their first year. This social
unit breaks up when the female comes
into her next estrus. After the breeding
season, the female and her yearlings
may travel together for a few weeks.
Black bears become sexually mature at
approximately 3 1/2 years of age, but
some females may not breed until their
fourth year or later.
In North America, black bear densities
range from 0.3 to 3.4 bears per square
mile (0.1 to 1.3 bears/km2). Densities
are highest in the Pacific Northwest
because of the high diversity of habitats and long foraging season. The
home range of black bears is dependent on the type and quality of the
habitat and the sex and age of the bear.
In mountainous regions, bears encounter a variety of habitats by moving up
or down in elevation. Where the terrain is flatter, bears typically range
more widely in search of food, water,
cover, and space. Most adult females
have well-defined home ranges that
vary from 6 to 19 square miles (15 to
50 km2). Ranges of adult males are
usually several times larger.
Black bears are powerful animals that
have few natural enemies. Despite
their strength and dominant position,
they are remarkably tolerant of
humans. Interactions between people
and black bears are usually benign.
When surprised or protecting cubs, a
black bear will threaten the intruder by
laying back its ears, uttering a series of
huffs, chopping its jaws, and stamping
its feet. This may be followed by a
charge, but in most instances it is only
a bluff, as the bear will advance only a
few yards (m) before stopping. There
are very few cases where a black bear
has charged and attacked a human.
Usually people are unaware that bears
are even in the vicinity. Most bears
will avoid people, except bears that
have learned to associate food with
people. Food conditioning occurs
most often at garbage dumps, campgrounds, and sites where people
regularly feed bears. Habituated, foodconditioned bears pose the greatest
threat to humans (Herrero 1985,
Kolenosky and Strathearn 1987).
Damage and Damage
Identification
Damage caused by black bears is quite
diverse, ranging from trampling sweet
corn fields and tearing up turf to
destroying beehives and even (rarely)
killing humans. Black bears are noted
for nuisance problems such as scavenging in garbage cans, breaking in
and demolishing the interiors of cabins, and raiding camper’s campsites
and food caches. Bears also become a
nuisance when they forage in garbage
dumps and landfills.
Black bears are about the only animals,
besides skunks, that molest beehives.
Evidence of bear damage includes broken and scattered combs and hives
showing claw and tooth marks. Hair,
tracks, scats, and other sign may be
found in the immediate area. A bear
will usually use the same path to
return every night until all of the
brood, comb, and honey are eaten.
Field crops such as corn and oats are
also damaged occasionally by hungry
black bears. Large, localized areas of
broken, smashed stalks show where
bears have fed in cornfields. Bears eat
the entire cob, whereas raccoons strip
the ears from the stalks and chew the
kernels from the ears. Black bears prefer corn in the milk stage.
Bears can cause extensive damage to
trees, especially in second-growth forests, by feeding on the inner bark or by
clawing off the bark to leave territorial
markings. Black bears damage
orchards by breaking down trees and
branches in their attempts to reach
fruit. They will often return to an
orchard nightly once feeding starts.
Due to the perennial nature of orchard
damage, losses can be economically
significant.
Few black bears learn to kill livestock,
but the behavior, once developed, usually persists. The severity of black bear
predation makes solving the problem
very important to the individuals who
suffer the losses. If bears are suspect,
look for deep tooth marks (about 1/2
inch [1.3 cm] in diameter) on the neck
directly behind the ears. On large
animals, look for large claw marks
(1/2 inch [1.3 cm] between individual
marks) on the shoulders and sides.
Bear predation must be distinguished
from coyote or dog attacks. Coyotes
typically attack the throat region. Dogs
chase their prey, often slashing the
hind legs and mutilating the animal.
Tooth marks on the back of the neck
are not usually found on coyote and
dog kills. Claw marks are less prominent on coyote or dog kills, if present
at all.
C-7
Different types of livestock behave
differently when attacked by bears.
Sheep tend to bunch up when
approached. Often three or more will
be killed in a small area. Cattle have a
tendency to scatter when a bear
approaches. Kills usually consist of
single animals. Hogs can evade bears
in the open and are more often killed
when confined. Horses are rarely
killed by bears, but they do get clawed
on the sides.
After an animal is killed, black bears
will typically open the body cavity and
remove the internal organs. The liver
and other vital organs are eaten first,
followed by the hindquarters. Udders
of lactating females are also preferred.
When a bear makes a kill, it usually
returns to the site at dusk. Bears prefer
to feed alone. If an animal is killed in
the open, the bear may drag it into the
woods or brush and cover the remains
with leaves, grass, soil, and forest
debris. The bear will periodically
return to this cache site to feed on the
decomposing carcass.
Black bears occasionally threaten
human health and safety. Dr. Stephen
Herrero documented 500 injuries to
humans resulting from encounters
with black bears from 1960 to 1980
(Herrero 1985). Of these, 90% were
minor injuries (minor bites, scratches,
and bruises). Only 23 fatalities due to
black bear attacks were recorded from
1900 to 1980. These are remarkably
low numbers, considering the geographic overlap of human and black
bear populations. Ninety percent of all
incidents were likely associated with
habituated, food-conditioned bears.
Legal Status
In the early 1900s, black bears were
classified as nuisance or pest species
because of agricultural depredations.
Times have changed and bear distributions and populations have diminished
because of human activity. Many
states, such as Colorado, Idaho, Minnesota, Montana, New Mexico, Oregon, Utah, and Wisconsin, manage the
black bear as a big game animal. Most
other states either consider black bears
C-8
as not present or completely protect
the species. In most western states,
livestock owners and property owners
may legally kill bears that are killing
livestock, damaging property, or
threatening human safety. Several
states require a permit before removing a bear when the damage situation
is not acute.
In states where complete protection is
required, the state wildlife agency or
USDA-APHIS-ADC will usually offer
prompt service when a problem
occurs. The problem bear will be livetrapped and moved, killed, and/or
compensation for damage offered. In a
life-threatening situation, the bear can
be shot, but proof of jeopardy may be
required to avoid a citation for illegal
killing.
Damage Prevention and
Control Methods
Exclusion
Fencing has proven effective in deterring bears from landfills, apiaries, cabins, and other high-value properties.
Fencing, however, is a relatively
expensive abatement measure. Consider the extent, duration, and expense
of damage when developing a prevention program.
Numerous fence designs have been
used with varying degrees of success.
Electric fence chargers increase effectiveness. Depending on the amount of
bear pressure, use an electric polytape
portable fence (Fig. 4), or a weldedwire permanent fence (Fig. 5).
Fence Energizing System and
Maintenance. To energize the fences,
use a 110-volt outlet or 12-volt deep
cell (marine) battery connected to a
high-output fence charger. Place the
fence charger and battery in a case or
empty beehive to protect them against
weather and theft. Drive a ground rod
5 to 7 feet (1.5 to 2.1 m) into the
ground, preferably into moist soil.
Connect the ground terminal of the
charger to the ground rod with a wire
and ground clamp. Connect the positive fence terminal to the fence with a
short piece of fence wire. Use connec-
tors to ensure good contact. Electric
fences must deliver an effective shock
to repel bears. Bears can be lured into
licking or sniffing the wire by attaching
attractants (salmon or tuna tins and
bacon rinds) to the fence. Grounding
may be increased, especially in dry,
sandy soil, by laying grounded chicken
wire around the outside perimeter of
the electric fence.
Check the fence voltage each week at a
distance from the fence charger; it
should yield at least 3,000 volts. To
protect against voltage loss, keep the
battery and fence charger dry and
their connections free of corrosion.
Make certain all connections are secure
and check for faulty insulators (arcing
between wire and post). Also clip
vegetation beneath the fence. Each
month, check the fence tension and
replace baits with new salmon tins and
bacon rinds. Always recharge the batteries during the day so that the fence
is energized at night.
Black bears are strong enough to tear
open doors, rip holes in siding, and
break glass windows to gain access to
food stored inside cabins, tents, and
other structures. Use solid frame construction, 3/4-inch (2-cm) plywood
sheeting, and strong, tight-fitting shutters and doors. Steel plating is more
impervious than wood.
Bear-proof containers are available for
campers in a variety of sizes. They can
be used to safely store food and other
bear attractants during backpacking
trips or other outdoor excursions. In
the absence of bear-proof containers,
store food in airtight containers and
suspend them by rope between two
tall trees that are at least 100 yards (100
m) downwind of your campsite.
Food, supplies, and beehives can be
stored 15 to 20 feet (4 to 6 m) above
ground on elevated platforms or bear
poles. Support poles should be at least
6 inches (15 cm) in diameter and
wrapped with a 4-foot-wide (1.4-m)
piece of galvanized sheet metal, 6 to 7
feet (2 m) above ground. You can also
place one or two hives on a flat or lowsloping garage roof. Be sure to add
extra roof braces because two hives
full of honey can weigh 800 pounds
Insulator
Insulator
36"
36"
Gate
handles
Gate
handles
26"
Salmon
Salmontins
tins
Beehive
Beehive
Bacon
rinds
Bacon
rinds
3'
16"
6"
6"
45°
12'
6"
6"
1'
1'
Guy wire
Guy wire
Ground rod
Ground rod
5'6"
5'6"
Electric polytape portable fence. One person can easily and quickly install this fence. It is
economical and dependable for low to moderate bear pressures. The fence consists of four strands of
electric polytape that are attached to posts with insulators. The cost per fence (33 x 33 feet) is about
$200.
1
12
48
4
1
1
200-yard roll of polytape
4-foot fence rods (5/16-inch diameter)
Insulators or clips
Gate handles
12-volt fence charger
12-volt deep cycle battery
Herbicides
To install: Drive in four corner posts 1 foot
deep and attach a guy wire. Clip vegetation in a
15-inch-wide strip under the fence and apply
herbicide. Attach insulators on the inside of corner posts and stretch the electroplastic wire
from the four posts at intervals of 6, 16, 26, and
36 inches from ground level. Hand tighten the
polytape and join the ends with four square
knots. Drive in the remaining posts at 12-foot
intervals, attach insulators (on the outside of
line posts), and insert polytape.
Fig. 4. Electric polytape portable fence
(360 kg) or more. An innovative technique for beekeepers is to place hives
on a fenced (three-strand electric)
flatbed trailer (8 feet x 40 feet [2.4 m x
12.2 m]). Though expensive, this
method makes hives less vulnerable to
bear damage and makes moving them
very easy.
Cultural Methods
Prevention is the best method of controlling black bear damage. Sanitation
and proper solid waste management
are key considerations. Store food,
organic wastes, and other bear attractants in bear-proof containers. Use garbage cans for nonfood items only.
Implement regular garbage pickup
and practice incineration. Reduce
access to landfills through fencing, and
bury refuse daily. Eliminate garbage
dumps.
Place livestock pens and beehives at
least 50 yards (50 m) away from
wooded areas and protective cover.
Confine livestock in buildings and
pens, especially during lambing or
calving seasons. Remove carcasses
from the site and dispose of them by
rendering or deep burial.
Plant susceptible crops (corn, oats,
fruit) away from areas of protective
cover. Pick and remove all fruit from
orchard trees.
Remove protective cover from a radius
of 50 yards (50 m) around occupied
buildings and residences. Locate
campgrounds, campsites, and hiking
trails in areas that are not frequented
by bears to minimize people/bear
encounters. Avoid seasonal feeding
and denning areas and frequently used
game trails. Where possible, clear hiking trails to provide a minimum viewing distance of 50 yards (50 m) down
the trail.
Frightening Devices and
Deterrents
Black bears can be frightened from an
area (such as buildings, livestock
corrals, orchards) by the extended use
C-9
insultor
Insulator
6'
6'
+
-
6'
6'
+
5"
12'
Top
View
Top
view
64"
56"
56"
48"
36"
Gate
Gatehandles
handles
Approx.
Approx. 12'
fence post
Fence
woven
Wovenwire
wire
hot
Hotwire
wire
Beehive
Beehive
-
20"
+
6"
6"
Ground
rodrod
Ground
Approx. 6'
2'
Woven-wire permanent fence. This fence, best used under high bear pressure, is the most
durable and expensive barrier. It can be installed by two people in 8 hours. The fence consists of
heavy, 5-foot woven wire, supported by wooden posts, ringed by two additional electrified wires.
The cost per fence (33 x 33 feet) is about $400.
1
1
24
40
1
6
1
1
50-yard roll of 6-inch square mesh, 5-foot woven wire
150-yard roll of high-tensile (14-gauge) smooth wire
8-foot treated wooden posts
Porcelain strain-insulators (screw-in types)
2-pound box of 1 1/2-inch fence staples
gate handles
12-volt fence charger
12-volt deep cycle battery
Herbicides
To install: Set posts 6 to 12 feet apart in 2-foot-deep holes. Align four corner posts at 5o angles
from the vertical. Brace corner and gate posts from the inside with posts set at 45o angles. Clip a
15-inch-wide strip clear of vegetation under the fence and apply herbicide. Place one length of
welded wire vertically into position and staple the end to a corner post. Pull the entire length of
wire taut with a vehicle and staple the welded wire to the line posts. Continue until all sides,
except the gate opening, are fenced. Fasten two strands of high-tensile wire to insulators
positioned 5 inches away from the welded wire, at intervals of 6 and 56 inches above ground level.
For a 12-foot gate opening, attach three strands of high-tensile wire to insulators on the gateposts.
Space the wires at intervals of 6, 36, and 56 inches above ground level. Connect them to the two
strands previously strung around the fence. These wires will be connected to the positive fence
charger terminal. Attach three more wires to gatepost insulators at intervals of 20, 48, and 64
inches above ground level. These three wires will be connected together and to the ground rod. Fit
insulated gate handles to the free ends of all six gate wires.
Fig. 5. Woven-wire permanent fence
C-10
of night lights, strobe lights, loud music, pyrotechnics, exploder canons,
scarecrows, and trained guard dogs.
The position of such frightening devices should be changed frequently.
Over a period of time, animals usually
become used to scare devices. Bears
often become tolerant of human activity, too. At this point, scare devices are
ineffective and human safety becomes
a concern.
Black bears are occasionally encountered in the backcountry on trails or at
campsites. They can usually be frightened away by shouting, clapping
hands, throwing objects, and by chasing. Such actions can be augmented by
the noise of pots banging, gunfire,
cracker shells, gas-propelled boat
horns, and engines revving. It is
important to attempt to determine the
motivation of the offending bears.
Habituated, food-conditioned bears
can be very dangerous. Aggressive
behavior toward a black bear should
not be carried so far as to threaten the
bear and elicit an attack.
Black bears can be deterred from landfills, occupied buildings, and other
sites by the use of 12-gauge plastic
slugs or 38-mm rubber bullets. Aim for
the large muscle mass in the hind
quarters. Avoid the neck and front
shoulders to minimize the risk of hitting and damaging an eye. Firearm
safety training is recommended.
Repellents
Capsaicin or concentrated red pepper
spray has been tested and used effectively on black bears. The spray range
on most products is less than 30 feet
(10 m), so capsaicin is only effective in
close encounters. Capsaicin spray may
become more popular where use of
firearms is limited.
Toxicants
None are registered.
Fumigants
None are registered.
Trapping
Culvert and Barrel Traps. Live
trapping black bears in culvert or barrel traps is highly effective and convenient (Fig. 6). Set one or two culvert
traps in the area where the bear is
causing a problem. Post warning signs
on and in the vicinity of the trap. Use
baits to lure the bear into the trap.
Successful baits include decaying fish,
beaver carcasses, livestock offal, fruit,
candy, molasses, and honey. When the
trap door falls, the bear is safely held
without a need for dangerous handling or transfer. Bears can be immobilized, released at another site, or
destroyed if necessary. Trapped bears
that are released should first be transported at least 50 miles (80 km), preferably across a substantial geographic
barrier such as a large river, swamp, or
mountain range, and released in a
remote area. Remote release mechanisms are highly recommended. Occasionally, food-conditioned bears will
repeat their offenses. A problem bear
should be released only once. If it
causes subsequent problems it should
be destroyed.
Foot Snares. The Aldrich-type foot
snare (Fig. 7) is used extensively by
USDA-APHIS-ADC and state wildlife
agency personnel to catch problem
bears. This method is safe, when correctly used, and allows for the release
of nontarget animals. Bears captured
in this manner can be tranquilized,
released, translocated, or destroyed.
Use baits as described previously to
attract bears to foot snare sets.
The tools required for the pipe set are
an Aldrich foot snare complete with
the spring throw arm, a 9-inch (23-cm)
long, 5-inch (13-cm) diameter piece of
stove pipe, iron pin, hammer, and
shovel. Cut a 1-inch (2.5-cm) slot,
6 1/2 inches (16.5 cm) long, down one
side of the pipe. Place the pipe in a
hole dug 9 inches (23 cm) deep into the
ground. Cut a groove in the ground to
accommodate the spring throw arm so
that the pan will extend through the
slot into the center of the pipe. The top
of the pipe should be level with the
ground surface. Anchor the pipe
securely to the ground, where possible, by attaching it to spikes or a
stake driven into the ground inside the
can. Bears will try to pull the pipe out
of the ground if it “gives.” The spring
throw arm should be placed with the
pan extending into the pipe slot 6
inches (15 cm) down from the top of
the pipe. Pack soil around the pipe 1
inch (2.5 cm) from the top. Leave the
pipe slot open and the spring uncovered. Loop the cable around the pipe,
leaving 1/2 inch (1.3 cm) of slack.
Place the cable over the hood on the
spring throw arm, then spike the cable
to the ground in back of the throw
arm. The cable is spiked to keep it
flush to the ground so that it will not
unkink or spring up prematurely.
Cover the cable loop with soil to the
top of the pipe. Anchor the cable
securely to a tree at least 8 inches (20
cm) in diameter. Cover the spring
throw arm and pipe slot with grass
and leaves. Place a few boughs and
some brush around the set to direct
the bear into the pipe. The slot in the
pipe and the spring throw arm should
be at the back of the set. The bear can
approach the set from either side or
the front. Melt bacon into the bottom
of the pipe and drop a small piece in.
The bacon should not lie on the pan.
Other bait or scent, such as a fishscented rag, may be used. Place a 15to 20-pound (6.8- to 9-kg) rock over the
top of the pipe. Melt bacon grease on
the top of it or rub it on. The rock will
serve to prevent humans, birds, nontarget wild animals, and livestock
from being caught in the snare. The
bear will approach the set and proceed
to lick the grease off the rock. It will
then roll the rock from the top of the
pipe and try to reach the bait with its
mouth. When this fails, it will use a
front foot, which will then be caught in
the snare.
The bear will try to reach the bait first
with its mouth and may spring the set
if the pan is not placed the required 6
inches (15 cm) below the top of the
pipe. Pipe sets are more efficient, more
economical, and safer than leghold
traps. Sources of bear foot snares are
found in Supplies and Materials.
C-11
Steel plate inserted in
slot cut in culvert
Fig. 6. Culvert trap for live capture of bears.
Trigger detail
Frame
Suspend bait from
rope or wire.
Cross section
Drop door
Rear
C-12
Front
Bacon grease
Anchor cable to tree
or heavy log
Rock
Twig and grass cover
Snare
Ground level
Anchor pipe securely into ground with
stake
Bacon grease
2-pound coffee can or 10 inches of
5-inch stovepipe
Iron pin to control cable and snap lift
of snare
Fig. 7. Pipe snare set with Aldrich foot snare.
Shooting
Shooting is effective, but often a last
resort, in dealing with a problem black
bear. Permits are required in most
states and provinces to shoot a bear
out of season. To increase the probability of removing the problem bear,
shooting should be done at the site
where damage has occurred. Bears
are most easily attracted to baits from
dusk to dark. Place baits in the
damaged area where there are safe
shooting conditions and clear visibility. Use large, well-anchored carcass
baits or heavy containers filled with
rancid meat scraps, fat drippings, and
rotten fruit or vegetables. Establish a
stand roughly 100 yards (100 m)
downwind from the bait and wait for
the bear to appear. Strive for a quick
kill, using a rifle of .30 caliber or larger.
The animal must be turned over to
wildlife authorities in most states and
provinces.
Calling bears with a predator call has
been reported to offer limited success.
If nothing else works, it can be tried. It
is best to use two people when calling
since the bear may come up in an ugly
mood, out of sight of the caller. As
with any method of bear control, be
cautious and use an adequate-caliber
rifle to kill the bear. Call in the vicinity
of the damage, taking proper precautions by wearing camouflage clothing,
orienting the wind to blow the human
scent away from the direction of the
bear’s approach, and selecting an area
that provides clear visibility for shooting. See Blair (1981) for bear-calling
methods.
Some states allow the use of dogs to
hunt bears. Guides and professional
hunters with bear dogs can be called
for help. Place the dogs on the track of
the problem bear. Often the dogs will
be able to track and tree the bear,
allowing it to be killed, and thus solving the bear problem quickly.
Avoiding Human-Bear Conflicts
Preventing Bear Attacks. Black
and grizzly bears must be respected.
They have great strength and agility,
and will defend themselves, their
young, and their territories if they feel
threatened. Learn to recognize the differences between black and brown
bears. Knowledge and alertness can
help avoid encounters with bears that
could be hazardous. They are unpredictable and can inflict serious injury.
NEVER feed or approach a bear.
To avoid a bear encounter, stay alert
and think ahead. Always hike in a
C-13
group. Carry noisemakers, such as
bells or cans containing stones. Most
bears will leave a vicinity if they are
aware of human presence. Remember
that noisemakers may not be effective
in dense brush or near rushing water.
Be especially alert when traveling into
the wind since bears may not pick up
your scent and may be unaware of
your approach. Stay in the open and
avoid food sources such as berry
patches and carcass remains. Bears
may feel threatened if surprised.
Watch for bear sign—fresh tracks, digging, and scats (droppings). Detour
around the area if bears or their fresh
sign are observed.
NEVER approach a bear cub. Adult
female black bears are very defensive
and may be aggressive, making threatening gestures (laying ears back,
huffing, chopping jaws, stomping feet)
and possibly making bluff charges.
Black bears rarely attack humans, but
they have a tolerance range which,
when encroached upon, may trigger
an attack. Keep a distance of at least
100 yards (100 m) between you and
bears.
Bears are omnivores, eating both vegetable and animal matter, so don’t
encourage them by leaving food or
garbage around camp. When bears
associate food with humans, they often
lose their fear of humans and are
attracted to campsites. Food-conditioned bears are very dangerous.
In established campgrounds, keep
your campsite clean, and lock food in
the trunk of your vehicle. Don’t leave
dirty utensils around the campsite,
and don’t cook or eat in tents. After
eating, place garbage in containers
provided by the campground.
In the backcountry, establish camp
away from animal or walking trails
and near large, sparsely branched trees
that can be climbed should it become
necessary. Choose another area if fresh
bear sign is present. Cache food away
from your tent, preferably suspended
from a tree that is 100 yards (100 m)
downwind of camp. Hang food from a
strong branch at least 15 feet (4.5 m)
high and 8 feet (2.4 m) from the trunk
C-14
of the tree. Use bear-proof or airtight
containers for storing food and other
attractants. Freeze-dried foods are
light-weight and relatively odor-free.
Pack out all noncombustible garbage.
Burying it is useless and dangerous.
Bears can easily smell it and dig it up.
The attracted bear may then become a
threat to the next group of hikers. Always have radio communication and
emergency transportation available for
remote base or work camps, in case of
accidents or medical emergencies.
Don’t take dogs into the backcountry.
The sight or smell of a dog may attract a
bear and provoke an attack. Most dogs
are no match for a bear. When in trouble,
the dog may come running back to the
owner with the bear in pursuit. Trained
guard dogs are an exception and may be
useful in detecting and chasing away
bears in the immediate area.
Bear Confrontations. If a bear is
seen at a distance, make a wide detour.
Keep upwind if possible so the bear
can pick up human scent and recognize human presence. If a detour or
retreat is not possible, wait until the
bear moves away from the path.
Always leave an escape route and
never harass a bear.
If a bear is encountered at close range,
keep calm and assess the situation. A
bear rearing on its hind legs is not always aggressive. If it moves its head
from side to side it may only be trying
to pick up scent and focus its weak
eyes. Remain still and speak in low
tones. This may indicate to the animal
that there is no threat. Assess the surroundings before taking action. There
is no guaranteed life-saving method of
handling an aggressive bear, but some
behavior patterns have proven more
successful than others.
Do not run. Most bears can run as fast as
a racehorse, covering 30 to 40 feet (9 to 12
m) per second. Quick, jerky movements
can trigger an attack. If an aggressive
bear is met in a wooded area, speak softly
and back slowly toward a tree. Climb a
good distance up the tree. Most black
bears are agile climbers, so a tree offers
limited safety, but you can defend yourself in a tree with branches or a boot heel.
Adult grizzlies don’t climb as a rule, but
large ones can reach up to 10 feet (3 m).
Occasionally, bears will bluff by charging within a few yards (m) of an unfortunate hiker. Sometimes they charge
and veer away at the last second. If
you are charged, attempt to stand your
ground. The bear may perceive you as
a greater threat than it is willing to
tackle and may leave the area.
Black bears are less formidable than
grizzly bears, and may be frightened
off by acting aggressively toward the
animal. Do not play dead if a black
bear is stalking you or appears to consider you as prey. Use sticks, rocks,
frying pans, or whatever is available to
frighten the animal away.
As a last resort, when attacked by a
grizzly/brown bear, passively resist by
playing dead. Drop to the ground face
down, lift your legs up to your chest,
and clasp both hands over the back of
your neck. Wearing a pack will shield
your body. Brown bears have been
known to inflict only minor injuries
under these circumstances. It takes
courage to lie still and quiet, but resistance is usually useless.
Many people who work in or frequent
bear habitat carry firearms for personal
protection. High-powered rifles (such as
a .458 magnum with a 510-grain softpoint bullet or a .375 magnum with a
300-grain soft-point bullet) or shotguns
(12-gauge with rifled slugs) are the best
choices, followed by large handguns (.44
magnum or 10 mm). Although not a
popular solution, killing a bear that is
attacking a human is justifiable.
Economics of Damage
and Control
Black bear damage to the honey
industry is a significant concern. Damage to apiaries in the Peace River area
of Alberta was estimated at $200,000 in
1976. Damage incidents in Yosemite
National Park were estimated to be as
high as $113,197 in 1975, with $96,594
resulting from damage to vehicles in
which food was stored. Thirty percent
of all trees over 6 inches (15 cm) tall
were reported to be damaged by black
bears on a 3,360 acre (1,630 ha) parcel
in Washington State. In Wisconsin, one
female black bear and her cubs caused
an estimated $35,000 of damage to
apple trees during a two-day period in
1987. In general, black bears can inflict
significant economic damage in localized areas.
Some states pay for damage caused by
black bears. In western states, losses
caused by black bears are usually less
than 10% of total predation losses,
although records are not complete.
The extent of claims paid are not high
but usually are greater than the license
income that state wildlife agencies
receive from black bear hunters.
Deems and Pursley (1983) listed the
states and provinces that pay for black
bear depredations.
Acknowledgments
Much of the text was adapted from the chapter
“Black Bears” by M. Boddicker from the 1986
revision of Prevention and Control of Wildlife
Damage.
Figure 1 from Schwartz and Schwartz (1981).
Figure 2 from Graf et al. (1992).
Figure 3 from Burt and Grossenheider (1976),
adapted by Dave Thornhill, University of
Nebraska-Lincoln.
Figures 4 and 5 from Hygnstrom and Craven
(1986).
Figure 6 from Boddicker (1986).
Figure 7 courtesy of Gregerson Manufacturing
Co., adapted by Jill Sack Johnson.
Figure 8 from Manitoba Fish and Wildlife agency
publications, adapted by Jill Sack Johnson.
Figure 9 by M. Boddicker.
For Additional
Information
Blair, G. 1981. Predator caller’s companion.
Winchester Press, Tulsa, Oklahoma. 267 pp.
Boddicker, M. L., ed. 1980. Managing Rocky
Mountain furbearers. Colorado Trapper’s
Assoc., LaPorte, Colorado. 176 pp.
Bromley, M., ed. 1989. Bear-people conflicts:
proceedings of a symposium on
management strategies. Northwest Terr.
Dep. Renew. Resour. Yellowknife. 246 pp.
Burt, W. H., and R. P. Grossenheider. 1976. A
field guide to the mammals, 3d ed.
Houghton Mifflin Co., Boston. 289 pp.
Davenport, L. B., Jr. 1953. Agriculture
depredation by the black bear in Virginia. J.
Wildl. Manage. 17:331-340.
Deems, E. F., and D. Pursley, eds. 1983. North
American furbearers: a contemporary
reference. Int. Assoc. Fish Wildl. Agencies
and Maryland Dep. Nat. Resour. Annapolis,
Maryland. 223 pp.
Erickson, A. W. 1957. Techniques for livetrapping and handling black bears. Trans.
North Amer. Wildl. Conf. 22:520-543.
Graf, L. H., P. L. Clarkson, and J. A. Nagy. 1992.
Safety in bear country: a reference manual,
rev. ed. Northwest Terr. Dep. Renew.
Resour. Yellowknife. 135 pp.
Herrero, S. 1985. Bear attacks: their causes and
avoidance. New Century Publ. Piscataway,
New Jersey. 288 pp.
Hygnstrom, S. E., and S. R. Craven. 1986. Bear
damage and nuisance problems in
Wisconsin. Univ. Wisconsin Ext. Publ.
G3000. Madison, Wisconsin. 6 pp.
Hygnstrom, S. E., and T. M. Hauge. 1989. A
review of problem black bear management
in Wisconsin. Pages 163-168 in M. Bromley,
ed. Bear-people conflicts: proceedings of a
symposium on management strategies.
Northwest Terr. Dep. Renew. Resour.
Yellowknife.
Jonkel, C. J., and I. McT. Cowan. 1971. The black
bear in the spruce-fir forest. Wildl. Monogr.
27. 57 pp.
Jope, K. L. 1985. Implications of grizzly bear
habituation to hikers. Wildl. Soc. Bull.
13:32-37.
Kolenosky, G. B., and S. M. Strathearn. 1987.
Black bear. Pages 442-454 in M. Novak, J. A.
Baker, M. E. Obbard, and B. Malloch, eds.
Wild furbearer management and
conservation in North America. Ontario
Ministry of Nat. Resour. Toronto.
McArthur, K. L. 1981. Factors contributing to
effectiveness of black bear transplants. J.
Wildl. Manage. 45:102-110.
Meechan, W. R., and J. F. Thilenius. 1983. Safety
in bear country: protective measures and
bullet performance at short range. Gen. Tech.
Rep. PNW-152. US Dep. Agric., For. Serv.
Portland, Oregon. 16 pp.
Rogers, L. L. 1984. Reactions of free-ranging
black bears to capsaicin spray repellent.
Wildl. Soc. Bull. 12:58-61.
Rogers, L. L., D. W. Kuehn, A. W. Erickson, E. M.
Harger, L. J. Verme, and J. J. Ozoga. 1976.
Characteristics and management of black
bears that feed in garbage dumps, camp
grounds or residential areas. Int. Conf. Bear
Res. Manage. 3:169-175.
Rutherglen, R. A. 1973. The control of problem
black bears. British Columbia Fish Wildl.
Branch, Wildl. Manage. Rep. 11. 78 pp.
Schwartz, C. W., and E. R. Schwartz. 1981. The
wild mammals of Missouri, rev. ed. Univ.
Missouri Press, Columbia. 356 pp.
Singer, D. J. 1952. American black bear. Pages
97-102 in J. Walker McSpadden, ed. Animals
of the world. Garden City Books, Garden
City, New York.
Van Wormer, J. 1966. The world of the black
bear. J. B. Lippincott Co., Philadelphia. 168
pp.
Wynnyk, W. P., and J. R. Gunson. 1977. Design
and effectiveness of a portable electric fence
for apiaries. Alberta Rec., Parks, and Wildl.
Fish Wildl. Div. Alberta, Canada. 11 pp.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
C-15
C-16
Charles Jonkel
GRIZZLY/BROWN
BEARS
Director
Ursid Research Center
Missoula, Montana 59802
Fig. 1. Grizzly/brown bear, Ursus arctos
Damage Prevention And
Control Methods
Exclusion
Use heavy, chain-link or woven-wire
fencing topped with barbed wire
and buried at the bottom. Add
outriggers and electrified wires to
the outside perimeter. Metal (bar)
cages and metal buildings will protect
workers, food, and other attractants.
Repellents and Deterrents
Shooting
Capsaicin spray. Install “early warning”
or detection systems around field
stations or campsites. Use trained
dogs to detect or deter bears. Use
plastic slugs to deter bears.
Weapons that offer the best protection
are high-powered rifles of .350
caliber or larger, and 12-gauge
pump shotguns with rifled slugs.
Handguns (.44 magnum) should be
carried only for quick defense.
Toxicants
None are registered.
Fumigants
None are registered.
Cultural Methods
Trapping
Keep threatened areas free of all
attractants. Establish campsites, bee
yards, and livestock bedding areas
away from vegetation or other cover.
Use proper solid waste management
procedures. Prevent any rewards to
bears, and immediately discourage
all approaches by bears.
Use culvert traps or foot snares; for
bait use only wild animal road kills
and scents.
Frightening Devices
Boat horns, cracker shells, rifle shots,
helicopter chases, yard lights, strobe
lights.
Immobilizing and Handling
Drugs used on bears are strictly
controlled, require licensing, and
are potentially dangerous to the
animal, the drugging team, and
unauthorized users. Postimmobilization care is very
important.
Other Methods
Aversive Conditioning. Captured
and confined bears can be trained to
fear and avoid humans through
repeated confrontations and the use
of repellents. Properly trained
personnel and holding facilities
designed for aversive conditioning
are required.
Public Education. Implement
programs to promote the
prevention of bear problems.
Avoiding Human-Bear Conflicts
Avoid bear encounters by staying
alert. Never approach bear cubs.
Avoid high bear-use areas.
Eliminate bear attractants.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-17
Introduction
Although wildlife management concepts were formed nearly 100 years
ago, bears and their management have
been poorly understood. Recent concern for the environment, species preservation, and ecosystem management
are only now starting to affect the way
we manage grizzly/brown bears
(Ursus arctos, Fig. 1). Indeed, the difficulty in understanding brown bear biology, behavior, and ecology may have
precluded sufficient change to prevent
the ultimate loss of the species south of
Canada. Grizzly/brown bears must be
managed at the ecosystem level. The
size of their ranges and their need for
safe corridors between habitat units
bring them into increasing conflict
with people, and there seems to be
little guarantee that people will sufficiently limit their activities and landuse patterns to reduce brown bear
damage rates and the consequent need
for damage control. Drastic changes
may be needed in land-use management, zoning, wilderness designation,
timber harvest, mining, real estate development, and range management to
preserve the species and still meet
damage control needs.
Identification
The brown bears of the world include
numerous subspecies in Asia, Europe,
and North America. Even the polar
bear, taxonomically, may be a white
phase of the brown bear. Support for
this concept is provided by new
electrophoresic studies and the fact
that offspring of brown/polar bear
crosses are fertile. The interior grizzly
(Ursus arctos horribilis) is generally
smaller than the coastal (Ursus arctos
gyas) or island (Ursus arctos middendorffi) subspecies of North American
brown bear, and it has the classic
“grizzled” hair tips.
Brown bears in general are very large
and heavily built. Male brown bears
are almost twice the weight of females.
They walk with a plantigrade gait (but
can walk upright on their hind legs),
and have long claws for digging (black
C-18
bears and polar bears have sharper,
shorter claws). The males can weigh
up to 2,000 pounds (900 kg), but grizzly males are normally around 400 to
600 pounds (200 to 300 kg). Wherever
brown bears live, their size is influenced by their subspecies status, food
supply, and length of the feeding season. Bone growth continues through
the sixth year, so subadult nutrition often dictates their size potential.
Brown bears are typically brown in
color, but vary from pure white to
black, with coastal brown bears and
Kodiak bears generally lighter, even
blond or beige. The interior grizzly
bears are typically a dark, chocolate
brown or black, with pronounced
silver tips on the guard hairs. This coloration often gives them a silvery
sheen or halo. They lack the neck ruff
of the coastal bears, and grizzlies may
even have light bands before and
behind the front legs. Some particularly grizzled interior brown bears
have a spectacled facial pattern similar
to that of the panda or spectacled
bears of Asia and South America.
White grizzlies (not albinos) are also
found in portions of Alberta and
Montana, and in south-central British
Columbia. Such white brown bears
may be genetically identical to the
polar bear, but so far electrophoresic
studies have not been completed to
determine the degree of relatedness.
The interior grizzly’s “hump,” an
adaptation to their digging lifestyle, is
seen less in the coastal brown bears,
polar bears, or black bears. The brown
bears (including the grizzly) are also
characterized by their high eye profile,
dish-shaped face, and short, thick ears.
Range
The brown bears of North America
have lost considerable range, and are
currently restricted to western Canada,
Alaska, and the northwestern United
States (Fig. 2). Their populations are
considered secure in Canada and
Alaska, but have declined significantly
in the lower 48 states. Before settlement, 100,000 brown bears may have
Fig. 2. Distribution of grizzly/brown bears in
North America.
ranged south of Canada onto the Great
Plains along stream systems such as
the Missouri River, and in isolated,
small mountain ranges such as the
Black Hills of South Dakota. They
were scattered rather thinly in Mexico
and in the southwestern United States,
but may have numbered about 10,000
in California, occupying the broad,
rich valleys as well as the mountains.
A few brown bears (the “Mexican” or
“California” grizzly) may still exist in
northern Mexico. Occasionally, barrenground grizzlies are found hunting
seals on the sea ice north of the Canadian mainland. The barren-ground
grizzlies appear to be brown bear/
polar bear crosses, and could represent
an intergrade form. Brown bears also
occur on three large islands in the gulf
of Alaska, and are isolated geographically from very similar coastal brown
bears.
A nearly isolated population (the
Yellowstone grizzly) occurs in southern Montana, Wyoming, and southern
Idaho. There could still be a few grizzlies in the mountains of southwestern
Colorado, and a few still range out
onto the prairies of Alberta and Montana, where the extinct Plains grizzly
used to roam.
Habitat
Grizzly/brown bear habitat is considerably varied. Brown bears may
occupy areas of 100 to 150 square
miles (140 to 210 km2), including
desert and prairie as well as forest and
alpine extremes. The areas must provide enough food during the 5 to 7
months in which they feed to meet
their protein, energy, and other nutritional requirements for reproduction,
breeding, and denning. They often
travel long distances to reach seasonally abundant food sources such as
salmon streams, burned areas with
large berry crops, and lush lowlands.
Denning habitats may be a limiting
factor in brown bear survival. Grizzly
bears seek and use denning areas only
at high elevations (above 6,000 feet
[1,800 m]), where there are deep soils
for digging, steep slopes, vegetative
cover for roof support, and isolation
from other bears or people. Since grizzlies select and build their dens in late
September, when their sensitivity to
danger is still very high, even minor
disturbances may deter the bears from
using the best sites. Unfortunately, the
habitat types bears choose in September are scarce, and human recreational
use of the same high-elevation areas is
increasing.
Travel corridors connecting large areas
of grizzly habitat to individual home
ranges are critical for maintaining grizzly populations. Adequate cover is
also needed to provide free movement
within their range without detection
by humans. The land uses with the
greatest impact on bear habitats and
populations include road development, mining, clear-cut logging, and
real estate development.
Coastal brown bears use totally different habitats than the interior grizzly.
They establish home ranges along
coastal plains and salmon rivers where
they feed on grasses, sedges, forbs,
and fish. While the fishing brown
bears may use very small ranges for
extended periods, almost all bears
make occasional, long-distance movements to other areas where food is
abundant. This far-ranging behavior
often leads to unexpected human-bear
conflicts far from typical brown bear
range.
Social factors within bear populations
influence habitat value—the removal
of one dominant bear or the sudden
deaths of several bears can cause the
remaining bears to greatly alter their
habitat-use patterns. Such changes
occur simply because the social
hierarchy within bear populations
typically gives large bears dominance
over the smaller ones, and each bear
uses its range based on its relationship
to the other bears in the area.
Food Habits
Food gathering is a top priority in the
life of grizzly/brown bears. They feed
extensively on both vegetation and
animal matter. Their claws and front
leg muscles are remarkably well
adapted to digging for roots, tubers,
and corms. They may also dig to
capture ground squirrels, marmots,
and pocket gophers. Brown bears are
strongly attracted to succulent forbs,
sedges, and grasses. In spring and
early summer they may ingest up to 90
pounds (40 kg) of this high-protein
forage per day. Bears gain their fat
reserves to endure the 5- to 7- month
denning period by feeding on highenergy mast (berries, pine nuts) or
salmon. The 2 1/2- to 3-month
summer feeding period is particularly
crucial for reaching maximum body
frame and preparing for the breeding
season and winter.
Being ultimate opportunists, brown
bears feed on many other food items.
For example, the Yellowstone grizzlies
have clearly become more predatory
since the closure of the garbage dumps
in the Yellowstone area. They are
exploiting the abundant elk and bison
populations that have built up within
the park. They hunt the elk calves in
the spring, and some bears learn to
hunt adult elk, moose, and even bison.
The ungulate herds, domestic sheep,
and cows also provide an abundant
carrion supply each spring—the animals that die over winter thaw out just
when the bears need a rich food
source.
Bears are adept at securing food from
human sources such as garbage
dumps, dumpsters, trash cans, restaurants, orchards, and bee yards. Some
bears learn to prey on livestock, espe-
cially sheep that graze on open, remote
rangeland.
General Biology,
Reproduction, and
Behavior
Brown bears are typical of all bears
physiologically, behaviorally, and ecologically. They are slow growing and
long-lived (20 to 25 years). Their ability
to store and use fat for energy makes
long denning periods (5 to 7 months)
possible. During denning they enter a
form of hibernation in which their respiration rate (approximately 1 per
minute) and heart rate (as low as 10
beats per minute) are greatly reduced.
Their body temperature remains just a
few degrees below normal; they do not
eat, drink, defecate, or urinate, and
their dormancy is continuous for 3 to 7
months. The adaptive value of winter
denning relates to survival during
inclement weather, when reduced
food availability, decreased mobility,
and increased energy demands for
thermoregulation occur.
In most populations, brown bears
breed from mid-May to mid-July. Both
males and females are polygamous,
and although males attempt to defend
females against other males, they are
generally unsuccessful. Implantation
of the fertilized ova is delayed until the
females enter their dens, from late
October to November. One to three
(usually two) cubs are born in January
in a rather undeveloped state. They require great care from their mothers,
which leads to strong family bonding
and transfer of information from
mothers to offspring. Brown bears
may not produce young until 5 to 6
years of age and may skip 3 to 6 years
between litters. Because of their low
reproductive potential, bear populations cannot respond quickly to
expanded habitats or severe population losses.
During the breeding season, male and
female grizzly/brown bears spend
considerable time together, and family
groups break up. The young females
are allowed to remain in the area, taking over a portion of their mother’s
C-19
range. They are not threatened by the
males, even though they are still
vulnerable without their mother’s protection. The young males, however,
must leave or be killed by the adult
males. Many subadult males disperse
into marginal bear habitats while
trying to establish their own territories.
This often leads to increased humanbear conflicts and the need for
management and control actions.
Home ranges vary in size, shape, and
amount of overlap among individuals.
Abundance and distribution of food is
the major factor determining bear
movements and home range size.
Home ranges are smallest in southeastern Alaska and on Kodiak Island.
The largest home ranges are found in
the Rocky Mountains of Canada and
Montana, the tundra regions of Alaska
and Canada, and the boreal forest of
Alberta. In areas where food and cover
are abundant, brown bear home
ranges can be as small as 9 square
miles (24 km2). Where food resources
are scattered, the ranges must be at
least ten times larger to provide an
adequate food base.
Some bears establish seasonal patterns
of movement in relation to dependable
high-calorie foods sources, such as
salmon streams and garbage dumps.
Such movements are likely to place
bears in close contact with humans. In
addition to finding food, bears spend
considerable time in attempting to
detect people, evaluating situations,
and taking corrective actions to avoid
conflict with humans. People, on the
other hand, typically go noisily about
their business, often without ever
knowing that a bear is nearby.
Damage and Damage
Identification
Brown bears have many unique
behaviors that subject them to situations in which they are perceived as a
threat to humans or personal property.
They are opportunistic feeders that
may switch to scavenging humanproduced food and garbage if made
available, becoming a problem around
parks, camp grounds, cottages, suburC-20
ban areas, and garbage dumps. Bears
that are conditioned to human foods
become used to the presence of
humans and are therefore the most
dangerous. Bear activity is intensely
oriented to the summer months when
people are also most active in the
mountains and forests. Brown bear
attacks have resulted in injuries ranging from superficial to debilitating, disfiguring, and fatal. Dr. Stephen
Herrero documented 165 injuries to
humans resulting from encounters
with brown bears in North America
from 1900 to 1980 (Herrero 1985). Fifty
percent of the injuries were classified
as major, requiring hospitalization for
more than 24 hours or resulting in
death. In addition to the 19 grizzly
bear-inflicted deaths that Herrero
reported, two Department of Public
Safety employees reported 22 deaths in
Alaska.
Brown bears also occasionally cause
problems around orchards, bee yards,
growing crops, and livestock. Some
bears occasionally kill cattle, sheep,
pigs, horses, goats, and poultry, but
most do not prey on livestock. Bears
kill livestock by pursuing them at high
speed, slashing from the rear and pulling the prey down. They hold the prey
with their own weight while biting the
head or neck area and delivering
blows. The ventral area is then ripped
open, and the hide sometimes skinned,
sometimes devoured along with subcutaneous and visceral fat. Bears eat
large volumes of flesh and body parts,
leaving many large scats. Adult brown
bear scats are 2 inches (5 cm) or more
in diameter. The bear will often cover
the remains with all types of nearby
debris—vegetation, leaves, sticks, and
soil, and then bed nearby. The investigator should look carefully for (and
record) all wounds, tracks, hairs, and
any other sign that would prove bear
predation. It is important to document
accurately the cause of death, the manner of killing, and all signs in the area
that would indicate predation by
bears. The lack of any such evidence
should preclude brown bear control.
Sheep predation may be more subtle to
document since, when frightened,
sheep readily stampede and injure or
kill themselves on felled timber or
cliffs. In such a case, examiners should
look carefully for neck and head bites,
or smashed skulls, as well as tracks,
bear hair, bear droppings, and other
sign. Survey the overall scene—the
flight path of the sheep, the place of
cover and possible attack relative to
the flight route, the amount consumed,
and the freshness of any flesh or tissues in the bear droppings.
Grizzly/brown bear attacks are often
easily identified by tracks alone. The
foot prints are very large, with claw
marks on the front foot extending up
to 4 inches (10 cm) in front of the toe
marks. The toes of a grizzly are in a
much straighter line than those of a
black bear, and the grizzly paw includes greater “webbing” between the
toes, which may show up in a mud
print. Grizzly hair found in the area is
another positive identifying characteristic. Look carefully on the ends of
broken sticks, in rough areas on logs,
under high logs, in the bark of trees, or
in any pitch patches on conifers where
a bear may have rubbed. Also check
the barbs of any wire fencing nearby.
All hair should be collected carefully in
small envelopes and sent to a wildlife
agency or university lab for identification.
Most bear depredations are easily
identified, especially if there is wet or
soft ground in the area. Bears are not
sneaky—they march right in and take
what they consider is theirs.
Legal Status
Grizzly bears south of Canada are protected as a “threatened species” under
the US Endangered Species Act of
1973. Wyoming and Montana have
limited grizzly bear hunting seasons as
authorized under the act, but the seasons are currently closed pending
clarification of the act through legal
challenges in court and further actions
by the states. Without state hunting
seasons, killing of grizzlies is allowed
only through official control actions or
defense of self and property. North of
the Canadian border, grizzlies are
hunted to varying extents in Alaska,
Alberta, British Columbia, the Yukon,
and the Northwest Territories.
Wrongful killing of a grizzly bear mandates a severe penalty—up to $20,000
in fines. “Taking” is being more liberally defined as court challenges establish that even habitat destruction can
be interpreted as taking or killing.
Damage Prevention and
Control Methods
Exclusion
The challenges of exclusion are formidable. Bears are incredibly adept at
problem solving where food is concerned, no doubt as a result of their
extreme orientation to food for a few
short months. Brown bears will
expend a great amount of energy and
time digging under, breaking down, or
crawling over barriers to food. They
know how to use their great weight
and strength to open containers. They
will chew metal cans “like bubble
gum” to extract the food.
To exclude bears, use heavy, chain-link
or woven-wire fencing at least 8 feet
(2.4 m) high and buried 2 feet (0.6 m)
below ground. Install metal bar extensions at an outward angle to the top of
the fence and attach barbed wire or
electrified smooth wire. Also consider
attaching an electrified outrigger wire
to the fence.
Electric fencing is also very effective if
built correctly. At a minimum, 12gauge, high-tensile fencing should be
used—nine wires high, spaced 6 inches
(15 cm) at the top and 4 inches (10 cm)
at the bottom, with alternating hot and
ground wires. Both the top and bottom
wires should be hot. Use a lowimpedance charger with a minimum
output of 5,000 volts.
In backcountry situations, an electric
fence perimeter may be the only sure
protection from grizzly/brown bear
damage. Secure the camp, supplies,
and livestock within the confined area.
In the absence of fencing, bear-proof
containers provide the best protection
for food and other supplies. Use 45gallon (200-l) oil drums with locking
lids to secure all bear attractants. Back-
packers in bear country should use
portable bear-proof containers.
Attractants (food, meat, feed) can also
be hung in an elaborate, bear-proof
manner, at least 20 feet (6.5 m) above
ground, and free from any aerial
approach. Tower caches, 20 feet high
or higher, can also be constructed
using heavy poles and timbers.
Cultural Methods
Once a bear has developed a detrimental behavior, it may be impossible to
change it. Prevention is directed
mostly at keeping the bear population
wild and fearful of people. If the
mothers teach their young to avoid
humans, problems will be minimal,
though not nonexistent. Hunting pressure automatically teaches bears to
avoid humans.
Choose campsites, bee yards, and
livestock bedding sites in areas not frequented by bears. Avoid riparian
areas, rough ground, heavy cover,
aspen groves, and berry-covered hillsides. In spring and early summer,
bears frequent riparian areas, lowelevation flood plains, hillside parks,
and alluvial fans where high protein
grasses, sedges, and forbs are plentiful.
In late June or early July, bears turn to
areas with berries and other highenergy foods. Often, livestock need to
be held out of such areas only an extra
2 weeks, until the bears turn to other
foods. In areas with a history of bear
problems, livestock should be confined
in buildings or pens that are at least 50
yards (50 m) from wooded areas and
protective cover, especially during the
lambing or calving season. Remove
carcasses from the site and dispose of
them by rendering or deep burial.
Bears should never be fed or intentionally given access to food scraps or
garbage. Eliminate all sources of
human foods around campsites, cabins, restaurants, and suburban areas.
Keep garbage in clean and tightly
sealed metal or plastic containers.
Spray garbage cans and dumpsters
regularly with disinfectants to reduce
odors. Maintain regular garbage
pickup schedules and bury or burn all
garbage at fenced sanitary landfills.
Frightening Devices
Boat horns, cracker shells, rifle shots,
and other loud noises may frighten
bears from an area. Roaring engines
and helicopter chases may also be
effective. Barking dogs can be very
useful, but they must be trained to
bark on sight or smell of a bear. In
addition, good bear dogs will chase
bears, but they must be trained to pursue and corner without closing on the
bear.
Lights and strobe flashes are only
marginally effective for bear damage
prevention.
Repellents and Deterrents
Capsaicin spray has been reported to
be an effective repellent. It may work
only once, however, so a backup deterrent should always be available.
Well-trained dogs can provide an
“early warning system” as well as a
deterrence to bears. Unfortunately, not
many trained dogs are available in the
United States or Canada. Plastic slugs
may also be an effective deterrent
against bears. Bears usually move
rapidly to the nearest cover when
frightened, so care must be taken to
avoid being positioned between the
bear and escape cover.
Trapping
The capture and translocation of bears
can be effective in damage control.
Unfortunately, relocation often only
moves the problem to another site, and
bears have been known to travel great
distances to return to a trapping site.
The handling process, if done correctly, is itself sufficiently traumatic to
teach the bears to avoid humans. Use
culvert traps or foot snares to capture
bears. Care must be taken in baiting to
avoid conditioning bears to people—
use only natural scents and baits such
as wild animal road kills. Only properly trained personnel should be
assigned to such work. The Ursid
Research Center in Missoula,
Montana, offers courses in capturing
and handling bears. Consult state
regulations and wildlife agency
personnel before implementing any
bear-trapping program.
C-21
Immobilizing and Handling
Bears are occasionally captured by
injection with an immobilizing drug
administered from a syringe dart fired
from a capture gun. Bears have been
successfully immobilized with darts
fired from close range. Bears can be
approached on foot, from vehicles, and
from helicopters. The drugs most commonly used include a mixture of
ketamine hydrochloride and xylazine
hydrochloride (Ketaset-Rompun). This
mixture has a high therapeutic index
and results in little distress to the
animal.
The drugs chosen, the degree of
sanitation, the approach to the set, the
weapons carried, and the size of capture crews are extremely crucial in
tending the animal. Interning with a
recognized expert, or attending a certified course should be required before
attempting to capture brown bears.
Shooting
Many grizzlies have been killed in
response to livestock depredations, as
allowed under the US Endangered
Species Act. Over time, public tolerance for this approach has declined
and fewer bears are now being killed
or removed. Currently, shooting is
used most often on adult males, since
they are not considered essential in a
population. This may, however, be
short-sighted, considering that all
other bears in an area modify their
own behavior based on the activities of
the dominant adult male bear. Left
alone, a bear often will not kill livestock again, or could be trained
through aversive conditioning not to
attack livestock again.
Firearms should be carried by people
working with bears or in areas where
the risk of bear attack is high. The best
protective weapons are high-powered
rifles of .350 caliber or larger and 12gauge pump shotguns with rifled
slugs. Handguns (.44 magnum) should
be carried for quick defense only.
Aversive Conditioning
Aversive conditioning may be effective
in teaching bears to fear humans. In
C-22
Montana, problem bears were
captured and brought into holding
facilities where they were repeatedly
confronted by humans and repelled
with chemical sprays. Treatment was
complete when the bear fled instantly
to the “sanctuary” portion of an
enclosure. The bear was then quickly
returned to the wild. The captive process, called “bear school,” lasts only 4
to 6 days. This method can only be
conducted by fully trained personnel.
Field treatment may follow, using
radio collars, 24-hour monitoring, and
firearm backup. Aversive conditioning
may cost up to $6,000 per animal, but
it may be cost-effective, considering
the alternatives.
Public Education
Public attitudes are crucial in determining what damage prevention or
control is practical. The State of Montana now has two staff members
authorized to work closely with people
in grizzly range not only to solve bear
problems but to meet with the public
and listen to their concerns. They talk
in schools and at rural functions and
work with individual ranchers to solve
special problems or help in emergencies.
Avoiding Human-Bear Conflicts
Preventing Bear Attack. Grizzly/
brown bears must be respected. They
have great strength and agility, and
will defend themselves, their young,
and their territories if they feel threatened. They are unpredictable and can
inflict serious injury. NEVER feed or
approach a bear.
To avoid a bear encounter, stay alert
and think ahead. Always hike in a
group. Carry noisemakers such as bells
or cans containing stones. Most bears
will leave a vicinity if they are aware of
a human presence. Remember that
noisemakers may not be effective in
dense brush and near rushing water.
Be especially alert when traveling into
the wind since bears may not pick up
your scent and may be unaware of
your approach. Stay in the open and
avoid food sources such as berry
patches and carcass remains. Bears
may feel threatened if surprised.
Watch for bear sign—fresh tracks,
digging, and scats. Detour around the
area if bears or their fresh sign are
observed.
NEVER approach a bear cub. Adult
female brown bears are very defensive
and may be aggressive, making threatening gestures (laying ears back,
huffing, chopping jaws, stomping feet)
and possibly making bluff charges.
Bears have a tolerance range which,
when encroached upon, may trigger
an attack. Keep a distance of at least
100 yards (100 m) between you and
bears.
Bears are omnivorous, eating both
vegetable and animal matter, so don’t
encourage bears by leaving food or
garbage around camp. When bears
associate food with humans, they may
lose their fear of humans. Foodconditioned bears are very dangerous.
In established campgrounds, keep
your campsite clean and lock food in
the trunk of your vehicle. Don’t leave
dirty utensils around the campsite,
and don’t cook or eat in tents. After
eating, place garbage in containers
provided at the campground.
In the backcountry, establish camps
away from animal or walking trails,
and near large, sparsely branched trees
that can be climbed should it become
necessary. Choose another area if fresh
bear sign is present. Cache food away
from your tent, preferably suspended
from a tree that is 100 yards (100 m)
downwind of camp. Use bear-proof or
airtight containers for storing food and
other attractants. Freeze-dried foods
are lightweight and relatively odorfree. Pack out all noncombustible
garbage. Always have radio communication and emergency transportation
available at remote base or work
camps in case of accidents or medical
emergencies.
Don’t take dogs into the backcountry.
The sight or smell of a dog may attract
a bear and stimulate an attack. Most
dogs are no match for a bear. When in
trouble, the dog may come running
back to the owner with the bear in pursuit. Trained guarding dogs are an
exception and may be very useful in
detecting and chasing away bears in
the immediate area.
Bear Confrontations. If a brown
bear is seen at a distance, make a wide
detour. Keep upwind if possible so the
bear can pick up human scent and recognize human presence. If a detour or
retreat is not possible, wait until the
bear moves away from the path.
Always leave an escape route and
never harass a bear.
If a brown bear is encountered at close
range, keep calm and assess the situation. A bear rearing on its hind legs is
not always aggressive. If it moves its
head from side to side it may only be
trying to pick up scent and focus its
eyes. Remain still and speak in low
tones. This may indicate to the animal
that there is no threat. Assess the surroundings before taking action. There
is no guaranteed life-saving method of
handling an aggressive bear, but some
behavior patterns have proven more
successful than others.
Do not run. Most bears can run as fast
as a racehorse, covering 30 to 40 feet (9
to 12 m) per second. Quick, jerky
movements can trigger an attack. If an
aggressive bear is met in a wooded
area, speak softly and back slowly
toward a tree. Climb a good distance
up the tree. Adult grizzlies don’t climb
as a rule, but large ones can reach up
to 10 feet (3 m). Defend yourself in a
tree with branches or a boot heel if
necessary.
Occasionally, bears will bluff by charging within a few yards (m) of an unfortunate hiker. Sometime they charge
and veer away at the last second. If
you are charged, attempt to stand your
ground. The bear may perceive you as
a greater threat than it is willing to
tackle and may leave the area.
As a last resort when attacked by a
grizzly/brown bear, passively resist by
playing dead. Drop to the ground face
down, lift your legs up to your chest,
and clasp both hands over the back of
your neck. Wearing a pack will shield
your body. Brown bears have been
known to inflict only minor injuries
under these circumstances. It takes
courage to lie still and quiet, but resistance is usually useless.
Many people who work in or frequent
bear habitat carry firearms for personal
protection. Although not a popular
solution, it is justifiable to kill a bear
that is attacking a human.
For Additional
Information
Economics of Damage
and Control
Boddicker, M. L. 1986. Black bears. Pages C5C15 in R. M. Timm, ed. Prevention and
control of wildlife damage. Univ. Nebraska,
Coop. Ex. Lincoln.
The US Endangered Species Act dictates that the bear be favored and protected. In terms of a natural resource,
individual grizzlies are considered
worth $500,000 by some accounts, and
the $20,000 penalty for a wrongful
death underscores the importance of
management. In terms of tourism, recreation, film making, photography,
hunting, and all the other cultural and
art values of the grizzly, each bear is
certainly worth the half million dollars
cited above. Yet in Montana, where the
future of the grizzly is in jeopardy,
their value was only recently raised
from $50 to $500. Bear parts have illegally sold for as much as $250 per
front claw, $200 per paw, $10,000 for
the hide, $500 for the skull, and
$30,000 for the gall bladder. Poachers
would likely be fined only $10,000 if
caught.
Bromley, M. ed. 1989. Bear-people conflicts:
proceedings of a symposium on
management strategies. Northwest Terr.
Dep. Renew. Resour. Yellowknife. 246pp.
One hope for brown bears may be
found in the private sector—people
who value bears highly and contribute
to organizations that support proper
bear management. Damage prevention
and control costs could also be met by
such organizations. Because hunting is
no longer widely practiced, revenues
for bear management have declined.
Wildlife agencies must develop a
higher value for the brown bear and
divert fees collected from hunting
other species to meet the rising costs of
bear management.
Best, R. C. 1976. Ecological energetics of the
polar bears (Ursus maritimus Phipps 1974).
M.S. Thesis. Univ. Guelph, Ontario. 136pp.
Brown, D. E. 1985. The grizzly in the Southwest:
documentary of an extinction. Univ.
Oklahoma Press, Norman. 274pp.
Bunnell, F. L., and D. E. N. Tait. 1981.
Population dynamics of bears—implications.
Pages 75-98 in C. W. Fowler and T. D. Smith,
eds. Dynamics of large mammal
populations. John Wiley & Sons, New York.
Clarkson, P. L., and L. Sutterlin. 1984. Bear
essentials. Ursid Res. Center, Missoula,
Montana. 67pp.
Craighead, J. J., and J. A. Mitchell. 1982. Grizzly
bear. Pages 515-556 in J. A. Chapman and G.
A. Feldhamer, eds. Wild mammals of North
America: biology, management, and
economics. The Johns Hopkins Univ. Press,
Baltimore, Maryland.
Graf, L. H., P. L. Clarkson, and J. A. Nagy. 1992.
Safety in bear country: a reference manual.
Rev. ed. Northwest Terr. Dep. Renew.
Resour. Yellowknife. 135pp.
Herrero, S. 1985. Bear attacks: their causes and
avoidance. Winchester Press, Piscataway,
New Jersey. 287pp.
Jonkel, C. J. 1986. How to live in bear country.
Ursid Res. Center Pub. 1. 33pp.
Jonkel, C. J. 1987. Brown bear. Pages 456-473 in
M. Novak, J. A. Baker, M. E. Obbard, and B.
Malloch, eds. Wild furbearer management
and conservation in North America. Ontario
Ministry Nat. Resour. Toronto.
Jonkel, C. J. 1993. Bear trapping drugging and
handling manual. US Fish Wildl. Serv.
Missoula, Montana.
McNamee, T. 1984. The grizzly bear. A. Knopf
Pub., New York. 308pp.
Acknowledgments
I am indebted to Julie Mae Ringelberg for help
in preparing this manuscript. Tim Manley
and Mile Madel of the Montana Department
of Fish, Wildlife, and Parks provided advice
and information.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
Figure 1 drawn by Clint E. Chapman, University
of Nebraska.
C-23
C-24
Peter L. Clarkson
Wolf/Grizzly Bear Biologist
Renewable Resources
Government of the N.W.T.
Inuvik, Northwest Territories
Canada X0E 0T0
POLAR BEARS
Ian Stirling
Polar Bear Biologist
Canadian Wildlife Service
Edmonton, Alberta
Canada T6H 2S5
Fig. 1. Polar bear, Ursus maritimus
Damage Prevention and
Control Methods
Store garbage, human waste, food, and
other products in areas not
accessible to bears.
Exclusion
Deterrents and Frightening
Devices
Heavy woven-wire fences (minimum
6 feet [2 m] tall).
Specifically designed electric fences.
High metal walls (offshore oil rig
caisson or drilling ship).
Sturdy metal buildings and iron cages.
Cultural Methods
Remove snow around buildings and
work areas to increase visibility.
Install good lighting in areas where it
is essential to detect bears that may
be in the vicinity.
Loud noises, vehicle engines, cracker
shells, rifle shots, barking dogs, and
air horns.
Trained bear dogs.
Employ trained bear monitors with
firearms and deterrents to protect
communities, industry camps, and
work places.
Nonlethal firearm deterrents such as
12-gauge plastic slugs and 1 1/2inch (38-mm) rubber bullets.
Vehicles, heavy construction
equipment, snowmobiles, and
helicopters can be used to chase
polar bears away from work and
living areas.
Detection Systems
Dogs, bear monitors, trip-wire
fences, and electronic (infra-red,
microwave, modulated light beam)
alarm systems.
Constant vigilance of personnel
working at the site.
Repellents
Capsaicin spray.
Toxicants
None are registered.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-25
Fumigants
None are registered.
Trapping
Live traps (culvert and barrel traps)
and snares (Aldrich foot snares).
Shooting
Twelve-gauge shotgun and rifled slugs
at close range.
High-powered rifle of .30-06 caliber or
larger at close or long range.
Other Methods
Identification
The polar bear (Fig. 1) is the largest
member of the family Ursidae. Males
are approximately twice the size of
females. On average, adult males
weigh 500 to 900 pounds (250 to 400
kg), depending on the time of year. An
exceptionally large individual might
reach 1,320 to 1,760 pounds (600 to 800
kg). Adult females weigh 330 to 550
pounds (150 to 250 kg) on average,
although a pregnant female just prior
to going into a maternity den could be
double that weight.
Polar bears have a heavy build overall,
large feet, and a longer neck relative to
their body size than other species of
bears. The fur is white, but the shade
may vary among white, yellow, grey,
or almost brown, depending on the
time of year or light conditions. The
pelage consists of a thick underfur
about 2 inches (5 cm) in length and
guard hairs about 6 inches (15 cm)
long. Polar bears have a plantigrade
gait and five toes on each paw with
short, sharp, nonretractable claws.
Females normally have four functional
mammae. The vitamin A content of
the liver ranges between 15,000 and
30,000 units per gram and is toxic to
humans if consumed in any quantity.
C-26
Greenland
Alaska
Drugging and immobilization with
Telazol (safest and most reliable
drug) administered by a dart gun or
jabstick. Other drugs can be used
with suitable care.
Canada
Fig. 2. Polar bear distribution map.
Range
ice, probably because of the low density of seals there.
Polar bears are distributed throughout
the circumpolar Arctic. In North
America, their range extends from the
Canadian Arctic Islands and the
permanent multiyear pack ice of the
Arctic Ocean to the Labrador coast
and southern James Bay. The southern
limit of their distribution in open ocean
areas such as the Bering Sea or Davis
Strait varies depending on how far
south seasonal pack ice moves during
the winter (Fig. 2).
Polar bears use a variety of habitats
when hunting seals, including stable
fast-ice with deep snowdrifts along
pressure ridges that are suitable for
seal birth lairs and breathing holes, the
floe edge where leads are greater than
1 mile wide (1.6 km), and areas of
moving ice with seven-eighths or more
of ice cover. Bears may be near the
coast or far offshore, depending on the
distribution of these habitats. Ringed
seals (Phoca hispida) and sometimes
bearded seals (Erignathus barbatus)
maintain their breathing holes from
freezeup in the fall to breakup in the
spring. Bears can hunt more successfully in areas where wind, water current, or tidal action cause the ice to
continually crack and subsequently
refreeze.
Habitat
From freezeup in the fall, through the
winter, and until breakup in the
spring, polar bears are dispersed over
the annual ice along the mainland
coast of continental North America,
the inter-island channels, and the shore
lead and polynia systems associated
with them. Polar bears are not abundant in areas of extensive multiyear
During winter, bears are less abundant
in deep bays or fiords in which
expanses of flat annual ice have consolidated through the winter. In places
where the snow cover in the fiords is
deep, large numbers of ringed seals
give birth to their pups in subnivean
lairs in the spring. Consequently, polar
bears in general, but especially females
with newborn cubs, move into such
areas in April and May to hunt seal
pups.
During summer, the response of the
bears to the annual ice melts varies
depending on where they live. Bears in
the Beaufort and Chukchi seas may
move hundreds of miles to stay with
the ice. Bears in the Canadian arctic
archipelago make seasonal movements
of varying distances depending on ice
conditions. Polar bears travel seasonally to remain where ice is present
because they depend on the sea ice for
most of their hunting.
In Hudson Bay, James Bay, parts of
Foxe Basin, and the southeastern coast
of Baffin Island, the ice melts completely in the summer and there are no
alternate areas with ice close enough to
migrate to. In these areas the bears
may be forced ashore as early as the
end of July to fast on land until
November. Some bears remain along
the coast while others move inland to
rest in pits in snow banks or in earth
dens in areas of discontinuous permafrost. By late September or early October, bears that spent the summer on
land tend to move toward the coast in
anticipation of freezeup. Many conflicts with people occur in the fall
when bears are waiting along coastal
areas for the sea ice to form.
Food Habits
Polar bears feed on ringed seals and to
a lesser degree on bearded seals.
About half of the ringed seals killed
during the spring and early summer
are the young of the year. These young
seals are up to 50% fat by weight and
are probably easy to catch because
they are vulnerable and inexperienced.
Less frequently taken prey include
walrus (Odobenus rosmarus), white
whales (Delphinapterus leucas), narwhals (Monodon monoceros), and harp
seals (Pagophilus groenlandicus). Polar
bears also eat small mammals, bird
eggs, sea weed, grass, and other vegetation, although these food sources
are much less common and probably
not significant.
Polar bears are curious animals and
will investigate human settlements and
garbage. They have been observed to
ingest a wide range of indigestible and
hazardous materials, such as plastic
bags, styrofoam, car batteries, ethylene
glycol, and hydraulic fluid.
General Biology,
Reproduction, and
Behavior
Polar bears mate on the sea ice in April
and May. Implantation of the embryo
is delayed until the following September. The adult sex ratio is even, but
because females normally keep their
young for about 2 1/2 years, they usually mate only once every 3 years. This
creates a functional sex ratio of three
or more males per female that results
in intensive competition among males
for access to estrus females.
Maternity dens are usually dug in
deep snow banks on steep slopes or
stream banks near the sea by late October or early November, depending on
the availability of snow. In the Beaufort Sea, a large proportion of the
females den on the multiyear pack ice
several hundred miles (km) offshore.
On the Ontario and Manitoba coasts of
Hudson Bay, female polar bears may
have their maternity dens 30 to 60
miles (50 to 100 km) or more inland,
though this is quite unusual elsewhere
in polar bear range.
Pregnant females normally have 2
young between about late November
and early January. At birth, cubs
weigh about 1.3 pounds (0.6 kg), have
a covering of fine hair, and are blind.
They are nursed inside the den until
sometime between the end of February
and the middle of April, depending on
latitude. When the female opens her
den, the cubs weigh 22 to 26 pounds
(10 to 12 kg). The family remains near
the den, sleeping in it at night or during inclement weather for up to
another 2 weeks while the cubs exer-
cise and acclimatize to the cold, after
which they move to the sea ice to hunt
seals.
The mean age of adults in a population
is 9 to 10 years and average life expectancy is about 15 to 18 years. Maximum
recorded age of a male in the wild is 29
years. Few male polar bears live past
20 years because of the intense competition and aggression among them. The
oldest age recorded for a wild female
polar bear is 32 years.
Depending on the age and sex class,
polar bears spend 19% to 25% of their
total time hunting in the spring and
30% to 50% of their time hunting in the
summer. Polar bears capture seals
mainly by stalking them, by waiting
for them to surface at a breathing hole
or, in the spring, by digging out seal
pups and sometimes adults from birth
lairs beneath the snow. When a polar
bear kills a seal it immediately eats as
much as it can and then leaves. Polar
bears do not cache food and normally
only remain with a kill for a short time.
In the case of a large food supply such
as a dead whale or a garbage dump,
individual bears may remain in an
area for several days or even weeks.
Polar bears sleep about 7 to 8 hours a
day. They tend to be more active at
“night” during the 24-hour daylight
that prevails in the summer months,
and to sleep during the day. Within 1
or 2 hours after feeding, they will usually sleep, regardless of the time of
day. Before sleeping, females with
cubs often move away from areas
where other bears are active, probably
to reduce the risk of predation on the
cubs by adult males.
Damage and Damage
Identification
Threat or damage from a polar bear
differs from that of other bears because
it can occur at any time of the year.
Conflicts are commonly referred to as
“threat to life or property” (TLP) or
“defense of life or property” (DLP).
Although polar bears are the most
predatory of the three North American
bears, their threat to human life has
C-27
been low. Historically, northern people
(Inu, Inuit, Inuvialuit, and Inupiat)
were aware of the threat posed by
polar bears. Legends and artwork portray conflicts between northern people
and polar bears. In recent times, polar
bears have injured or killed people living and working in the Arctic. Fleck
and Herrero (1988) provide a detailed
discussion of polar bear-people conflicts in the Northwest Territories and
other areas. The Bear-People Conflict
Proceedings (Bromley 1989) includes
several papers on handling and preventing encounters with bears.
Damage to property can be serious in
the remote and sometimes harsh arctic
environment, where food and shelter
may be essential to survival. Most
property damage occurs at small semipermanent hunting camps, industrial
camps, and in communities. Damage
includes destruction of buildings and
their contents, predation of tied dogs,
destruction of snowmobile seats and
other plastic or rubber products or
equipment, and raiding of food caches.
Legal Status
Polar bears are protected in Canada
and the United States. In Canada,
polar bears are legally hunted. Seasons, protected categories, and quotas
apply. In Alaska, polar bear hunting is
not legal, but native people may kill
animals for subsistence. In Russia and
Svalbard, polar bears are completely
protected. In Greenland, polar bears
are legally harvested by Inuk hunters.
Females with cubs in dens are protected.
Deterring polar bears in Alaska is
restricted to wildlife officers because
polar bears are protected by the
Marine Mammal Protection Act. This
policy is being questioned because it
does not allow companies or private
individuals to deter a bear in a problem situation. It is, however, legal for
anyone to shoot a bear in defense of
life. In Canada it is legal for anyone to
attempt to deter, and if necessary
destroy, a bear in defense of life or
property. Any bear killed in either
jurisdiction must be reported to the
nearest wildlife office.
C-28
Damage Prevention and
Control Methods
Preventing Polar Bear-People
Conflicts
Preventing bear-people conflicts has
been given considerable attention in
the Canadian and Alaskan Arctic since
the mid-1970s. Reducing the number
of polar bear-people conflicts has
increased the safety of people living
and working in the Arctic and reduced
the number of polar bears killed in
problem situations. An active public
information and education program
will help inform people how to prevent bear problems. Most wildlife
agencies in bear country have a variety
of public education materials available
that are specifically designed to help
people prevent bear problems and better handle any that may occur. Special
information and training workshops
have been developed by the Department of Renewable Resources, Northwest Territories, and adopted by
wildlife agencies and industry in other
jurisdictions. The workshops instruct
people on how to prevent bear conflicts. Two publications to assist workshop instructors are available
(Clarkson and Sutterlin 1983, and
Clarkson 1986a). The Safety in Bear
Country Manual (Bromley 1985, Graf et
al. 1992) has been used as a reference
text for most workshops.
Many bear problems occur at industry
camps and work sites. When designing and setting up camps, the number
of conflicts can be reduced by considering the potential bear problems.
Keeping a clean camp and reducing
the number of attractants will reduce
bear problems. Once a bear has
received a food or garbage reward
from a camp, it will quickly associate
the camp with available food. Most
bears that are habituated to human
food or garbage are destroyed in a
problem bear situation. To reduce the
number of problems and problem bear
deaths, careful planning and precautions should be taken.
A “Problem Bear Site Operations
Plan” was developed to help industrial operations better plan and pre-
vent bear problems (Clarkson et al.
1986b). The plan helps camp safety officers, team leaders, and managers locate and design facilities and programs
that are site specific. It contains information and emergency contact telephone numbers, site design, personnel
responsibilities, and techniques to
detect and deter bears. The plan can be
included in the Safety in Bear Country
Manual as an additional chapter. Problem Bear Site Operation Plans have
been developed for polar bear concerns at the arctic weather stations and
for oil exploration activities in the
Beaufort Sea. Each plan deals with
being prepared for and preventing polar bear problems at specific sites.
Avoiding and responding to close
encounters with polar bears is
addressed by Bromley (1985), Fleck
and Herrero (1988), Stirling (1988a),
and Graf et al. (1992). While each polar
bear encounter is different, the chance
of a serious or fatal bear problem can
be reduced by keeping alert and being
informed and prepared to deal with
any bear problems that may arise.
Exclusion
Heavy woven-wire fences are effective
in keeping bears out of an area. Fences
must be constructed of sturdy materials and properly maintained to prevent bears from entering the exclosure.
The fence should be a minimum of 6
feet (2 m) high, and the bottom should
be secured to the ground or a cement
foundation to prevent bears from lifting the fence and crawling under the
wire. Keep fence gates closed when
not in use to prevent bears from entering the area.
Electric fences have been tested on
polar bears with limited success;
grounding problems during winter
months have been the primary
obstacle. Davis and Rockwell (1986)
describe an electric fence they used to
protect a camp during the summer
months along the Hudson Bay coast.
The use of high metal platforms, such
as oil rig caissons, or offshore drilling
ships, prevents bears from getting
access to work and living areas. Sturdy
metal buildings and iron bar cages
have been successfully used to store
food and equipment, and prevent
polar bear access.
Cracker shell
Cultural Methods
Regular snow removal from work and
living areas in polar bear habitat will
help make these sites safer by reducing
potential hiding spots and increasing
visibility for personnel. Install lighting
around the work site to increase visibility and staff safety. Proper design
and set-up of work and living sites will
help reduce potential problems. Regular camp maintenance and proper handling and storage of food, wastes, and
oil products will help reduce bear
problems.
150 yards
200 yards
Deterrents and Frightening
Devices
Nonlethal deterrents are used on polar
bears in an attempt to scare them away
rather than destroy them. Deterrents
range from snowmobiles and vehicles
to 12-gauge plastic slugs and cracker
shells. Choosing an appropriate deterrent will depend on the type of problem and specific location (Table 1).
Regardless of the type of deterrent
used, all encounters with bears should
be supported by an additional person
equipped with a loaded firearm.
Graf et al. (1992) reviewed several
deterrents that are useful for polar
bears. Clarkson (1989) recommends
the use of a 12-gauge shotgun and a
“three-slug system” (cracker shell,
plastic slug, and lead slug). Deter bears
from a site as soon as they are seen in
the area, to prevent them from approaching closer and receiving some
type of food or garbage reward. Figure
3 identifies the appropriate distances
for deterring versus destroying a bear.
Each bear deterrent situation is different, and depends on the bear’s behavior and safety options available at the
site. When deterring a bear with a
plastic slug, aim for the large muscle
mass area in the hind quarters (Fig. 4).
The neck and front shoulders should
be avoided to minimize the risk of hitting and damaging an eye.
Plastic slug
30 to 60 yards
Lead slug
0 to 30 yards
Fig. 3. Deterring and destroying a bear with a 12-gauge shotgun.
C-29
Table 1. Review of deterrent methods.
C-30
Method
Effectiveness
Practicality
Advantages
Limitations
Warning shots
-will not scare some bears
-repeated use may decrease
effectiveness
-practical for most situations
where portable, short-term
deterrent is needed
-readily available
-easy to use
-portable
-may injure bear, if not
carefully placed
Cracker shells
-same as for warning shots
-should not be relied on for
personal protection
-same as for warning shots
-same as for warning shots
-improper storage and/or
old stock can misfire
-may be a fire hazard
Blank pistol
Screamer/banger
-same as for cracker shell
-same as for warning shots
-safe
-loud, unusual, and
prolonged noise
-long range 100+ yards
-may be a fire hazard
Pencil flare gun
-same as for cracker shell
-same as for warning shots
-same as for warning shots
-same as for cracker shells
Propane cannon
-will protect livestock and
apiaries
-practical as immediate
response to emergency
situations
-easy to set up and use
-portable
-restricted to isolated
areas as sound carries
long distance
12-gauge
plastic slugs
-very effective though some
bears not deterred
-suitable for most problem
bear situations
-can be fired from a
12-gauge shotgun
-portable
-may injure bear if used
at a range closer than
recommended
Rubber bullet
(38 mm)
-very effective
-useful in most situations
when a Renewable Resource
Officer or R.C.M.P. can be
contacted
-bears do not react
aggressively
-use limited to renewable
resource officers and
R.C.M.P. in Canada
-intensive training and
practice necessary
-may injure bear if shot
not placed properly
-special gun required
Electric
fence
-fence built to proper
specifications will keep out
polar bears
-suitable for temporary, semipermanent, and permanent
installations
-permanent deterrent
method
-24 hours protection
-effort required for
installation
-regular maintenance
required
Capsaicin sprays
-effective for polar bears in
some circumstances
-should not be relied on for
personal protection
-portable
-useful as a backup for other
deterrent methods
-useful while traveling or in
small camp areas where
other deterrents not allowed
-readily available
-portable
-easy to use
-may not be useful in all
situations (wind)
-limited range (6-8 yards)
-not reliable in sub-zero
temperatures
Vehicles
(snowmachines,
all terrain vehicles,
helicopters)
-engine noise often frightens
bears away
-chasing bears for a short
distance is effective
-useful while traveling or
in small camps where
vehicles or helicopters
are used
-easy if vehicle is
accessible
-may be hazardous to
persons and bears if not
used properly
Air horns
(boat horns)
-same as for warning shots
and cracker shells
-same as for warning shots
-same as for warning shots
-not reliable in cold
temperatures
-may provoke aggressive
or curious reaction
-source of noise is from
person
Dogs
-specially trained dogs may be
effective in some cases
-not reliable
-suitable for camps of all sizes
-easy
-untrained dogs can
aggravate a bear and/or
lead it back to camp
-dogs can be killed
-require a responsible
handler
Bear monitors
-can be highly effective if
experienced with bears,
deterrents, and firearms
-especially useful at large,
established camps
-flexible
-need several monitors
for 24-hour protection
-need good
communication
Table 2. Review of bear detection systems.
Method
Practicality
Effectiveness
Advantages
Limitations
Trip-wire fence
-small or temporary camps
-100% successful in field
tests
-small, light, portable
-24-hour protection
-inexpensive
-easy to set up and operate
-requires minimal
equipment
-may be triggered by
other animals
-must be reset manually
Microwave motion
detection system
-large, semipermanent, and
permanent camps
-100% successful in field
tests
-24 hour protection
-easy to install and
maintain
-resets automatically
-powered by AC current
or 12V batteries
-perimeter limitation of
450 yards for single unit
-may be triggered by
other animals
-relatively expensive
-not easily moved
-site levelling may be
required
-units must be “bearproofed”
Dogs
-most situations (requirements
for dogs must be met, refer
to text)
-inconsistent results
-simple
-inexpensive
-portable
-protection may be
inconsistent
-dog may be mauled or
killed
-dogs may attract bears
-some risk involved until
you have seen a dog’s
reaction to bears
Bear monitors
-medium to large semipermanent and permanent
camps
-effectiveness depends on
experiernce and training
of monitor
-flexible
-provide protection as
well as warning
-thorough training
necessary to obtain
maximum effectiveness
Infra-red system
-potentially useful for large
sites
-100% successful in
preliminary field tests
-24 hour protection
-flexible
-useful where unstable
ground/ice conditions
exist
-portable
-expensive
-must be operated by
trained personnel
-poor functional
operating distance
-poor video image
Conventional
security system
-potentially useful for most
situations
-have been successfully used
for detecting people
-have not been field-tested on
bears
-easy to use
-portable
-flexible
-effectiveness to detect
bears has not been
determined
-some systems are
expensive
Detection Systems
Detecting a polar bear that is
approaching a work or living area is
an important part of handling bear
problems. Bear detection systems
range from a simple tripwire to more
technical electronic monitoring devices
(Table 2). If a bear is approaching a
work or living area, the personnel on
site should have time first to ensure
their safety and second to prepare to
deter the bear. Detection systems must
be properly installed and maintained
to be effective. If bear problems are
rare, a system that is too technical or
difficult to maintain will soon be
neglected. Bear monitors and dogs
should have previous experience with
bears. An experienced bear dog can act
both as a detection and deterrent
system.
Repellents
Capsaicin (oleoresin of capsicum or
concentrated red pepper) spray has
been tested and used on black and
grizzly bears (Hunt 1984), but has not
yet been tested on polar bears. It may
become more popular where restrictions on firearms are in place. Capsaicin needs to be scientifically tested
before it can be formally recommended for polar bear protection.
Toxicants
No toxicants are registered for use on
polar bears.
Fumigants
No fumigants are registered for use on
polar bears.
Trapping
Live traps used to capture polar bears
include culvert or barrel traps and foot
snares. Both have been used to capture
all three bear species in North
America. The culvert trap has been
used to capture polar bears at Churchill, Manitoba, and in the eastern
Northwest Territories. It can also be
used for short-term holding and transporting of captured polar bears. Foot
snares were used in polar bear
research in the early 1970s and are
useful in some situations today. A
C-31
detailed description of using the culvert trap and foot snare is found in the
Black Bears chapter in this handbook.
In the early to mid-1900s, large leghold
traps were used along the Arctic coast.
These are no longer used today.
Deterrent
Deterrent or lethal
Shooting
Unfortunately, some bear-people conflicts require that problem bears be
shot. Polar bears can be aggressive in
attempting to obtain food, especially if
they are in poor condition and near
starving. If it is necessary to destroy a
polar bear, it should be done as efficiently and humanely as possible. The
12-gauge pump action shotgun with
lead slugs is an effective weapon for
destroying a bear at close range (less
than 100 feet [30 m]). It can also be
used to deter a polar bear. Highpowered rifles of .30-06 or larger caliber are also effective in destroying
bears. A rifle used for bear protection
should be equipped with open sights
for close-range use.
Generally, if a bear is beyond 150 feet
(45 m), destroying it is not necessary
because the bear can be deterred
before it comes closer. If it is necessary
to destroy a bear beyond 100 feet (30
m), a high-powered rifle will be more
accurate and have more penetration
energy. Whether a shotgun or rifle is
used, bears should be shot in the
chest/vital organ area (Fig. 4). Handguns are not recommended for bear
protection or for destroying problem
bears. Proper training and practice is
necessary to effectively use a firearm
for bear protection or for destroying a
bear.
Other Methods
Drugging/Immobilization. Polar
bears are often immobilized in problem situations. Bears can be drugged
while free ranging by darting them
from the ground or from a helicopter,
or darting after capture in a culvert
trap or foot snare. Darts can be fired
from a rifle or pistol. A jab stick can be
used to immobilize bears captured in a
culvert trap, but is not recommended
for bears in a foot snare.
C-32
Fig. 4. Recommended deterrent and lethal hit locations on bears.
Darting from a helicopter (Bell 206 Jet
Ranger or similar size), has been used
for research and problem bear management. The helicopter should be
equipped with a shooting window and
have sling capabilities for moving
bears. The helicopter should slowly
approach the bear from behind at an
altitude of 20 to 30 feet (6 to 10 m).
Shooting distance from a helicopter is
usually less than 30 feet (10 m). Bears
should be darted in the large muscle
areas of the neck, shoulder, or upper
midback. Several immobilizing drugs
have been used on polar bears in the
past, however, Telazol is presently
considered the most effective. Telazol
is a safe and predictable drug to work
with because there is a wide range of
tolerance to high dosages, the reactions
of darted bears can be easily interpreted, and the bears are able to thermoregulate while immobilized.
Dosages of 8 to 9 mg/kg or greater are
usually necessary to fully immobilize a
polar bear for measuring and tagging.
Immobilization time for adult bears
depends on the injection site and
weight of the bear. On the average, a
bear will be immobilized in 4 to 5 minutes after the first injection of Telazol.
Cubs of the year can be immobilized
by hand or with a jabstick after being
captured on or near their immobilized
mother.
Holding, Transporting, and
Relocating. Problem polar bears that
are captured or immobilized and not
destroyed are usually held in a culvert
trap or other suitable facility. Bears can
be transported from a problem site
with a culvert trap and released at
another location if a road system
exists. Road systems are limited in the
arctic and relocating problem bears
with culvert traps is usually not an
effective option. In most cases, captured and immobilized bears need to
be relocated by helicopter. Take precautions to ensure that bears are not
injured or suffering from hyperthermia
when transporting them in a cargo net
below a helicopter.
In Churchill, Manitoba, polar bears are
captured in or near the town limits,
held in a polar bear holding facility
and then flown out to an area north of
Churchill and released. Capturing and
holding the bears in the “polar bear
jail” prevents these bears from causing
problems while they are waiting for
the ice to form on Hudson Bay. Bears
kept in a holding facility can be given
water, but food is not recommended
because the bears may begin to associate people and the holding facility with
food. Although an expensive program,
the polar bear jail at Churchill has
reduced the number of polar bear
problems and polar bear mortalities.
Relocating problem bears usually does
not solve the problem since they often
return, sometimes from considerable
distances. Polar bears that are waiting
along a coastline for ice to form should
be moved in the general direction they
would normally travel. Most of the
polar bears released north of Churchill
travel out on the sea ice and do not
return to the townsite.
Economics of Damage
and Control
No specific studies or reports have
documented the economic costs of
polar bear damage in the Arctic. Past
polar bear problems have ranged in
cost from nothing to several thousands
of dollars. With the remote locations of
camps and communities and the
expense of transporting food and
products in the Arctic, replacement
costs are high. Lost work time of personnel and programs can also be substantial because of polar bear
problems. In September 1983, Esso
Resources Canada had to suspend
drilling until a wildlife officer could
drug and remove a bear that had happened onto the artificial island, costing
Esso about $125,000. A similar incident
occurred in 1985, and cost Esso
approximately $250,000 in lost work
time.
Hiring bear monitors can cost up to
$250 per day to protect personnel, a
camp, or an industrial site from polar
bears. The cost of government staff
and programs that are responsible for
handling polar bear problems will
depend on the number of problems.
Churchill, Manitoba, has the most
intensive government program to
handle polar bear problems. This program costs the Manitoba government
approximately $120,000 per year (M.
Shoesmith, pers. commun.).
Purchasing detection and deterrent
equipment and educating people on
the proper procedures to prevent and
handle bear problems will cost companies and agencies. These costs, however, are minimal when compared to
personnel safety, replacement costs of
property in the Arctic, and long-term
polar bear conservation concerns.
Acknowledgments
We gratefully acknowledge the following for
their continued support of our research on bears
in general, and polar bears in particular: the
Northwest Territories Department of Renewable
Resources, the Canadian Wildlife Service, Polar
Continental Shelf Project, Manitoba Department
of Natural Resources, World Wildlife Fund
(Canada), Northern Oil and Gas Assessment
Program, and the Natural Sciences and Engineering Research Council of Canada. All people,
organizations, government departments, and
industry previously involved in the Northwest
Territories’ “Safety in Bear Country Program”
are thanked for their past concern and support.
L. Graf and K. Embelton assisted in wordprocessing and editing.
Tables 1 and 2 were adapted from Graf et al.
(1992).
Figure 1 drawn by Clint Chapman, University of
Nebraska.
Figure 2 was adapted from Sterling (1988) by
Dave Thornhill, University of Nebraska.
Figures 3 and 4 are from Clarkson (1989).
For Additional
Information
Amstrup, S. E. 1986. Research on polar bears in
Alaska, 1983-1985. Proc. Working Meeting of
the IUCN/SSC Polar Bear Specialist Group.
9:85-108.
Arco Alaska, Inc. 1990. Fireweed No. 1
exploratory well. Polar Bear/Personnel
Encounter and Monitoring Plans. 16 pp.
Banfield, A. W. F. 1974. The mammals of
Canada. Univ. Toronto Press, Toronto.
438 pp.
Bromley, M. 1985. Safety in bear country: a
reference manual. Northwest Territ. Dep.
Renew. Resour., Yellowknife. 120 pp.
Bromley, M., ed. 1989. Bear-people conflicts.
Proc. Symp. Manage. Strategies Northwest
Territ. Dep. Renew. Resour., Yellowknife.
246 pp.
Calvert, W., I. Stirling, M. Taylor, L. J. Lee, G. B.
Kolenosky, S. Kearney, M. Crete, B. Smith,
and S. Luttich. 1991. Polar bear management
in Canada 1985-87. Rep. to the IUCN Polar
Bear Specialist Group. Proc. IUCN/SSC
Polar Bear Specialists Group. IUCN Report
No. 7:1-10.
Clarkson, P. L. 1986a. Safety in bear country
instructors’ guide. Northwest Territ. Dep.
Renew. Resour., Yellowknife. 32 pp.
Clarkson, P. L. 1986b. Eureka and Mould Bay
weather stations problem bear site
evaluation and recommendation. Northwest
Territ. Dep. Renew. Resour., Yellowknife.
42 pp.
Clarkson, P. L. 1989. The twelve-gauge shotgun:
a bear deterrent and protection weapon.
Pages 55-59 in M. Bromley, ed. Bear-people
conflicts. Proc. Sym. Manage. Strategies.
Northwest Territ. Dep. Renew. Resour.,
Yellowknife.
Clarkson, P. L., and P. Gray. 1989. Presenting
safety in bear country information to
industry and the public. Pages 203-207 in M.
Bromley, ed. Bear-people conflicts. Proc.
Sym. Manage. Strategies. Northwest Territ.
Dep. Renew. Resour., Yellowknife.
Clarkson, P. L., P. A. Gray, J. E. McComiskey, L.
R. Quaife, and J. G. Ward. 1986a. Managing
bear problems in northern development
areas. Northern Hydrocarbon Development
Environment Problem Solving. Proc. Ann.
Meeting Int. Soc. Petroleum Ind. Biol.
10:47-56.
Clarkson, P. L., G. E. Henderson, and P. Kraft.
1986b. Problem bear site operation plans.
Northwest Territ. Dep. Renew. Resour.,
Yellowknife. 12 pp.
Clarkson, P. L., and L. Sutterlin. 1983. Bear
essentials: a source book and guide to
planning bear education programmes.
Faculty Environ. Design, Univ. Calgary.
69 pp.
Davis, J. C., and R. F. Rockwell. 1986. An electric
fence to deter polar bears. Wild. Soc. Bull.
14:406-409.
DeMaster, D. P., and I. Stirling. 1981. Ursus
maritimus. Mammal. Species 145:1-7.
Fleck, S., and S. Herrero. 1988. Polar bear
conflicts with humans. Contract Rep. No. 3.
Northwest Territ. Dep. Renew. Resour.,
Yellowknife. 155 pp.
Graf, L. H., P. L. Clarkson, and J. A. Wagy. 1992.
Safety in bear country: a reference manual,
rev. ed. Northwest Territ. Dep. Renew.
Resour., Yellowknife. 135 pp.
Gray, P. A., and M. Sutherland. 1989. A review
of detection systems. Pages 61-67 in M.
Bromley, ed. Bear-people conflicts. Proc.
Symp. Manage. Strategies. Northwest Territ.
Dep. Renew. Resour., Yellowknife.
Hunt, C. L. 1984. Behavioral responses of bears
to tests of repellents, deterrents, and aversive
conditioning. M.S. Thesis. Montana State
Univ., Bozeman. 136 pp.
Hygnstrom, S. E. 1994. Black bears. in S. E.
Hygnstrom, R. M. Timm and G. E. Larson,
eds. Prevention and Control of Wildlife
Damage. Coop. Ext., Univ. Nebraska,
Lincoln.
Lewis, R. W., and J. A. Lentfer. 1967. The
vitamin A content of polar bear liver: range
and variability. Compar. Biochem. Physiol.
22:923-926.
Lunn, N. J., and I. Stirling. 1985. The significance
of supplemental food to polar bears during
the ice-free period of Hudson Bay. Can. J.
Zool. 63:2291-2297.
C-33
Meehan, W. R., and J. F. Thilenius. 1983. Safety
in bear country: protective measures and
bullet performance at short range. US Dep.
Agric. For. Serv. Gen. Rep PNW-152. 16 pp.
Stirling, I., and A. E. Derocher. 1990. Factors
affecting the evolution and behavioural
ecology of the modern bears. Int.. Conf. Bear
Res. Manage. 8:189-204.
Rodahl, K. 1949. Toxicity of polar bear liver.
Nature 164:530.
Stirling, I., and M. A. Ramsay. 1986. Polar bears
in Hudson Bay and Foxe Basin: present
knowledge and research opportunities.
Pages 341-354 in I. P. Martini, ed. Canadian
Inland Seas. Elsevier Sci. Publ., Amsterdam.
494 pp.
Ramsay, M. A., and I. Stirling. 1988.
Reproductive biology and ecology of female
polar bears Ursus maritimus. J. Zool. London.
214:601-634.
Schliebe, S. 1991. Polar bear management in
Alaska. Report to the IUCN Polar Bear
Specialist Group. Proc. IUCN/SSC Polar
Bear Specialists Group. IUCN Rept. No.
7:62-69.
Schweinsburg, R. E., L. J. Lee, and P. B. Latour.
1982. Distribution, movement, and
abundance of polar bears in Lancaster
Sound, Northwest Territories. Arctic
35:159-169.
Stenhouse, G. B, L. J. Lee, and K. G. Poole. 1988.
Some characteristics of polar bears killed
during conflicts with humans in the
Northwest Territories. Arctic 41:275-378.
Stirling, I. 1975. Summary of a fatality involving
a polar bear attack in the Mackenzie Delta,
January 1975. Can. Wildl. Serv. Polar Bear
Proj. Spec. Rep. 89. 2 pp.
Stirling, I. 1988a. Polar bears. Univ. Michigan
Press., Ann Arbor. 220 pp.
Stirling, I. 1988b. Attraction of polar bears Ursus
maritimus to offshore drilling sites in the
eastern Beaufort Sea. Polar Record
24(148):1-8.
C-34
Stirling, I., D. Andriashek, and W. Calvert. 1993.
Habitat preferences of polar bears in the
western Canadian Arctic in late winter and
spring. Polar Record 29:13-24.
Stirling, I., C. Spencer, and D. Andriashek. 1989.
Immobilization of polar bears Ursus
maritimus with Telazol in the Canadian
Arctic. J. Wildl. Diseases. 25:159-168.
Struzik, E. 1987. Nanook: in the tracks of the
great wanderer. Equinox Jan.-Feb. 1987.
pp. 18-32.
Urquhart, D. R., and R. E. Schweinsburg. 1984.
Polar bear: life history and known
distribution of the polar bear in the
Northwest Territories up to 1981. Northwest
Territ., Dep. Renew. Resour., Yellowknife.
69 pp.
Uspenskii, S. M. 1977. The polar bear. Nauka,
Moscow, 107 pp. (English trans. by Canadian
Wildl. Serv., 1978).
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
Dallas Virchow
BOBCATS
Extension Assistant-Wildlife
Damage Control
Department of Forestry, Fisheries
and Wildlife
University of Nebraska
Scottsbluff, Nebraska 69361
Denny Hogeland
District Director
Nebraska Fur Harvesters
Bridgeport, Nebraska 69336
Fig. 1. Bobcat, Lynx rufus
Repellents
Damage Prevention and
Control Methods
None are registered.
Fumigants
Exclusion
None are registered.
Fence poultry and other small
livestock located near human
residence.
Toxicants
None are registered.
Cultural Methods
Trapping
Clear brush and timber in and around
farmsteads and between large
expanses of bobcat habitat and
farmsteads.
Fur trappers may be willing to trap
and remove bobcats year-round in
problem situations in exchange for
trapping rights when pelts are
prime.
Frightening
Place flashing white lights, loud music,
or dogs with livestock.
Steel leghold traps (No. 2, preferably
No. 3 offset or No. 4 offset or
padded).
Cage traps, 15 x 15 x 40 inches (38 x 38
x 100 cm) up to 24 x 24 x 48 inches
(60 x 60 x 120 cm).
Large body-gripping traps (Victor®
No. 330 Conibear®) in “cubby” sets.
Kill snares (1/16- or 5/64-inch steel
[0.15- or 0.2-cm] cable, 6 to 8 feet
[1.9 to 2.5 m] long).
Live snares (3/32-inch [0.25-cm] steel
cable, 6 to 8 feet [1.9 to 2.6 m] long)
with protective clothing and
equipment.
Shooting
Predator calls, experienced trail
hounds, and centerfire rifles.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-35
Identification
The bobcat (Lynx rufus), alias “wildcat,” is a medium-sized member of the
North American cat family. It can be
distinguished at a distance by its
graceful catlike movements, short (4to 6-inches [10- to 15-cm]) “bobbed”
tail, and round face and pointed ears
(Fig. 1). Visible at close distances are
black hair at the tip of the tail and
prominent white dots on the upper
side of the ears.
Body hair color varies, but the animal’s
sides and flanks are usually brownish
black or reddish brown with either
distinct or faint black spots. The back
is commonly brownish yellow with a
dark line down the middle. The chest
and outside of the legs are covered
with brownish to light gray fur with
black spots or bars. Bobcats living at
high elevations and in northern states
and Canada have relatively long hair.
In southern states, bobcats may have a
yellowish or reddish cast on their
backs and necks.
Similar Species. The bobcat is two to
three times the size of the domestic cat
and appears more muscular and fuller
in the body. Also, the bobcat’s hind
legs are proportionately longer to its
front legs than those of the domestic
cat.
The Canada lynx appears more slender and has proportionately larger feet
than the bobcat. At close distances, the
ear tufts of the lynx can be seen. The
tail of the lynx appears shorter than
the bobcat’s and its tip looks like it was
dipped in black paint. The bobcat’s tail
is whitish below the tip. Lynx commonly occur in Canada’s coniferous
forests and, rarely, in the Rocky Mountains. Where both species occur, lynx
occupy the more densely forested
habitats with heavy snow cover.
Male bobcats tend to be larger than
females. Adult males range from 32 to
40 inches (80 to 102 cm) long and
weigh from 14 to 40 pounds (6 to 18
kg) or more. Bobcats in Wyoming
average between 20 and 30 pounds (9
and 14 kg). Nationwide, adult females
range from 28 to 32 inches (71 to 81
C-36
cm) long and weigh from 9 to 33
pounds (4 to 15 kg). Records indicate a
tendency for heavier bobcats in the
northern portions of their range and in
western states at medium altitudes.
The skull has 28 teeth. Milk teeth are
replaced by permanent teeth when
kittens are 4 to 6 months old. Females
have 6 mammae.
Range and Habitat
The bobcat occurs in a wide variety of
habitats from the Atlantic to the Pacific
ocean and from Mexico to northern
British Columbia (Fig. 2). It occurs in
the 48 contiguous states.
The bobcat is as adapted to subtropical
forests as it is to dense shrub and hardwood cover in temperate climates.
Other habitats include chaparral,
wooded streams, river bottoms,
canyonlands, and coniferous forests to
9,000 feet (2,743 m). Bobcats prefer
areas where these native habitat types
are interspersed with agriculture and
escape cover (rocky outcrops) close by.
The bobcat has thrived where agriculture is interspersed through the above
native habitat types, as in southern
Canada.
Food Habits
Bobcats are capable of hunting and
killing prey that range from the size of
a mouse to that of a deer. Rabbits, tree
squirrels, ground squirrels, woodrats,
Fig. 2 Range of the bobcat in North America.
porcupines, pocket gophers, and
ground hogs comprise most of their
diet. Opossums, raccoon, grouse, wild
turkey, and other ground-nesting birds
are also eaten. Occasionally, insects
and reptiles can be part of the bobcat’s
diet. In Canada, the snowshoe hare is
the bobcat’s favorite fare. Bobcats
occasionally kill livestock. They also
resort to scavenging.
General Biology,
Reproduction, and
Behavior
Bobcats are secretive, shy, solitary, and
seldom seen in the wild. They are
active during the day but prefer twilight, dawn, or night hours. Bobcats
tend to travel well-worn animal trails,
logging roads, and other paths. They
use their acute vision and hearing for
locating enemies and prey.
Bobcats do not form lasting pair
bonds. Mating can occur between
most adult animals. In Wyoming,
female bobcats reach sexual maturity
within their first year but males are not
sexually mature until their second
year. Nationwide, breeding can occur
from January to June. In Wyoming,
breeding typically begins in February
and the first estrus cycle in midMarch. The gestation period in bobcats
ranges from 50 to 70 days, averaging
62 days.
Nationwide, young are born from
March to July, with litters as late as
October. The breeding season may be
affected by latitude, altitude, and longitude, as well as by characteristics of
each bobcat population. In Wyoming,
births peak mid-May to mid-June and
can occur as late as August or September. These late litters may be from
recycling or late-cycling females, probably yearlings. In Utah, births may
peak in April or May. In Arkansas,
births may peak as early as March.
Bobcats weigh about 2/3 pound (300
g) at birth. Litters contain from 2 to 4
kittens. Kittens nurse for about 60 days
and may accompany their mother
through their first winter. Although
young bobcats grow very quickly
during their first 6 months, males may
not be fully grown until 1 1/2 years
and females until 2 years of age. Bobcats may live for at least 12 years in the
wild.
Bobcats reach densities of about 1 per
1/4 square mile (0.7 km2) on some of
the Gulf Coast islands of the southeastern United States. Densities vary from
about 1 per 1/2 square mile (1.3 km2)
in the coastal plains to about 1 cat per
4 square miles (10.7 km2) in portions of
the Appalachian foothills. Mid-Atlantic and midwestern states usually have
scarce populations of bobcats.
The social organization and home
range of bobcats can vary with climate,
habitat type, availability of food, and
predators. Bobcats are typically territorial and will maintain the same territories throughout their lives. One
study showed home ranges in south
Texas to be as small as 5/8 square mile
(1.0 km2). Another study showed that
individual bobcats in southeastern
Idaho maintain home ranges from 2.5
square miles to 42.5 square miles (6.5
km2 to 108 km2) during a year. Females
and yearlings with newly established
territories tend to have smaller and
more exclusive ranges than males.
Females also tend to use all parts of
their range more intensively than adult
males.
Bobcats commonly move 1 to 4 miles
(2 to 7 km2) each day. One study found
that bobcats in Wyoming moved from
3 to 7.5 miles (5 to 12 km) each day.
Transient animals can move much
greater distances; for example, a
juvenile in one study moved 99 miles
(158 km).
Adult bobcats are usually found
separately except during the breeding
season. Kittens may be seen with their
mothers in late summer through
winter. An Idaho study found adult
bobcats and kittens in den sites during
periods of extreme cold and snow.
Females with kittens less than 4
months old generally avoid adult
males because they kill kittens.
In Canada and the western United
States, bobcat population levels tend to
follow prey densities. Some biologists
believe that coyote predation restricts
bobcat numbers. Unfortunately, not
enough is known about the relative
importance of factors such as litter
size, kitten survival, adult sex ratios,
and survival rates to predict changes
in local bobcat populations. Also, relatively low densities and variable trapping success hinder researchers from
easily predicting changes in populations.
Since the late 1970s, state game agencies have been tagging bobcat pelts
harvested in their states. Information
from these pelts is being used to estimate bobcat population trends and
factors that contribute to those
changes.
Damage and Damage
Identification
Bobcats are opportunistic predators,
feeding on poultry, sheep, goats, house
cats, small dogs, exotic birds and game
animals, and, rarely, calves. Bobcats
can easily kill domestic and wild turkeys, usually by climbing into their
night roosts. In some areas, bobcats
can prevent the successful introduction
and establishment of wild turkeys or
can deplete existing populations.
Bobcats leave a variety of sign. Bobcat
tracks are about 2 to 3 inches (5 to 8
cm) in diameter and resemble those of
a large house cat. Their walking stride
length between tracks is about 7 inches
(18 cm).
Carcasses of bobcat kills are often distinguishable from those of cougar, coyote, or fox. Bobcats leave claw marks
on the backs or shoulders of adult deer
or antelope. On large carcasses, bobcats usually open an area just behind
the ribs and begin feeding on the viscera. Sometimes feeding starts at the
neck, shoulders, or hindquarters. Bobcats and cougar leave clean-cut edges
of tissue or bone while coyotes leave
ragged edges where they feed.
Bobcats bite the skull, neck, or throat
of small prey like lambs, kids, or
fawns, and leave claw marks on their
sides, back, and shoulders. A single
bite to the throat, just behind the
victim’s jaws, leaves canine teeth
marks 3/4 to 1 inch (2 to 2.5 cm) apart.
Carcasses that are rabbit-size or
smaller may be entirely consumed at
one feeding. Bobcats may return several times to feed on large carcasses.
Bobcats, like cougars, often attempt to
cover unconsumed remains of kills by
scratching leaves, dirt, or snow over
them. Bobcats reach out about 15
inches (38 cm) in raking up debris to
cover their kills, while cougars may
reach out 24 inches (61 cm).
Bobcats also leave signs at den sites.
Young kittens attempt to cover their
feces at their dens. Females with
young kittens may mark prominent
points around den sites with their
feces. Adult bobcats leave conspicuous
feces along frequently traveled rocky
ridges or other trails. These are sometimes used as territorial markings at
boundaries.
Adult bobcats also mark trails or cave
entrances with urine. This is sprayed
on rocks, bushes, or snow banks. Bobcats may leave claw marks at urine or
feces scent posts by scraping with their
hind feet. These marks are 10 to 12
inches (25 to 30 cm) long by 1/2 inch
(1.25 cm) wide.
Bobcats also occasionally squirt a
pasty substance from their anal glands
to mark areas. The color of this substance is white to light yellow in young
bobcats but is darker in older bobcats.
Legal Status
Among midwestern states, the bobcat
is protected in Iowa, Illinois, Indiana,
Ohio, and in most counties of Kentucky. It is managed as a furbearer or
game animal in the plains states. Western states generally exempt depredating bobcats from protected status.
They can usually be killed by landowners or their agent. In the more
eastern states and states where bobcats
are totally protected, permits are
required from the state wildlife agency
to destroy bobcats. Consult with your
state wildlife agency regarding local
regulations and restrictions.
C-37
Damage Prevention and
Control Methods
Exclusion
Use woven-wire enclosures to discourage bobcats from entering poultry and
small animal pens at night. Bobcats
can climb, so wooden fence posts or
structures that give the bobcat footing
may not be effective. Bobcats also have
the ability to jump fences 6 feet (1.8 m)
or more in height. Use woven wire
overhead if necessary. Fences are seldom totally effective except in very
small enclosures.
Cultural Methods
Bobcats prefer areas with sufficient
brush, timber, rocks, and other cover,
and normally do not move far from
these areas. Keep brush cut or sprayed
around ranches and farmsteads to
eliminate routes of connecting vegetation from bobcat habitat to potential
predation sites.
Frightening
Use night lighting with white flashing
lights, or bright continuous lighting, to
repel bobcats. You can also use blaring
music, barking dogs, or changes in
familiar structures to temporarily discourage bobcats.
be lured from their course of travel
more than a few yards (m). The
bobcat’s use of dense cover for capturing rodents and rabbits can be used in
capture techniques to guide the animal
or even its footsteps.
In the past, the demand for bobcat
pelts was moderately high due to fur
values. This had encouraged late fall
and winter harvest periods. Also, the
bobcat’s high fur quality attracts harvest for recreation or utility. If bobcat
depredations are common over time,
consider inviting a fur trapper to take
bobcats during prime fur periods.
Fewer bobcats may result in less competition for native foods and less depredation. Fur trappers may undertake
the capture and relocation of bobcats
during spring and summer months
from areas where depredations are
occurring in return for fur trapping
rights during fall and winter months.
Many of the same sets used for foxes
and coyotes will also catch bobcats.
Few sets that target bobcats will catch
other predators. Bobcats can be led by
guide sticks or brush to dirt hole or flat
sets where proper lures are used.
Leghold Traps. Steel leghold traps,
Nos. 2, 3, and 4 are commonly used to
capture bobcats. Trap size selection
depends on the area and weather conditions. For coarse-textured sandy
soils, use a No. 2 coilspring trap. Use a
No. 3 trap for wet or fine-textured clay
soils. Use No. 4 traps for frozen soils
or in deep snow sets.
A bobcat is easy to hold, but sometimes more power and jaw spread is
required than a No. 2 coilspring provides. The bobcat’s foot may be too
large for proper foot placement and a
good catch. Guide sticks and stones
can be used (Fig. 3).
Bobcats prefer fresh baits such as rabbit, muskrat, or poultry. Scattered bits
of fur and feathers work well. Bobcats
can be drawn to traps by “flags” hung
from trees or rocks located near trap
sets (Fig. 4). Suspend flags about 4 feet
(1.3 m) above the ground with fine
wire or string. A combination of stiff
wire with string attached to its end
prevents entangling in tree branches.
Where animal parts are illegal, aluminum foil or jar lids or imitation fur can
be used. Location is the key to trapping bobcats. If the location is not correct, no flags or baits will work.
A flag set uses a piece of fur or a
couple of feathers suspended about 4
feet (120 cm) above ground with fine
wire or string. Build a small mound of
soil under the flag 1 foot (30 cm) high
and 2 feet (60 cm) in diameter. Bobcats
step onto these mounds to reach the
flag. Bury steel leghold traps in the
Repellents, Fumigants, and
Toxicants
No chemical repellents, fumigants, or
toxicants are currently registered for
bobcats. Commercial house cat repellents might be effective in some very
unusual circumstances. A hindrance to
development of toxicants is the bobcat’s preference to feed on fresh kills.
Trapping
Bobcats are more easily trapped than
are coyotes or foxes, but the bobcat’s
reclusiveness makes set locations difficult to find. When hunting, bobcats
use their sense of smell less than
coyotes do, so lures and baits are usually not effective. The bobcat’s acute
vision, hearing, and inquisitiveness
however, can be capitalized upon.
Even with the best sets, bobcats cannot
C-38
Bobcat trail
Fig. 3. Blind or trail set using guide sticks
and stones.
Stones
(Traps
bedded
in ground)
Pebbles
mound. Steel leghold traps can also be
used in other sets. See instructions in
the Mountain Lions chapter.
Trash or mound sets take advantage of
bobcats covering their scat and leftover
food (Fig. 5). This set is very common.
Pull up a pile of trash or litter over a
large bait, to mimic bobcat behavior.
A smaller mound can be made with
urine poured over the trash. These sets
are useful where exposed baits are illegal. Both sets should be used where
backing such as rocks or trees are
available. Place a steel leghold trap
and guide sticks in front of trash pile
sets.
Body-gripping Traps. Body-
gripping traps are very effective killer
traps for eliminating bobcats. These
kill traps are spring-loaded. When the
trigger is released, the trap closes on
the animal in a scissors-like action. An
example of this type of trap is the Victor® No. 330 Conibear®. This trap, and
others like it, can be very dangerous to
use, breaking arms, or killing large
dogs if improperly set. Check local
regulations to determine if they are
legal to use in your area. For bobcats,
set these traps in trails at the base of a
cliff or in brush. Use bait or lures
beyond the trap to entice the bobcat to
walk through it. Strategic bait placement also keeps bobcats preoccupied.
These sets can be made in dense cover
in trails, at the entrances to dens, or at
gaps in fences or brush where bobcats
travel. These traps can also be set in
entrances to cubbies constructed to
trap bobcats. Place an attractive bait at
the rear of the cubby and place the kill
trap so that the bobcat must go
through it to reach the bait. See
Mountain Lions for other sets made
with body-gripping traps.
Specific instructions on trapping bobcats are found in Boddicker (1980).
Extensive bobcat trapping methods
can also be found in Weiland (1976),
Young (1941), Johnson (1979), and
Musgrave and Blair (1979). Check all
local and state laws for using traps,
snares, baits, or lures.
Wire Cage Traps. Very large cage
Flag (feathers, fur, tinsel)
Mound 1' high x 1 1/2' diameter
Use brush or grass on the top and
sides of the cage to give the appearance of a natural “cubby” or recess in a
rock outcrop or brush. Traps should be
set in the vicinity of depredations,
travelways to and from bobcat cover,
Fig. 4. Flag set made with a buried steel leghold trap in a mound.
T
r
a
i
l
traps, made of wire mesh or metal,
when properly set, are effective. Commercial traps from 15 x 15 x 40 inches
(38 x 38 x 100 cm) up to 24 x 24 x 48
inches (60 x 60 x 120 cm) are available.
See the Supplies and Materials
chapter.
Guide rocks
or brush
Tree
Mound
Top view
Partially
exposed
bait
Mound
of
trash
Trap
Trail
8"-10"
from
mound
Side view
Fig. 5. Trash or scat mound set.
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Stakes to tie down tunnel
Brush or grass
to cover outside
of tunnel
Guiding brush
Hanging bait
Woven wire
or cribbing
Snare
position
5' snare, one on each
end of tunnel
6"-8"
10"-12"
4'-5'
2'
the furbearer season or for animals for
which relocation has failed (Fig. 8).
They are best made from fine steel
cable, 1/16 inch (0.15 cm) or 5/64 inch
(0.2 cm) in diameter. Positive locks
work well. Set kill snares with the bottom of the loop about 10 to 12 inches
(25 to 30 cm) off the ground with a
loop 6 to 8 inches (15 to 20 cm) in
diameter. This loop must be set perpendicular to the trail.
Fig. 6. Cubby set with snare.
Live snare sets capture and hold bobcats alive. They differ from kill snare
sets by their cable size, locks, and
entanglement precautions. Larger
cables and relaxed locks on live snare
sets can reduce injury if set properly.
Relaxed locks tighten onto animals but
relax as the animal stops struggling.
This allows the animal to breath normally and regain composure.
Base of steep hill or
rock outcrop “fence”
with rocks, brush, grass
Fig. 7. Trail set with snare.
and around bobcat trails, dens, and
hunting sites. Cover the cage bottom
with soil. Bait the cage with poultry,
rabbit, or muskrat carcasses, or live
animals. Check local and state laws for
restrictions.
Snares. Snares are very effective for
bobcats but require expertise and caution. When properly set, a snare can be
used to either kill or restrain a bobcat.
Snares can be placed in the same locations and situations as body-gripping
traps. They are particularly effective in
cubby sets, bobcat runways, and den
entrances (Fig. 6). Properly placed,
snares offer the advantages of bodygripping traps without the danger to
pets and nontarget wildlife.
C-40
Set snares in trails where bobcats are
known to travel (Fig. 7). Baits and
lures are usually not used with snares
and may hinder success. Use camouflage only to break up some of the outline of the snare, preferably with native
material, like grasses. Do not tie camouflage material to the loop of the
snare. Spring-loaded snares work best.
Put “memory” into the snare by placing tension on the inside of the lock
against the cable with your finger as
you close the snare once or twice. This
prevents a bobcat from walking
through a snare. Cables respond to the
memory by closing easily.
Kill snares actually kill the captured
bobcat and are most often used during
Kill snares may be tied off to a 3-inch
(7.5-cm) diameter tree or larger . To
aid quick kills, hammer 2-foot (60-cm)
stakes into the ground, leaving 6 to 8
inches (15 to 20 cm) aboveground. Killsnare locks (Gregerson, Camlock,
Thompson, Keflock) are in several of
the supply catalogs listed in Supplies
and Materials.
The live snare set (Fig. 9) requires
more expertise than the kill snare set.
Also, capture and transport of bobcats
is very dangerous. Use 3/32-inch
(0.25-cm) steel cable 6 to 8 feet (1.9 to
2.5 m) long. Use snares with high
quality swivels located midway or
closer to the loop. Stake live snares to
the ground with steel stakes, hammered to just below ground level. Use
loop sizes as in the kill snare set. Clear
Kink in cable at
lock on end of snare
To stake
Place grass or brush on both sides of snare and guide
to break up outline.
Tree stump
or brush permissible
6"-8"
2' tangle stakes
4"-6"
10"-12"
Snare
support
wire
Stake at
ground level
Fig. 8. Kill snare with washer lock.
Grass
“fence”
6"-8"
Stake at
ground level
Total area surrounding stake is
cleared of entanglements
(rocks, brush, stumps)
10"-12"
Fig. 9. Live snare with washer lock.
C-41
brush and other entanglements from
the area.
Use extreme caution when releasing a
snared animal. Catch poles with
adjustable steel nooses, thick leather
gloves or gauntlets, and other protective clothing are necessary. Immobilizing drugs such as ketamine hydrochloride should be accessible. Two
people should handle captures; one
at the neck and the other at the back
feet to remove the snare. Cut a 1/2- x
4-inch (1.2- x 10-cm) slot from the
bottom up toward the center of a 3- x
3-foot (1- x 1-m), 5/8-inch (1.6-cm) or
larger piece of plywood. A handle
should be attached at the upper end.
Place the plywood between you and
the snared animal and let the cable run
through the slot as you approach,
keeping the cable tight. Check live
snare sets frequently to avoid unnecessary stress and loss of captured bobcats to predators, such as eagles, coyotes, and mountain lions. See Supplies
and Materials for suppliers of bobcat
snares. Always ask for expert advice
before attempting live captures. Extensive instructions on snaring can be
found in Grawe (1981) and Krause
(1981).
Shooting
Bobcats respond to predator calls at
night and can be shot. Use a red, blue,
or amber lens with an 80,000- to
200,000-candlepower (lumen) spotlight
to locate bobcats. Sources of predator
calls are found in Supplies and
Materials.
Dogs trained to track bobcats can be
useful in removing problem animals.
Bobcats can be shot after being treed.
Bobcats may develop a time pattern
in their depredations on livestock or
poultry. You can lie in wait and
ambush the bobcat as it comes in for
the kill. Rifles of .22 centerfire or
larger, or shotguns with 1 1/4 ounces
(35 g) or more of No. 2 or larger shot
are recommended, since bobcats are
rather large and require considerable
killing power.
Economics of Damage
and Control
Damage by bobcats is rather uncommon and statistics related to this damage are not well developed. In western
states where data have been obtained,
losses of sheep and goats have comprised less than 10% of all predation
losses. Typical complaints of bobcat
predation involve house cats and poultry allowed to roam at will in mountain subdivisions and ranches. Bobcats
are taken by trappers and by hunters
using hounds. The pelts are used for
coats, trim, and accessories, the spotted belly fur being most valuable. Bobcat pelts are used for wall decorations
and rugs. In recent years, North
American bobcat harvests have produced about 25,000 pelts valued at $2.5
million annually. Aesthetically, the
bobcat is a highly regarded carnivore.
To many people the bobcat represents
the essence of wildness in any habitat
it occupies.
Bailey, T. N. 1974. Social organization in a
bobcat population. J. Wildl. Manage.
38:435-446.
Bailey, T. N. 1980. Factors of bobcat social
organization and some management
implications. Proc. Worldwide Furbearer
Conf. 2:984-1000.
Blair, C. 1981. Predator caller’s companion.
Winchester Press, Tulsa, Oklahoma. 267 pp.
Blum, L. G., and P. C. Escherich. 1979. Bobcat
research conference proceedings, current
research on biology and management of
Lynx rufus. Natl. Wildl. Fed. Sci. Tech. Ser. 6
137 pp.
Boddicker, M. L., (ed.). 1980. Managing Rocky
Mountain furbearers. Colorado Trappers
Assoc. LaPorte, Colorado. 176 pp.
Clark, T. W., and M. R. Stromberg. 1987.
Mammals in Wyoming. Univ. Kansas
Museum Nat. Hist. 319 pp.
Crowe, D. M. 1972. The presence of annuli in
bobcat tooth cementum layers. J. Wildl.
Manage. 36:1330-1332.
Crowe, D. M. 1975a. A model for exploited
bobcat populations in Wyoming. J. Wildl.
Manage. 39:408-415.
Crowe, D. M. 1975b. Aspects of aging, growth,
and reproduction of bobcats from Wyoming.
J. Mammal. 56:177-198.
Deems, E. F., and D. Pursley, (eds.). 1983. North
American furbearers — a contemporary
reference. Int. Assoc. Fish Wildl. Agencies
and Maryland Dep. Nat. Resour., Annapolis.
223 pp.
Acknowledgments
Fredrickson L. 1981. Bobcat management. South
Dakota Conserv. Digest 48:10-13.
Thanks are due to Major Boddicker, who
authored this chapter in the 1983 edition of this
manual. The sections on identification, habitat,
food habits, general biology, and economics
were adapted from his work. Thanks also go to
Bill Phillips, Arizona Game and Fish
Department, and Chuck McCullough, Nebraska
Game and Parks Commission, for their
information.
Gluesing, E. A., S. D. Miller, and R. M. Mitchell.
1986. Management of the North American
bobcat: information needs for
nondetrimental findings. Trans. N. A. Wildl.
Nat. Resour. Conf. 51:183-192.
Figure 1 from Schwartz and Schwartz (1981).
Figure 2 by Sheri Bordeaux.
Figures 3 through 6, 8 and 9 by Denny
Hogeland, adapted by Sheri Bordeaux.
Figure 7 adapted from M. L. Boddicker, 1980.
C-42
For Additional
Information
Grawe, A. 1981. Grawe’s snaring methods.
Wahpeton, North Dakota. 48 pp.
Johnson, C. 1979. The bobcat trappers bible.
Spearman Publ. Sutton, Nebraska. 32 pp.
Karpowitz, J. F., and J. T. Flinders. 1979. Bobcat
research in Utah—a progress report. Natl.
Wildl. Fed. Sci. Tech. Ser. 6:70-73
Koehler, G. 1987. The bobcat. Pages 399-409 in R.
L. De Silvestro, ed. Audubon Wildlife Report
1987. Natl. Audubon Soc., New York.
Krause, T. 1981. Dynamite snares and snaring.
Spearman Pub., Sutton, Nebraska. 80 pp.
McCord, C. M., and L. E. Cardoza. 1982. Bobcat
and lynx. Pages 728-768 in J. A. Chapman
and G. A. Feldhamer, eds. Wild mammals of
North America: biology, management, and
economics. The Johns Hopkins Univ. Press,
Baltimore, Maryland.
Musgrave, B., and C. Blair. 1979. Fur trapping.
Winchester Press, Tulsa, Oklahoma. 246 pp.
Robinson, W. B. 1953. Population trends of
predators and fur animals in 1080 station
areas. J. Mammal. 34:220-227.
Rue, L. 1981. Furbearing animals of North
America. Crown Pub., New York. 343 pp.
Sampson, F. W. 1967. Missouri bobcats. Missouri
Conserv. 28:7.
Schwartz, C. W., and E. R. Schwartz. 1981. The
wild mammals of Missouri, rev. ed. Univ.
Missouri Press, Columbia. 356 pp.
Scott, J. 1977. On the track of the lynx. Colorado
Outdoors 26:1-3.
Wassmer, D. A., D. D. Guenther, and J. N. Layn.
1988. Ecology of the bobcat in south-central
Florida. Bulls. Florida St. Museum, Biol. Sci.
33:159-228.
Weiland, G. 1976. Long liner cat trapping.
Garold Weiland, Pub. Glenham, South
Dakota. 25 pp.
Young, S. P. 1941. Hints on bobcat trapping. US
Fish Wildl. Serv. Circ. No. 1, US Govt. Print.
Off., Washington, DC. 6 pp.
Young, S. P. 1958. The bobcat of North America.
Stackpole Co., Harrisburg, Pennsylvania.
193 pp.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
C-43
C-44
William D. Fitzwater
Director
New Mexico Outdoor Communicators
7104 Bellrose Avenue, NE
Albuquerque, New Mexico 87110
HOUSE CATS (Feral)
Fig. 1. House cat, Felis domesticus
Damage Prevention and
Control Methods
Exclusion
Practical for protecting small poultry
and mammals.
Cultural Methods
Clean up debris, burn refuse and
brush piles, seal buildings, reduce
habitat and food sources.
Repellents
Fumigants
None are registered.
Trapping
Box traps.
No. 1, 1.5, or 2 leghold traps.
No. 220 Conibear® or body-gripping
traps.
Snares.
Shooting
Many products are registered but are
practical only for small areas.
Centerfire rifles, .22 rimfire rifles, and
shotguns are effective for quick
removal.
Frightening
Other Methods
Dogs.
Responsible care by cat owners.
Toxicants
None are registered.
Identification
The cat has been the most resistant to
change of all the animals that humans
have domesticated. All members of the
cat family, wild or domesticated, have
a broad, stubby skull, similar facial
characteristics, lithe, stealthy movements, retractable claws (except the
cheetah), and nocturnal habits.
Feral cats (Fig. 1) are house cats living
in the wild. They are small in stature,
weighing from 3 to 8 pounds (1.4 to 3.6
kg), standing 8 to 12 inches (20 to 30.5
cm) high at the shoulder, and 14 to 24
inches (35.5 to 61 cm) long. The tail
adds another 8 to 12 inches (20 to 30.5
cm) to their length. Colors range from
black to white to orange, and an amazing variety of combinations in
between. Other hair characteristics
also vary greatly.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-45
Range
Cats are found in commensal relationships wherever people are found. In
some urban and suburban areas, cat
populations equal human populations.
In many suburban and eastern rural
areas, feral house cats are the most
abundant predators.
Habitat
Feral cats prefer areas in and around
human habitation. They use abandoned buildings, barns, haystacks,
post piles, junked cars, brush piles,
weedy areas, culverts, and other
places that provide cover and protection.
Food Habits
Feral cats are opportunistic predators
and scavengers that feed on rodents,
rabbits, shrews, moles, birds, insects,
reptiles, amphibians, fish, carrion, garbage, vegetation, and leftover pet food.
General Biology,
Reproduction, and
Behavior
Feral cats produce 2 to 10 kittens during any month of the year. An adult
female may produce 3 litters per year
where food and habitat are sufficient.
Cats may be active during the day but
typically are more active during twilight or night. House cats live up to 27
years. Feral cats, however, probably
average only 3 to 5 years. They are territorial and move within a home range
of roughly 1.5 square miles (4 km2).
After several generations, feral cats can
be considered to be totally wild in
habits and temperament.
Damage
Feral cats feed extensively on songbirds, game birds, mice and other
rodents, rabbits, and other wildlife. In
doing so, they lower the carrying
capacity of an area for native predators
such as foxes, raccoons, coyotes, bobcats, weasels, and other animals that
compete for the same food base.
C-46
Where documented, their impact on
wildlife populations in suburban and
rural areas—directly by predation and
indirectly by competition for food—
appears enormous. A study under
way at the University of Wisconsin
(Coleman and Temple 1989) may provide some indication of the extent of
their impact in the United States as
compared to that in the United Kingdom, where Britain’s five million
house cats may take an annual toll of
some 70 million animals and birds
(Churcher and Lawton 1987). Feral
cats occasionally kill poultry and injure
house cats.
Feral cats serve as a reservoir for
human and wildlife diseases, including
cat scratch fever, distemper, histoplasmosis, leptospirosis, mumps, plague,
rabies, ringworm, salmonellosis,
toxoplasmosis, tularemia, and various
endo- and ectoparasites.
Legal Status
Cats are considered personal property
if ownership can be established
through collars, registration tags, tattoos, brands, or legal description and
proof of ownership. Cats without identification are considered feral and are
rarely protected under state law. They
become the property of the landowner
upon whose land they exist. Municipal
and county animal control agencies,
humane animal shelters, and various
other public and private “pet” management agencies exist because of feral
or unwanted house cats and dogs.
These agencies destroy millions of
stray cats annually.
State, county, and municipal laws
related to cats vary. Before lethal control is undertaken, consult local laws.
If live capture is desired, consult the
local animal control agency for instructions on disposal of cats.
Damage Prevention and
Control Methods
Exclusion
Exclusion by fencing, repairing windows, doors, and plugging holes in
buildings is often a practical way of
eliminating cat predation and nuisance. Provide overhead fencing to
keep cats out of bird or poultry pens.
Wire mesh with openings smaller than
2.5 inches (6.4 cm) should offer adequate protection.
Cultural Methods
Cat numbers can be reduced by eliminating their habitat. Old buildings
should be sealed and holes under
foundations plugged. Remove brush
and piles of debris, bale piles, old
machinery, and junked cars. Mow
vegetation in the vicinity of buildings.
Elimination of small rodents and other
foodstuffs will reduce feral cat
numbers.
Repellents
The Environmental Protection Agency
(EPA) has registered the following
chemicals individually and in combination for repelling house cats: anise
oil, methyl nonyl ketone, Ro-pel, and
Thymol. There is little objective evidence, however, of these chemicals’
effectiveness. Some labels carry the
instructions that when used indoors,
“disciplinary action” must reinforce
the repellent effect. Some repellents
carry warnings about fabric damage
and possible phytotoxicity. When used
outdoors, repellents must be reapplied
frequently. Outdoor repellents can be
used around flower boxes, furniture,
bushes, trees, and other areas where
cats are not welcomed. Pet stores and
garden supply shops carry, or can
order, such repellents. The repellents
are often irritating and repulsive to
humans as well as cats.
Frightening
Dogs that show aggression to cats provide an effective deterrent when
placed in fenced yards and buildings
where cats are not welcome.
Toxicants
No toxicants are registered for control
of feral cats.
Fumigants
No fumigants are registered for control of feral house cats. Live-trapped
cats or cats in holes or culverts can be
euthanized with carbon dioxide gas or
pulverized dry ice (carbon dioxide) at
roughly 1/2 pound per cubic yard (0.3
kg/m3) of space.
Trapping
Live Traps. Live-trapping cats in
commercial or homemade box traps
(Fig. 2) is a feasible control alternative,
particularly in areas where uncontrolled pets are more of a problem
than wild cats. Trap openings should
be 11 to 12 inches (28 to 30 cm) square
and 30 inches (75 cm) or more long.
Double-ended traps should be at least
42 inches (105 cm) long. The cat can be
captured and turned over to animal
control agencies without harm, given
back to the owner with proper warnings, or euthanized by shooting, lethal
injection, or asphyxiation with carbon
dioxide gas. Sources for commercial
traps are found in Supplies and
Materials. Set live traps in areas of
feral cat activity, such as feeding and
loafing areas, travelways along fences,
tree lines, or creeks, dumps, and garbage cans. Successful baits include
fresh or canned fish, commercial cat
foods, fresh liver, and chicken or
rodent carcasses. Catnip and rhodium
oil are often effective in attracting cats.
1 - Door up in grooves guiding its fall.
2 - Treadle board resting on a fulcrum. (Fulcrum
made by nailing a small piece of wood across
floor of trap. Weight of animal on back part of
treadle depresses treadle, pulls back trigger wire
and allows door to fall.)
3 - Trigger wire. (Three-gauge wire is connected
to a screw eye at one side of treadle and back of
fulcrum, extended along side of box to top of
trap and passed through a second screw eye.
When trap is set, door rests on the projecting
end of trigger wire.)
4 - Back wall with 3-inch square opening. (Inside
of opening is screened and provided with a tight
door on outside to permit observation of captive
animal and introduction of a fumigant for its
disposal. Door is open when trap is set; closed
when fumigant is introduced.)
5 - Uprights containing grooves in which door
slides. (Grooves should be greased for easy
action of door.)
5
1
5
3
4
2
Fig. 2a. Front and partial interior of box trap set.
Leghold Traps. Leghold traps No. 1,
1.5, or 2 are sufficient to catch and hold
feral cats (Fig. 3). These traps are particularly useful on cats that are not susceptible to box traps. Place the traps in
a shallow hole the size and shape of
the set trap. Cover the pan with waxed
paper and then cover the trap with
sifted soil, sawdust, or potting soil.
Place the bait material far enough
beyond the trap that the cat must step
on the trap to reach it. Traps can be set
at entrances to holes where cats are
hiding, entryways to buildings, or near
garbage cans. Domestic cats caught in
leghold traps should be handled with
care. Cover the cat with a blanket,
sack, or coat; pin it down with body
weight; and release the trap. Catch
poles can also be used to subdue
trapped cats.
Conibear® or Body-gripping
Traps. Conibear® or body-gripping
traps are lethal traps that work like
Groove for door
Bait
Trigger wire
End of trigger wire on which door
rests when trap is set
Treadle board
Fulcrum
Fig. 2b. Side view of cat trap.
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double-jawed mouse traps. They
should be set only where no other animals will get into them. The No. 220
size is most effective for cats. Set traps
in front of culverts or entry holes, in
garbage cans, or boxes with the bait
Bait (inside)
placed in the back (Fig. 3).
Wooden box
Stake
Snares. Snare sizes No. 1 and 2 are
very effective as live traps or kill traps
when set properly. Place snares in
entrances to dens or crawlthroughs, in
trails in weeds, or in garbage cans,
boxes, or other restricted access
arrangements where bait is placed
(Fig. 4). Sources for snares are found
in Supplies and Materials.
Shooting
Feral cats can be shot with .22 rimfire
and other calibers of centerfire rifles
and shotguns in rural areas where it is
safe. In buildings and urban areas,
powerful air rifles are capable of killing cats with close-range head shots.
Cats can be lured out of heavy cover
for a safe shot by using predator calls,
elevated decoys of fur or feathers, or
meat baits.
Other Methods
Supplemental feeding of feral or freeroaming house cats will probably have
little effect in reducing their depredations on songbirds and other wildlife.
Even well-fed cats will often bring
home a small prey they have caught
and proudly display it to their owners
without eating it. Laboratory studies
suggest that hunger and hunting are
controlled by separate neurological
centers in the cat brain, so the rate of
predation is not affected by the availability of cat food.
The hunter is often the hunted. Dogs
and coyotes, which are adapting to
urban environments, are probably the
greatest predators of cats, next to
humans and cars. Feral cats are often
found on the borders of human habitation. Large predators such as bobcats,
mountain lions, fox, coyotes, and feral
dogs eliminate cats that stray too far
afield.
C-48
No. 220 Conibear®
No. 1 Leghold
(place leghold trap instead of No.
220 Conibear® at opening of box)
Stake
Fig. 3. Cubby set (box set) with Conibear® or leghold trap.
Wrap wire in brush to obtain the
proper height of snare loop.
Clamp 14-gauge wire on snare cable here.
Bend snare cable here.
Don’t let any brush touch the snare loop.
Suspend the bottom of the loop 6 to 8 inches
from the ground.
The loop should be 6 to 8 inches
in diameter.
6"-8"
Cat trail
14-gauge wire
Fig. 4. Trail snare set
In the final analysis, many problems
with feral cats could be avoided if cat
owners would practice responsible pet
ownership. The same licensing and
leash laws pertaining to dogs should
be applied to cats. Spaying or neutering should be encouraged for household pets not kept for breeding
purposes. Neutering is not a costeffective program for controlling feral
populations. Unwanted cats should be
humanely destroyed, not abandoned
to fend for themselves.
Economics of Damage
and Control
The place of cats in the modern urban
world is certainly secure even though
their reputation as rodent controllers
has not been supported by objective
research. Cats have replaced dogs as
the most common family pet in the
United States. Their owners support a
growing segment of the economy in
the pet food and pet supplies industries. On the other hand, feral cats are
responsible for the transmission of
many human and wildlife diseases
and kill substantial amounts of
wildlife.
Acknowledgments
I wish to acknowledge M. L. Boddicker, who
was the author of the “House Cats” chapter in
the 1983 edition of Prevention and Control of
Wildlife Damage.
Figure 1 by Emily Oseas Routman.
Figure 2 adapted from Boddicker (1978),
“Housecats” in F. R. Henderson, Prevention and
Control of Wildlife Damage, Kansas State Univ.,
Manhattan.
Figure 3 by M. L. Boddicker, adapted by Jill Sack
Johnson.
Figure 4 courtesy of Gregerson Manufacturing
Co., adapted by Jill Sack Johnson.
For Additional
Information
Anonymous. 1974. Ecology of the surplus dog
and cat problem. Proc. Natl. Conf. Am.
Humane Assoc., Denver, Colorado. 128pp.
Bisseru, B. 1967. Diseases of man acquired from
his pets. Wm. Heinermann Medical Books,
London. 482 pp.
Boddicker, M. L. 1979. Controlling feral and
nuisance house cats. Colorado State Univ.
Ext. Serv., S.A. Sheet No. 6.508, Ft. Collins.
Coman, B. J., and H. Brunner. 1972. Food habits
of the feral house cat in Victoria. J. Wildl.
Manage. 36:848-853.
Errington, P. L. 1936. Notes on food habits of
southern Wisconsin house cats. J. Mammal.
17:64-65.
Fitzwater, W. D. 1986. Extreme care needed
when controlling cats. Pest Control 54:10.
Jackson, W. B. 1951. Food habits of Baltimore,
Maryland cats in relation to rat populations.
J. Mammal. 32:458-461.
Parmalee, P. W. 1953. Food habits of the feral
house cat in east-central Texas. J. Wildl.
Manage. 17:375-376.
Remfry, J. 1985. Humane control of feral cats.
Pages 41-49 in D. P. Britt, ed. Humane
control of land mammals/birds. Univ. Fed.
An. Welfare. United Kingdom.
Rolls, E. C. 1969. They all ran wild: the story of
pests on the land in Australia. Angus and
Robertson, Sydney and London. 444pp.
Tuttle, J. L. 1978. Dogs and cats need responsible
owners. Univ. Illinois Coop. Ext. Serv. Circ.
No. 1149.
Warner, R. E. 1985. Demography and
movements of free-ranging domestic cats in
rural Illinois. J. Wildl. Manage. 49:340-346.
Webb, C. H. 1965. Pets, parasites, and pediatrics.
Pediatrics 36:521-522.
Churcher, P. B., and J. H. Lawton. 1987.
Predation by domestic cats in an English
village. J. Zool. (London) 212:439-455.
Coleman, J. S., and S. A. Temple. 1989. Effects of
free-ranging cats on wildlife: a progress
report. Proc. Eastern Wildl. Damage Control
Conf. 4:9-12.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
C-49
C-50
Jeffrey S. Green
Assistant Regional Director
USDA-APHISAnimal Damage Control
Lakewood, Colorado 80228
COYOTES
F. Robert Henderson
Extension Specialist
Animal Damage Control
Kansas State University
Manhattan, Kansas 66506-1600
Mark D. Collinge
State Director
USDA-APHISAnimal Damage Control
Boise, Idaho 83705
Fig. 1. Coyote, Canis latrans
Damage Prevention and
Control Methods
Exclusion
Produce livestock in confinement.
Herd livestock into pens at night.
Exclusion fences (net-wire and/or
electric), properly constructed and
maintained, can aid significantly in
reducing predation.
Cultural Methods and
Habitat Modification
Select pastures that have a lower
incidence of predation to reduce
exposure of livestock to predation.
Herding of livestock generally reduces
predation due to human presence
during the herding period.
Change lambing, kidding, and calving
seasons.
Shed lambing, kidding, and calving
usually reduce coyote predation.
Remove carrion to help limit coyote
populations.
Frightening Agents and
Repellents
Guarding dogs: Some dogs have
significantly reduced coyote
predation.
Donkeys and llamas: Some are
aggressive toward canines and have
reduced coyote predation.
Sonic and visual repellents: Strobe
lights, sirens, propane cannons, and
others have reduced predation on
both sheep and calves.
Chemical odor and taste repellents:
None have shown sufficient
effectiveness to be registered for
use.
Toxicants
M-44 ejector devices for use with
sodium cyanide-loaded plastic
capsules. They are most effective
during cold weather (fall to spring).
Livestock protection collars (LPC)
containing Compound 1080
(sodium monofluoroacetate) are
registered for use only in certain
states.
Fumigants
Gas cartridges are registered as a
burrow (den) fumigant.
Trapping
Leghold traps (Nos. 3 and 4) are
effective and are the most versatile
control tool.
Snares are effective where coyotes pass
through or under net-wire fences
and in trail sets.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-51
Shooting
Shooting from the ground is effective.
Use rabbit distress calls or mimic
howling or other coyote sounds to
bring coyotes within shooting
distance.
Habitat
In body form and size, the coyote
(Canis latrans) resembles a small collie
dog, with erect pointed ears, slender
muzzle, and a bushy tail (Fig. 1).
Coyotes are predominantly brownish
gray in color with a light gray to
cream-colored belly. Color varies
greatly, however, from nearly black to
red or nearly white in some individuals and local populations. Most have
dark or black guard hairs over their
back and tail. In western states, typical
adult males weigh from 25 to 45
pounds (11 to 16 kg) and females from
22 to 35 pounds (10 to 14 kg). In the
East, many coyotes are larger than
their western counterparts, with males
averaging about 45 pounds (14 kg) and
females about 30 pounds (13 kg).
Many references indicate that coyotes
were originally found in relatively
open habitats, particularly the grasslands and sparsely wooded areas of
the western United States. Whether or
not this was true, coyotes have
adapted to and now exist in virtually
every type of habitat, arctic to tropic,
in North America. Coyotes live in
deserts, swamps, tundra, grasslands,
brush, dense forests, from below sea
level to high mountain ranges, and at
all intermediate altitudes. High densities of coyotes also appear in the suburbs of Los Angeles, Pasadena,
Phoenix, and other western cities.
Coyote-dog and coyote-wolf hybrids
exist in some areas and may vary
greatly from typical coyotes in size,
color, and appearance. Also, coyotes in
the New England states may differ in
color from typical western coyotes.
Many are black, and some are reddish.
These colorations may partially be due
to past hybridization with dogs and
wolves. True wolves are also present
in some areas of coyote range, particularly in Canada, Alaska, Montana,
northern Minnesota, Wisconsin, and
Michigan. Relatively few wolves
remain in the southern United States
and Mexico.
Coyotes often include many items in
their diet. Rabbits top the list of their
dietary components. Carrion, rodents,
ungulates (usually fawns), insects
(such as grasshoppers), as well as livestock and poultry, are also consumed.
Coyotes readily eat fruits such as
watermelons, berries, and other vegetative matter when they are available.
In some areas coyotes feed on human
refuse at dump sites and take pets
(cats and small dogs).
Historically, coyotes were most common on the Great Plains of North
America. They have since extended
their range from Central America to
the Arctic, including all of the United
States (except Hawaii), Canada, and
Mexico.
Other Methods
Denning: Remove adult coyotes and/
or their young from dens.
Hunting with dogs is effective for trailing coyotes from kill sites, locating
dens, running coyotes, and assisting
with aerial hunting or calling.
Identification
Range
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Aerial hunting is effective in removing
coyotes where terrain, ground
cover, vegetation, regulations, and
landownership conditions permit.
Food Habits
Coyotes are opportunistic and generally take prey that is the easiest to
secure. Among larger wild animals,
coyotes tend to kill young, inexperienced animals, as well as old, sick, or
weakened individuals. With domestic
animals, coyotes are capable of catching and killing healthy, young, and in
some instances, adult prey. Prey selection is based on opportunity and a
myriad of behavioral cues. Strong,
healthy lambs are often taken from a
flock by a coyote even though smaller,
weaker lambs are also present. Usually, the stronger lamb is on the
periphery and is more active, making
it more prone to attack than a weaker
lamb that is at the center of the flock
and relatively immobile.
Coyote predation on livestock is generally more severe during early spring
and summer than in winter for two
reasons. First, sheep and cows are usually under more intensive management during winter, either in feedlots
or in pastures that are close to human
activity, thus reducing the opportunity
for coyotes to take livestock. Second,
predators bear young in the spring and
raise them through the summer, a process that demands increased nutritional input, for both the whelping and
nursing mother and the growing
young. This increased demand corresponds to the time when young sheep
or beef calves are on pastures or rangeland and are most vulnerable to attack.
Coyote predation also may increase
during fall when young coyotes disperse from their home ranges and
establish new territories.
General Biology,
Reproduction, and
Behavior
Coyotes are most active at night and
during early morning hours (especially
where human activity occurs), and
during hot summer weather. Where
there is minimal human interference
and during cool weather, they may be
active throughout the day.
Coyotes bed in sheltered areas but do
not generally use dens except when
raising young. They may seek shelter
underground during severe weather
or when closely pursued. Their physical abilities include good eyesight and
hearing and a keen sense of smell.
Documented recoveries from severe
injuries are indicative of coyotes’
physical endurance. Although not as
fleet as greyhound dogs, coyotes have
been measured at speeds of up to 40
miles per hour (64 km/hr) and can
sustain slower speeds for several miles
(km).
Distemper, hepatitis, parvo virus, and
mange (caused by parasitic mites) are
among the most common coyote diseases. Rabies and tularemia also occur
and may be transmitted to other animals and humans. Coyotes harbor
numerous parasites including mites,
ticks, fleas, worms, and flukes. Mortality is highest during the first year of
life, and few survive for more than 10
to 12 years in the wild. Human activity
is often the greatest single cause of
coyote mortality.
Coyotes usually breed in February and
March, producing litters about 9
weeks (60 to 63 days) later in April and
May. Females sometimes breed during
the winter following their birth, particularly if food is plentiful. Average
litter size is 5 to 7 pups, although up to
13 in a litter has been reported. More
than one litter may be found in a single
den; at times these may be from
females mated to a single male. As
noted earlier, coyotes are capable of
hybridizing with dogs and wolves, but
reproductive dysynchrony and
behaviors generally make it unlikely.
Hybrids are fertile, although their
breeding seasons do not usually correspond to those of coyotes.
Coyote dens are found in steep banks,
rock crevices, sinkholes, and underbrush, as well as in open areas. Usually their dens are in areas selected for
protective concealment. Den sites are
typically located less than a mile (km)
from water, but may occasionally be
much farther away. Coyotes will often
dig out and enlarge holes dug by
smaller burrowing animals. Dens vary
from a few feet (1 m) to 50 feet (15 m)
and may have several openings.
Both adult male and female coyotes
hunt and bring food to their young for
several weeks. Other adults associated
with the denning pair may also help in
feeding and caring for the young. Coyotes commonly hunt as singles or
pairs; extensive travel is common in
their hunting forays. They will hunt in
the same area regularly, however, if
food is plentiful. They occasionally
bury food remains for later use.
the site. The quantity of sheep or calf
remains left after a kill vary widely
depending on how recently the kill
was made, the size of the animal
killed, the weather, and the number
and species of predators that fed on
the animal.
Pups begin emerging from their den
by 3 weeks of age, and within 2
months they follow adults to large
prey or carrion. Pups normally are
weaned by 6 weeks of age and frequently are moved to larger quarters
such as dense brush patches and/or
sinkholes along water courses. The
adults and pups usually remain
together until late summer or fall
when pups become independent.
Occasionally pups are found in groups
until the breeding season begins.
One key in determining whether a
sheep or calf was killed by a predator
is the presence or absence of subcutaneous (just under the skin) hemorrhage at the point of attack. Bites to a
dead animal will not produce hemorrhage, but bites to a live animal will. If
enough of the sheep carcass remains,
carefully skin out the neck and head to
observe tooth punctures and hemorrhage around the punctures. Talon
punctures from large birds of prey will
also cause hemorrhage, but the location of these is usually at the top of the
head, neck, or back. This procedure
becomes less indicative of predation as
the age of the carcass increases or if the
remains are scanty or scattered.
Coyotes are successful at surviving
and even flourishing in the presence of
people because of their adaptable
behavior and social system. They typically display increased reproduction
and immigration in response to
human-induced population reduction.
Damage and Damage
Identification
Coyotes can cause damage to a variety
of resources, including livestock, poultry, and crops such as watermelons.
They sometimes prey on pets and are a
threat to public health and safety when
they frequent airport runways and
residential areas, and act as carriers of
rabies. Usually, the primary concern
regarding coyotes is predation on livestock, mainly sheep and lambs. Predation will be the focus of the following
discussion.
Since coyotes frequently scavenge on
livestock carcasses, the mere presence
of coyote tracks or droppings near a
carcass is not sufficient evidence that
predation has taken place. Other evidence around the site and on the carcass must be carefully examined to aid
in determining the cause of death.
Signs of a struggle may be evident.
These may include scrapes or drag
marks on the ground, broken vegetation, or blood in various places around
Coyotes, foxes, mountain lions, and
bobcats usually feed on a carcass at the
flanks or behind the ribs and first consume the liver, heart, lungs, and other
viscera. Mountain lions often cover a
carcass with debris after feeding on it.
Bears generally prefer meat to viscera
and often eat first the udder from lactating ewes. Eagles skin out carcasses
on larger animals and leave much of
the skeleton intact. With smaller animals such as lambs, eagles may bite off
and swallow the ribs. Feathers and
“whitewash” (droppings) are usually
present where an eagle has fed.
Coyotes may kill more than one animal in a single episode, but often will
only feed on one of the animals.
Coyotes typically attack sheep at the
throat, but young or inexperienced
coyotes may attack any part of the
body. Coyotes usually kill calves by
eating into the anus or abdominal area.
Dogs generally do not kill sheep or
calves for food and are relatively
indiscriminate in how and where they
attack. Sometimes, however, it is
difficult to differentiate between dog
and coyote kills without also looking
at other sign, such as size of tracks
(Fig. 2) and spacing and size of canine
C-53
tooth punctures. Coyote tracks tend to
be more oval-shaped and compact
than those of common dogs. Nail
marks are less prominent and the
tracks tend to follow a straight line
more closely than those of dogs. The
average coyote’s stride at a trot is 16 to
18 inches (41 to 46 cm), which is typically longer than that of a dog of similar size and weight. Generally, dogs
attack and rip the flanks, hind quarters, and head, and may chew ears.
The sheep are sometimes still alive but
may be severely wounded.
Accurately determining whether or
not predation occurred and, if so, by
what species, requires a considerable
amount of knowledge and experience.
Evidence must be gathered, pieced
together, and then evaluated in light of
the predators that are in the area, the
time of day, the season of the year, and
numerous other factors. Sometimes
even experts are unable to confirm the
cause of death, and it may be necessary to rely on circumstantial information. For more information on this
subject, refer to the section Procedures
for Evaluating Predation on Livestock
and Wildlife, in this book.
Legal Status
The status of coyotes varies depending
on state and local laws. In some states,
including most western states, coyotes
are classified as predators and can be
taken throughout the year whether or
not they are causing damage to livestock. In other states, coyotes may be
taken only during specific seasons and
often only by specific methods, such as
trapping. Night shooting with a spotlight is usually illegal. Some state laws
allow only state or federal agents to
use certain methods (such as snares) to
take coyotes. Some states have a provision for allowing the taking of protected coyotes (usually by special
permit) when it has been documented
that they are preying on livestock. In
some instances producers can apply
control methods, and in others, control
must be managed by a federal or state
agent. Some eastern states consider the
coyote a game animal, a furbearer, or a
protected species.
C-54
3"
5"
Coyote
Wolf
2 1/2"
4"
Red fox
Large dog
Fig. 2. Footprints of canid predators
Federal statutes that pertain to wildlife
damage control include the Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA), which deals with
using toxicants, and the Airborne
Hunting Act, which regulates aerial
hunting.
Laws regulating coyote control are not
necessarily uniform among states or
even among counties within a state,
and they may change frequently. A
1989 Supreme Court action established
that it was not legal to circumvent the
laws relative to killing predators, even
to protect personal property (livestock)
from predation.
Damage Prevention and
Control Methods
For managing coyote damage, a variety of control methods must be available since no single method is effective
in every situation. Success usually
involves an integrated approach, combining good husbandry practices with
effective control methods for short
periods of time. Regardless of the
means used to stop damage, the focus
should be on damage prevention and
control rather than elimination of coyotes. It is neither wise nor practical to
kill all coyotes. It is important to try to
prevent coyotes from killing calves or
sheep for the first time. Once a coyote
has killed livestock, it will probably
continue to do so if given the
opportunity. Equally important is
taking action as quickly as possible to
stop coyotes from killing after they
start.
1/4" x 4 1/2" carriage bolt
galvanized woven wire
Exclusion
Most coyotes readily cross over,
under, or through conventional livestock fences. A coyote’s response to a
fence is influenced by various factors,
including the coyote’s experience and
motivation for crossing the fence. Total
exclusion of all coyotes by fencing,
especially from large areas, is highly
unlikely since some eventually learn to
either dig deeper or climb higher to
defeat a fence. Good fences, however,
can be important in reducing predation, as well as increasing the effectiveness of other damage control methods
(such as snares, traps, or guarding
animals).
69"
56"
72" galvanized
fencing
6" stays
4" vertical
spacing at top
1 1/2" at the
bottom
23" apron
(old fencing)
Recent developments in fencing equipment and design have made this
technique an effective and economically practical method for protecting
sheep from predation under some
grazing conditions. Exclusion fencing
may be impractical in western range
sheep ranching operations.
Net-Wire Fencing. Net fences in
good repair will deter many coyotes
from entering a pasture. Horizontal
spacing of the mesh should be less
than 6 inches (15 cm), and vertical
spacing less than 4 inches (10 cm). Digging under a fence can be discouraged
by placing a barbed wire at ground
level or using a buried wire apron
(often an expensive option). The fence
should be about 5 1/2 feet (1.6 m) high
to discourage coyotes from jumping
over it. Climbing can usually be prevented by adding a charged wire at
the top of the fence or installing a wire
overhang.
Barrier fences with wire overhangs
and buried wire aprons were tested in
Oregon and found effective in keeping
coyotes out of sheep pastures (Fig. 3).
The construction and materials for
such fencing are usually expensive.
Therefore, fences of this type are rarely
used except around corrals, feedlots,
or areas of temporary sheep confinement.
3" treated pole
7' long
28"
Fig. 3. Barrier fence with wire overhang and
buried apron.
Electric Fencing. Electric fencing,
used for years to manage livestock, has
recently been revolutionized by the
introduction of new energizers and
new fence designs from Australia and
New Zealand. The chargers, now also
manufactured in the United States,
have high output with low impedance,
are resistant to grounding, present a
minimal fire hazard, and are generally
safe for livestock and humans. The
fences are usually constructed of
smooth, high-tensile wire stretched to
a tension of 200 to 300 pounds (90 to
135 kg). The original design of electric
fences for controlling predation consisted of multiple, alternately charged
and grounded wires, with a charged
trip wire installed just above ground
level about 8 inches (20 cm) outside the
main fence to discourage digging.
Many recent designs have every wire
charged.
The number of spacings between wires
varies considerably. A fence of 13
strands gave complete protection to
sheep from coyote predation in tests at
the USDA’s US Sheep Experiment Station (Fig. 4). Other designs of fewer
wires were effective in some studies,
ineffective in others.
The amount of labor and installation
techniques required vary with each
type of fencing. High-tensile wire
fences require adequate bracing at corners and over long spans. Electric fencing is easiest to install on flat, even
terrain. Labor to install a high-tensile
electric fence may be 40% to 50% less
than for a conventional livestock fence.
Labor to keep electric fencing functional can be significant. Tension of the
wires must be maintained, excessive
vegetation under the fence must be
removed to prevent grounding, damC-55
age from livestock and wildlife must
be repaired, and the charger must be
checked regularly to ensure that it is
operational.
Fiberglass
line post
66'
6'
Fiberglass
stays
22'
11'
Fiberglass
line post
Charged wire
Ground wire
+ 8"
- 8"
+ 8"
- 8"
+ 8"
+
+
+
-
Fiberglass
stay
8"
8"
8"
4"
4"
4"
4"
Trip wire
8"
6"
Note:
Drawing not to scale
Ground
level
Fig. 4. High-tensile, electric, antipredator fence.
Coyotes and other predators occasionally become “trapped” inside electric
fences. These animals receive a shock
as they enter the pasture and subsequently avoid approaching the fence to
escape. In some instances the captured
predator may be easy to spot and
remove from the pasture, but in
others, particularly in large pastures
with rough terrain, the animal may be
difficult to remove.
Electric Modification of Existing
Fences. The cost to completely
replace old fences with new ones,
whether conventional or electric, can
be substantial. In instances where
existing fencing is in reasonably good
condition, the addition of one to several charged wires can significantly
enhance the predator-deterring ability
of the fence and its effectiveness for
controlling livestock (Fig. 5). A
charged trip wire placed 6 to 8 inches
(15 to 230 cm) above the ground about
8 to 10 inches (20 to 25 cm) outside the
fence is often effective in preventing
coyotes from digging and crawling under. This single addition to an existing
fence is often the most effective and
economical way to fortify a fence
against coyote passage.
If coyotes are climbing or jumping a
fence, charged wires can be added to
the top and at various intervals. These
wires should be offset outside the
fence. Fencing companies offer offset
brackets to make installation relatively
simple. The number of additional
wires depends on the design of the
original fence and the predicted habits
of the predators.
Outrigger post
with four wires
Fig. 5. Existing woven-wire livestock fence modified with electrified wire.
C-56
Portable Electric Fencing. The
advent of safe, high-energy chargers
has led to the development of a variety
of portable electric fences. Most are
constructed with thin strands of wire
running through polyethylene twine or
ribbon, commonly called polywire or
polytape. The polywire is available in
single and multiple wire rolls or as
mesh fencing of various heights. It can
be quickly and easily installed to serve
as a temporary corral or to partition
off pastures for controlled grazing.
Perhaps the biggest advantage of portable electric fencing is the ability to set
up temporary pens to hold livestock at
night or during other predator control
activities. Portable fencing increases
livestock management options to
avoid places or periods of high predation risk. Range sheep that are not
accustomed to being fenced, however,
may be difficult to contain in a portable fence.
Fencing and Predation Management. The success of various types of
fencing in keeping out predators has
ranged from poor to excellent. Density
and behavior of coyotes, terrain and
vegetative conditions, availability of
prey, size of pastures, season of the
year, design of the fence, quality of
construction, maintenance, and other
factors all interplay in determining
how effective a fence will be. Fencing
is most likely to be cost-effective where
the potential for predation is high,
where there is potential for a high
stocking rate, or where electric modification of existing fences can be used.
Fencing can be effective when incorporated with other means of predation
control. For example, combined use of
guarding dogs and fencing has
achieved a greater degree of success
than either method used alone. An
electric fence may help keep a guarding dog in and coyotes out of a pasture. If an occasional coyote does pass
through a fence, the guarding dog can
keep it away from the livestock and
alert the producer by barking.
Fencing can also be used to concentrate predator activity at specific places
such as gateways, ravines, or other
areas where the animals try to gain
access. Traps and snares can often be
set at strategic places along a fence to
effectively capture predators. Smaller
pastures are easier to keep free from
predators than larger ones encompassing several square miles (km2).
Fencing is one of the most beneficial
investments in predator damage control and livestock management where
practical factors warrant its use.
As a final note, fences can pose problems for wildlife. Barrier fences in particular exclude not only predators, but
also many other wildlife species. This
fact should be considered where fencing intersects migration corridors for
wildlife. Ungulates such as deer may
attempt to jump fences, and they occasionally become entangled in the top
wires.
Cultural Methods and Habitat
Modification
At the present time, there are no documented differences in the vulnerability
of various breeds of sheep to coyote or
dog predation because there has been
very little research in this area. Generally, breeds with stronger flocking
behaviors are less vulnerable to predators.
A possible cause of increased coyote
predation to beef cattle calves is the
increased use of cattle dogs in herding.
Cows herded by dogs may not be as
willing to defend newborn calves from
coyotes as those not accustomed to
herding dogs.
Flock or Herd Health. Healthy
sheep flocks and cow/calf herds have
higher reproductive rates and lower
overall death losses. Coyotes often
prey on smaller lambs. Poor nutrition
means weaker or smaller young, with
a resultant increased potential for predation. Ewes or cows in good condition through proper nutrition will raise
stronger young that may be less vulnerable to coyote predation.
Record Keeping. Good record-
keeping and animal identification systems are invaluable in a livestock
operation for several reasons. From the
standpoint of coyote predation,
records help producers identify loss
patterns or trends to provide baseline
data that will help determine what
type and amount of coyote damage
control is economically feasible.
Records also aid in identifying critical
problem areas that may require attention. They may show, for example, that
losses to coyotes are high in a particular pasture in early summer, thus highlighting the need for preventive
control in that area.
Counting sheep and calves regularly is
important in large pastures or areas
with heavy cover where dead livestock
could remain unnoticed. It is not
unusual for producers who do not
regularly count their sheep to suffer
fairly substantial losses before they
realize there is a problem. Determining
with certainty whether losses were due
to coyotes or to other causes may
become impossible.
Season and Location of Lambing
or Calving. Both season and location
of lambing and calving can significantly affect the severity of coyote predation on sheep or calves. The highest
predation losses of sheep and calves
typically occur from late spring
through September due to the food
requirements of coyote pups. In the
Midwest and East, some lambing or
calving occurs between October and
December, whereas in most of the
western states lambing or calving
occurs between February and May. By
changing to a fall lambing or calving
program, some livestock producers
have not only been able to diversify
their marketing program, but have
also avoided having a large number of
young animals on hand during periods
when coyote predation losses are typically highest.
Shortening lambing and calving periods by using synchronized or group
breeding may reduce predation by
producing a uniform lamb or calf crop,
thus reducing exposure of small livestock to predation. Extra labor and
facilities may be necessary, however,
when birthing within a concentrated
period. Some producers practice early
weaning and do not allow young to go
to large pastures, thus reducing the
chance of coyote losses. This also gives
orphaned and weak young a greater
chance to survive.
The average beef cattle calf production
is about 78% nationwide. First-calf
heifers need human assistance to give
birth to a healthy calf about 40% of the
time. Cow/calf producers who average 90% to 95% calf crops generally
check their first-calf heifers every 2
hours during calving. Also, most good
producers place first-calf heifers in
C-57
small pastures (less than 160 acres [64
ha]). When all cows are bred to produce calves in a short, discreet (e.g.
60-day) period, production typically
increases and predation losses
decrease. The birth weight of calves
born to first-calf heifers can be decreased by using calving-ease bulls,
thus reducing birthing complications
that often lead to coyote predation.
Producers who use lambing sheds or
pens for raising sheep and small pastures or paddocks for raising cattle
have lower predation losses than those
who lamb or calve in large pastures or
on open range. The more human presence around sheep, the lower the predation losses. Confining sheep entirely
to buildings virtually eliminates predation losses.
Corrals. Although predation can
occur at any time, coyotes tend to kill
sheep at night. Confining sheep at
night is one of the most effective
means of reducing losses to predation.
Nevertheless, some coyotes and many
dogs are bold enough to enter corrals
and kill sheep. A “coyote-proof” corral
is a wise investment. Coyotes are more
likely to attack sheep in unlighted corrals than in corrals with lights. Even if
the corral fence is not coyote-proof, the
mere fact that the sheep are confined
reduces the risk of predation. Penning
sheep at night and turning them out at
mid-morning might reduce losses. In
addition, coyotes tend to be more
active and kill more sheep on foggy or
rainy days than on sunny days. Keeping the sheep penned on foggy or rainy
days may be helpful.
Aside from the benefits of livestock
confinement, there are some problems
associated it. Costs of labor and materials associated with building corrals,
herding livestock, and feeding livestock must be considered. In addition,
the likelihood of increased parasite
and disease problems may inhibit
adoption of confinement as a method
of reducing damage.
Carrion Removal. Removal and
proper disposal of dead sheep and
cattle are important since livestock carcasses tend to attract coyotes,
habituating them to feed on livestock.
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Some producers reason that coyotes
are less likely to kill livestock if there is
carrion available. This may be a valid
preventative measure if an adequate
supply of carrion can be maintained
far away from livestock. If a coyote
becomes habituated to a diet of livestock remains, however, it may turn to
killing livestock in the absence of carcasses. Wherever there is easily accessible carrion, coyotes seem to gather
and predation losses are higher. Conversely, where carrion is generally not
available, losses are lower. A study in
Canada showed that the removal of
livestock carcasses significantly
reduced overwinter coyote populations and shifted coyote distributions
out of livestock areas.
Habitat Changes. Habitat features
change in some areas, depending on
seasonal crop growth. Some cultivated
fields are devoid of coyotes during
winter but provide cover during the
growing season, and a corresponding
increase in predation on nearby livestock may occur.
The creation of nearly 40 million acres
(16 million ha) of Conservation
Reserve Program (CRP) acres may
benefit many species of wildlife,
including predators. These acres harbor prey for coyotes and foxes, and an
increase in predator populations can
reasonably be predicted. Clearing
away weeds and brush from CRP
areas may reduce predation problems
since predators usually use cover in
their approach to livestock. Generally,
the more open the area where livestock are kept, the less likely that
coyote losses will occur. Often junk
piles are located near farmsteads.
These serve as good habitat for rabbits
and other prey and may bring coyotes
into close proximity with livestock,
increasing the likelihood for opportunistic coyotes to prey on available livestock. Removing junk piles may be a
good management practice.
Pasture Selection. If sheep or beef
cattle are not lambed or calved in
sheds or lots, the choice of birthing
pastures should be made with potential coyote predation problems in
mind. Lambs and calves in remote or
rugged pastures are usually more vul-
nerable to coyote predation than those
in closer, more open, and smaller pastures. In general, a relatively small,
open, tightly fenced pasture that can
be kept under close surveillance is a
good choice for birthing livestock that
are likely targets of coyotes. Past experience with predators as well as
weather and disease considerations
should also serve as guides in the
selection of birthing pastures.
A factor not completely understood is
that, at times, coyotes and other predators will kill in one pasture and not in
another. Therefore, changing pastures
during times of loss may reduce predation. There may seem to be a relationship between size of pasture and
predator losses, with higher loss rates
reported in larger pastures. In reality,
loss rates may not be related as much
to pasture size as to other local conditions such as slope, terrain, and human
populations. Hilly or rugged areas are
typically sparsely populated by humans and are characterized by large
pastures. These conditions are ideal for
coyotes.
Sheep pastures that contain or are
adjacent to streams, creeks, and rivers
tend to have more coyote problems
than pastures without such features.
Water courses serve as hunting and
travel lanes for coyotes.
Herders. Using herders with sheep or
cattle in large pastures can help reduce
predation, but there has been a trend
away from herders in recent years
because of increasing costs and a
shortage of competent help. Nevertheless, tended flocks or herds receive
closer attention than untended livestock, particularly in large pastures,
and problems can be solved before
they become serious. We recommend
two herders per band of range sheep.
If herders aren’t used, daily or periodic
checking of the livestock is a good husbandry practice.
Frightening Devices and
Repellents
Frightening devices are useful for
reducing losses during short periods
or until predators are removed. The
devices should not be used for long
periods of time when predation is not
a problem. To avoid acclimation you
can increase both the degree and duration of effectiveness by varying the
position, appearance, duration, or frequency of the frightening stimuli, or
using them in various combinations.
Many frightening methods have been
ridiculed in one way or another; nevertheless, all of the techniques discussed
here have helped producers by saving
livestock and/or buying some time to
institute other controls.
Lights. A study involving 100 Kansas
sheep producers showed that using
lights above corrals at night had the
most marked effect on losses to coyotes of all the devices examined. Out
of 79 sheep killed by coyotes in corrals,
only three were killed in corrals with
lights. Nearly 40% of the producers in
the study used lights over corrals.
There was some indication in the
study that sheep losses to dogs were
higher in lighted corrals, but the
sample size for dog losses was small
and the results inconclusive. Most of
the producers (80%) used mercury
vapor lights that automatically turned
on at dusk and off at dawn.
Another advantage of lighted corrals is
that coyotes are more vulnerable when
they enter the lighted area. Coyotes
often establish a fairly predictable pattern of killing. When this happens in a
lighted corral, it is possible for a producer to wait above or downwind of
the corral and to shoot the coyote as it
enters. Red or blue lights may make
the ambush more successful since coyotes appear to be less frightened by
them than by white lights.
Revolving or flashing the lights may
enhance their effectiveness in frightening away predators. There is some
speculation that the old oil lamps used
in highway construction repelled
coyotes, presumably because of their
flickering effect.
Bells and Radios. Some sheep producers place bells on some or all of
their sheep to discourage predators.
Where effects have been measured,
however, no difference in losses was
detected.
Some producers use a radio tuned to
an all-night station to temporarily
deter coyotes, dogs, and other predators.
Vehicles. Parking cars or pickups in
the area where losses are occurring often reduces predation temporarily.
Effectiveness can be improved or
extended by frequently moving the
vehicle to a new location. Some producers place a replica of a person in
the vehicle when losses are occurring
in the daylight. If predators continue
to kill with vehicles in place, the
vehicle serves as a comfortable blind in
which to wait and shoot offending
predators.
Propane Exploders. Propane
exploders produce loud explosions at
timed intervals when a spark ignites a
measured amount of propane gas. On
most models, the time between explosions can vary from about 1 minute to
15 minutes. Their effectiveness at
frightening coyotes is usually only
temporary, but it can be increased by
moving exploders to different locations and by varying the intervals between explosions. In general, the timer
on the exploder should be set to fire
every 8 to 10 minutes, and the location
should be changed every 3 or 4 days.
In cattle pastures, these devices should
be placed on rigid stands above the
livestock. Normally, the exploder
should be turned on just before dark
and off at daybreak, unless coyotes are
killing livestock during daylight hours.
Motion sensors are now available and
likely improve their effectiveness,
though it is still only temporary.
Exploders are best used to reduce
losses until more permanent control or
preventive measures can be implemented. In about 24 coyote depredation complaints over a 2-year period in
North Dakota, propane exploders
were judged to be successful in stopping or reducing predation losses until
offending coyotes could be removed.
“Success time” of the exploders appears to depend a great deal on how
well they are tended by the livestock
producer.
Strobe Lights and Sirens. The
USDA’s Denver Wildlife Research
Fig. 6. Electronic Guard frightening device
Center developed a frightening device
called the Electronic Guard (EG) (Fig.
6). The EG consists of a strobe light
and siren controlled by a variable
interval timer that is activated at night
with a photoelectric cell. In tests conducted in fenced pastures, predation
was reduced by about 89%. The device
is used in Kansas and other states to
protect cows/calves from coyote predation. Most research on the effectiveness of this device, however, has been
done on sheep operations. Suggestions
for using the unit differ for pastured
sheep and range operations.
To use the EG in fenced pastures (farm
flocks):
1. Place EGs above the ground on
fence posts, trees, or T-posts so they
can be heard and seen at greater
distances and to prevent livestock
from damaging them.
2. Position EGs so that rain water cannot enter them and cause a malfunction.
3. Locate EGs so that light can enter
the photocell port or window. If
positioned in deep shade, they may
not turn on or off at the desired
times.
4. The number of EGs used to protect
sheep in fenced pastures depends
on pasture size, terrain features, and
the amount and height of vegetation
in or around the pasture. In general,
at least two units should be used in
small (20 to 30 acres [8 to 12 ha]),
level, short-grass pastures. Three to
four units should be used in larger
(40 to 100 acres [16 to 40 ha]), hilly,
tall grass, or wooded pastures.
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5. Don’t use EGs in pastures larger
than about 100 acres (40 ha) because
their effective range is limited. The
device could be useful in larger pastures when placed near areas where
sheep congregate and bed at night.
6. EGs should be placed on high spots,
where kills have been found, at the
edge of wooded areas, near or on
bedgrounds, or near suspected
coyote travelways. They should be
moved to different locations every
10 to 14 days to reduce the likelihood of coyotes getting used to
them.
To use the EG in open range (herded
or range sheep):
1. The number of EGs used will
depend on the number of sheep in
the band and the size of the
bedground. Four units should be
used to protect bands of 1,000 ewes
and their lambs.
2. When possible, place one EG in the
center of the bedground and the
other three around the edge of the
bedground. Try to place the units
on coyote travelways.
3. EGs should be placed on high
points, ridge tops, edges of clearings, or on high rocks or
outcroppings. Hang the devices on
tree limbs 5 to 7 feet (1.5 to 2.1 m)
above ground level. If used above
timberline or in treeless areas, hang
them from a tripod of poles.
4. Herders who bed their sheep tightly
will have better results than those
who allow sheep to bed over large
areas. Sheep that are bedded about
200 yards (166 m) or less in diameter, or are spread out not more
than 200 to 400 yards (166 to 332 m)
along a ridge top, can usually be
protected with EGs.
Repellents. The notion of repelling
coyotes from sheep or calves is
appealing, and during the 1970s, university and government researchers
tested a wide variety of potentially repellent chemical compounds on sheep.
Both olfactory (smell) and gustatory
(taste) repellents were examined. The
underlying objective was to find a
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compound that, when applied to
sheep, would prevent coyotes from
killing them. Tests were conducted
with various prey species including
rabbits, chickens, and sheep. Some
repellents were applied by dipping target animals in them, others were
sprayed on, and some were applied in
neck collars or ear tags.
Coyotes rely heavily on visual cues
while stalking, chasing, and killing
their prey. Taste and smell are of lesser
importance in actually making the kill.
These factors may in part account for
the fact that the repellent compounds
were not able to consistently prevent
coyotes from killing, although some of
the repellents were obviously offensive
to coyotes and prevented them from
consuming the killed prey. Several
compounds were tested on sheep
under field conditions, but none
appeared to offer significant, prolonged protection.
If an effective chemical repellent were
to be found, the obstacles in bringing it
to industry use would be significant.
The compound would not only need
to be effective, but also persistent
enough to withstand weathering while
posing no undue risk to the sheep,
other animals, or the environment. It
would also have to withstand the rigorous Environmental Protection
Agency (EPA) approval process.
High-frequency sound has also been
tested as a repellent for coyotes, but
the results were no more encouraging
than for chemical repellents. Coyotes,
like dogs, responded to particular
sound frequencies and showed some
aversion to sounds broadcast within
one foot (30 cm) of their ear. Researchers, however, were unable to broadcast the sound a sufficient distance to
test the effects under field conditions.
Aversive Conditioning. The objective of aversive conditioning is to feed
a coyote a preylike bait laced with an
aversive agent that causes the coyote
to become ill, resulting in subsequent
avoidance of the prey. Most of the
research on this technique has
involved the use of lithium chloride, a
salt, as the aversive agent.
Aversive conditioning is well documented for averting rodents from food
sources, but significant problems must
be overcome before the method can be
used to reduce coyote predation on
sheep. Coyotes must be induced to eat
sheeplike baits that have been treated
with the aversive chemical. The chemical must cause sufficient discomfort,
such as vomiting, to cause coyotes to
avoid other baits. Furthermore, the
avoidance must be transferred to live
sheep and must persist long enough
without reinforcement for the method
to offer realistic protection to sheep.
To date, pen and field tests with
aversive conditioning have yielded
conflicting and inconclusive results. It
does not appear that aversive conditioning is effective in reducing predation, but additional field tests would
be useful.
Guarding Animals.
Livestock Guarding Dogs. A live-
stock guarding dog is one that generally stays with sheep or cattle without
harming them and aggressively repels
predators. Its protective behaviors are
largely instinctive, but proper rearing
plays a part. Breeds most commonly
used today include the Great Pyrenees,
Komondor, Anatolian Shepherd, and
Akbash Dog (Fig. 7). Other Old World
breeds used to a lesser degree include
Maremma, Sharplaninetz, and Kuvasz.
Crossbreeds are also used.
The characteristics of each sheep
operation will dictate the number of
dogs required for effective protection
from predators. If predators are scarce,
one dog is sufficient for most fenced
pasture operations. Range operations
often use two dogs per band of sheep.
The performance of individual dogs
will differ based on age and experience. The size, topography, and habitat
of the pasture or range must also be
considered. Relatively flat, open areas
can be adequately covered by one dog.
When brush, timber, ravines, and hills
are in the pasture, several dogs may be
required, particularly if the sheep are
scattered. Sheep that flock and form a
cohesive unit, especially at night, can
be protected by one dog more effectively than sheep that are continually
working unless the dog is chained or
confined while the control takes place.
Dogs caught in a steel trap set for
predators are rarely injured seriously if
they are found and released within a
reasonable period of time. If snares
and traps are used where dogs are
working, the producer should: (1)
encourage the use of sets and devices
that are likely not to injure the dog if it
is caught, and (2) know where traps
and snares are set so they can be
checked if a dog is missing. Aerial
hunting, as well as calling and shooting coyotes, should pose no threat to
guarding dogs. Ensuring the safety of
the dog is largely the producer’s
responsibility.
Fig. 7. Livestock guarding dog (Akbash dog)
scattered and bedded in a number of
locations.
The goal with a new puppy is to channel its natural instincts to produce a
mature guardian dog with the desired
characteristics. This is best accomplished by early and continued association with sheep to produce a bond
between the dog and sheep. The optimum time to acquire a pup is between
7 and 8 weeks of age. The pup should
be separated from litter mates and
placed with sheep, preferably lambs,
in a pen or corral from which it can’t
escape. This socialization period
should continue with daily checks
from the producer until the pup is
about 16 weeks old. Daily checks don’t
necessarily include petting the pup.
The primary bond should be between
the dog and the sheep, not between the
dog and humans. The owner, however, should be able to catch and handle the dog to administer health care
or to manage the livestock. At about 4
months, the pup can be released into a
larger pasture to mingle with the other
sheep.
A guarding dog will likely include
peripheral areas in its patrolling. Some
have been known to chase vehicles
and wildlife and threaten children and
cyclists. These activities should be discouraged. Neighbors should be alerted
to the possibility that the dog may
roam onto their property and that
some predator control devices such as
traps, snares, and M-44s present a
danger to it. Many counties enforce
stringent laws regarding owner
responsibility for damage done by
roaming dogs. It is in the best interests
of the owner, dog, and community to
train the dog to stay in its designated
area.
The use of guarding dogs does not
eliminate the need for other predation
control actions. They should, however,
be compatible with the dog’s behavior.
Toxicants (including some insecticides
and rodenticides) used to control various pest species can be extremely hazardous to dogs and are therefore not
compatible with the use of guarding
dogs.
The M-44 is particularly hazardous to
dogs. Some people have successfully
trained their dogs to avoid M-44s by
allowing the dog to set off an M-44
filled with pepper or by rigging the
device to a rat trap. The unpleasant
experience may teach the dog to avoid
M-44s, but the method is not foolproof—one error by the dog, and the
result is usually fatal. With the exception of toxic collars, which are not legal
in all states, toxicants should not be
used in areas where guarding dogs are
Dogs may be viewed as a first line of
defense against predation in sheep and
cow/calf operations in some cases.
Their effectiveness can be enhanced by
good livestock management and by
eliminating predators with suitable
removal techniques.
Donkeys. Although the research has
not focused on donkeys as it has on
guarding dogs, they are gaining in
popularity as protectors of sheep and
goat flocks in the United States. A
recent survey showed that in Texas
alone, over 2,400 of the 11,000 sheep
and goat producers had used donkeys
as guardians.
The terms donkey and burro are synonymous (the Spanish translation of
donkey is burro) and are used interchangeably. Donkeys are generally
docile to people, but they seem to
have an inherent dislike of dogs and
other canids, including coyotes and
foxes. The typical response of a donkey to an intruding canid may include
braying, bared teeth, a running attack,
kicking, and biting. Most likely it is
acting out of aggression toward the
intruder rather than to protect the
sheep. There is little information on a
donkey’s effectiveness with noncanid
predators such as bears, mountain
lions, bobcats, or birds of prey.
Reported success of donkeys in reducing predation is highly variable.
Improper husbandry or rearing practices and unrealistic expectations
C-61
probably account for many failures.
Donkeys are significantly cheaper to
obtain and care for than guarding
dogs, and they are probably less prone
to accidental death and premature
mortality than dogs. They may provide a longer period of useful life than
a guarding dog, and they can be used
with relative safety in conjunction with
snares, traps, M-44s, and toxic collars.
Researchers and livestock producers
have identified several key points to
consider when using a donkey for predation control:
1. Use only a jenny or a gelded jack.
Intact jacks are too aggressive and
may injure livestock. Some jennies
and geldings may also injure livestock. Select donkeys from
medium-sized stock.
2. Use only one donkey per group of
sheep. The exception may be a
jenny with a foal. When two or
more adult donkeys are together or
with a horse, they usually stay
together, not necessarily near the
sheep. Also avoid using donkeys in
adjacent pastures since they may
socialize across the fence and ignore
the sheep.
3. Allow about 4 to 6 weeks for a
naive donkey to bond to the sheep.
Stronger bonding may occur when
a donkey is raised from birth with
sheep.
4. Avoid feeds or supplements containing monensin or lasolacid. They
are poisonous to donkeys.
5. Remove the donkey during lambing, particularly if lambing in confinement, to avoid injuries to lambs
or disruption of the lamb-ewe bond.
6. Test a new donkey’s response to
canids by challenging it with a dog
in a pen or small pasture. Discard
donkeys that don’t show overt
aggression to an intruding dog.
7. Use donkeys in smaller (less than
600 acres [240 ha]), relatively open
pastures with not more than 200 to
300 head of livestock. Large pastures with rough terrain and vegetation and widely scattered livestock
lessen the effectiveness of a donkey.
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Llamas. Like donkeys, llamas have an
inherent dislike of canids, and a growing number of livestock producers are
successfully using llamas to protect
their sheep. A recent study of 145
ranches where guard llamas were used
to protect sheep revealed that average
losses of sheep to predators decreased
from 26 to 8 per year after llamas were
employed. Eighty percent of the
ranchers surveyed were “very satisfied” or “satisfied” with their llamas.
Llamas reportedly bond with sheep
within hours and offer advantages
over guarding dogs similar to those
described for donkeys.
Other Animals. USDA’s Agricultural
Research Service tested the bonding of
sheep to cattle as a method of protecting sheep from coyote predation.
There was clearly some protection
afforded the sheep that remained near
cattle. Whether this protection resulted
from direct action by the cattle or by
the coyotes’ response to a novel stimulus is uncertain. Later studies with
goats, sheep, and cattle confirmed that
when either goats or sheep remained
near cattle, they were protected from
predation by coyotes. Conversely,
goats or sheep that grazed apart from
cattle, even those that were bonded,
were readily preyed on by coyotes.
There are currently no research data
available on the ideal ratio of cattle to
sheep, the breeds of cattle, age of cattle
most likely to be used successfully, or
on the size of bonded groups to obtain
maximum protection from predation.
Multispecies grazing offers many
advantages for optimum utilization of
forage, and though additional study
and experience is needed, it may also
be a tool for coyote damage control.
Any animal that displays aggressive
behavior toward intruding coyotes
may offer some benefit in deterring
predation. Other types of animals
reportedly used for predation control
include goats, mules, and ostriches.
Coyotes in particular are suspicious of
novel stimuli. This behavior is most
likely the primary reason that many
frightening tactics show at least temporary effectiveness.
Toxicants
Pesticides have historically been an
important component in an integrated
approach to controlling coyote damage, but their use is extremely
restricted today by federal and state
laws. All pesticides used in the United
States must be registered with the EPA
under the provisions of FIFRA and
must be used in accordance with label
directions. Increasingly restrictive
regulations implemented by EPA
under the authority of FIFRA, the
National Environmental Policy Act
(NEPA), presidential order, and the
Endangered Species Act have resulted
in the near elimination of toxicants
legally available for predator damage
control.
The only toxicants currently registered
for mammalian predator damage control are sodium cyanide, used in the
M-44 ejector device, and Compound
1080 (sodium monofluoroacetate), for
use in the livestock protection collar.
These toxicants are Restricted Use Pesticides and may be used only by certified pesticide applicators. Information
on registration status and availability
of these products in individual states
may be obtained from the respective
state’s department of agriculture.
Sodium Cyanide in the M-44. The
M-44 is a spring-activated device used
to expel sodium cyanide into an
animal’s mouth. It is currently registered by EPA for use by trained personnel in the control of depredating
coyotes, foxes, and dogs.
The M-44 consists of a capsule holder
wrapped in an absorbent material, an
ejector mechanism, a capsule containing approximately 0.9 grams of a powdered sodium cyanide mixture, and a
5- to 7-inch (15- to 18-cm) hollow stake
(Fig. 8). For most effective use, set
M-44s in locations similar to those for
good trap sets. Drive the hollow stake
into the ground. Cock the ejector unit
and secure it in the stake. Screw the
wrapped capsule holder containing the
cyanide capsule onto the ejector unit,
and apply fetid meat bait to the capsule holder. Coyotes attracted by the
bait will try to bite the baited capsule
holder. When the M-44 is pulled, the
their ability to remain effective during
rain, snow, and freezing conditions.
c
d
b
a
Fig. 8. The M-44 device consists of the (a) base,
(b) ejector, (c) capsule holder, and (d) cyanidecontaining plastic capsule.
spring-activated plunger propels
sodium cyanide into the animal’s
mouth, resulting in death within a few
seconds.
The M-44 is very selective for canids
because of the attractants used and the
unique requirement that the device be
triggered by pulling on it. While the
use of traps or snares may present a
hazard to livestock, M-44s can be used
with relative safety in pastures where
livestock are present. Although not
recommended, they can also be used
in the presence of livestock guarding
dogs if the dogs are first successfully
conditioned to avoid the devices. This
can be done by allowing them to pull
an M-44 loaded with pepper. An additional advantage of M-44s over traps is
While M-44s can be used effectively as
part of an integrated damage control
program, they do have several disadvantages. Because canids are less
responsive to food-type baits during
warm weather when natural foods are
usually abundant, M-44s are not as
effective during warmer months as
they are in cooler weather. M-44s are
subject to a variety of mechanical malfunctions, but these problems can be
minimized if a regular maintenance
schedule is followed. A further disadvantage is the tendency for the cyanide
in the capsules to absorb moisture over
time and to cake, becoming ineffective.
Maximum effectiveness of M-44s is
hampered by the requirement to follow 26 use restrictions established by
the EPA in the interest of human and
environmental safety. The M-44 is not
registered for use in all states, and in
those where it is registered, the state
may impose additional use restrictions. A formal training program is
required before use of M-44s. Some
states allow its use only by federal
ADC specialists, whereas other states
may allow M-44s to be used by trained
and certified livestock producers.
1080 Livestock Protection Collar.
The livestock protection collar (LP
collar or toxic collar) is a relatively
new tool used to selectively kill
coyotes that attack sheep or goats.
Collars are placed on sheep or goats
that are pastured where coyotes are
likely to attack. Each collar contains a
small quantity (300 mg) of Compound
1080 solution. The collars do not
attract coyotes, but because of their
design and position on the throat,
most attacking coyotes will puncture
the collar and ingest a lethal amount of
the toxicant. Unlike sodium cyanide,
1080 is slow-acting, and a coyote
ingesting the toxicant will not exhibit
symptoms or die for several hours. As
a result, sheep or goats that are
attacked are usually killed. The collar
is registered only for use against
coyotes and may be placed only on
sheep or goats.
The LP collar must be used in conjunction with specific sheep and goat husbandry practices to be most effective.
Coyote attacks must be directed or targeted at collared livestock. This may
be accomplished by temporarily placing a “target” flock of perhaps 20 to 50
collared lambs or kids and their
uncollared mothers in a pasture where
coyote predation is likely to occur,
while removing other sheep or goats
from that vicinity. In situations where
LP collars have been used and found
ineffective, the common cause of failure has been poor or ineffective targeting. It is difficult to ensure effective
targeting if depredations are occurring
infrequently. In most instances, only a
high and regular frequency of depredations will justify spending the time,
effort, and money necessary to become
trained and certified, purchase collars,
and use them properly.
The outstanding advantage in using
the LP collar is its selectivity in eliminating individual coyotes that are
responsible for killing livestock. The
collar may also be useful in removing
depredating coyotes that have eluded
other means of control. Disadvantages
include the cost of collars (approximately $20 each) and livestock that
must be sacrificed, more intensive
management practices, and the costs
and inconvenience of complying with
use restrictions, including requirements for training, certification, and
record keeping. One use restriction
limits the collars to use in fenced pastures only. They cannot be used to protect sheep on open range. Also, collars
are not widely available, because they
are registered for use in only a few
states.
Fumigants
Carbon monoxide is an effective burrow fumigant recently re-registered by
the EPA. Gas cartridges, which contain
65% sodium nitrate and 35% charcoal,
produce carbon monoxide, carbon
dioxide, and other noxious gases when
ignited. They were registered by the
EPA in 1981 for control of coyotes in
dens only. This is the only fumigant
currently registered for this purpose.
C-63
Trapping
There are many effective methods for
trapping coyotes, and success can be
enhanced by considering several key
points. Coyotes learn from past events
that were unpleasant or frightening,
and they often avoid such events in the
future. In spring and summer, most
coyotes limit their movements to a
small area, but in late summer, fall,
and winter they may roam over a
larger area. Coyotes follow regular
paths and crossways, and they prefer
high hills or knolls from which they
can view the terrain. They establish
regular scent posts along their paths,
and they depend on their ears, nose,
and eyes to sense danger.
The following describes one method of
trapping that has proven effective for
many beginners.
Items Needed to Set a Coyote Trap:
7.
Roll of plastic sandwich bags to
cover and prevent soil from getting under the pan of the trap.
8.
Screen sifter for sifting soil over
the traps.
9.
Rib bone for leveling off soil over
the traps once they are set in place
and covered.
10. Bottle of coyote urine to attract the
coyote to the set (keep urine away
from other equipment).
Locating the Set. Coyotes travel where
walking is easy, such as along old roads,
and they have preferred places to travel,
hunt, rest, howl, and roam. Do not set
traps directly in a trail but to one side
where coyotes may stop, such as on a
hilltop, near a gate, or where cover
changes. Make the set on level ground to
ensure that the coyote walks across level
ground to it.
4.
Straight claw hammer to dig a
hole in the ground for trap placement and to pound the stake into
the ground.
5.
Leather gloves to protect fingers
while digging the trap bed.
Good locations for a set are often indicated by coyote tracks. The following
are good locations on most farms and
ranches for setting traps: high hills and
saddles in high hills; near isolated land
features or isolated bales of hay; trail
junctions, fences, and stream crossings;
pasture roads, livestock trails, waterways, game trails, and dry or shallow
creek beds; near pond dams, field borders, field corners, groves of trees, and
eroded gullies; sites near animal carcasses, bone or brush piles; and under
rim rocks.
6.
Cloth (or canvas) feed sack to
kneel on while digging a trap bed
and pounding the stake.
Making the Set. Place three to five
trap sets near the area where coyotes
have killed livestock.
1.
One 5-gallon (19-l) plastic bucket
to carry equipment.
2.
Two No. 3 or No. 4 traps per set.
3. One 18- to 24-inch (46- to 61-cm)
stake for holding both traps in
place.
Fig. 9. A piece of canvas, about 3 feet x 6 feet, used as a kneeling
cloth, makes preparing the trap site much easier.
C-64
1. First, observe the area where the
losses are occurring and look for
tracks and droppings to determine
the species responsible. Study the
paths used by predators. If you
have 4 hours to spend setting traps,
spend at least 3 of them looking for
coyote sign.
2. Decide where to place the trap sets.
Always place them in an open, flat
area because of wind currents, dispersion of scent, and visibility. Never
place traps uphill or downhill from
the coyote’s expected path of
approach. Look for open places where
coyote tracks indicate that the animal
milled around or stopped.
3. Place the set upwind from the path (or
site of coyote activity) so the prevailing wind will carry the scent across
the area of expected coyote activity.
4. Choose a level spot as close as possible to, but not directly on, the coyote’s
path. The coyote’s approach should
never be over dry leaves, tall grass,
stones, sticks, weeds, or rough ground.
Make each set where the coyote has
clear visibility as it approaches.
5. Place the set using two No. 3 traps
with a cold-shut chain repair link
affixed to the top of a steel stake. The
link should swivel around the stake
top. The stake should be at least 18
inches (46 cm) long, or longer if the
soil is loose. Use two stakes set at an
angle to each other if the soil will not
hold with a single stake.
Figures 9 through 29 illustrate the procedures for making a set.
Fig. 10. Kneel down on the cloth and outline a trench approximately
3 feet long, 7 inches wide, and 2 inches deep. Dig the trench so that it
runs lengthwise to the prevailing wind.
Fig 11. Dig out the soil with tools and by hand.
Fig 14. Compress this spring below the jaw hinge, then bend the
spring as shown above.
Fig. 12. Pile the excavated soil from the trench on the kneeling
cloth.
Fig 15. Hold the compressed spring with your right leg as shown
above, then compress the left spring. Hold this spring down with
your left hand.
Fig. 13. Place one of the traps on your left leg just above your knee.
Grasp the trap spring nearest your right leg as shown, and
compress the spring.
Fig. 16. Carefully spread the jaws. Reach under the jaws with your
left hand, holding the pan up while you ease the two springs’
tension so that the trap will remain set.
C-65
C-66
Fig. 17. Twist the springs back toward the trigger. Always set the
trap in the ground so that the animal walks into it over the jaw
that is nearest to the bottom of the trench, as shown above.
Fig 20. Take out or add soil until the trap pan and jaws are about
1/2 inch below the level of the surrounding ground. Build a ridge
for the jaw opposite the trigger to sit on. On the side of the trap
that has the trigger, place soil under the trap pan cover on either
side of the trigger to hold the pan cover up tight against the bottom
of the jaws.
Fig. 18. Drive a steel stake into the center of the trench so that the
top of the stake is even with the bottom of the trench. Place one of
the set traps at each end of the trench. Place the trap so it sits
solidly and will not tip if the coyote steps on the spring or jaws.
Fig 21. Stretch the pan cover tightly across the pan and under the
jaws. Pan and jaws should be level and flat. In cold weather,
plastic can be placed under the trap. Place plastic baggies on each
spring and mix table salt with dry soil or peat moss to cover the
trap. Set the other trap as shown above. Place the pan cover so that
the dog or trigger can move upward without binding it in.
Anything that slows the action of the trap can cause a miss or a toe
hold.
Fig. 19. Place canvas, plastic, screen, cloth, wax paper, or a similar
material over the pan and under the trap jaws. Be sure the pan sits
level with the trap jaws.
Fig. 22. Use a sifter of 1/4-inch hail screen on a wood frame, 7 inches
by 10 inches and 2 inches deep. Sift soil from the canvas kneeling
cloth over the set, covering the entire trench back to ground level
(except directly over the traps).
Fig. 23. The trap should be set about 1/4 inch below the level of
the surrounding ground. The set must look natural. The soil
around the trap and over the springs, chains, and stake should be
packed to the same firmness as the ground the coyote walks on in
its approach to the set. Only soft soil should be directly over the
trap pan within the set jaw area. Use a curved stick, brush, or rib
bone to level soil over the trap.
Fig. 26. Carefully brush out all tracks and signs of activity.
Fig. 24. Place an object over the buried stake that can be easily
seen; the further away it can be seen, the better. Use an old, dried
bleached bone, a dried cow chip, a small bush or clump of grass,
an old dried root, a small stake, or a stump. The object should be
about 6 to 8 inches high and be very visible.
Fig. 27. Use the canvas kneeling cloth to carry away all loose soil.
This cloth can also be used to carry soil to the set. In summer it is a
good idea to store fine dry soil for use in winter. You can often
locate dry soil in wet weather under bridges, on cut banks, or in
old sheds.
Fig. 25. Place a tablespoon of coyote urine on the projection. When
smelling the scent and seeing the projection, the coyote will likely
walk directly into the wind and step into a trap as it approaches
the projection. A coyote dropping placed nearby will improve the
set.
Fig. 28. Discard the material removed from the trap site.
C-67
gripping traps are dangerous and illegal in some states for catching coyotes.
When pet dogs might be present, use a
padded-jaw No. 3 double coilspring
trap.
Fig. 29. Leave the trap area as near to its original condition as
possible. The coyote’s keen sense of sight and smell will quickly
alert it to danger.
Always bury the traps and stake in the
ground using dry, finely sifted soil.
One of the most difficult aspects of
using traps is trapping when the
ground is frozen, muddy, wet, or
damp. If the weather is expected to
turn cold and/or wet, you should use
one or a combination of the following
materials in which to set and cover the
traps: Canadian sphagnum peat moss,
very dry soil, dry manure, buckwheat
hulls, or finely chopped hay. A mixture of one part table salt or calcium
chloride with three parts dry soil will
prevent the soil from freezing over the
trap. When using peat moss or other
dry, fluffy material, cover the material
with a thin layer of dry soil mixed with
1/4 teaspoon of table salt. This will
blend the set with the surrounding soil
and prevent the wind from blowing
peat moss away from the trap. As an
alternative, traps could be set in a bed
of dry soil placed over the snow or frozen ground.
Guiding Coyote Footsteps. Use a
few strategically placed dirt clods,
sticks, small rocks, or stickers around
the set to guide the coyote’s foot to the
traps. Coyotes will tend to avoid the
obstacles and place their feet in bare
areas. Do not use this method to the
extent that the set looks unnatural.
Care of Coyote Traps. New traps
can be used to trap coyotes, but better
results may be obtained by using traps
that have been dyed. Dyeing traps
helps prevent rust and removes odors.
Wood chips or crystals for dyeing
C-68
traps are available from trapping supply outlets. Some trappers also wax
their traps to prevent them from rusting and to extend the life of the traps.
Inevitably, rusting will occur when
traps are in use. It does not harm the
traps, but after their continued use the
rust often will slow the action of the
trap and cause it to miss a coyote.
Traps also become contaminated with
skunk musk, gasoline, oil, blood, or
other odors. It is important that traps
be clean and in good working condition. Rusted traps should be cleaned
with a wire brush to ensure that the
trigger and pan work freely. Check the
chain links for open links. File the triggers and receivers to eliminate all
rounded edges. Make any adjustments
necessary so that the pan will sit level
and the trap perform smoothly.
Size of Traps for Coyotes. There
are many suitable traps for catching
coyotes. Both the No. 3 and No. 4 are
good choices. Many trappers prefer a
No. 3 coilspring round-jawed off-set
trap. It is a good idea to use superweld
kinkless chain. The length of chain varies depending on whether the trap is
staked or a drag is used. A longer
chain should be used with a drag. The
off-set jaws are designed to reduce
broken foot bones, which can allow the
coyote to escape by wriggling out of
the trap. Traps with coil springs are
good coyote traps, but they require
more upkeep than a double longspring trap. The type and size of trap
may be regulated in each state. Body
While additional testing needs to be
conducted, results of research to
reduce injury using padded-jaw traps
have been encouraging. In tests with
No. 3 Soft-Catch® coilsprings, No. 3
NM longsprings, and No. 4 Newhouse
longsprings, capture rates for coyotes
were 95%, 100%, and 100%, respectively. Soft-Catch traps caused the
least visible injury to captured coyotes.
Anchoring Traps. Chain swivels are
necessary for trapping coyotes. One
swivel at the stake, one in the middle
of the chain, and one at the trap are
recommended. Drags (Fig. 30) instead
of stakes can be used where there is an
abundance of brush or trees or where
the ground is too rocky to use a stake.
Use a long chain (5 feet [1.5 m] or
more) on a drag.
Lures and Scents. Coyotes are interested in and may be attracted to odors
in their environment. Commercially
available lures and scents or natural
odors such as fresh coyote, dog, or cat
droppings or urine may produce good
results. Coyote urine works the best.
Problems in Trapping Coyotes.
A great deal of experience is required
to effectively trap coyotes. Trapping by
experienced or untrained people may
serve to educate coyotes, making them
very difficult to catch, even by experienced trappers. Coyotes, however,
exhibit individualized patterns of
behavior. Many, but not all, coyotes
become trap-shy after being caught
and then escaping from a trap. There is
a record of one coyote having been
caught eight times in the same set.
Some coyotes require considerably
more time and thought to trap than
others. With unlimited time, a person
could trap almost any coyote.
If a coyote digs up or springs a trap
without getting caught, reset the trap
in the same place. Then carefully set
one or two traps near the first set. Use
gloves and be careful to hide the traps.
Changing scents or using various
Killing a Trapped Coyote. A coyote
Drag hook with S
link for coyote traps
1 1/2"
offset
twist
Mild steel rod
5/16" diameter
8" long
Side
view
Mild steel rod
7/16" diameter
about 28" long
10 1/2"
About 1" weld
on both sides
Points sharpened and
given 1 1/2" offset
twist
7"
Fig. 30. Trapping drag
tricks, such as a lone feather as a visual
attraction near a set, or a ticking clock
in a dirt hole set as an audible attraction, may help in trying to catch wary
coyotes.
Resetting Traps and Checking
Trap Sets. Once a coyote is caught at
a set, reset the trap in the same place.
The odor and disturbance at the set
where a coyote has been caught will
often attract other coyotes. Sometimes
other coyotes will approach but not
enter the circle where the coyote was
caught. If signs indicate that this has
happened, move the trap set outside of
the circle. Leave all sets out for at least
2 weeks before moving the traps to a
new location. Check the traps once
every 24 hours, preferably in the
morning around 9 or 10 o’clock.
Reapply the scent every 4 days, using
8 to 10 drops of coyote urine.
Human Scent and Coyote Trapping. Minimize human scent around
trap sets as much as possible. If traps
are being set in warm months, make
sure the trapper has recently bathed,
has clean clothes, and is not sweating.
Leave no unnecessary foreign odors,
such as cigarette butts or gum wrappers, near the set. Wear clean gloves
and rubber footwear while setting
traps. A landowner may have an
advantage over a stranger who comes
to set traps since the coyotes are
acquainted with the landowner’s scent
and expect him/her to be there.
Coyotes have been known to leave an
area after encountering an unfamiliar
human scent.
Because of human scent, coyotes are
more difficult to catch with traps in
wet or humid weather. Wear gloves,
wax traps, and take other precautionary measures in areas where humans
are not commonly present, where wet
weather conditions are common, and
where coyotes have been trapped for
several years and have learned to
avoid traps.
will make its most desperate attempt
to get out of the trap as a person
approaches. As soon as you get within
a few feet (m) of the coyote, check to
see that the trap has a firm hold on the
coyote’s foot. If so, shoot the coyote in
the head, with a .22 caliber weapon. It
is often a good idea to reset the trap in
the same place. The blood from the
coyote will not necessarily harm the
set as long as it is not on the trap or on
the soil over the reset traps. Reset the
trap regardless of the species of animal
captured, skunks included.
Draw Stations. Draw stations are
natural areas or places set up intentionally to draw coyotes to a particular
location. For example, the straw and
cleanings from a chicken house can be
placed in an area where coyote tracks
are found. Traps can then be set
around the edges of the straw. Areas
around carcasses or parts of animals,
such as a cow’s head, are good places
to set traps. Wire the carcass to a stake
driven into the ground and out of
sight. Once coyotes start feeding, set
traps 30 to 60 feet (9 to 18 m) upwind
from the carcasses or draw station.
Never set traps very close to carcasses
because nontarget animals such as vultures, eagles, hawks, skunks, and
opossums will be caught. If sheep
graze in an area where traps are set,
cover the traps with a disc blade or
brush during the day and uncover
them at night when the sheep are
penned.
Opposition to Traps. Opposition to
foothold traps is based primarily on
two objections: (1) a lack of selectivity
for the animal which the trap is set for
and (2) foot injury sustained by the
captured animal. Trap pan tension
devices such as sticks, forked twigs,
springs, and sponges placed under the
trap pan have been used for many
years to reduce captures of nontarget
species. Many coyote traps have an
adjustable pan tension screw. One
study evaluated two pan tension
devices. Preliminary results indicated
that the use of either device could
exclude nearly 90% of the gray foxes,
swift foxes, striped skunks, opossums,
and jackrabbits that stepped on traps,
C-69
Wrap snare around
snare support
Swivel
Slide
lock
U-shaped
snare
support
2.5' to 10'
galvanized
aircraft cable
Fig. 31. Coyote snare
Bend snare to
prevent wind from
closing it
Fig. 33. Setting the snare
Cable, NOT
wire, holds
snare to
stake
36" galvanized
No. 9 wire
Notched
driving rod
1/2"
rebar stake
V bend
prevents
movement
Fig. 32. Driving the support wire
as compared with 24% on average for
unequipped traps. A variety of other
species were excluded at even higher
rates. Some coyotes were also
excluded, but because more traps
remained functional, the net result
appeared to be an increase in coyote
trapping efficiency. Advances in trap
design, including off-set jaws and
padded-jaw traps, have increased the
humaneness of foothold traps. Traps
should be checked once or twice each
day to minimize the length of time that
an animal must remain in a trap.
Snares
Snaring is the technique of setting a
steel-cable loop in an animal’s path to
C-70
Fig. 34. Fastening the snare to the stake
capture it by the neck, body, or leg.
Snares usually consist of a 2.5- to 10foot (0.75- to 3.0-m) long piece of
galvanized aircraft cable containing a
slide lock that forms a loop in the cable
(Fig. 31). On short snares, a swivel to
prevent twisting and breaking the
cable is attached to the end of the cable
opposite the loop. On longer snares,
swivels can be located near the middle
of the cable and at one end.
Snares offer several advantages over
steel foothold traps. They are lightweight, compact, simple in function,
affected little by weather, easy to set,
low in cost, and offer a high degree of
human safety. In a south Texas study,
snares were 10 times more selective
over steel foothold traps for target species of coyotes and bobcats. Snares,
however, can be a greater hazard than
traps to livestock. Recent research has
produced deer stops and break-away
or relaxing locks that have significantly
improved snare specificity.
Preparation of Snares. New commercial snares and extension cables
can be cleaned by boiling each dozen
snares in a pan or bucket of water with
4 tablespoons (16 gm) of baking soda
for one hour. The snares will turn a
dull gray after being removed from
this bath and hung up to dry outdoors.
Darken snares by boiling them in
Keep slide
clear of
fence
7" to 10"
diameter round
loop
Snares set in holes under woven-wire
fences can be held in place about 1 to 2
inches (2.5 to 5 cm) from the fence with
the snare support system (Fig. 35). The
snare should be set far enough away
from the fence to prevent the lock from
catching on the bottom wire of the
fence. The bottom of the loop should
be about 2 inches (5 cm) above the bottom of the hole. The snares can be anchored to the heavy-gauge wire on the
bottom of the fence. Two strands of
baling wire or S hooks can be used to
fasten the snare to the bottom wire.
About 2"
Fig. 35. Snare set for woven wire
Small loop
(about 5")
Loop on ground to
side of opening
Fig. 36. Leg snare set
brown logwood crystals and dye.
After boiling, snares should be kept
clean of foreign odors. Wear clean
gloves when handling and setting
snares.
How to Set Snares. Snares designed
to capture predators by the neck or leg
are set directly in the animal’s path of
movement and are held in place using
various techniques. One support that
works particularly well can be constructed from a 36-inch (0.9-m) piece of
12-gauge galvanized or 9-gauge soft
wire. Form a V bend in the support
wire, about 4 inches (10 cm) from the
end, and drive the wire into the
ground with a notched rod (Fig. 32) to
ing. A lead cable that is at least as
strong as the snare cable can be used
to attach short snares to the rebar
stake. Avoid using 9-gauge (0.38-cm)
wire or several strands of 14-gauge
(0.21-cm) wire to anchor snares to a
rebar stake because they may bend
back and forth, crystallize, and break.
When used for coyotes, snares also can
be secured to a dead tree limb that is at
least 6 inches (15 cm) in diameter and
6 feet (2 m) long.
prevent the support from moving in
the wind. Wrap the snare around the
support about three times and hold it
in place with a U bend formed in the
upper end of the snare support. Bend
the snare cable upward slightly, just
inside the lock, to ensure that the snare
loop is not closed by the wind (Fig. 33).
Snares should be attached to a solid
object so that captured animals cannot
escape (Fig. 34). A steel 1/2-inch (1.3cm) diameter rebar, 24 to 30 inches (61
to 72 cm) long (depending on soil
hardness), makes a good anchor for
coyotes and smaller predators. Attach
snares to the rebar with a strong
swivel to prevent tangling and break-
If there is a chance of accidentally
catching a pet dog, a leg snare set is
recommended (Fig. 36). Set a small
loop about 5 inches (13 cm) or less to
one side of the opening, and set the
bottom of the loop on the ground.
When a coyote goes under a fence, it
places both front feet firmly on the
ground, and sticks its head just under
the bottom wire. Once its head is past
the bottom wire, the coyote begins to
raise its head. The idea is to set the leg
snare so that one front foot will pass
through the snare.
Snares are usually set in the form of a
round or oval loop. In a trail set (Fig.
37), a round loop that is 12 inches (30
cm) in diameter can form an oval loop
that is about 14 inches (36 cm) high
and 10 inches (25 cm) wide. Use a
5/64- or 3/32-inch (0.2- or 0.24-cm)
diameter galvanized aircraft cable for
snaring coyotes. Varying round loop
diameters and heights above ground is
recommended when snaring coyotes
(Table 1). The loop size in a hole in a
fence should vary depending upon the
size of the hole.
C-71
Table 1.Specific loop dimensions for
snaring coyotes.
Type
of set
Round loop
diameter in
inches
(cm)
Height of
loop above
ground in
inches
(cm)
Trail
9-12
(23-30)
10-12
(25-30)
Under
fence
7-10
(18-25)
2
(5)
Where to Set Snares. Animals usu-
ally follow the easiest route through
heavy cover. These routes, which generally consist of trails, are excellent
locations to snare predators. Snares are
effective along trails leading to draw
stations. Some effective locations for
snaring coyotes include: (1) along trails
in thickets or heavy vegetation leading
to a carcass, (2) on trails under fences,
(3) on livestock trails in vacant pastures, (4) in the bottoms of ravines, and
5) on narrow paths inside weeds or
brush. Trails can be created by driving
on weeds or stubble with a pickup, by
walking in snow, or by mowing a trail
through weeds or grass with a weed
eater.
Regulations for Snaring. Snares
are not legal in all states. Where snares
are legal, most states have regulations
which require that snares be visually
inspected every 24 hours. Snares
should be checked early in the morning to increase the probability of releasing nontarget animals unharmed.
Methods to Avoid Capturing Nontarget Animals. Sites where snares
are set should be carefully selected to
avoid capturing nontarget animals.
Avoid setting snares: (1) in pastures
with livestock, (2) within 25 yards
(23 m) of animal carcasses (to prevent
capturing birds of prey and other scavengers), (3) within major deer, elk, or
antelope wintering areas (these big
game animals are much less susceptible to foothold traps), (4) on any trails
being used by livestock, deer, elk, and
other nontarget animals (attract predators away from these trails with specific baits and lures), (5) under fences
where livestock, antelope, deer, or
nontarget dogs are using the “crawl
space,” and (6) where people can
readily view captured animals.
C-72
Not more
than 1"
Eye guide
points
9" to
12"
Steel stake
Eye guide
points
10" to 12"
No. 9 extension cable
(NOT wire)
Trail
Fig. 37. Trail snare set
Use a short snare cable to reduce injuries where accidentally captured dogs
might jump over a fence or a tree
branch. Also avoid using entangling
devices (attachments that increase the
chance of killing the snared animal)
where dogs might be captured. Use
the lightest snare lock (breakaway
lock) possible to capture the desired
animal. If livestock, deer, elk, or antelope are captured by a leg, they can
usually break a light lock but may be
held by heavy locks. Record the location and number of snares on a map so
they can be found, and remove all
snares when damage stops or when
they cannot be checked frequently.
Shooting
Shooting coyotes is legal in many situations, and it often ranks high among
the choices for removing a predator.
Safety, however, is a critical factor that
in some circumstances may preclude
the use of firearms (for example, local
laws may prohibit shooting, or neighbors may be too close).
For shooting coyotes, a mediumpowered bolt-action rifle fitted with a
scope is recommended. The .223 Remington, .22-250, .220 Swift, or the .243
Winchester are all capable of killing a
coyote up to a distance of 250 yards
(225 m). Since coyotes are able to
detect human scent, the shooter should
take a stand downwind from where
the coyote will likely approach. An
elevated location where the lighting
works to the shooter’s advantage is a
good choice. If predators are killing
sheep in the daytime, construct a comfortable blind at a vantage point in the
pasture where the killing has occurred.
Whenever possible, rest the rifle on a
solid support while aiming. A homemade shooting stick will improve
accuracy over shooting freehand.
A shotgun, preferably a 12-gauge
semi-automatic, can be used for shooting at short range (less than 50 yards
[45 m]). Often it is advisable to have
both a 12-gauge shotgun and a scoped
rifle available. Copper-coated (BB)
lead shot, No. 4 buckshot (lead), and in
newer shotguns, the larger-sized steel
shot works well for killing coyotes.
Shooting From Ground Vehicles.
Shooting from vehicles (snowmobiles,
motorcycles, and pickups) in open, flat
prairie country can be effective and
provide immediate results. Under
most circumstances, however, this
method is not practical as it requires
keen driving skills, is dangerous, and
is illegal in most states.
Calling and Shooting Coyotes.
Coyotes may respond to predator
calls. Calling, like other methods of
predation control, should be used
sparingly and only when needed.
Coyotes can be called at any time of
the day although the first couple of
hours after dawn and the last few
hours before darkness are usually best.
Call in areas where there are signs of
coyotes, such as tracks or droppings.
In some situations, coyotes can be
located by listening to their howling at
sundown and sunrise. Some hunters
use sirens to elicit howls from coyotes.
Often a voice imitation of a coyote
howl works as well. Coyotes often
come to a howl without howling back,
so the prudent hunter is always ready
to shoot.
Hunting at Night. Not many people
have witnessed predators killing livestock because it usually occurs at
night, away from human activity. As
stated previously, calling and shooting
predators at night is illegal in many
states. Where legal, however, hunting
at night with the use of artificial lights
may be effective. Red or blue light
tends to spook predators less readily
than white light does. Calling without
the use of artificial lights is effective
only with snow cover and the light of a
full moon.
Aerial Hunting. The use of aircraft
for shooting coyotes is strictly regulated by the provisions of the Airborne
Hunting Act and is allowed only
under special permit in states where
legal. Aerial hunting is selective and
allows taking only the target species.
Although it is costly, it may be one of
the most cost-effective methods of reducing predator damage when all factors are considered. It is often the best
method where conditions are right for
removing depredating animals that
have successfully evaded traditional
ground control methods such as trapping.
Fixed-wing aerial hunting is limited
primarily to open areas with little
vegetative cover. The greater maneuverability of helicopters makes them
more useful for hunting in areas of
brush, scattered timber, and rugged
terrain.
Although aerial hunting can be conducted over bare ground, it is most
effective where there is deep snow
cover. Animals are more visible
against a background of snow and are
much less mobile in their attempts to
avoid the aircraft. Under optimal conditions of clear, sunny skies and fresh
snow cover, much of the hunting can
be accomplished by searching for and
following fresh coyote tracks. Aerial
hunting success can be increased when
conducted with the assistance of a
ground crew. Before the plane arrives,
a ground crew can locate coyotes in
the hunting area by eliciting howls
with a siren, a mouth-blown howler
call, or a voice howl. Two-way radio
communication allows the ground
crew to direct the aircraft toward the
sound of the coyotes, thus reducing
hunting time.
Aerial hunting is not recommended
for, nor undertaken by, most livestock
producers because of the special skills
required of both pilot and gunner and
the danger inherent with the low-level
flight. Although weather, terrain, and
state laws limit the application of this
method, it can often provide a prompt
resolution to depredation problems.
Denning
Predation can frequently be resolved
by locating coyote dens and removing
the pups and/or the adults responsible
for depredations. Denning may also be
warranted as a preventive control
strategy if coyote predation has historically and consistently occurred in a
particular area during the lambing
season.
Breeding pairs of coyotes are extremely territorial. They vigorously defend
their territories against other canine
intruders. Coyotes often den year after
year in the same general location. If a
particular denning pair of coyotes has
a history of existing with and not preying on livestock, it may be to the
producer’s advantage to leave them
alone. Their removal will open up a
territory that may become occupied
with coyotes that are more likely to
prey on livestock.
Although tracking a coyote from a
livestock kill back to its den requires
skill and persistence, it is probably the
most foolproof method to locate the
den of the offending animals. If tracking is not feasible because of poor
tracking conditions or lack of the
required skills, there are alternatives
that may be used.
Coyotes will usually howl in response
to a howl from another coyote near
their den. One or both adult coyotes
will often be near the den between 7:30
to 9:00 a.m. A response can be elicited
by voice howling, blowing a coyote
howler call, or broadcasting recorded
calls from a tape player. It is usually
best to wait 30 minutes to 1 hour
between howls because the same
coyotes may not respond again within
that period.
Once the approximate location of a
den is determined, careful planning is
required to ensure the best chance of
immediately removing the adult
coyotes. The hunter should approach
the den unseen and downwind to
within calling distance, armed with a
high powered rifle and/or repeating
shotgun loaded with heavy shot. A call
that imitates the whines or yelps of a
coyote pup can be very effective under
these circumstances, especially when
used in conjunction with a dog to act
as a decoy. A small- to medium-sized
dog moving in the vicinity of the den
gives the coyotes something to focus
on and reduces the likelihood that the
hunter will be detected. The sounds of
a pup in distress along with the sight
of a dog so near the den will cause
most coyotes to display highly aggressive behavior, frequently chasing the
dog back to within close proximity of
the hunter.
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After the adults are removed, the pups
can be killed by fumigating the den
with a gas cartridge registered for this
purpose, or the pups can be dug out
by hand. If attempts to shoot one or
both adults are unsuccessful, the
chances of trapping or snaring them
are improved if the pups are left alive
and confined in the den. This can be
accomplished by driving stakes 2
inches (5 cm) apart down through the
den entrance. Carefully place blind
sets in the den trails or at the den
mound. Capture will often result when
the adults return to investigate the
area. If the adults are not captured
within a reasonable period of time, the
pups should be destroyed. Removal of
the pups is often effective in stopping
predation even if the adult coyotes are
not removed.
An airplane can be used very effectively to locate coyote dens when depredations occur in spring or early
summer in open prairies or sagebrush
terrain. Early morning hours provide
the best light conditions for locating
adult animals near the den site or as
they return from hunting. The low
angle light reflects on the coyote and
provides good contrast with the surrounding vegetation and soil. Actual
den sign, however, shows up better
during the middle of the day with light
coming from directly overhead. Dens
are most easily located after the pups
have begun venturing outside. The
pups soon trample down the vegetation around the den, making the site
more visible from the air. If aerial
shooting is legal, it is often possible to
remove the adults and pups in one
operation. In open terrain, landings
can often be made within walking distance of the den.
Although denning requires special
skills, training, and often considerable
time, the advantages can be significant.
A cost-benefit analysis conducted during one study determined that the cost
to remove a den of depredating
coyotes could be recovered if only 3.6
lambs were saved. In the same study,
the average number of lambs killed by
each depredating pair of coyotes was
4.9 per week. While these findings in-
C-74
dicate that denning could be cost effective after only a few days, the benefits
actually continue in most instances for
the duration of the season. Denning
can be very selective for the offending
animals and can resolve some depredation problems at relatively low cost.
Hunting with Dogs. Several breeds
are generally known as trailing
hounds, including Walkers, Julys, redbones, blueticks, black and tans, Plott
hounds, and English fox hounds. Trail
hounds follow the scent left by a
predator and run it to tree or bay it on
the ground. Coyotes are seldom
caught and killed by trail hounds. In
most instances, trail hounds are used
in combination with sight hounds. The
trail hounds run coyotes into the open,
and then sight hounds are released to
capture the fleeing coyote. More commonly, coyotes are shot as they run
from the pack of hounds. Sight
hounds, generally greyhounds or Russian wolf hounds, are used in open
prairie country to run coyotes down
and kill them.
Economics of Damage
and Control
Sheep numbers in the United States
have declined about 80% from 1942 to
1976 (Gee et al. 1977). Former sheep
producers reported that the principal
reasons for leaving the sheep industry
included high predation losses, low
lamb and wool prices, a shortage of
good hired labor, and the producer’s
age.
The US Fish and Wildlife Service
(1978) estimated the economic impact
of coyote predation on producers with
predator problems, on producers without predator problems, and on consumers during 1977. They used an
average lamb loss rate of 4% (267,000
lambs) and a ewe loss rate of 1.5%
(125,000 ewes) to estimate an economic
loss of $19 million to producers from
coyote predation in the 17 western
states. The reduced number of sheep
and lambs resulted in a higher market
price, which benefited producers by $6
million. The net impact of coyote
predation on sheep producers was a
loss of $13 million, and the impact on
consumers was $4 million in additional costs. The General Accounting
Office (GAO 1990) estimated that
coyotes in 17 western states killed
sheep and lambs valued at $18 million
in 1989. The National Agricultural
Statistical Service (NASS 1991)
reported that sheep and lamb losses to
coyotes in the United States were
valued at $18.3 million in 1990.
The US Fish and Wildlife Service
(1978) reported calf losses between
birth and weaning to coyotes across
the United States at 0.4%, with predation decreasing to nearly zero by
weaning time. Dorrance (1982)
reported that coyotes were responsible
for 16% of the 1,520 confirmed predation losses of cattle in Alberta from
1974 to 1978. Coyote predation on
calves caused producers with coyote
problems across the United States to
lose an estimated $20 million. However, because of the greater price flexibility of beef compared with sheep,
the reduction in the number of beef
calves marketed (estimated at 0.4%, or
115,000 fewer calves) resulted in a
higher price, which benefited beef producers by $81 million. The net impact
of the reduced supply of beef as a
result of coyote predation was a gain
of $61 million to beef producers, but it
cost consumers an additional $98
million in higher prices for beef, resulting in an overall loss of $37 million.
NASS (1992) reported that cattle and
calf losses to coyotes in the United
States were valued at $24.3 million in
1991.
Coyote predation also can cause
substantial losses of domestic goats. In
three studies in Texas, where an estimated 1.1 million goats (about 90% of
the goats in the United States) are
raised (Scrivner et al. 1985), predators
were reported to take 18.1% of the
adults and 33.9% of the kids (Pearson
1986). NASS (1991) reported that goat
losses to coyotes in the United States
were valued at $5.7 million in 1990.
Pearson (1986) stated that predators,
particularly coyotes, accounted for
losses of hundreds of chickens and
turkeys in the 14 western states. In one
study, Andelt and Gipson (1979)
reported that between June 4 and
August 31, 1976, a mated pair of
coyotes apparently killed 268 domestic
turkeys in Nebraska valued at $938.
Although the average value of livestock losses to coyotes reflected the
overall impact on producers, it did not
reflect the severity of losses to some
individuals. Balser (1964) and Gee et
al. (1977) indicated that coyote predation is much more serious for some
producers than others. Most sheep
producers suffer no or minor predator
losses, whereas 20% to 25% of the
producers suffer losses that are significantly higher than the average (US
Fish Wildl. Serv. 1978). These losses
can drive producers out of business
because of low profit margins. Nonfatal injuries and harassment of livestock by coyotes also can result in
reduced weight gain and subsequent
reductions in profit.
Acknowledgments
Much of the information and several of the
figures for this chapter were adapted from the
SID Sheep Production Handbook, Predator
Damage Control chapter, published by the
American Sheep Industry Association, Inc.
(1990) and various publications authored by
F. R. Henderson, J. S. Green, W. F. Andelt, G. E.
Connolly, and D. A. Wade.
The section on economics of damage and control
was adapted from Andelt (1987).
Figure 1 by Emily Oseas Routman.
Figure 6 adapted from a USDA-APHIS-ADC
illustration by Renee Lanik, University of
Nebraska-Lincoln.
For Additional
Information
Alberta Agriculture. 1990. Methods of
investigating predation of livestock. Alberta
Agric., Crop Prot. Branch, Agdex 684-4.
36 pp.
General Accounting Office (GAO). 1990.
Wildlife management effects of Animal
Damage Control program on predators.
GAO/RCED-90-149, US General Account.
Office, Washington, DC. 31 pp.
Gier, H. T. 1968. Coyotes in Kansas. Revised.
Kansas State Coll. Agric. Exp. Stn. Bull. 393.
118 pp.
Andelt, W. F. 1987. Coyote predation. Pages
128-140 in M. Novak, J. A. Baker, M. E.
Obbard, and B. Malloch. Wild furbearer
management and conservation in North
America. Ontario Ministry. Nat. Resour.
Green, J. S. ed. 1987. Protecting livestock from
coyotes: a synopsis of the research of the
Agricultural Research Service. Natl. Tech.
Info. Serv. PB 88 133590/AS. 105 pp.
Andelt, W. F. 1988. Proper use of snares for
capturing furbearers. Colorado State Univ.
Coop. Ext. Serv. Pub. 6.517, Fort Collins. 4 pp.
Green, J. S., and R. A. Woodruff. 1991. Livestock
guarding dogs protect sheep from predators.
US Dep. Agric., Agric. Info. Bull. No. 588.
31 pp.
Andelt, W. F., and P. S. Gipson. 1979. Domestic
turkey losses to radio-tagged coyotes. J.
Wildl. Manage. 4:673-679.
Henderson, F. R. 1986. “How to Call a Coyote,”
Kansas State Univ., Coop. Ext. Serv.,
Manhattan. Pub. C-400. 4 pp.
Balser, D. S. 1964. Management of predator
populations with antifertility agents. J.
Wildl. Manage. 28:352-358.
Henderson, F. R. 1987. How to trap a coyote.
Kansas State. Univ., Coop. Ext. Serv., Pub.
C-660. 12 pp.
Bateman, J. 1971. Animal traps and trapping.
Stackpole Books. Harrisburg, Pennsylvania.
286 pp.
Henderson, F. R. 1988. Use of snares for
capturing coyotes. CES, Kansas State Univ.,
Coop. Ext. Serv. Pub. C-698., Manhattan.
4 pp.
Bekoff, M., ed. 1978. Coyotes: biology, behavior,
and management. Academic Press, New York.
384 pp.
Boggess, E. K., F. R. Henderson, and C. W.
Spaeth. 1980. Managing predator problems:
practices and procedures for preventing and
reducing livestock losses. Coop. Ext. Serv.
C-620, Kansas State Univ., Manhattan. 19 pp.
Connolly, G. 1992a. Sheep and goat losses to
predators in the United States. Proc. Eastern
Wildl. Damage Control Conf. 5:75-82.
Connolly, G. 1992b. Coyote damage to livestock
and other resources. Pages 161-169 in A. H.
Boer, ed. Proceedings, ecology and
management of the eastern coyote. Univ.,
New Brunswick, Fredericton.
Connolly, G. E. 1988. M-44 sodium cyanide ejectors
in the Animal Damage Control program, 19761986. Proc. Vertebr. Pest Conf. 13:220-225.
Connolly, G. E. and W. M Longhurst. 1975. The
effects of control on coyote populations — a
simulation model. Univ. California, Coop.
Ext. Serv. Bull. 1872. 37 pp.
deCalesta, D. S. 1983. Building an electric
antipredator fence. Pacific Northwest Ext.
Pub. 225. 11 pp.
Dorrance, M. J. 1982. Predation losses of cattle in
Alberta. J. Range Manage. 35:690-692.
Gee, C. K., W. R. Bailey, R. L. Gum, and L. M.
Arthur. 1977. Sheep and lamb losses to
predators and other causes in the western
United States. US Dep. Agric., Econ. Res.
Serv., Agric. Econ. Rep. 369. 41 pp.
Gee, C. K., D. B. Nielsen and D. M. Stevens.
1977. Factors in the decline of the western
sheep industry. US Dep. Agric., Econ. Res.
Serv., Agric. Econ. Rep. 377. 31 pp.
Henderson, F. R., E. K. Boggess, and R. J. Robel.
1977. Understanding the coyote. Kansas
State Univ. Coop. Ext. Serv., Pub. C-578.,
Manhattan. 24 pp.
Hulet, C. V., D. M. Anderson, J. N. Smith, W. L.
Shupe, C. A. Taylor, Jr., and L. W. Murray.
1989. Bonding of goats to sheep and cattle
for protection from predators. Appl. An.
Behav. Sci. 22:261-267.
Knowlton, F. F. 1972. Preliminary interpretations
of coyote population mechanics with some
management implications. J. Wildl. Manage.
36:369-382.
Linhart, S. B., G. J. Dasch, and F. J. Turkowski. 1981.
The steel leghold trap: techniques for reducing
foot injury and increasing selectivity. Proc.
Worldwide Furbearer Conf. 3:1560-1578.
Linhart, S. B., J. D. Roberts, and G. J. Dasch. 1981.
Electric fencing reduces coyote predation on
pastured sheep. J. Range Manage. 35:276-281.
Linhart, S. B., R. T. Sterner, G. J. Dasch, and J. W.
Theade. 1984. Efficacy of light and sound
stimuli for reducing coyote predation upon
pastured sheep. Prot. Ecol. 6:75-84.
Meduna, R. 1977. Relationship between sheep
management and coyote predation. M.S. Thesis,
Kansas State Univ., Manhattan. 140 pp.
National Agricultural Statistics Service (NASS).
1991. Sheep and goat predator loss. US Dep.
Agric., Agric. Statistics Board, Washington,
DC.
National Agricultural Statistics Service (NASS).
1992. Cattle and calves death loss. US Dep
Agric., Agric. Statistics Board, Washington,
DC.
C-75
Pearson, E. W. 1986. A literature review of livestock
losses to predators in western U.S. US Fish
Wildl. Serv. Final Rep., Denver, Colorado. 20
pp.
Robel, R. J., A. D. Dayton, F. R. Henderson, R. L.
Meduna, and C. W. Spaeth. 1981. Relationships
between husbandy methods and sheep losses
to canine predators. J. Wildl. Manage. 45:894911.
Scrivner, J. H. 1983. The 1080 toxic collar: economics
of field use in Texas. Proc. Western Wildl.
Damage Control Conf. 1:201-204.
Wagner, F. H. 1988. Predator control and the
sheep industry: the role of science in policy
formation. Regina Books, Claremont,
California. 230 pp.
Walton, M. T., and C. A. Feild. 1989. Use of donkeys
to guard sheep and goats in Texas. Eastern
Wildl. Damage Control Conf. 4:87-94.
Young, S. P., and H. T. Jackson. 1951. The clever
coyote. The Stackpole Co., Harrisburg,
Pennsylvania, and the Wildl. Manage. Inst.,
Washington, DC. 411 pp.
Scrivner, J. H., D. A. Wade, G. E. Connolly, and
L. C. Howard, Jr. 1985. The effects of
predation on an Angora goat ranch. Nat.
Wool Grower. 75:10-13.
Video Tapes
Shelton, M. 1984. The use of conventional and
electric fencing to reduce coyote predation
on sheep and goats. Texas Agric. Exp. Stn.
MP 1556. 12 pp.
Video tape, VHS. “Livestock Guarding Dogs,
Protecting Sheep From Coyotes.” US Dep.
Agric., An. Plant Health Inspect. Serv., An.
Damage Control.
Till, J. A., and F. F. Knowlton. 1983. Efficacy of
denning in alleviating coyote depredations
on domestic sheep. J. Wildl. Manage.
47:1018-1025.
Video tape, VHS. “How to Call a Coyote.”
Kansas State Univ., Coop. Ext. Serv.
Manhattan.
Todd, A. W. and L. B. Keith. 1976. Responses of
coyotes to winter reductions in agricultural
carrion. Alberta Wildl. Tech. Bull. 5. 32 pp.
USDA. 1993. Animal Damage Control Program.
Supplement to the Draft Environmental
Impact Statement-1992. US Dep. Agric.
Washington, DC.
US Fish and Wildlife Service. 1978. Predator
damage in the West: a study of coyote
management alternatives. US Fish Wildl.
Serv., Washington, DC. 168 pp.
Wade, D. A. 1973. Control of damage by coyotes
and some other carnivores. Colorado State
Univ., Coop. Ext. Serv. Bull. 482a. 16 pp.
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Wade, D. A. 1976. The use of aircraft in predator
control. Vertebr. Pest Conf. Proc. 7:154-160.
Video tape VHS. “How to Snare a Coyote.”
Kansas State Univ. Coop. Ext. Serv.,
Manhattan.
Video tape, VHS. “A Matter of Perspective.”
Texas A&M Coop. Ext. Serv. San Angelo.
Video tape, VHS. “How to Trap a Coyote.”
Colorado State Univ. Coop. Ext. Serv., Fort
Collins.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
Jeffrey S. Green
Assistant Regional Director
USDA-APHISAnimal Damage Control
Lakewood, Colorado 80228
FERAL DOGS
Philip S. Gipson
Unit Leader
Kansas Cooperative Fish and
Wildlife Research Unit
Kansas State University
Manhattan, Kansas 66506-3501
Fig. 1. Feral dog, Canis familiaris
Damage Prevention and
Control Methods
Exclusion
Net wire fences.
Toxicants
Other Methods
Sodium cyanide in M-44 ejector
devices.
Eliminate food supplies.
Fumigants
None are registered.
Electric fences.
Trapping
Frightening
Live traps.
Yard lights, effigies, pyrotechnics.
No. 3 or 4 steel leghold traps.
Electronic Guard.
Cable neck snares.
Livestock guarding animals.
Shooting
Repellents
Hunting from the air.
Several products are registered but are
practical only for small areas.
Destroy dens.
Catch poles.
Jab sticks.
Cultural Considerations
Public education.
Dog control laws.
Professional carnivore damage control
specialists.
Hunting from the ground.
Capsaicin and anise oil may protect
humans from attack by dogs.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-77
Identification
In appearance, most feral dogs (Fig. 1)
are difficult, if not impossible, to distinguish from domestic dogs. Like
domestic dogs, feral dogs (sometimes
referred to as wild or free-ranging
dogs) manifest themselves in a variety
of shapes, sizes, colors, and even
breeds. McKnight (1964) noted German shepherds, Doberman pinschers,
and collies as breeds that often become
feral. Most feral dogs today are
descendants of domestic dogs gone
wild, and they often appear similar to
dog breeds that are locally common.
The primary feature that distinguishes
feral from domestic dogs is the degree
of reliance or dependence on humans,
and in some respect, their behavior
toward people. Feral dogs survive and
reproduce independently of human
intervention or assistance. While it is
true that some feral dogs use human
garbage for food, others acquire their
primary subsistence by hunting and
scavenging like other wild canids.
Feral and domestic dogs often differ
markedly in their behavior toward
people. Scott and Causey (1973) based
their classification of these two types
by observing the behavior of dogs
while confined in cage traps. Domestic
dogs usually wagged their tails or
exhibited a calm disposition when a
human approached, whereas most
feral dogs showed highly aggressive
behavior, growling, barking, and
attempting to bite. Some dogs were
intermediate in their behavior and
couldn’t be classified as either feral or
domestic based soley on their reaction
to humans. Since many feral dogs have
been pursued, shot at, or trapped by
people, their aggressive behavior
toward humans is not surprising.
Gipson (1983) described the numerous
lead pellets imbedded under the skin
of a feral dog caught in Arkansas as a
testament to its relationship with
people.
Feral dogs are usually secretive and
wary of people. Thus, they are active
during dawn, dusk, and at night much
like other wild canids. They often
travel in packs or groups and may
C-78
have rendezvous sites like wolves.
Travel routes to and from the gathering or den sites may be well defined.
Food scraps and other evidence of concentrated activity may be observed at
gathering sites.
The appearance of tracks left by feral
dogs varies with the size and weight of
the animal. Generally, dog tracks are
rounder and show more prominent
nail marks than those of coyotes, and
they are usually larger than those of
foxes. Since a pack of feral dogs likely
consists of animals in a variety of sizes
and shapes, the tracks from a pack of
dogs will be correspondingly varied,
unlike the tracks of a group of coyotes.
The publication by Acorn and
Dorrance (1990) contains a comparative illustration of canid tracks.
Range
Feral dogs are the most widespread of
the wild canids. They may occur
wherever people are present and permit dogs to roam free or where people
abandon unwanted dogs. Feral dogs
probably occur in all of the 50 states,
Canada, and Central and South
America. They are also common in
Europe, Australia, Africa, and on
several remote ocean islands, such as
the Galapagos.
Home ranges of feral dogs vary considerably in size and are probably
influenced by the availability of food.
Dog packs that are primarily dependent on garbage may remain in the
immediate vicinity of a dump, while
other packs that depend on livestock
or wild game may forage over an area
of 50 square miles (130 km2) or more.
Habitat
Feral dogs are often found in forested
areas or shrublands in the vicinity of
human habitation. Some people will
not tolerate feral dogs in close proximity to human activity; thus they take
considerable effort to eliminate feral
dogs in such areas. Feral dogs may be
found on lands where human access is
limited, such as military reservations
and large airports. They may also live
in remote sites where they feed on
wildlife and native fruits. The only
areas that do not appear to be suitable
for feral dogs are places where food
and escape cover are not available, or
where large native carnivores, particularly wolves, are common and prey on
dogs.
Food Habits
Like coyotes, feral dogs have catholic
diets and are best described as opportunistic feeders. They can be efficient
predators, preying on small and large
animals, including domestic livestock.
Many rely on carrion, particularly
road-killed animals, crippled waterfowl, green vegetation, berries and
other fruits, and refuse at garbage
dumps.
General Biology,
Reproduction, and
Behavior
Feral dogs are highly adaptable, social
carnivores. Most are about the size of a
coyote or slightly larger. Many breeds
of dogs are capable of existing in the
wild, but after a few generations of
uncontrolled breeding, a generalized
mongrel tends to develop. Often it has
a German shepherd or husky-like
appearance. Feral dogs on the
Galapagos Islands resemble the original introduced breeds: hounds,
pointers, and Borzoi.
Gipson (1983) suggested that family
groups of feral dogs are more highly
organized than previously believed.
Pup rearing may be shared by several
members of a pack. Survival of pups
born during autumn and winter has
been documented, even in areas with
harsh winter weather. Gipson found
that only one female in a pack of feral
dogs studied in Alaska gave birth during two years of study, even though
other adult females were present in the
pack. The breeding female gave birth
during late September or early October
during both years. It is noteworthy
that all pups from both litters had
similar color markings, suggesting that
the pups had the same father. Adult
males of different colors were present
in the pack.
Nesbitt (1975) commented on the rigid
social organization of a pack of feral
dogs where nonresident dogs were
excluded, including females in estrus.
In one instance, Nesbitt used three
separate female dogs in estrus as bait
(dogs were chained in the back of a
corral-type trap) over a 59-day period
and captured no feral dogs. He then
baited the same trap with carrion, and
a pack of feral dogs, including four
adult males, entered the trap within
1 week.
Hybridization between feral dogs and
other wild canids can occur, but nonsynchronous estrus periods and pack
behavior (that is, excluding nonresident canids from membership in the
pack) may preclude much interbreeding.
Dens may be burrows dug in the
ground or sheltered spots under abandoned buildings or farm machinery.
Feral dogs commonly use former fox
or coyote dens.
Damage and Damage
Identification
Livestock and poultry can be victims
of harassment, injury, and death from
both domestic and feral dogs. Distinguishing between livestock killed by
domestic or feral dogs and that killed
by coyotes may be difficult since the
mode of attack can be similar. Coyotes
usually attack an animal at the throat;
domestic dogs are relatively indiscriminate in how and where they
attack. Sometimes, however, dogs kill
the way coyotes do, and young and
inexperienced coyotes may attack any
part of the body of their prey as dogs
would. The survival of feral dogs,
much like that of other wild canids,
depends on their ability to secure food.
Therefore feral dogs are usually adept
predators. Unlike most domestic dogs,
feral dogs rely on their prey for food,
and thus consume much of what they
kill. Feral dogs favor the hindquarters
and viscera (liver, spleen, heart, lungs).
When domestic dogs attack domestic
animals, they may injure or kill several, but they seldom consume their
victims. Rather, they leave the impression that they were involved in vicious
play rather than an attempt to obtain
food. The most diagnostic characteristic of injuries caused by dogs is usually
the slashing and biting of prey animals
over much of their bodies. Wade and
Bowns (1983) and Acorn and Dorrance
(1990) present a detailed pictorial and
descriptive aid to identifying predators that damage livestock.
Feral dogs may become skilled at
hunting in groups for small game such
as rabbits and hares and large game
including deer and even moose. Some
wildlife managers feel that feral dogs
are a serious threat to deer, especially
in areas with heavy snows (Lowry
1978). Others have found no evidence
that feral dogs pose a significant threat
to deer (Causey and Cude 1980).
Clearly, the impact of feral dogs, both
on livestock and wildlife, varies by
location and is influenced by factors
such as availability of other food, the
number of dogs, and competition by
other predators.
Feral dogs may feed on fruit crops
including melons, berries, and grapes,
and native fruits such as persimmons
and blackberries. Damage to melons is
similar to that caused by coyotes. The
side of a ripe melon is usually bitten
open and the insides eaten.
Feral dogs commonly kill house cats,
and they may injure or kill domestic
dogs. In areas where people have not
hunted and trapped feral dogs, the
dogs may not have developed fear of
humans, and in those instances such
dogs may attack people, especially
children. This can be a serious problem
in areas where feral dogs feed at and
live around garbage dumps near human dwellings. Such situations occur
most frequently around small remote
towns.
On the Galapagos Islands, feral dogs
have significantly impacted native
populations of tortoises, iguanas, and
birds.
Legal Status
State and local laws concerning feral
and free-ranging dogs vary considerably, but most states have some regulations. Many states, particularly those
in the west, permit individuals to
shoot dogs that are chasing or killing
game animals or livestock. State agencies or agriculture departments usually
are responsible for controlling feral
dogs in rural areas. No states consider
feral dogs to be game animals. Most
cities have animal control agents to
pick up abandoned and free-ranging
domestic dogs.
Damage Prevention and
Control Methods
Exclusion
Protect livestock and poultry from
feral and domestic dogs with wellmaintained net fences. Horizontal
spacing of the mesh should be less
than 6 inches (15 cm); vertical spacing
should be less than 4 inches (10 cm).
Barbed wire at ground level or a buried wire apron will discourage dogs
from digging under the fence. The
fence should be about 6 feet (1.8 m)
high to hinder animals from jumping
over. The effectiveness of fences can be
increased by adding one or more electrically charged wires along the bottom and top. Charged wires are
positioned so that the intruding dog
encounters them before digging under
or climbing over the fence.
Electric fences consisting of up to 12
alternating ground and charged wires
have been effective at deterring dogs
(Dorrance and Bourne 1980). Other
configurations have also been successful (Shelton 1984, deCalesta 1983).
Electric fences must be checked regularly to ensure that the wires are sufficiently charged. Maintenance of fences
may be difficult in areas with drifting
snow and where large wild animals
are common. Moose and bears can be
particularly destructive to electric
fences.
Fencing is one of the most beneficial
investments in dealing with predator
C-79
damage and livestock management if
practicality warrants its use.
Frightening
Several visual and auditory devices
(yard lights, effigies, loud music, pyrotechnics) have been used to frighten
coyotes from livestock pens and pastures, and are likely to be effective
with feral dogs.
Researchers at the Denver Wildlife
Research Center developed and tested
a device called the Electronic Guard, a
combination strobe light and siren that
periodically activates during the night.
The noise and light have been effective
in reducing coyote predation on flocks
of sheep. Similar results could reasonably be anticipated with feral dogs.
Guarding dogs that have been reared
with livestock and trained to remain
with them can be a deterrent to depredating feral dogs (Green and Woodruff 1991). Since a pack of feral dogs is
quite capable of killing other dogs,
more than one guarding dog may be
needed where feral dogs are a threat.
Donkeys and llamas have also been
used to keep dogs away from livestock.
Repellents
Methyl nonyl ketone, mostly in granular form or in liquid sprays, is widely
used to prevent urination or defecation
by dogs in yards and storage areas.
Several other chemicals are registered
for repelling dogs including anise oil,
Bitrex, capsaicin, d-linonene, dried
blood, essential oils, napthalene,
nicotene, Ropel, Thiram, Thymol, and
tobacco dust. These chemicals may be
useful in keeping feral dogs from establishing scent stations or relieving
themselves on selected sites, but they
probably have little value in protecting
livestock or poultry. Capsaicin (oleoresin of capsicum) and oil of anise may
be effective in protecting humans from
attack by dogs.
Toxicants
There are no toxicants widely used for
controlling feral dogs in the United
States. The USDA-APHIS-ADC program holds a Federal Insecticide, FunC-80
gicide, and Rodenticide Act (FIFRA)
Section 3 registration for sodium cyanide used in M-44 delivery devices.
Although the product label for M-44
cyanide capsules lists wild dogs
among the canids that can be controlled when they are preying on livestock (others include coyotes and red
and gray foxes), ADC policy prohibits
using M-44s for specifically killing
dogs. Some dogs are killed by M-44s
when they are being used to kill coyotes, but dogs are not the target animal. In addition, at least one state has
a law prohibiting ADC from using
M-44s to intentionally kill dogs.
Several states hold their own registrations for using M-44s, and their policy
with regard to feral dogs may be different from that of ADC. Consult state
and local regulations with respect to
M-44 use. In all instances, M-44s can
only be used by certified applicators.
Toxic collars containing Compound
1080 (sodium monofluoroacetate)
placed on domestic animals may kill
depredating dogs if the dogs puncture
the collar during an attack. The collars,
however, are only registered for use
against coyotes.
Fumigants
No fumigants are registered for the
control of feral dogs.
Trapping
Live traps are generally effective in
capturing feral dog pups and occasionally adult dogs. Steel leghold traps
(No. 3 or 4) are convenient and effective for trapping wild dogs. Carrion
and scent baits used to lure coyotes to
traps may be effective in attracting
feral dogs. Nontarget species or pets
inadvertently captured can be
released. Caution should be exercised
when approaching a dog in a trap,
since feral dogs may be vicious when
confined, and even pet dogs may bite
under those circumstances. Cable neck
snares may be set at openings in fences
or along narrow trails used by dogs.
Use care when setting snares because
they may kill pets or livestock that are
caught.
Shooting
Aerial shooting is one of the most efficient control techniques available for
killing feral dogs. Where a pack of
damaging feral dogs is established, it
may be worthwhile to trap one or two
members of the pack, fit them with
radio transmitters, and release them.
Feral dogs are highly social, and by
periodically locating the radio-tagged
dogs with a radio receiver, it is possible to locate other members of the
group. When other members of the
pack are destroyed, the radioed dogs
can be located and shot. This technique has been used effectively by the
Alaska Department of Fish and Game
to eliminate packs of problem wolves.
Hunting from the ground has been
used to control feral dogs. A predator
call may lure dogs within rifle range.
Establishing a shooting blind can be
helpful, especially along a trail used by
dogs, near a den, a garbage dump, or a
large animal carcass.
Other Methods
Fencing garbage dumps, burying
garbage in sanitary landfills frequently, or removing livestock carrion
may help reduce local feral dog populations. Locating and destroying dens,
especially when pups are present, may
also be helpful. Use catch poles to capture and restrain feral dogs. Dart guns
and jab sticks can be used to administer tranquilizing or euthanizing agents.
Cultural Considerations
The long-term solution to most problems caused by unconfined dogs,
including feral dogs, is responsible dog
ownership and effective local dog
management programs. Many depredation problems can be solved by
confining dogs to kennels or to the
owner’s property. Dog breeding must
be controlled. Unwanted dogs should
be placed for adoption or destroyed
rather than abandoned, since the latter
leads to the formation of free-living,
feral populations.
Dog management programs should
include the following: (1) public educa-
tion about proper care and confinement of dogs; (2) laws that identify
that dog owners are legally responsible
for damage caused by dogs; (3) laws
that prohibit abandonment of
unwanted dogs and require humane
disposal of unwanted dogs; (4) holding
facilities and personnel trained to
handle unwanted or nuisance dogs;
and (5) assistance by professional
control specialists where feral dogs are
established.
Economics of Damage
and Control
Feral dogs may destroy livestock and
poultry valued at thousands of dollars.
In such instances, the costs of controlling dogs may be warranted. Boggess
and his co-workers (1978) examined
5,800 claims of domestic livestock lost
to dogs and coyotes in Iowa between
1960 and 1974. Dogs were considered
responsible for 49% of the reported
sheep losses, 45% of the cattle losses,
66% of the swine losses, and 82% of
the poultry losses. Denny (1974) conducted a nationwide survey of state
departments of agriculture, wildlife
conservation agencies, and related
agencies to determine problems
caused by unconfined dogs. Damage
to wildlife, especially deer, small
game, and birds was considered the
primary problem caused by dogs.
Damage to game animals may be a
serious local problem. In view of the
value placed on game animals by
hunters and other wildlife enthusiasts,
local control to benefit wild game may
be economically justified. The second
most serious problem reported was
damage to livestock.
Acknowledgments
Figure 1 drawn by Reneé Lanik, University of
Nebraska-Lincoln.
For Additional
Information
Acorn, R. C., and M. J. Dorrance. 1990. Methods
of investigating predation of livestock.
Alberta Agric. Agdex 684-14. Edmonton,
Alberta, Canada.
Barnett, B. D. 1986. Eradication and control of
feral and free-ranging dogs in the Galapagos
Islands. Proc. Vertebr. Pest Conf. 12:359-368.
Linhart, S. B., G. J. Dasch, R. R. Johnson, J. D.
Roberts, and C. J. Packham. 1992. Electronic
frightening devices for reducing coyote
predation on domestic sheep: efficacy under
range conditions and operational use. Proc.
Vertebr. Pest Conf. 15:386-392.
Lowry, D. A. 1978. Domestic dogs as predators
on deer. Wildl. Soc. Bull. 6:38-39.
McKnight, T. 1964. Feral livestock in AngloAmerica. Univ. Calif. Publ. Geogr., Vol. 16.
Univ. Calif. Press, Berkeley.
Nesbitt, W. H. 1975. Ecology of a feral dog pack
on a wildlife refuge. Pages 391-396 in M. W.
Fox, ed. The wild canids. Van Nostrand
Reinhold Co., New York.
Boggess, E. K., R. D. Andrews, and R. A. Bishop.
1978. Domestic animal losses to coyotes and
dogs in Iowa. J. Wildl. Manage. 42:362-372.
Nesse, C. E., W. M. Longhurst, and W. E.
Howard. 1976. Predation and the sheep
industry in California 1972-1974. Univ.
Calif., Div. Agric. Sci. Bull. 1878. 63 pp.
Causey, M. K., and C. A. Cude. 1980. Feral dog
and white-tailed deer interactions in
Alabama. J. Wildl. Manage. 44:481-484.
Scott, M. D., and K. Causey. 1973. Ecology of
feral dogs in Alabama. J. Wildl. Manage.
37:253-265.
deCalesta, D. S. 1983. Building an electric
antipredator fence. Pacific Northwest Ext.
Publ. 225:11.
Shelton, M. 1984. The use of conventional and
electric fencing to reduce coyote predation
on sheep and goats. Tex. Agric. Exp. Stn. MP
1556:12.
Denny, R. N. 1974. The impact of uncontrolled
dogs on wildlife and livestock. Trans. N.A.
Wildl. Nat. Resour. Conf. 39:257-291.
Dorrance, M. J., and J. Bourne. 1980. An
evaluation of anti-coyote electric fencing. J.
Range Manage. 33:385-387.
Gipson, P. S. 1983. Evaluations of behavior of
feral dogs in interior Alaska, with control
implications. Vertebr. Pest Control Manage.
Mater. 4th Symp. Am. Soc. Testing Mater.
4:285-294.
US Fish and Wildlife Service. 1979. Final
environmental impact statement for the U.S.
Fish and Wildlife Service’s mammalian
predator damage management for livestock
protection in the western United States. US
Dep. Inter. Washington, DC. 789 pp.
Wade, D. A., and J. E. Bowns. 1983. Procedures
for evaluating predation on livestock and
wildlife. Bull. No. B-1429. Texas A & M
Univ., College Station. 42 pp.
Gipson, P. S., and J. A. Sealander. 1977.
Ecological relationships of white-tailed deer
and dogs in Arkansas. Pages 3-16 in R. L.
Phillips and C. Jonkel, eds. Proc. 1975
Predator Symp. Montana For. Conserv.
Exper. Stn., Univ. Montana, Missoula.
268 pp.
Walton, M. T., and C. A. Field. 1989. Use of
donkeys to guard sheep and goats in Texas.
Proc. Eastern Wildl. Damage Control Conf.
4:87-94.
Green, J. S. 1989. Donkeys for predation control.
Proc. Eastern Wildl. Damage Control Conf.
4:83-86.
Editors
Green, J. S., and R. A. Woodruff. 1991. Livestock
guarding dogs: protecting sheep from
predators. US Dep. Agric., Agric. Info. Bull.
No. 588. 31 pp.
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
C-81
C-82
Robert L. Phillips
FOXES
Wildlife Research Biologist
Denver Wildlife Research Center
USDA-APHIS-ADC
Denver, Colorado 80225-0266
Robert H. Schmidt
Assistant Professor
Department of Fisheries and Wildlife
Utah State University
Logan, Utah 84322-5210
Fig. 1. Red fox, Vulpes vulpes (left) and gray fox,
Urocyon cinereoargenteus (right).
Damage Prevention and
Control Methods
Exclusion
Frightening
Trapping
Flashing lights and exploders may
provide temporary protection.
Steel leghold traps.
Net wire fence.
Well-trained livestock guarding dogs
may be effective in some situations.
Electric fence.
Repellents
Cultural Methods
None are registered for livestock
protection.
Protect livestock and poultry during
most vulnerable periods (for
example, shed lambing, farrowing
pigs in protective enclosures).
Cage or box traps.
Snares.
Shooting
Predator calling techniques.
Aerial hunting.
Toxicants
Other Methods
M-44® sodium cyanide mechanical
ejection device, in states where
registered.
Den hunting. Remove young foxes
from dens to reduce predation by
adults.
Fumigants
Gas cartridges for den fumigation,
where registered.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-83
Identification
The red fox (Vulpes vulpes) is the most
common of the foxes native to North
America. Most depredation problems
are associated with red foxes, although
in some areas gray foxes (Urocyon
cinereoargenteus) can cause problems.
Few damage complaints have been
associated with the swift fox (V. velox),
kit fox (V. macrotis), or Arctic fox
(Alopex lagopus).
The red fox is dog-like in appearance,
with an elongated pointed muzzle and
large pointed ears that are usually
erect and forward. It has moderately
long legs and long, thick, soft body fur
with a heavily furred, bushy tail (Fig.
1). Typically, red foxes are colored
with a light orange-red coat, black legs,
lighter-colored underfur and a whitetipped tail. Silver and cross foxes are
color phases of the red fox. In North
America the red fox weighs about 7.7
to 15.4 pounds (3.5 to 7.0 kg), with
males on average 2.2 pounds (1 kg)
heavier than females.
Gray foxes weigh 7 to 13 pounds (3.2
to 5.9 kg) and measure 32 to 45 inches
(81 to 114 cm) from the nose to the tip
of the tail (Fig. 1). The color pattern is
generally salt-and-pepper gray with
buffy underfur. The sides of the neck,
back of the ears, legs, and feet are
rusty yellow. The tail is long and
bushy with a black tip.
Other species of foxes present in North
America are the Arctic fox, swift fox,
and kit fox. These animals are not usually associated with livestock and
poultry depredation because they typically eat small rodents and lead a
secretive life in remote habitats away
from people, although they may cause
site-specific damage problems.
Range
Red foxes occur over most of North
America, north and east from southern
California, Arizona, and central Texas.
They are found throughout most of the
United States with the exception of a
few isolated areas (Fig. 2).
C-84
Gray foxes are found throughout the
eastern, north central, and southwestern United States They are found
throughout Mexico and most of the
southwestern United States from
California northward through western
Oregon (Fig. 3).
Kit foxes are residents of arid habitats.
They are found from extreme southern
Oregon and Idaho south along the Baja
Peninsula and eastward through
southwestern Texas and northern
Mexico (Fig. 4).
The present range of swift foxes is
restricted to the central high plains.
They are found in Kansas, the Oklahoma panhandle, New Mexico, Texas,
Nebraska, South Dakota, Wyoming,
and Colorado (Fig. 4).
Fig. 2. Range of the red fox in North America.
As its name indicates, the Arctic fox
occurs in the arctic regions of North
America and was introduced on a
number of islands in the Aleutian
chain.
Habitat
The red fox is adaptable to most
habitats within its range, but usually
prefers open country with moderate
cover. Some of the highest fox densities reported are in the north-central
United States, where woodlands are
interspersed with farmlands. The
range of the red fox has expanded in
recent years to fill habitats formerly
occupied by coyotes (Canis latrans).
The reduction of coyote numbers in
many sagebrush/grassland areas of
Montana and Wyoming has resulted
in increased fox numbers. Red foxes
have also demonstrated their adaptability by establishing breeding populations in many urban areas of the
United States, Canada, and Europe.
Gray foxes prefer more dense cover
such as thickets, riparian areas, swamp
land, or rocky pinyon-cedar ridges. In
eastern North America, this species is
closely associated with edges of
deciduous forests. Gray foxes can also
be found in urban areas where suitable
habitat exists.
Fig. 3. Range of the gray fox in North America.
Fig 4. Range of the swift fox (dark) and the kit
fox (light) in North America..
Food Habits
Foxes are opportunists, feeding mostly
on rabbits, mice, bird eggs, insects, and
native fruits. Foxes usually kill animals
smaller than a rabbit, although fawns,
pigs, kids, lambs, and poultry are
sometimes taken. The fox’s keen hearing, vision, and sense of smell aid in
detecting prey. Foxes stalk even the
smallest mice with skill and patience.
The stalk usually ends with a sudden
pounce onto the prey. Red foxes sometimes kill more than they can eat and
bury food in caches for later use. All
foxes feed on carrion (animal carcasses) at times.
General Biology,
Reproduction, and
Behavior
Foxes are crepuscular animals, being
most active during the early hours of
darkness and very early morning
hours. They do move about during the
day, however, especially when it is
dark and overcast.
Foxes are solitary animals except from
the winter breeding season through
midsummer, when mates and their
young associate closely. Foxes have a
wide variety of calls. They may bark,
scream, howl, yap, growl, or make
sounds similar to a hiccup. During
winter a male will often give a yelling
bark, “wo-wo-wo,” that seems to be
important in warning other male foxes
not to intrude on its territory. Red
foxes may dig their own dens or use
abandoned burrows of a woodchuck
or badger. The same dens may be used
for several generations. Gray foxes
commonly use wood piles, rocky outcrops, hollow trees, or brush piles as
den sites. Foxes use their urine and
feces to mark their territories.
Mating in red foxes normally occurs
from mid-January to early February.
At higher latitudes (in the Arctic) mating occurs from late February to early
March. Estrus in the vixen lasts 1 to 6
days, followed by a 51- to 53-day gestation period. Fox pups can be born
from March in southern areas to May
in the arctic zones. Red foxes generally
produce 4 to 9 pups. Gray foxes usually have 3 to 7 pups per litter. Arctic
foxes may have from 1 to 14 pups, but
usually have 5 or 6. Foxes disperse
from denning areas during the fall
months and establish breeding areas in
vacant territories, sometimes dispersing considerable distances.
Damage and Damage
Identification
Foxes may cause serious problems for
poultry producers. Turkeys raised in
large range pens are subject to damage
by foxes. Losses may be heavy in small
farm flocks of chickens, ducks, and
geese. Young pigs, lambs, and small
pets are also killed by foxes. Damage
can be difficult to detect because the
prey is usually carried from the kill site
to a den site, or uneaten parts are
buried. Foxes usually attack the throat
of young livestock, but some kill by inflicting multiple bites to the neck and
back. Foxes do not have the size or
strength to hold adult livestock or to
crush the skull and large bones of their
prey. They generally prefer the viscera
and often begin feeding through an
entry behind the ribs. Foxes will also
scavenge carcasses, making the actual
cause of death difficult to determine.
Pheasants, waterfowl, other game
birds, and small game mammals are
also preyed upon by foxes. At times,
fox predation may be a significant
mortality factor for upland and wetland birds, including some endangered species.
Rabies outbreaks are most prevalent
among red foxes in southeastern
Canada and occasionally in the eastern
United States. The incidence of rabies
in foxes has declined substantially
since the mid-1960s for unexplained
reasons. In 1990, there were only 197
reported cases of fox rabies in the
United States as compared to 1,821 for
raccoons and 1,579 for skunks. Rabid
foxes are a threat to humans, domestic
animals, and wildlife.
Legal Status
Foxes in the United States are listed as
furbearers or given some status as
game animals by most state governments. Most states allow for the taking
of foxes to protect private property.
Check with your state wildlife agency
for regulations before undertaking fox
control measures.
Damage Prevention and
Control Methods
Exclusion
Construct net wire fences with openings of 3 inches (8 cm) or less to exclude red foxes. Bury the bottom of the
fence 1 to 2 feet (0.3 m to 0.9 m) with
an apron of net wire extending at least
12 inches (30 cm) outward from the
bottom. A top or roof of net wire may
also be necessary to exclude all foxes,
since some will readily climb a fence.
A 3-wire electric fence with wires
spaced 6 inches, 12 inches, and 18
inches (15 cm, 31 cm, and 46 cm)
above the ground can repel red foxes.
Combination fences that incorporate
net and electric wires are also effective.
Cultural Methods
The protection of livestock and poultry
from fox depredation is most important during the spring denning period
when adults are actively acquiring
prey for their young. Watch for signs
of depredation during the spring, especially if there is a history of fox depredation. Foxes, like other wild canids,
will often return to established denning areas year after year. Foxes frequently den in close proximity to
human habitation. Dens may be located close to farm buildings, under
haystacks or patches of cover, or even
inside hog lots or small pastures used
for lambing. Because of the elusive
habits of foxes, dens in these locations
may not be noticed until excessive
depredations have occurred.
The practice of shed lambing and farrowing in protected enclosures can be
useful in preventing fox depredation
on young livestock. Also, removal of
C-85
livestock carcasses from production
areas can make these areas less attractive to predators.
Frightening
Foxes readily adapt to noise-making
devices such as propane exploders,
timed tape recordings, amplifiers, or
radios, but such devices may temporarily reduce activity in an area.
Flashing lights, such as a rotating beacon or strobe light, may also provide
temporary protection in relatively
small areas or in livestock or poultry
enclosures. Combinations of frightening devices used at irregular intervals
should provide better protection than
use of a single device because animals
may have more difficulty in adapting
to these disturbances.
When properly trained, some breeds
of dog, such as Great Pyrenees and
Akbash dogs, have been useful in preventing predation on sheep. The effectiveness of dogs, even the “guard dog”
breeds, seems to depend entirely on
training and the individual disposition
of the dog.
Trapping
Trapping is a very effective and selective control method. A great deal of
expertise is required to effectively trap
foxes. Trapping by inexperienced
people may serve to educate foxes,
making them very difficult to catch,
even by experienced trappers. Traps
suitable for foxes are the Nos. 1 1/2, 1
3/4, and 2 double coilspring trap and
the Nos. 2 and 3 double longspring
trap. Traps with offset and padded
jaws cause less injury to confined animals and facilitate the release of nontarget captures. State and provincial wildlife agencies regulate the traps and sets
that can be used for trapping. Consult
your local agency personnel for
restrictions that pertain to your area.
Proper set location is important when
trapping foxes. Sets made along trails,
at entrances to fields, and near
carcasses are often most productive
(Fig. 5). Many different sets are suc-
cessful, and can minimize the risk of
nontarget capture. One of the best is
the dirt-hole set (Fig. 6). Dig a hole
about 6 inches (15 cm) deep and 3
inches (8 cm) in diameter at a downward angle just behind the spot where
the trap is to be placed. Four to five
drops of scent should be placed in the
back of the hole. Move back from the
bait hole and dig a hole 2 inches (5 cm)
deep that is large enough to accommodate the trap and chain. Fasten the
trap chain to a trap stake with a chain
swivel and drive the stake directly
under the place where the trap is set.
Fold and place the chain under or
beside the trap. Set the trap about 1/2
inch (1.3 cm) below the ground. Adjust
the tension device on the trap to eliminate the capture of lighter animals.
When the set is completed, the pan of
the trap should be approximately 5
inches (13 cm) from the entrance of the
hole with the pan slightly offset from
the center of the hole (Fig. 6). Cover
Toxicants
The M-44®, a sodium cyanide mechanical ejection device, is registered for
control of red and gray foxes nationwide by USDA-APHIS-ADC personnel, and in some states by certified
pesticide applicators. Information on
the safe, effective use of sodium
cyanide is available from the appropriate state agency charged with the registration of pesticides. M-44s are
generally set along trails and at crossings regularly used by foxes.
Fumigants
Gas cartridges made by USDAAPHIS-ADC are registered for fumigating the dens of coyotes, pocket
gophers, ground squirrels, and other
burrowing rodents. Special Local
Needs permits 24(c) are available in
North and South Dakota and
Nebraska for gas cartridge fumigation
of fox dens. State and local regulations
should be consulted before using den
fumigants.
Fenceline
Gateway
Saddle
Haystack
Trail
Dike
Pond
Carcass pile
Fig. 5. Good locations for setting leghold traps for foxes.
C-86
the area between the jaws and over the
trap pan with a piece of waxed paper,
light canvas, or light screen wire. The
trap must be firmly placed so that it
does not move or wobble. The entire
trap should be covered lightly with
sifted soil up to the original ground
level.
Fox scents and lures can be homemade, but this requires some knowledge of scent making as described in
various trapping books. Commercial
trap scents can be purchased from
most trapping suppliers (see Supplies
and Materials). Experiment with various baits and scents to discover the
combination of odors that will be most
appropriate for your area.
Fig. 6. A dirt-hole set showing proper trap placement.
Equipment needed for trapping foxes
includes traps, a sifter with a 3/16- or
1/2-inch screen (0.5 or 1.3 cm), trap
stakes, trowel, gloves (which should
be used only for trapping), a 16- to 20ounce (448- to 560-g) carpenter’s hammer with straight claws, and a bottle of
scent. Remove the factory oil finish on
the traps by boiling the traps in water
and vinegar or by burying the traps in
moist soil for one to two weeks until
lightly rusted. The traps should then
be dyed with commercially available
trap dye to prevent further corrosion.
Do not allow the traps and other trapping equipment to come in contact
with gasoline, oil, or other strongsmelling and contaminating materials.
Cleanliness of equipment is absolutely
necessary for consistent trapping
success.
Cage traps are sometimes effective for
capturing juvenile red foxes living in
urban areas. It is uncommon to trap an
adult red fox in a cage or a box trap;
however, kit and swift foxes can be
readily captured using this method.
Fig. 7. Properly set neck snare for foxes.
Snares made from 1/16-inch, 5/64inch, and 3/32-inch (0.15 cm, 0.2 cm,
and 0.25 cm) cable can be very effective for capturing both red and gray
foxes. Snares are generally set in trails
or in crawl holes (under fences) that
are frequented by foxes. The standard
loop size for foxes is about 6 inches (15
cm) with the bottom of the loop about
10 to 12 inches (25 to 30 cm) above
ground level (Fig. 7). Trails leading to
C-87
and from den sites and to carcasses
being fed on by foxes make excellent
locations for snares.
Shooting
Harvest of foxes by sport hunters and
fur trappers is another method of reducing fox populations in areas where
damage is occurring. Livestock and
poultry producers who have predation
problems during the late fall and winter can sometimes find private fur
trappers willing to hunt or trap foxes
around loss sites. Depredations are
usually most severe, however, during
the spring when furs are not saleable,
and it is difficult to interest private
trappers at that time.
Artificial rabbit distress calls can be
used to decoy foxes to within rifle or
shotgun range. Select a spot that faces
into the wind, at the edge of a clearing
or under a bush on a slight rise where
visibility is good. Blow the call at 1/2to 1-minute intervals, with each call
lasting 5 to 10 seconds. If a fox appears, remain motionless and do not
move the rifle or shotgun until ready
to shoot. If a fox does not appear in
about 20 minutes, move to a new spot
and call again.
Aerial hunting can be used in some
western states to remove problem
foxes. This activity is closely regulated
and is usually limited to USDAAPHIS-ADC personnel or individuals
with special permits from the state
regulatory agency.
Den Hunting
Fox depredations often increase during the spring whelping season.
Damage may be reduced or even
eliminated by locating and removing
the young foxes from the den. Locate
fox dens by observing signs of fox
activity and by careful observation
C-88
during the early and late hours of the
day when adult foxes are moving
about in search of food. Preferred denning sites are usually on a low rise
facing a southerly direction. When fox
pups are several weeks old, they will
spend time outside the den in the early
morning and evening hours. They
leave abundant signs of their presence,
such as matted vegetation and remnants of food, including bits of bone,
feathers, and hair. Frequently used
den sites have a distinctive odor.
Fox pups may be removed by trapping
or by fumigating the den with gas cartridges if they are registered for your
area. In some situations it may be
desirable to remove the pups without
killing them. The mechanical wire ferret has proved to be effective in chasing the pups from the den without
harming them. This device consists of
a long piece of smooth spring steel
wire with a spring and wooden plug at
one end and a handle at the other. This
wire is twisted through the den passageways, chasing foxes out of other
den openings where they can be captured by hand or with dip nets. Small
dogs are sometimes trained to retrieve
pups unharmed from dens. Wire-cage
box traps placed in the entrance of the
den can also be useful for capturing
young foxes.
Acknowledgments
We thank Norman C. Johnson, whose chapter
“Foxes” in the 1983 edition of this manual
provided much of the information used in this
section. F. Sherman Blom, Ronald A. Thompson,
and Judy Loven (USDA-APHIS-ADC) provided
useful comments.
Figure 1 from Schwartz and Schwartz (1981)
adapted by Jill Sack Johnson.
Figures 2, 3, and 4 courtesy of Pam Tinnin.
Figure 5 courtesy of Bob Noonan.
Figures 6 and 7 courtesy of Tom Krause.
For Additional
Information
Burt, W. H., and R. P. Grossenheider. 1976. A
field guide to mammals, 3d ed. Houghton
Mifflin Co., Boston. 289 pp.
Foreyt, W. J. 1980. A live trap for multiple
capture of coyote pups from dens. J. Wildl.
Manage. 44:487-88.
Fritzell, E. K., and K. J. Haroldson. 1982. Urocyon
cinereoargenteus. Mammal. Sp. 189:1-8.
Dolbeer, R. A., N. R. Holler, and D. W.
Hawthorne. 1994. Identification and control
of wildlife damage. Pages 474-506 in T. A.
Bookhout ed. Research and management
techniques for wildlife and habitats. The
Wildl. Soc., Bethesda, Maryland.
Krause, T. 1982. NTA trapping handbook — a
guide for better trapping. Spearman Publ.
and Printing Co., Sutton, Nebraska. 206 pp.
Samuel, D. E., and B. B. Nelson. 1982. Foxes.
Pages 475-90 in J. A. Chapman and G. A
Feldhamer eds., Wild mammals of North
America: biology, management, and
economics. The Johns Hopkins Univ. Press,
Baltimore, Maryland.
Schwartz, C. W., and E. R. Schwartz. 1981. The
wild mammals of Missouri, rev. ed. Univ.
Missouri Press, Columbia. 356 pp.
Storm, G. L., R. D. Andrews, R. L. Phillips, R. A.
Bishop, D. B. Siniff, and J. R. Tester. 1976.
Morphology, reproduction, dispersal and
mortality of midwestern red fox
populations. Wildl. Mono. No. 49. The Wildl.
Soc., Inc., Washington, DC. 82 pp.
Storm, G. L., and K. P. Dauphin. 1965. A wire
ferret for use in studies of foxes and skunks.
J. Wildl. Manage. 29:625-26.
Voigt, D. R. 1987. Red fox. Pages 379-93 in
M. Novak, J. A. Baker, M. E. Obbard, and
B. Malloch eds., Wildlife Furbearer
Management and Conservation in North
America. Ontario Ministry of Nat. Resour.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
Edward K. Boggess
MINK
Wildlife Program Manager
Minnesota Department of
Natural Resources
St. Paul, Minnesota 55155
Fig. 1. The mink, Mustela vison, is a semiaquatic
furbearer well known for its high-quality fur.
Identification
Toxicants, Fumigants, Repellents
Damage Prevention and
Control Methods
None are registered.
Trapping
Exclusion
Exclusion usually is the best solution
to mink predation on domestic
animals. Confine animals in fenced
areas. Seal all openings larger than 1
inch (2.5 cm).
Mink can be captured most easily in
leghold or Conibear®-type traps,
but live traps may work around
farmsteads.
Shooting
Habitat Modification
May not be legal.
Generally not feasible.
Normally difficult and impractical.
Frightening
No methods are effective.
The mink (Mustela vison, Fig. 1) is a
member of the weasel family. It is
about 18 to 24 inches (46 to 61 cm) in
length, including the somewhat bushy
5- to 7-inch (13- to 18-cm) tail, and
weighs 1 1/2 to 3 pounds (0.7 to 1.4
kg). Females are about three-fourths
the size of males. Both sexes are a rich
chocolate-brown color, usually with a
white patch on the chest or chin and
scattered white patches on the belly.
The fur is relatively short with the coat
consisting of a soft, dense underfur
concealed by glossy, lustrous guard
hairs. Mink also have anal musk
glands common to the weasel family
and can discharge a disagreeable musk
if frightened or disturbed. Unlike
skunks, however, they cannot forcibly
spray musk.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-89
Range and Habitat
Legal Status
Mink are found throughout North
America, with the exception of the desert
southwest and tundra areas (Fig. 2).
Mink are protected furbearers in most
states, with seasons established for taking them when their fur is prime. Most
states, however, have provisions for
landowners to control furbearers
which are damaging their property at
anytime of the year. Check with your
state wildlife agency before using any
lethal controls.
Mink are shoreline dwellers and their
one basic habitat requirement is a suitable permanent water area. This may
be a stream, river, pond, marsh,
swamp, or lake. Waters with good
populations of fish, frogs, and aquatic
invertebrates and with brushy or
grassy ungrazed shorelines provide
the best mink habitat. Mink use many
den sites in the course of their travels
and the availability of adequate den
sites is a very important habitat consideration. These may be muskrat
houses, bank burrows, holes, crevices,
log jams, or abandoned beaver lodges.
Food Habits
The mink is strictly carnivorous.
Because of its semiaquatic habits, it
obtains about as much food on land as
in water. Mink are opportunistic feeders with a diet that includes mice and
rats, frogs, fish, rabbits, crayfish,
muskrats, insects, birds, and eggs.
General Biology,
Reproduction, and
Behavior
Mink are polygamous and males may
fight ferociously for mates during the
breeding season, which occurs from
late January to late March. Gestation
varies from 40 to 75 days with an average of 51 days. Like most other members of the weasel family, mink exhibit
delayed implantation; the embryos do
not implant and begin completing their
development until approximately 30
days before birth. The single annual litter of about 3 to 6 young is born in late
April or early May and their eyes open
at about 3 weeks of age. The young are
born in a den which may be a bank
burrow, a muskrat house, a hole under
a log, or a rock crevice. The mink family stays together until late summer
when the young disperse. Mink
become sexually mature at about 10
months of age.
C-90
Fig. 2. Distribution of mink in North America.
Mink are active mainly at night and
are active year-round, except for brief
intervals during periods of low temperature or heavy snow. Then they
may hole up in a den for a day or
more. Male mink have large home
ranges and travel widely, sometimes
covering many miles (km) of shoreline.
Females have smaller ranges and tend
to be relatively sedentary during the
breeding season.
Damage and Damage
Identification
Mink may occasionally kill domestic
poultry around farms. They typically
kill their prey by biting them through
the skull or neck. Closely spaced pairs
of canine tooth marks are sign of a
mink kill.
Mink will attack animals up to the size
of a chicken, duck, rabbit, or muskrat.
While eating muskrats, a mink will
often make an opening in the back or
side of the neck and skin the animal by
pulling the head and body through the
hole as it feeds. Like some other members of the weasel family, mink occasionally exhibit “surplus killing”
behavior (killing much more than they
can possibly eat) when presented with
an abundance of food, such as in a
poultry house full of chickens. Mink
may place many dead chickens neatly
in a pile. Mink can eat significant numbers of upland nesting waterfowl or
game bird young, particularly in areas
where nesting habitat is limited.
Damage Prevention and
Control Methods
Mink damage usually is localized. If
needed, lethal controls can be directed
at the individual mink causing the
damage.
Exclusion
Usually the best solution to mink predation on domestic animals is to physically exclude their entry, sealing all
openings larger than 1 inch (2.5 cm)
with wood or tin and by using 1-inch
(2.5-cm) mesh poultry netting around
chicken yards and over ventilation
openings. Mink do not gnaw like
rodents, but they are able to use burrows or gnawed openings made by
rats.
Habitat Modification
Habitat modification generally is not a
feasible means of reducing mink predation problems on farms. If the objective is to increase natural production
of upland nesting wild birds, however,
habitat modification may be applicable. The best method of increasing
upland nesting success is usually to
increase the size and quality of cover
areas such as grasslands, legumes, or
set-aside areas. Although increasing
the density of nesting cover may
reduce nest predation by mink, it
could lead to an increase in nest predation by species which favor dense
cover, such as the Franklin ground
squirrel. Because mink frequently use
multiple den sites, elimination of
potential denning areas may reduce
their densities.
Frightening
There are no known frightening
devices that are effective for deterring
mink predation.
Repellents, Toxicants, and
Fumigants
There are no repellents, toxicants, or
fumigants registered for mink damage
control.
Trapping
Mink can most easily be captured in
leghold traps (No. 11 double longspring or No. 1 1/2 coilspring) or in
Conibear®-type body-gripping traps
equivalent to No. 120 traps. Mink are
suspicious of new objects and are
difficult to capture in live traps. Singledoor live traps may be effective if
baited and placed in dirt banks or rock
walls. Double-door live traps can be
effective in runways, particularly if the
trap doors are wired open and the trap
is left in place for some time before
activating the trap. Live traps may also
be effective around farmyards because
mink are more accustomed to encountering human-made objects in those
areas.
“Blind sets” are very effective for mink
if suitable locations can be found.
These sets do not require bait or lures
and are placed in areas along mink
travel lanes where the animals are
forced to travel in restricted areas (Fig.
3). Good sites for blind sets include
small culverts, tiles, narrow springs,
muskrat runs, and areas under overhanging banks or under the roots of
streamside trees (Fig. 4). If necessary,
the opening can be restricted with the
use of a few sticks or grass to direct the
mink over the trap.
Another good mink set is the “pocket
set” using bait (Fig. 5). This set is made
by digging a 3-inch (7.6-cm) diameter
hole horizontally back into a bank at
the water level. The bottom of the hole
should contain about 2 inches (5 cm) of
water, and it should extend back at
least 10 inches (25 cm) into the bank.
Place a bait (fresh fish, muskrat
carcass, or frog) in the back of the hole
above water level and place the trap
Fig. 3. An obstruction set catches a mink where it is traveling along the bank and is forced into the
water. Disturbance at the trap site should be kept to a minimum.
Fig. 4. The spring set catches the mink where a small feeder stream or tile outlet enters a larger stream
or impoundment.
Fig. 5. The pocket set is effective for mink. Bait or lure is placed in the back of the hole above the water
level. (Note: the stake is set off to one side and its top should be driven below the water line).
C-91
underwater at the opening of the hole.
Traps should be solidly staked and
connected to a drowning wire leading
to deep water.
Use live traps around a farmyard if
there is a high likelihood of catching
pets. Otherwise, leghold or Conibear®
traps can be used with or without bait
in runs or holes used by mink.
Shooting
Some states may have restrictions on
shooting mink, although many will
make exceptions in damage situations.
If a mink is raiding poultry and can be
caught in the act, shooting the animal
is a quick way to solve the problem.
Normally, though, it is difficult to
shoot mink because of their nocturnal
habits.
Economics of Damage
and Control
Although an individual incident of
mink predation can be costly, overall
the problem is not very significant to
agriculture. Mink damage control on a
case-by-case basis generally can be justified from a cost/benefit standpoint,
but large-scale control programs are
neither necessary nor desirable. Exclusion procedures may or may not be
economically justifiable, depending on
the severity of the problem and the
amount of repairs needed. Normally,
such costs can be justified for a recurring problem when amortized over the
life of the exclusion structures. Usually
damage from other predators and
rodents is reduced as well.
Mink are important semiaquatic carnivores in wetland wildlife communities,
and are also valuable as a fur resource.
About 400,000 to 700,000 wild mink
are harvested each year throughout
North America, for an annual income
exceeding $5 million. Therefore, all
lethal control should be limited to specific instances of documented damage.
C-92
Acknowledgments
Information for this section came from a variety
of published and unpublished sources.
Information on damage identification was
adapted from Dolbeer et al. (1994).
Figures 1 and 2 from Schwartz and Schwartz
(1981).
Figures 3, 4, and 5 by Michael D. Stickney, from
the New York Department of Environmental
Conservation publication, Trapping Furbearers,
Student Manual (1980), by R. Howard, L.
Berchielli, C. Parsons, and M. Brown. The
figures are copyrighted and are used with
permission.
For Additional
Information
Dolbeer, R. A., N. R. Holler, and D. W.
Hawthorne. 1994. Identification and control
of wildlife damage. Pages 474-506 in T. A.
Bookhout, ed. Research and management
techniques for wildlife and habitats. The
Wildl. Soc., Bethesda, Maryland.
Eagle, T. C., and J. S. Whitman. 1987. Mink.
Pages 614-625 in M. Novak, J. A. Baker, M. E.
Obbard, and B. Mallock, eds. Wild furbearer
management and conservation in North
America. Ontario Trappers Assoc. and
Ontario Ministry Nat. Resour.
Linscombe, C., N. Kinler, and R. J. Aukrich.
1982. Mink. Pages 629-643 in J. A. Chapman
and G. A. Feldhamer, eds. Wild mammals of
North America: biology, management, and
economics. The Johns Hopkins Univ. Press,
Baltimore, Maryland.
Schwartz, C. W., and E. R. Schwartz. 1981. The
wild mammals of Missouri. rev. ed. Univ.
Missouri Press, Columbia. 356 pp.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
James E. Knight
Extension Wildlife Specialist
Animal and Range Sciences
Montana State University
Bozeman, MT 59717
MOUNTAIN LIONS
Fig. 1. Mountain lion, Felis concolor
Damage Prevention and
Control Methods
Exclusion
Install heavy woven-wire or electric
fences to protect poultry and
domestic animals of high value.
Repellents
Shooting
None are registered.
Used in conjunction with predator kill
watching, or calling.
Toxicants
None are registered.
Fumigants
The use of hounds trained to trail and
tree lions is very effective.
None are registered.
Cultural Methods
Trapping
Remove brush and timber near farm
or ranch buildings.
Leghold traps sizes No. 4 and 4 1/2
Newhouse.
Frightening
Leghold snares.
Night lighting, blaring music, or
barking dogs may repel lions.
Other Methods
Snares.
Cage traps.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-93
Fig. 2. Range of the mountain lion in North
America.
Identification
The mountain lion (cougar, puma,
catamount, panther; Fig. 1) is the largest cat native to North America. The
head is relatively small, and the face is
short and rounded. The neck and body
are elongate and narrow. The legs are
very muscular and the hind legs are
considerably longer than the forelegs.
The tail is long, cylindrical, and wellhaired. The pelage of the mountain
lion varies considerably. There are two
major color phases — red and gray.
The red phase varies from buff, cinnamon, and tawny to a very reddish
color, while the gray phase varies from
silvery gray to bluish and slate gray.
The sides of the muzzle are black. The
upper lip, chin, and throat are whitish.
The tail is the same color as the body,
except for the tip, which is dark brown
or black. The young are yellowish
brown with irregular rows of black
spots. Male mountain lions are usually
considerably larger than females.
Adults range from 72 to 90 inches (183
to 229 cm) in total length including the
tail, which is 30 to 36 inches (76 to 91
cm) long. They weigh from 80 to 200
pounds (36 to 91 kg). The mountain
lion’s skull has 30 teeth. Female mountain lions have 8 mammae.
Range
The range of the mountain lion in
North America is shown in figure 2. Its
C-94
primary range occurs in western
Canada and in the western and southwestern United States. Sparse populations occur in the south, from Texas to
Florida. Several mountain lion
sightings have occurred in midwestern
and eastern states but populations are
not recognized.
running speeds for short distances and
are agile tree climbers. Generally solitary, they defend territories. Dominant
males commonly kill other males,
females, and cubs. A mountain lion’s
home range is usually 12 to 22 square
miles (31 to 57 km2), although it may
travel 75 to 100 miles (120 to 161 km)
from its place of birth.
Habitat
The mountain lion does not have a
definite breeding season, and mating
may take place at any time. In North
America there are records of births in
every month, although the majority of
births occur in late winter and early
spring. The female is in estrus for
approximately 9 days. After a gestation period of 90 to 96 days, 1 to 5
young (usually 3 or 4) are born. The
kittens can eat meat at 6 weeks
although they usually nurse until
about 3 months of age. The young usually hunt with their mother through
their first winter.
The mountain lion can be found in a
variety of habitats including coniferous
forests, wooded swamps, tropical forests, open grasslands, chaparral,
brushlands, and desert edges. They
apparently prefer rough, rocky,
semiopen areas, but show no particular preferences for vegetation types. In
general, mountain lion habitat corresponds with situations where deer
occur in large, rugged, and remote
areas.
Food Habits
Mountain lions are carnivorous. Their
diet varies according to habitat, season, and geographical region.
Although deer are their preferred prey
and are a primary component of their
diet, other prey will be taken when
deer are unavailable. Other prey range
from mice to moose, including rabbits,
hares, beaver, porcupines, skunks,
martens, coyotes, peccaries, bear cubs,
pronghorn, Rocky Mountain goats,
mountain sheep, elk, grouse, wild
turkeys, fish, occasionally domestic
livestock and pets, and even insects.
Mountain lions, like bobcats and lynx,
are sometimes cannibalistic.
Historically, the North American
mountain lion population was drastically reduced by the encroachment of
civilization and habitat destruction.
Some populations in the West are
growing rapidly. Local populations
may fluctuate in response to changes
in prey populations, particularly deer,
their primary food source.
The mountain lion is usually hunted as
a trophy animal with the aid of trail
and sight hounds. Pelts are used for
trophy mounts and rugs; claws and
teeth are used for jewelry and novelty
ornaments. The mountain lion is not
an important species in the fur trade.
In North America, it is primarily harvested in Arizona, New Mexico, Utah,
Colorado, Idaho, western Montana,
British Columbia, and Alberta.
General Biology,
Reproduction, and
Behavior
Damage and Damage
Identification
Mountain lions are shy, elusive, and
primarily nocturnal animals that occasionally are active during daylight
hours. For this reason they are seldom
observed, which leads the general public to believe that they are relatively
rare, even in areas where lion populations are high. They attain great
Mountain lions are predators on
sheep, goats, cattle, and horses. House
cats, dogs, pigs, and poultry are also
prey. Damage is often random and
unpredictable, but when it occurs, it
can consist of large numbers of livestock killed in short periods of time.
Cattle, horse, and burro losses are
often chronic in areas of high lion
populations. Lions are considered to
have negative impacts on several
bighorn sheep herds in New Mexico,
Arizona, Nevada, and Colorado.
In areas of low deer numbers, mountain lions may kill deer faster than deer
can reproduce, thus inhibiting deer
population growth. This usually
occurs only in situations where alternative prey keep lions in the area and
higher deer populations are not close
by.
Lions are opportunistic feeders on
larger prey, including adult elk and
cattle. Individual lions may remain
with a herd and prey on it consistently
for many weeks, causing significant
number reductions. Mountain lions
cause about 20% of the total livestock
predation losses in western states
annually. Historically, lion damage
was suffered by relatively few livestock producers who operate in areas
of excellent lion habitat and high lion
populations. This historic pattern has
changed in recent years, as lion distribution has spread, resulting in frequent sightings and occasional
damage in residential developments
adjacent to rangelands, montane forests, and other mountain lion habitat.
Predation typically is difficult to
manage although removal of the offending animals is possible if fresh kills
can be located.
Sheep, goats, calves, and deer are typically killed by a bite to the top of the
neck or head. Broken necks are common. Occasionally, mountain lions will
bite the throat and leave marks similar
to those of coyotes. The upper canine
teeth of a mountain lion, however, are
farther apart and considerably larger
than a coyote’s (1 1/2 to 2 1/4 inches
[3.8 to 5.7 cm] versus 1 1/8 to 1 3/8
inches [2.8 to 3.5 cm]). Claw marks are
often evident on the carcass. Mountain
lions tend to cover their kills with soil,
leaves, grass, and other debris. Long
scratch marks (more than 3 feet [1 m])
often emanate from a kill site. Occasionally, mountain lions drag their
prey to cover before feeding, leaving
well-defined drag marks.
Tracks of the mountain lion are generally hard to observe except in snow or
on sandy ground. The tracks are relatively round, and are about 4 inches
(10 cm) across. The three-lobed heel
pad is very distinctive and separates
the track from large dog or coyote
tracks. Claw marks will seldom show
in the lion track. Heel pad width
ranges from 2 to 3 inches (5 to 8 cm).
The tracks of the front foot are slightly
larger than those of the hind foot. The
four toes are somewhat teardrop
shaped and the rear pad has three
lobes on the posterior end.
Although uncommon, mountain lion
attacks on humans occasionally occur.
Fifty-three unprovoked mountain
attacks on humans were documented
in the US and Canada from 1890 to
1990. Nine attacks resulted in 10
human deaths. Most victims (64%)
were children who were either alone
or in groups of other children. Attacks
on humans have increased markedly
in the last two decades (see Beier
1991).
Legal Status
All of the western states except California allow the harvest of lions. They
are protected in all other states where
present. Generally, western states
manage mountain lions very conservatively as big game animals. Lion harvests are severely restricted by the
harvest methods allowed and by
quotas.
If mountain lion predation is suspected in states where lions are protected,
contact a local wildlife management
office for assistance. Most states allow
for the protection of livestock from
predators by landowners or their
agents when damage occurs or is
expected. Some states, however,
require that a special permit for the
control of mountain lions be obtained
or that the wildlife agency personnel
or their agent do the control work.
Several states have a damage claim
system that allows for recovery of the
value of livestock lost to mountain
lion predation.
Damage Prevention and
Control Methods
Exclusion
Heavy woven-wire fencing at least 10
feet (3 m) high is required to discourage lions. Overhead fencing is also
necessary for permanent and predictable protection. Fencing is practical
only for high-value livestock and
poultry. Night fencing under lights or
in sealed buildings is useful where
practical.
Electric fencing with alternating hot
and ground wires can effectively
exclude mountain lions. Wires should
be 10 feet (3 m) high, spaced 4 inches
(10 cm) apart, and charged with at
least 5,000 volts.
Cultural Methods
Mountain lions prefer to hunt and stay
where escape cover is close by. Removal of brush and trees within 1/4
mile (0.4 km) of buildings and livestock concentrations may result in reduced predation.
Chronic mountain lion predation has
led to some ranchers shifting from
sheep to cattle production. In areas
with high levels of predation, some
ranchers have changed from cow-calf
to steer operations.
Frightening
Bright lights, flashing white lights,
blaring music, barking dogs, and
changes in the placement of scarecrow
objects in livestock depredation areas
may temporarily repel mountain lions.
The Electronic Guard, a strobe light/
siren device developed by USDAAPHIS-ADC, may also deter lions.
Repellents
No chemical repellents are registered
for mountain lions.
Toxicants
No chemical toxicants are registered
for mountain lion control. Since lions
prefer to eat their own kills and fresh
untainted meats, an efficient delivery
system for toxicants has not been
developed.
C-95
rhodium, and house cat urine and
gland materials are effective attractants. Mountain lions are very curious
and respond to hanging and moving
flags of skin, feathers, or bright objects.
1" sifted dirt
Plastic pan cover
Leg Snares. Leg snares are effective
Trap jaw
No. 4 or 4 1/2 Newhouse trap
when set as described in the Black
Bears chapter, and as shown here in
figures 4, 5, and 6. Substitute leg snares
for the No. 4 or 4 1/2 leghold traps.
The Aldrich-type foot snare can be
used to catch mountain lions. This set
is made on trails frequented by lions;
stones or sticks are used to direct foot
placement over the triggering device.
Snares. Snares can be set to kill
mountain lions or hold them alive for
tranquilization. Commercially made
mountain lion snares are available
from Gregerson Manufacturing (see
Supplies and Materials). They should
be suspended in lion runways and
trails (Fig. 7), or set with baits in cubby
arrangements (Figs. 8 and 9).
Stake 24" to 36"
Fig. 3. Bedded trap
No. 9 wire attachment to large drag
200 -pound rock, log, or tree
Lion-killed horse
Kill snares should be placed with the
bottom of the loop approximately 16
inches (40 cm) above the ground with
a loop diameter of 12 to 16 inches (30
to 41 cm). Snares intended to capture
lions alive should be placed with the
bottom of the loop 14 inches (36 cm)
from the ground and a loop diameter
of 18 to 20 inches (46 to 51 cm). Snares
set for live capture should be checked
daily from a distance.
Cage Traps. Large, portable cage
No. 4 1/2 Newhouse trap
Fig. 4. Trap set at mountain lion kill.
Fumigants
No chemical fumigants are registered
for use on lions.
Trapping
Leghold Traps. Mountain lions are
extremely strong and require very
strong traps. Well-bedded Newhouse
traps in size No. 4 or 4 1/2 are recommended (Fig 3). Recommended sets
are shown in figures 3 and 4. Use large
C-96
heavy drags, sturdy stakes, or substantial trees, posts, or rocks to anchor
traps to ensure against escape.
Mountain lions are easily trapped
along habitual travel ways, in areas
of depredations, and at kill sites.
Although blind sets are usually made
in narrow paths frequented by lions,
baits made of fish products, poultry,
porcupine, rabbits, or deer parts, as
well as curiosity lures like catnip, oil of
traps are used by USDA-APHIS-ADC
personnel in California to capture
moutain lions that kill pets and livestock in suburban areas and on small
rural holdings. The traps are constructed of 4-foot (120-cm) wide, 4-foot
(120-cm) high, 10-foot (3-m) long
welded-wire stock panels with 2 x
4-inch (5 x 10-cm) grid. The trap is
placed where the mountain lion left
the kill, and it is baited with the
remains of the kill. See Shuler (1992)
for details on this method.
Shooting
Mountain lions sometimes return to a
fresh kill to feed and can be shot from
ambush when they do so. Locate an
ambush site where the shooter cannot
be seen and the wind carries the
shooter’s odor away from the direction
that the cat will use to approach the
kill site. Set up at least 50 yards (45 m)
from the kill site. Calibers from .222
Remington and larger are recommended. Mountain lions can be called
into shooting range with predator
calls, particularly sounds that simulate
the distress cry of a doe deer. See Blair
(1981) for additional information on
calling lions.
Pie tin nailed on tree over catnip-vaseline
soaked cloth
Other Methods
Lion trail
No. 4 1/2
trap
Guide stick
Fig. 5. Lion catnip set
Chain or cable
Swivel
Guide stones
Snare with lock
Lion trail
Stepping stick
Coffee or juice can
buried in soil
Snare laid on tinfoil
or heavy paper
Tinfoil cover with an X cut
in surface
Buried coffee can
Fig. 6. Lion-trail leg-snare set
Trained dogs can be used to capture or
kill depredating lions. The dogs are
most often released at the kill site,
where they pick up the lion’s scent and
track the lion until it is cornered or
climbs a tree. The lion can then be shot
and removed, or tranquilized and
transplanted at least 300 miles (480
km) away. Transplanting of lions is not
recommended unless they are moved
to an area where no present lion population exists, where habitat and
weather are similar to those of the
original area, and where there will be
no problem of potential depredation
by the translocated lions. Placing a
mountain lion in an area with which it
is unfamiliar reduces its chance of survival and is likely to disrupt the social
hierarchy that exists there. Lions from
a distant area may transmit a disease
or contaminate a gene pool that has
been maintained through a natural selection process for population survival
in a specific area. In addition, depredating lions are likely to cause depredation problems in the area to which
they are transplanted.
Hunting of mountain lions as big game
animals should be encouraged in areas
of predation to lower the competition
for native food sources. To reduce or
eliminate future losses, quick action
should be taken as soon as predation is
discovered.
Economics of Damage
and Control
Verifying livestock losses to mountain
lions is difficult because of the rough
mountainous terrain and vegetation
cover present where most lion
C-97
predation occurs. Many losses occur
that are never confirmed. Generally,
lion predation is responsible for only a
small fraction of total predation losses
suffered by ranchers, but individual
ranchers may suffer serious losses.
Wrap wire in brush to obtain the
proper height of snare loop.
Clamp 14-gauge wire on snare cable here.
Bend snare cable here.
Don’t let any brush touch the snare loop.
The bottom of the snare loop should be 16
to 18 inches above the ground with loop
diameter of 12 to 16 inches.
In Nevada, it was estimated that
annual losses of range sheep to
mountain lions averaged only 0.29%
(Shuminski 1982). These losses, however, were not evenly distributed
among ranchers. Fifty-nine sheep
(mostly lambs) were killed in one
incidence. The mountain lion involved
apparently killed 112 sheep in the area
before it was captured.
In states such as Colorado and Wyoming, where damages are paid for lion
predation, contact the state wildlife
agency for information about the
claims process and paperwork. Most
systems require immediate reporting
and verification of losses before
payments are made.
Lion trail
No. 9 wire
Fig. 7. Kill snare set
Rock overhang
Bait
Cubby sides
Guide stick
Fig. 8. Rock cubby snare set
C-98
Snare
Rock, stake, or drag
Bait
Woven-wire pen
4'
8' to 10'
Cover with grass, branches, brush
24" to 36" stake
Fig. 9. Woven-wire pen set (snare)
Acknowledgments
Much of this information was prepared by M. L.
Boddicker in “Mountain Lions,” Prevention and
Control of Wildlife Damage (1983).
I thank Keith Gregerson for use of the snare
suspension and anchoring diagram and the
Colorado Trapper’s Association for use of
diagrams of lion sets from its book (Boddicker
1980). Sections on identification, habitat, food
habits, and general biology are adapted from
Deems and Pursley (1983).
Figures 1 and 2 from Schwartz and Schwartz
(1981), adapted by Jill Sack Johnson.
Figures 3, 4, 5, and 6 from Boddicker (1980).
Figure 7 courtesy of Gregerson Manufacturing
Co., adapted by Jill Sack Johnson.
Figures 8 and 9 by Boddicker, adapted by Jill
Sack Johnson.
For Additional
Information
Paradiso, J. L. 1972. Status report on cats
(Felidae) of the world, 1971. US Fish Wildl.
Serv., Special Sci. Rep., Wildl. No. 157. 43 pp.
Beier, P. 1991. Cougar attacks on humans in the
United States and Canada. Wildl. Soc. Bull.
19:403-412.
Robinette, W. L., J. S. Gashwiler, and O. W.
Morris. 1959. Food habits of the cougar in
Utah and Nevada. J. Wildl. Manage. 23:261273.
Blair, G. 1981. Predator caller’s companion.
Winchester Press, Tulsa, Oklahoma. 267 pp.
Boddicker, M. L., ed. 1980. Managing rocky
mountain furbearers. Colorado Trappers
Assoc., LaPorte, Colorado. 176 pp.
Bowns, J. E. 1985. Predation-depredation. Pages
204-205 in J. Roberson and F. G. Lindzey, eds.
Proc. Mountain Lion Workshop, Salt Lake
City, Utah.
Deems, E. F. and D. Pursley, eds. 1983. North
American furbearers: a contemporary
reference. Int. Assoc. Fish Wildl. Agencies
and the Maryland Dep. Nat. Resour.,
Annapolis. 223 pp.
Hornocker, M. G. 1970. An analysis of mountain
lion predation upon mule deer and elk in the
Idaho primitive area. Wildl. Monogr. 21. 39
pp.
Hornocker, M. G. 1976. Biology and life history.
Pages 38-91 in G. C. Christensen and R. J.
Fischer, eds. Trans. mountain lion workshop,
Sparks, Nevada.
Lindzey, F. G. 1987. Mountain lion. Pages 657668 in M. Novak, J. A. Baker, M. E. Obbard,
and B. Malloch. Wild furbearer management
and conservation in North America. Minist.
Nat. Resour., Toronto, Ontario.
Schwartz, C. W. and E. R. Schwartz. 1981. The
wild mammals of Missouri. rev. ed. Univ.
Missouri Press, Columbia. 356 pp.
Sealander, J. A., and P. S. Gipson. 1973. Status of
the mountain lion in Arkansas, Proc.
Arkansas Acad. Sci. 27:38-41.
Sealander, J. A., M. G. Hornocker, W. V. Wiles,
and J. P. Messick. 1973. Mountain lion social
organization in the Idaho primitive area.
Wildl. Mono. 35:1-60.
Shaw, H. 1976. Depredation. Pages 145-176 in G.
C. Christensen and R. J. Fischer, eds. Trans.
mountain lion workshop, Sparks, Nevada.
Shuler, J. D. 1992. A cage trap for live-trapping
mountain lions. Proc. Vertebr. Pest Conf.
15:368-370.
Shuminski, H. R. 1982. Mountain lion predation
on domestic livestock in Nevada. Proc.
Vertebr. Pest Conf. 10:62-66.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
C-99
C-100
Edward K. Boggess
RACCOONS
Wildlife Program Manager
Minnesota Department of
Natural Resources
St. Paul, Minnesota 55155
Fig. 1. The distinctively marked raccoon
(Procyon lotor) is usually found in association
with water.
Damage Prevention and
Control Methods
Repellents, Toxicants, and
Fumigants
Identification
None are registered.
The raccoon (Procyon lotor), also called
“coon,” is a stocky mammal about 2 to
3 feet (61 to 91 cm) long, weighing 10
to 30 pounds (4.5 to 13.5 kg) (rarely 40
to 50 pounds [18 to 22.5 kg]). It is distinctively marked, with a prominent
black “mask” over the eyes and a
heavily furred, ringed tail (Fig. 1). The
animal is a grizzled salt-and-pepper
gray and black above, although some
individuals are strongly washed with
yellow. Raccoons from the prairie
areas of the western Great Plains are
paler in color than those from eastern
portions of the region.
Exclusion
Trapping
Usually the best method for coping
with almost all types of raccoon
damage.
Cage traps, body-gripping, and
foothold traps are very effective,
especially in conjunction with
exclusion and/or habitat
modification.
Habitat Modification
Remove obvious sources of food or
shelter around the premises; usually
not practical as a sole method of
controlling damage.
Frightening
Several methods may be effective, but
only for a short time.
Shooting
Can be very effective, particularly if
trained hounds are used to tree the
raccoons. Local regulations may
apply.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-101
birds and waterfowl. Contrary to
popular myth, raccoons do not always
wash their food before eating, although they frequently play with their
food in water.
Fig. 2. Distribution of the raccoon in North
America.
Range
The raccoon is found throughout the
United States, with the exception of
the higher elevations of mountainous
regions and some areas of the arid
Southwest (Fig. 2). Raccoons are more
common in the wooded eastern portions of the United States than in the
more arid western plains.
Habitat
Raccoons prefer hardwood forest
areas near water. Although commonly
found in association with water and
trees, raccoons occur in many areas of
the western United States around
farmsteads and livestock watering
areas, far from naturally occurring
bodies of permanent water. Raccoons
den in hollow trees, ground burrows,
brush piles, muskrat houses, barns and
abandoned buildings, dense clumps of
cattail, haystacks, or rock crevices.
Raccoons breed mainly in February or
March, but matings may occur from
December through June, depending on
latitude. The gestation period is about
63 days. Most litters are born in April
or May but some late-breeding females
may not give birth until June, July, or
August. Only 1 litter of young is raised
per year. Average litter size is 3 to 5.
The young first open their eyes at
about 3 weeks of age. Young raccoons
are weaned sometime between 2 and 4
months of age.
Raccoons are nocturnal. Adult males
occupy areas of about 3 to 20 square
miles (8 to 52 km2), compared to about
1 to 6 square miles (3 to 16 km2) for
females. Adult males tend to be territorial and their ranges overlap very little.
Raccoons do not truly hibernate, but
they do “hole up” in dens and become
inactive during severe winter weather.
In the southern United States they may
be inactive for only a day or two at a
time, whereas in the north this period
of inactivity may extend for weeks or
months. In northern areas, raccoons
may lose up to half their fall body
weight during winter as they utilize
stored body fat.
Raccoon populations consist of a high
proportion of young animals, with
one-half to three-fourths of fall populations normally composed of animals
less than 1 year in age. Raccoons may
live as long as 12 years in the wild, but
such animals are extremely rare. Usu-
General Biology,
Reproduction, and
Behavior
C-102
Family groups of raccoons usually
remain together for the first year and
the young will often den for the winter
with the adult female. The family
gradually separates during the following spring and the young become
independent.
Damage and Damage
Identification
Raccoons may cause damage or nuisance problems in a variety of ways,
and their distinctive tracks (Fig. 3)
often provide evidence of their
involvement in damage situations.
Raccoons occasionally kill poultry and
leave distinctive signs. The heads of
adult birds are usually bitten off and
left some distance from the body. The
crop and breast may be torn and
chewed, the entrails sometimes eaten,
and bits of flesh left near water. Young
poultry in pens or cages may be killed
or injured by raccoons reaching
through the wire and attempting to
pull the birds back through the mesh.
Legs or feet of the young birds may be
missing. Eggs may be removed completely from nests or eaten on the spot
with only the heavily cracked shell remaining. The lines of fracture will normally be along the long axis of the egg,
and the nest materials are often
disturbed. Raccoons can also destroy
bird nests in artificial nesting structures such as bluebird and wood duck
nest boxes.
6"
Walking
Raccoons are omnivorous, eating both
plant and animal foods. Plant foods include all types of fruits, berries, nuts,
acorns, corn, and other types of grain.
Animal foods are crayfish, clams, fish,
frogs, snails, insects, turtles and their
eggs, mice, rabbits, muskrats, and the
eggs and young of ground-nesting
ally less than half of the females will
breed the year after their birth,
whereas most adult females normally
breed every year.
Front foot
Hind foot
Fig. 3. The five long rear toes and the “handlike” front print are characteristic of raccoon
tracks. Except in soft mud or sand, the “heel” of
the hind foot seldom shows.
4 1/4"
Raccoons can cause considerable damage to garden or truck crops, particularly sweet corn. Raccoon damage to
sweet corn is characterized by many
partially eaten ears with the husks
pulled back. Stalks may also be broken
as raccoons climb to get at the ears.
Raccoons damage watermelons by
digging a small hole in the melon and
then raking out the contents with a
front paw.
Raccoons cause damage or nuisance
problems around houses and outbuildings when they seek to gain entrance
to attics or chimneys or when they raid
garbage in search of food. In many urban or suburban areas, raccoons are
learning that uncapped chimneys
make very adequate substitutes for
more traditional hollow trees for use
as denning sites, particularly in spring.
In extreme cases, raccoons may tear off
shingles or facia boards in order to
gain access to an attic or wall space.
Raccoons also can be a considerable
nuisance when they roll up freshly laid
sod in search of earthworms and
grubs. They may return repeatedly
and roll up extensive areas of sod on
successive nights. This behavior is particularly common in mid- to late summer as young raccoons are learning to
forage for themselves, and during
periods of dry weather when other
food sources may be less available.
The incidence of reported rabies in raccoons and other wildlife has increased
dramatically over the past 30 years.
Raccoons have recently been identified
as the major wildlife host of rabies in
the United States, primarily due to
increased prevalence in the eastern
United States.
Legal Status
Raccoons are protected furbearers in
most states, with seasons established
for running, hunting, or trapping.
Most states, however, have provisions
for landowners to control furbearers
that are damaging their property.
Check with your state wildlife agency
before using any lethal controls.
6"
6"
Fig. 4. Electric fencing can be very effective at excluding raccoons from sweet corn or other crops.
Two wires are recommended, but one wire 6 inches above the ground may be sufficient. Electric
fence chargers are available at farm supply dealers. The fence can be activated at dusk and turned
off after daybreak.
Damage Prevention and
Control Methods
Exclusion
Exclusion, if feasible, is usually the
best method of coping with raccoon
damage.
Poultry damage generally can be prevented by excluding the raccoons with
tightly covered doors and windows on
buildings or mesh-wire fences with an
overhang surrounding poultry yards.
Raccoons are excellent climbers and
are capable of gaining access by climbing conventional fences or by using
overhanging limbs to bypass the fence.
A “hot wire” from an electric fence
charger at the top of the fence will
greatly increase the effectiveness of a
fence for excluding raccoons.
Damage to sweet corn or watermelons
can most effectively be stopped by
excluding raccoons with a single or
double hot-wire arrangement (Fig. 4).
The fence should be turned on in the
evening before dusk, and turned off
after daybreak. Electric fences should
be used with care and appropriate caution signs installed. Wrapping filament
tape around ripening ears of corn (Fig.
5) or placing plastic bags over the ears
is an effective method of reducing raccoon damage to sweet corn. In general,
tape or fencing is more effective than
bagging. When using tape, it is important to apply the type with glass-yarn
filaments embedded within so that the
C-103
raccoons cannot tear through the tape.
Taping is more labor-intensive than
fencing, but may be more practical and
acceptable for small backyard gardens.
Store garbage in metal or tough plastic
containers with tight-fitting lids to
discourage raccoons from raiding
garbage cans. If lids do not fit tightly, it
may be necessary to wire, weight, or
clamp them down to prevent raccoons
from lifting the lid to get at garbage.
Secure cans to a rack or tie them to a
support to prevent raccoons from tipping them over.
Fig. 5. Wrapping a ripening ear of sweet corn
with reinforced filament tape as shown can
reduce raccoon damage by 70% to 80%. It is
important that each loop of the tape be wrapped
over itself so that it forms a closed loop that
cannot be ripped open by the raccoon.
Prevent raccoon access to chimneys by
securely fastening a commercial cap of
sheet metal and heavy screen over the
top of the chimney (Fig. 6). Raccoon
access to rooftops can be limited by
removing overhanging branches and
by wrapping and nailing sheets of slick
metal at least 3 feet (90 cm) square
around corners of buildings. This prevents raccoons from being able to get a
toehold for climbing (Fig. 7). While this
method may be practical for outbuildings, it is unsightly and generally
unacceptable for homes. It is more
practical to cover chimneys or other
areas attracting raccoons to the rooftop
or to remove the offending individual
animals than to completely exclude
them from the roof.
Homeowners attempting to exclude or
remove raccoons in the spring and
summer should be aware of the possibility that young may also be present.
Fig. 6. A cap or exclusion device will keep
raccoons and other animals out of chimneys.
These are available commercially and should be
made of heavy material. Tightly clamp or fasten
them to chimneys to prevent raccoons from
pulling or tearing them off.
C-104
Do not complete exclusion procedures
until you are certain that all raccoons
have been removed from or have left
the exclusion area. Raccoons frequently will use uncapped chimneys
as natal den sites, raising the young on
the smoke shelf or the top of the fireplace box until weaning. Homeowners
with the patience to wait out several
weeks of scratching, rustling, and
chirring sounds will normally be
rewarded by the mother raccoon
moving the young from the chimney at
the time she begins to wean them.
Homeowners with less patience can
often contact a pest removal or chimney sweep service to physically
remove the raccoons. In either case,
raccoon exclusion procedures should
be completed immediately after the
animals have left or been removed.
Habitat Modification
There are no practical means of modifying habitat to reduce raccoon depredations, other than removing any
obvious sources of food or shelter
which may be attracting the raccoons
to the premises. Raccoons forage over
wide areas, and anything other than
local habitat modification to reduce
raccoon numbers is not a desirable
technique for reducing damage.
Raccoons sometimes will roll up
freshly laid sod in search of worms or
grubs. If sodded areas are not extensive, it may be possible to pin the rolls
Fig. 7. Raccoon access to rooftops can be
eliminated by pruning back overhanging limbs
and tacking slick sheets of metal at least 3 feet
square around corners of buildings.
down with long wire pins, wooden
stakes, or nylon netting until the grass
can take root, especially if the damage
is restricted to only a portion of the
yard, such as a shaded area where the
grass is slower to take root. In more
rural areas, use of electric fences may
be effective (see section on exclusion).
Because the sod-turning behavior is
most prevalent in mid- to late summer
when family groups of raccoons are
learning to forage, homeowners may
be able to avoid problems by having
the sod installed in spring or early
summer. In most cases, however,
removal of the problem raccoons is
usually necessary.
Fig. 8. A cage-type live trap, although bulky and
expensive, is often the best choice for removing
raccoons near houses or buildings where there is
a likelihood of capturing dogs or cats.
Frightening
Although several techniques have
been used to frighten away raccoons,
particularly in sweet corn patches,
none has been proven to be effective
over a long period of time. These techniques have included the use of lights,
radios, dogs, scarecrows, plastic or
cloth streamers, aluminum pie pans,
tin can lids, and plastic windmills. All
of these may have some temporary
effectiveness in deterring raccoons, but
none will provide adequate long-term
protection in most situations.
Repellents, Toxicants, and
Fumigants
There are no repellents, toxicants, or
fumigants currently registered for
raccoon control.
Trapping
Raccoons are relatively easy to catch in
traps, but it takes a sturdy trap to hold
one. For homeowners with pets, a live
or cage-type trap (Fig. 8) is usually the
preferable alternative to a leghold trap.
Traps should be at least 10 x 12 x 32
inches (25.4 x 30.5 x 81.3 cm) and wellconstructed with heavy materials.
They can be baited with canned fishflavored cat food, sardines, fish, or
chicken. Place a pile of bait behind the
treadle and scatter a few small bits of
bait outside the opening of the trap
and just inside the entrance. Traps
with a single door should be placed
with the back against a wall, tree, or
other object. The back portion of the
trap should be tightly screened with
one-half inch (1.3 cm) or smaller mesh
wire to prevent raccoons from reaching through the wire to pull out the
bait.
Conibear®-type body-gripping traps
are effective for raccoons and can be
used in natural or artificial cubbies or
boxes. Because these traps do not allow for selective release of nontarget
catches, they should not be used in areas where risk of nontarget capture is
high. Box or leghold traps should be
used in those situations instead. It is
possible, however, to use body-gripping traps in boxes or on leaning poles
so that they are inaccessible to dogs
(Figs. 9 and 10). Check local state laws
for restrictions regarding use of
Conibear®-type traps out of water.
Raccoons also can be captured in foothold traps. Use a No. 1 or No. 1 1/2
coilspring or stoploss trap fastened to
a drag such as a tree limb 6 to 8 feet
(1.8 to 2.4 m) long. For water sets, use
a drowning wire that leads to deep
water. The D-P trap and Egg trap are
new foot-holding devices that are
highly selective, dog-proof, and show
promise for reducing trap-related
injury. They are available from trapping supply outlets.
Fig. 9. A “raccoon box” is suspended 6 inches
above the ground and is equipped with a
Conibear®-type trap. Suspended at this level,
this set is dog-proof.
The “pocket set” is very effective for
raccoons, and is made along the
water’s edge where at least a slight
bank is present (Fig. 11). Dig a hole
C-105
Fig. 10. The leaning-pole set for raccoons is another dog-proof set. The trigger should
be on top to prevent the trap from being sprung by squirrels or chipmunks. Bait
should be beyond the trap and covered so that it cannot be seen by birds. The set is
more effective if a few drops of fish oil or other lure are placed along the pole from
the ground level up to the trap.
3 to 6 inches (7.6 to 15.2 cm) in diameter horizontally back into the bank at
least 10 to 12 inches (25.4 to 30.5 cm).
The bottom 2 inches (5.1 cm) of the
hole should be below the water level.
Place a bait or lure (fish, frog, anise oil,
honey) in the back of the hole, above
the water level. Set the trap (a No. 1 or
1 1/2 coilspring, doublejaw or stoploss
is recommended) below the water
level in front of or just inside the opening. The trap should be tied to a movable drag or attached with a one-way
slide to a drowning wire leading to
deep water.
Dirt-hole sets (Fig. 12) are effective for
raccoons. Place a bait or lure in a small
hole and conceal the trap under a light
covering of soil in front of the hole. A
No. 1 or 1 1/2 coilspring trap is recommended for this set. It is important to
use a small piece of clean cloth, light
plastic, or a wad of dry grass to
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To deep
water
Fig. 11. The pocket set is very effective for raccoons and mink. Place a bait in the back of the hole
above the water level and attach the trap to a one-way slide on a drowning wire leading to deep
water, or to a movable drag such as a large rock or a section of tree limb 5 to 6 feet long and 3 to 5
inches in diameter.
Dirt-hole Set
Sifted soil
Trap
Bait
Acknowledgments
Although information for this section came from
a variety of sources, I am particularly indebted
to Eric Fritzell of the University of Missouri,
who provided a great deal of recently published
and unpublished information on raccoons in the
central United States. Information on damage
identification was adapted from Dolbeer et al.
1994.
Figures 1 through 3 from Schwartz and
Schwartz (1981).
Stake
Figures 4, 6, and 7 by Jill Sack Johnson.
Figure 5 from Conover (1987).
Bait hole
6" deep
Figures 8, 9, and 10 by Michael D. Stickney, from
the New York Department of Environmental
Conservation publication Trapping Furbearers,
Student Manual (1980), by R. Howard, L.
Berchielli, G. Parsons, and M. Brown. The
figures are copyrighted and are used with
permission.
Excavated
2" to 3" deep
Set before covering
Completed set
Fig. 12. The dirt-hole set is effective for all species of terrestrial furbearers, including raccoons. The
bait is placed in the hole and should be lightly covered with soil so that it is not visible.
prevent soil from getting under the
round pan of the trap and keeping it
from going down. If this precaution is
not taken, the trap may not go off.
Shooting
Raccoons are seldom seen during the
day because of their nocturnal habits.
Shooting raccoons can be effective at
night with proper lighting. Trained
dogs can be used to tree the raccoons
first. A .22-caliber rifle will effectively
kill treed raccoons.
Many states have restrictions on the
use of artificial light to spot and shoot
raccoons at night, and shooting is prohibited in most towns and cities. It is
advisable to check with state and local
authorities before using any lethal controls for raccoons.
Economics of Damage
and Control
Statistics are unavailable on the
amount of economic damage caused
by raccoons, but the damage may be
offset by their positive economic and
aesthetic values. In 1982 to 1983, raccoons were by far the most valuable
furbearer to hunters and trappers in
the United States; an estimated 4.8 million raccoons worth $88 million were
harvested. Raccoons also provide recreation for hunters, trappers, and
people who enjoy watching them.
Although raccoon damage and nuisance problems can be locally severe,
widespread raccoon control programs
are not justifiable, except perhaps to
prevent the spread of raccoon rabies.
From a cost-benefit and ecological
standpoint, prevention practices and
specific control of problem individuals
or localized populations are the most
desirable alternatives.
Figure 11 by J. Tom Parker, from Trapping
Furbearers: Managing and Using a Renewable
Natural Resource, a Cornell University
publication by R. Howard and J. Kelly (1976).
Used with permission.
Figure 12 adapted from Controlling Problem Red
Fox by F. R. Henderson (1973), Cooperative
Extension Service, Kansas State University,
Manhattan.
For Additional
Information
Conover, M. R. 1987. Reducing raccoon and bird
damage to small corn plots. Wildl. Soc. Bull.
15:268-272.
Dolbeer, R. A., N. R. Holler, and D. W.
Hawthorne. 1994. Identification and control
of wildlife damage. Pages 474-506 in T. A.
Bookhout, ed. Research and management
techniques for wildlife and habitats. The
Wildl. Soc. Bethesda, Maryland.
Kaufmann, J. H. 1982. Raccoon and allies. Pages
567-585 in J. A. Chapman and G. A.
Feldhamer, eds. Wild mammals of North
America: biology, management and
economics. The Johns Hopkins Univ. Press,
Baltimore, Maryland.
Schwartz, C. W., and E. R. Schwartz. 1981. The
wild mammals of Missouri, rev. ed. Univ.
Missouri Press, Columbia. 356 pp.
Sanderson, G. C. 1987. Raccoon. Pages 486-499
in M. Novak, J. A. Baker, M. E. Obbard, and
B. Malloch, eds. Wild furbearer management
and conservation in North America. Ontario
Trappers Assoc., North Bay.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
C-107
C-108
Edward P. Hill
Chief, Bird Control Research Section
Denver Wildlife Research Center
USDA-APHIS-ADC
Denver, Colorado 80225
RIVER OTTERS
Fig. 1. The North American river otter, Lutra
canadensis
Damage Prevention and
Control Methods
Exclusion
Fence small raceways, tanks, or ponds
with 3 x 3-inch (7.6 x 7.6-cm) mesh
wire.
Repellents
None are registered.
Toxicants
None are registered.
Fumigants
None are registered.
Trapping
Use Conibear® traps (Nos. 220 and
330), foothold traps (No. 2), and
snares to control river otters in
damage situations.
For restocking purposes, river otters
can be caught in live traps, modified
No. 1 1/2 soft-catch traps, and No.
11 longspring traps.
Shooting
If nonlethal approaches cannot be employed, shooting with shotgun or
small-caliber rifle can be effective in
damage situations that involve only
one or two otters.
Identification
River otters (Lutra canadensis, Fig. 1)
are best known for their continuous
and playful behavior, their aesthetic
value, and the value of their durable,
high-quality fur. They have long,
streamlined bodies, short legs, and a
robust, tapered tail, all of which are
well adapted to their mostly aquatic
habitat. They have prominent whiskers
just behind and below the nose, thick
muscular necks and shoulders, and
feet that are webbed between the toes.
Their short but thick, soft fur is brown
to almost black except on the chin,
throat, cheeks, chest, and occasionally
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-109
Fig. 2. Distribution of the river otter in North
America.
the belly, where it is usually lighter,
varying from brown to almost beige.
Adult males usually attain lengths of
nearly 48 inches (122 cm) and weights
of about 25 pounds (11.3 kg), but may
reach 54 inches (137 cm) and 33
pounds (15 kg). Their sex can be
readily distinguished by the presence
of a baculum (penile bone). Females
have 4 mammae on the upper chest
and are slightly smaller than males.
Female adults measure about 44 inches
(112 cm) and weigh 19 pounds (8.6 kg).
The mean weights and sizes of river
otters in southern latitudes tend to be
lower than those in latitudes farther
north.
Range and Habitat
River otters occur throughout North
America except the arctic slopes, the
arid portions of the Southwest, and the
intensive agricultural and industrialized areas of the midwestern United
States (Fig. 2). Their precolonial range
apparently included all of North
America except the arid Southwest
and the northernmost portions of
Alaska and Canada. Otter populations
are confined to water courses, lakes,
and wetlands, and therefore, population densities are lower than those of
terrestrial species. Their extirpation
from many areas is believed to have
been related more to poisoning by pesticides bio-magnified in fishes, and to
the indirect adverse effects of water
pollution on fish, their main food, than
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to excessive harvest. The loss of ponds
and other wetland habitat that resulted
from the extirpation of beaver in the
late 1800s may have adversely affected
continental populations of river otters
more than any other factor. Increases
in the range and numbers of river
otters in response to the return of beaver has been dramatic, particularly in
the southeastern United States. Recent
releases totaling more than 1,000 otters
have been made in Arizona, Colorado,
Iowa, Kansas, Kentucky, Missouri,
Nebraska, Oklahoma, Pennsylvania,
Tennessee, and West Virginia in efforts
to reestablish local populations.
River otters are almost invariably associated with water (fresh, brackish, and
salt water), although they may travel
overland for considerable distances.
They inhabit lakes, rivers, streams,
bays, estuaries, and associated riparian
habitats. They occur at much higher
densities in regions of the Great Lakes,
in brackish marshes and inlets, and in
other coastal habitats than farther
inland. In colder climates, otters frequent rapids and waterfall areas that
remain ice-free. Vegetative cover and
altitude do not appear to influence the
river otter’s distribution as much as do
good or adequate water quality, the
availability of forage fish, and suitable
denning sites.
Food Habits
The diet of the river otter throughout
its range is primarily fish. Numerous
species and varieties of fresh and
anadromous fishes are eaten, but shellfish, crayfish, amphibians, and reptiles
are also frequently eaten, as are several
species of crabs in coastal marshes.
Mammals and birds are rarely eaten.
Consumption of game fishes in comparison to nongame (rough) fishes is
generally in proportion to the difficulty, or ease, with which they can be
caught. Because of the availability of
abundant alternate food species in
warm water, losses of the warm water
sport fishes are believed minor compared to losses river otters can inflict
on cold water species such as trout
and salmon.
General Biology,
Reproduction, and
Behavior
The reproductive biology of river
otters and all other weasels is complex
because of a characteristic known as
delayed implantation. Following
breeding and fertilization in spring,
eggs (blastocysts) exist in a freefloating state until the following winter
or early spring. Once they implant,
fetal growth lasts 60 to 65 days until
the kits are born, usually in spring
(March through May) in most areas. In
the southern portion of the range the
dates of birth occur earlier, mostly in
January and February, implying
implantation in November and
December. Litters usually contain 2 to
4 kits, and the female alone cares for
the young. They usually remain
together as a family group though the
fall and into the winter months. Sexual
maturity in young is believed to occur
at about 2 years of age in females, but
later in males.
River otters are chiefly nocturnal, but
they frequently are active during daylight hours in undisturbed areas.
Socially, the basic group is the female
and her offspring. They spend much of
their time feeding and at what appears
to be group play, repeatedly sliding
down steep banks of mud or snow.
They habitually use specific sites
(toilets) for defecation. Their vocalizations include chirps, grunts, and loud
piercing screams. They are powerful
swimmers and are continuously
active, alert, and quick—characteristics
that give them immense aesthetic and
recreational value. Their webbed feet,
streamlined bodies, and long, tapered
tails enable them to move through
water with agility, grace, and speed.
Seasonally, they may travel distances
of 50 to 60 miles (80 to 96 km) along
streams or lake shores, and their home
ranges may be as large as 60 square
miles (155 km2). Males have been
recorded to travel up to 10 miles (16
km) in 1 night.
River otters use a variety of denning
sites that seem to be selected based on
availability and convenience. Hollow
logs, rock crevices, nutria houses, and
abandoned beaver lodges and bank
dens are used. They will also frequent
unused or abandoned human structures or shelters. Natal dens tend to be
located on small headwater branches
or streams leading to major drainages
or lakes.
Damage and Damage
Identification
The presence of river otter(s) around
or in a fish hatchery, aquaculture, or
fish culture facility is a good indication
that a damage problem is imminent.
Otter scats or toilets that contain
scales, exoskeletons, and other body
parts of the species being produced is
additional evidence that damage is ongoing. Uneaten parts of fish in shallow
water and along the shore is evidence
that fish are being taken. Otters usually
eat all of a small catfish except for the
head and major spines, whereas small
trout, salmon, and many of the scaled
fishes may be totally eaten. Uneaten
carcasses with large puncture holes are
likely attributable to herons. River
otters can occasionally cause substantial damage to concentrations of fishes
in marine aquaculture facilities. Often
the damage involves learned feeding
behavior by one or a family of otters.
Legal Status
The river otter is listed in Appendix II
of the Convention on International
Trade in Endangered Species of Flora
and Fauna (CITES). Its inclusion in this
appendix subjects it to international
restrictions and state/province export
quotas because of its resemblance to
the European Otter. Moreover, the
river otter is totally protected in 17
states. Twenty-seven states have trapping seasons, and four states and two
provinces have hunting seasons.
trol research and experimentation has
been done. Registration of repellents,
toxicants, or fumigants for river otter
control has not been sought. Alternate
aquacultural practices and species,
predator avoidance behavior, and use
of protective habitat have not been
fully explored. Careful assessment
should be made of reported damage to
determine if nonlethal preventative
measures can be employed, and to
ensure that if any lethal corrective
measures are employed, they do not
violate state or federal laws. Damage
problems should then be approached
on an individual basis. Cultural methods and habitat modification are normally not applicable. Opportunities to
use repellents, toxicants, fumigants,
and frightening devices are infrequent,
yet the development of any of these or
other effective nonlethal approaches
would be preferable to lethal control
measures.
Exclusion
Fencing with 3 x 3-inch (7.6 x 7.6-cm)
or smaller mesh wire can be an economically effective method of preventing damage at aquacultural sites that
are relatively small, or where fish or
aquaculture activities are concentrated.
Fencing is more economical for protection of small areas where research,
experimental, or propagation facilities
such as raceways, tanks, ponds, or
other facilities hold concentrations of
fish. Hog wire-type fences have also
been used effectively, but these should
be checked occasionally to ensure that
the lower meshes have not been
spread apart or raised to allow otters
to enter.
Electric fences have also been used,
but they require frequent inspection
and maintenance, and like other fencing, are usually impractical for protecting individual small ponds, raceways,
or tanks in a series. They are of greater
utility as a supplement to perimeter
fences surrounding an aquaculture
facility.
Trapping
Traps that have been used effectively
for river otters include the Conibear®
(sizes 220 and 330) or other similar
body-gripping traps and leghold traps
(modified No. 1 1/2 soft-catch and No.
11 double longspring). The latter two
are usually employed to capture river
otters for restocking purposes. In
water, body-gripping traps are usually
placed beneath the water surface or
partially submerged where runs
become narrow or restricted (Fig. 3).
They are effective when partially submerged at dam crossings, the main
runs in beaver ponds, or other locations where otters frequently leave the
water. Body-gripping traps are also
effective in otter trails that connect
pools of water or that cross small peninsulas. In these sets, the trap should
Damage Prevention and
Control Methods
Because river otter damage has been
minor compared to that of other species, and because of its legal status
under the CITES Agreement, little con-
Fig. 3. Body-gripping trap suspended with a pole through the spring loops in a channel set to capture a river otter.
C-111
be placed at a height to blend with the
surrounding vegetation to catch an
otter that is running or sliding. After
ice forms on the surface of streams and
lakes, some trappers bait the triggers
of body-gripping traps with whole
fish. River otter trapping is prohibited
in 21 states and one Canadian province. Check local regulations before
trapping.
Most of the wild otters used for
restocking in recent years were caught
with No. 11 longspring traps in coastal
Louisiana. These animals were usually
caught in sets for nutria, in traps that
were set in narrow trails and pullouts
where shallow water necessitated that
otters walk rather than swim. Leghold
traps are also effective when placed in
shallow edges of trails leading to otter
toilets or other areas they frequent.
Leghold traps set in out-of-water trails
and peninsula crossings should be
covered with damp leaves or other
suitable covering.
With the depression of fur prices, nuisance beaver problems and efforts to
control them have increased substantially throughout the United States.
The killing of otters during beaver control trapping can be minimized by
using snares, but they do occasionally
sustain moderate injuries. In most situations, snared river otters can be
released unharmed. Accordingly,
snares are neither the most effective,
nor the most convenient devices for
capturing river otters or removing
them from an area, and therefore are
not recommended for either.
C-112
Shooting
Acknowledgments
Shooting the offending otters that
cause damage problems will often
effectively prevent continued losses.
Although otters are shy, they are
inquisitive and will often swim within
close range of a small rifle or shotgun.
Extreme caution should be taken to
avoid ricochet when shooting a rifle at
objects surrounded by water.
Figure 1 from Schwartz and Schwartz (1981).
Shooting river otters for fur harvest is
legal in four states and one Canadian
province. Check your local, state, and
federal laws and permits governing
shooting, the use of lights after dark,
the seasons, and the possession of otter
carcasses or parts, to ensure that
planned activities are legal.
Economics of Damage
and Control
Although individual incidences of
river otter damage and predation on
fish can cause substantial losses to
pond owners and to fresh water and
marine aquacultural interests, their total effects are believed to be insignificant. Given the otter’s aesthetic and
recreational value, and its current legal
status, consideration of broad control
programs are unwarranted and
undesirable.
Figure 2 from Toweill and Tabor (1982), adapted
by Dave Thornhill, University of NebraskaLincoln.
Figure 3 by Clint Chapman, University of
Nebraska-Lincoln.
For Additional
Information
Hill, E. P. 1983. River otter (Lutra canadensis)
Pages 176-181 in E. F. Deems Jr. and D.
Pursley eds. North American furbearers, a
contemporary reference. Internat. Assoc.
Fish Wildl. Agencies and Maryland Dep.
Nat. Resour.
Hill, E.P., and V. Lauhachinda. 1980.
Reproduction in river otters from Alabama
and Georgia. Pages 478-486 in J. A. Chapman
and D. Pursley eds., Proc. worldwide
furbearer conf. Maryland Dep. Nat. Resour.,
Annapolis.
Melquist, W. E., and Ana E. Dronkert 1987.
River otter. Pages 626-641 in M. Novak, J. A.
Baker, M. E. Obbard, and B. Malloch eds.
Wild furbearer management and
conservation in North America. Ontario
Minister of Nat. Resour., Toronto.
Toweill, D. E., and J. E. Tabor. 1982. River otter.
Pages 688-703 in J. A. Chapman and G. A.
Feldhamer eds. Wild mammals of North
America: biology, management, and
economics. The Johns Hopkins Univ. Press.,
Baltimore, Maryland.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
James E. Knight
SKUNKS
Extension Wildlife Specialist
Animal and Range Sciences
Montana State University
Bozeman, MT 59717
Fig. 1. Left, the striped skunk, Mephitis mephitis;
right, the spotted skunk, Spilogale putorius
Repellents
Damage Prevention and
Control Methods
Some home remedies such as moth
balls or flakes or ammonia solution
may be useful, but no repellents are
registered.
Exclusion
Buildings: close cellar and outside
basement and crawl space doors;
seal and cover all openings
including window wells and pits.
Toxicants
None are registered.
Fumigants
Poultry yards: install wire mesh
fences.
Gas cartridges.
Beehives: elevate and install aluminum
guards.
Trapping
Habitat Modification
Leghold trap.
Removal of garbage, debris, and
lumber piles.
Shooting
Box trap.
Practical only when animals are far
from residential areas.
Frightening
Lights and sounds are of limited value.
Other Methods
Skunk removal.
Odor removal.
Identification
The skunk, a member of the weasel
family, is represented by four species
in North America. The skunk has
short, stocky legs and proportionately
large feet equipped with well-developed claws that enable it to be very
adept at digging.
The striped skunk (Fig. 1) is characterized by prominent, lateral white
stripes that run down its back. Its fur is
otherwise jet black. Striped skunks are
the most abundant of the four species.
The body of the striped skunk is about
the size of an ordinary house cat (up to
29 inches [74 cm] long and weighing
about 8 pounds [3.6 kg] ). The spotted
skunk (Fig. 1) is smaller (up to 21
inches [54 cm] long and weighing
about 2.2 pounds [1 kg]), more weasellike, and is readily distinguishable by
white spots and short, broken white
stripes in a dense jet-black coat.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-113
The hooded skunk (Mephitis macroura)
is identified by hair on the neck that is
spread out into a ruff. It is 28 inches
(71 cm) long and weighs the same as
the striped skunk. It has an extremely
long tail, as long as the head and body
combined. The back and tail may be all
white, or nearly all black, with two
white side stripes. The hog-nosed
skunk (Conepatus leucontus) has a long
snout that is hairless for about 1 inch
(2.5 cm) at the top. It is 26 inches (66
cm) long and weighs 4 pounds (1.8
kg). Its entire back and tail are white
and the lower sides and belly are
black. Skunks have the ability to discharge nauseating musk from the anal
glands and are capable of several discharges, not just one.
Habitat
Skunks inhabit clearings, pastures, and
open lands bordering forests. On
prairies, skunks seek cover in the
thickets and timber fringes along
streams. They establish dens in hollow
logs or may climb trees and use hollow
limbs.
Food Habits
Fig. 2a. Range of the striped skunk in North
America.
Range
The striped skunk is common throughout the United States and Canada (Fig.
2a). Spotted skunks are uncommon in
some areas, but distributed throughout most of the United States and
northern Mexico (Fig 2b). The hooded
skunk and the hog-nosed skunk are
much less common than striped and
spotted skunks. Hooded skunks are
limited to southwestern New Mexico
and western Texas. The hog-nosed
skunk is found in southern Colorado,
central and southern New Mexico, the
southern half of Texas, and northern
Mexico.
General Biology,
Reproduction, and
Behavior
Adult skunks begin breeding in late
February. Yearling females (born in the
preceding year) mate in late March.
Gestation usually lasts 7 to 10 weeks.
Older females bear young during the
first part of May, while yearling
females bear young in early June.
There is usually only 1 litter annually.
Litters commonly consist of 4 to 6
young, but may have from 2 to 16.
Younger or smaller females have
smaller litters than older or larger
C-114
Skunks eat plant and animal foods in
about equal amounts during fall and
winter. They eat considerably more
animal matter during spring and summer when insects, their preferred food,
are more available. Grasshoppers,
beetles, and crickets are the adult
insects most often taken. Field and
house mice are regular and important
items in the skunk diet, particularly in
winter. Rats, cottontail rabbits, and
other small mammals are taken when
other food is scarce.
Damage and Damage
Identification
Fig. 2b. Range of the spotted skunk in North
America.
females. The young stay with the
female until fall. Both sexes mature by
the following spring. The age potential
for a skunk is about 10 years, but few
live beyond 3 years in the wild.
The normal home range of the skunk is
l/2 to 2 miles (2 to 5 km) in diameter.
During the breeding season, a male
may travel 4 to 5 miles (6.4 to 8 km)
each night.
Skunks are dormant for about a month
during the coldest part of winter. They
may den together in winter for
warmth, but generally are not sociable.
They are nocturnal in habit, rather
slow-moving and deliberate, and have
great confidence in defending themselves against other animals.
Skunks become a nuisance when their
burrowing and feeding habits conflict
with humans. They may burrow under
porches or buildings by entering foundation openings. Garbage or refuse left
outdoors may be disturbed by skunks.
Skunks may damage beehives by
attempting to feed on bees. Occasionally, they feed on corn, eating only the
lower ears. If the cornstalk is knocked
over, however, raccoons are more
likely the cause of damage. Damage to
the upper ears of corn is indicative of
birds, deer, or squirrels. Skunks dig
holes in lawns, golf courses, and gardens to search for insect grubs found
in the soil. Digging normally appears
as small, 3- to 4-inch (7- to 10-cm)
cone-shaped holes or patches of upturned earth. Several other animals, including domestic dogs, also dig in
lawns.
Skunks occasionally kill poultry and
eat eggs. They normally do not climb
fences to get to poultry. By contrast,
rats, weasels, mink, and raccoons
regularly climb fences. If skunks gain
access, they will normally feed on the
eggs and occasionally kill one or two
fowl. Eggs usually are opened on one
end with the edges crushed inward.
Weasels, mink, dogs and raccoons
usually kill several chickens or ducks
at a time. Dogs will often severely mutilate poultry. Tracks may be used to
identify the animal causing damage.
Both the hind and forefeet of skunks
have five toes. In some cases, the fifth
toe may not be obvious. Claw marks
are usually visible, but the heels of the
forefeet normally are not. The hindfeet
tracks are approximately 2 1/2 inches
long (6.3 cm) (Fig. 3). Skunk droppings can often be identified by the
undigested insect parts they contain.
Droppings are 1/4 to 1/2 inch (6 to 13
mm) in diameter and 1 to 2 inches (2.5
to 5 cm) long.
Odor is not always a reliable indicator
of the presence or absence of skunks.
Sometimes dogs, cats, or other animals
that have been sprayed by skunks
move under houses and make owners
mistakenly think skunks are present.
Rabies may be carried by skunks on
occasion. Skunks are the primary carriers of rabies in the Midwest. When
rabies outbreaks occur, the ease with
which rabid animals can be contacted
increases. Therefore, rabid skunks are
prime vectors for the spread of the
virus. Avoid overly aggressive skunks
that approach without hesitation. Any
skunk showing abnormal behavior,
such as daytime activity, may be rabid
and should be treated with caution.
Report suspicious behavior to local
animal control authorities.
Legal Status
Front
Fig. 3. Tracks of the striped skunk.
Hind
Damage Prevention and
Control Methods
Exclusion
Keep skunks from denning under
buildings by sealing off all foundation
openings. Cover all openings with
wire mesh, sheet metal, or concrete.
Bury fencing 1 1/2 to 2 feet (0.4 to 0.6
m) where skunks can gain access by
digging. Seal all ground-level openings
into poultry buildings and close doors
at night. Poultry yards and coops
without subsurface foundations may
be fenced with 3-foot (1-m) wire mesh
fencing. Bury the lowest foot (0.3 m) of
fencing with the bottom 6 inches (15.2
cm) bent outward from the yard or
building. Skunks can be excluded from
window wells or similar pits with
mesh fencing. Place beehives on stands
3 feet (1 m) high. It may be necessary
to install aluminum guards around the
bases of hives if skunks attempt to
climb the supports. Skunks, however,
normally do not climb. Use tight-fitting lids to keep skunks out of garbage
cans.
Debris such as lumber, fence posts,
and junk cars provide shelter for
skunks, and may encourage them to
use an area. Clean up the area to discourage skunks.
Frightening
Lights and sounds may provide temporary relief from skunk activity.
Repellents
There are no registered repellents for
skunks. Most mammals, including
skunks, can sometimes be discouraged
from entering enclosed areas with
moth balls or moth flakes (naphthalene). This material needs to be used in
sufficient quantities and replaced often
if it is to be effective. Ammonia-soaked
cloths may also repel skunks. Repellents are only a temporary measure.
Permanent solutions require other
methods.
Toxicants
No toxicants are registered for use in
controlling skunks.
Fumigants
Striped skunks are not protected by
law in most states, but the spotted
skunk is fully protected in some. Legal
status and licensing requirements
vary. Check with state wildlife officials
before removing any skunks.
Habitat Modification
Properly dispose of garbage or other
food sources that will attract skunks.
Skunks are often attracted to rodents
living in barns, crawl spaces, sheds,
and garages. Rodent control programs
may be necessary to eliminate this attraction.
Two types of gas cartridges are registered for fumigating skunk burrows.
Fumigation kills skunks and any other
animals present in the burrows by
suffocation or toxic gases. Follow label
directions and take care to avoid fire
hazards when used near structures.
C-115
24"
6"
Top View
12"
Front view
36"
Side view
Metal triangle keeps
door from raising.
Galvanized metal door
Fig. 4. A box trap can be easily built using scrap lumber and small-mesh, welded-wire fencing.
Box Traps. Skunks can be caught in
live traps set near the entrance to their
den. When a den is used by more than
one animal, set several traps to reduce
capture time. Live traps can be purchased or built. Figures 4 and 5 illustrate traps that can be built easily.
Consult state wildlife agency personnel before trapping skunks.
Use canned fish-flavored cat food to
lure skunks into traps. Other food
baits such as peanut butter, sardines,
and chicken entrails are also effective.
Before setting live traps, cover them
with canvas to reduce the chances of a
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Shooting
Skunks caught in leghold traps may be
shot. Shooting the skunk in the middle
of the back to sever the spinal cord and
paralyze the hind quarters may prevent the discharge of scent. Shooting in
the back should be followed immediately by shooting in the head. Most
people who shoot trapped skunks
should expect a scent discharge.
Other Methods
Galvanized metal treadle
Trapping
Leghold Traps. Leghold traps
should not be used to catch skunks
near houses because of potential problem of scent discharge. To remove a
live skunk caught in a leghold trap, a
veterinarian or wildlife official may
first inject it with a tranquilizer, then
remove it from the trap for disposal or
release elsewhere.
24"
12"
completely covered, it is a proven,
effective method for relocating a
skunk. If the skunk is to be killed, the
US Department of Agriculture recommends shooting or euthanization with
CO2.
trapped skunk discharging its scent.
The canvas creates a dark, secure environment for the animal. Always approach a trap slowly and quietly to
prevent upsetting a trapped skunk.
Gently remove the trap from the area
and release or kill the trapped skunk.
Captured skunks should be transported at least 10 miles (16 km) and
released in a habitat far from human
dwellings. Attach a length of heavy
string or fishing line to the trap cover
and release the skunk from a distance.
Removing and transporting a livetrapped skunk may appear to be a
precarious business, but if the trap is
Skunk Removal. The following
steps are suggested for removing
skunks already established under
buildings.
1. Seal all possible entrances along the
foundation, but leave the main burrow open.
2. Sprinkle a layer of flour 2 feet (0.6
m) in circumference on the ground
in front of the opening.
3. After dark, examine the flour for
tracks which indicate that the skunk
has left to feed. If tracks are not
present, reexamine in an hour.
4. After the den is empty, cover the remaining entrance immediately.
5. Reopen the entrance the next day
for 1 hour after dark to allow any
remaining skunks to exit before permanently sealing the entrance.
A wooden door suspended from wire
can be improvised to allow skunks to
leave a burrow but not to reenter.
Burrows sealed from early May to
Trigger mechanism
Trigger hole and plate
1 1/4" trigger hole
Underside
1/2" hole in
end
5"
10"
Side view
2 1/2"
Notch
1/2" x 9"
dowel
6 1/2"
Attach bait
Fig. 5. Alternate design for a box trap.
C-117
mid-August may leave young skunks
trapped in the den. If these young are
mobile they can usually be boxtrapped easily using the methods previously described. Where skunks have
entered a garage, cellar, or house, open
the doors to allow the skunks to exit
on their own. Do not prod or disturb
them. Skunks trapped in cellar window wells or similar pits may be
removed by nailing cleats at 6-inch
(15-cm) intervals to a board. Lower the
board into the well and allow the
skunk to climb out on its own. Skunks
are mild-tempered animals that will
not defend themselves unless they are
cornered or harmed. They usually provide a warning before discharging
their scent, stamping their forefeet
rapidly and arching their tails over
their backs. Anyone experiencing such
a threat should retreat quietly and
slowly. Loud noises and quick, aggressive actions should be avoided.
Odor Removal. Many individuals
find the smell of skunk musk nauseating. The scent is persistent and difficult
to remove. Diluted solutions of vinegar or tomato juice may be used to
eliminate most of the odor from
people, pets, or clothing. Clothing may
also be soaked in weak solutions of
household chloride bleach or ammonia. On camping trips, clothing can be
smoked over a cedar or juniper fire.
Neutroleum alpha is a scent-masking
solution that can be applied to the
sprayed area to reduce the odor. It is
available through some commercial
cleaning suppliers and the local
USDA-APHIS-ADC office. Walls or
structural areas that have been
sprayed by skunks can be washed
down with vinegar or tomato juice
solutions or sprayed with neutroleum
alpha. Use ventilation fans to speed up
the process of odor dissipation. Where
musk has entered the eyes, severe
C-118
burning and an excessive tear flow
may occur. Temporary blindness of 10
or 15 minutes may result. Rinse the
eyes with water to speed recovery.
Economics of Damage
and Control
Skunks should not be needlessly
destroyed. They are highly beneficial
to farmers, gardeners, and landowners
because they feed on large numbers of
agricultural and garden pests. They
prey on field mice and rats, both of
which may girdle trees or cause health
problems. Occasionally they eat moles,
which cause damage to lawns, or insects such as white grubs, cutworms,
potato beetle grubs, and other species
that damage lawns, crops, or hay.
Skunks occasionally feed on groundnesting birds, but their impact is
usually minimal due to the large abundance of alternative foods. Skunks also
feed on the eggs of upland game birds
and waterfowl. In waterfowl production areas, nest destruction by eggseeking predators such as skunks can
significantly reduce reproduction. The
occasional problems caused by the
presence of skunks are generally outweighed by their beneficial habits.
Some people even allow skunks to den
under abandoned buildings or woodpiles. Unless skunks become really
bothersome, they should be left alone.
An economic evaluation of the feeding
habits of skunks shows that only 5% of
the diet is made up of items that are
economically valuable to people.
The hide of the skunk is tough, durable, and able to withstand rough use.
Generally there is little market for
skunk pelts but when other furbearer
prices are high, skunks are worth
pelting.
Acknowledgments
Much of the information for this chapter was
based on a publication by F. Robert Henderson.
Figures 1 and 2 from Schwartz and Schwartz
(1981).
Figures 3 through 5 by Jerry Downs, Graphic
Artist, Cooperative Extension Service, New
Mexico State University.
For Additional
Information
Burt, W. H., and R. P. Grossenheider. 1976. A
field guide to the mammals, 3d ed.
Houghton Mifflin Co., Boston. 289 pp.
Deems, E. F., Jr., and D. Pursley, eds. 1983.
North American furbearers: a contemporary
reference. Int. Assoc. Fish Wildl. Agencies
and Maryland Dep. Nat. Resour. 223 pp.
Godin, A. J. 1982. Striped and hooded skunks.
Pages 674-687 in J. A. Chapman and G. A.
Feldhamer, eds. Wild mammals of North
America: biology, management, and
economics. The Johns Hopkins Univ. Press,
Baltimore, Maryland.
Howard, W. E., and R. E. Marsh. 1982. Spotted
and hog-nosed skunks. Pages 664-673 in J. A.
Chapman and G. A. Feldhamer, eds. Wild
mammals of North America: biology,
management, and economics. The Johns
Hopkins Univ. Press, Baltimore, Maryland.
Rosatte, Richard C. 1987. Striped, spotted,
hooded, and hog-nosed skunk. Pages 598613 in M. Novak, J. A. Baker, M. E. Obbard,
and B. Malloch, eds. Wild furbearer
management and conservation in North
America. Ministry of Nat. Resour., Ontario,
Canada.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
F. Robert Henderson
Extension Specialist
Animal Damage Control
Department of Animal Sciences
and Industry
Kansas State University
Manhattan, Kansas 66506
WEASELS
Fig. 1. Least weasel, Mustela nivalis (left); Shorttailed weasel, M. erminea, in summer coat
(middle); Short-tailed weasel in winter coat
(right).
Damage Prevention and
Control Methods
Exclusion
Block all entrances 1 inch (2.5 cm) or
larger with 1/2-inch (1.3-cm) hail
screen or similar materials.
Trapping
Set No. 0 or No. 1 leghold traps inside
a protective wooden box.
Live traps.
Other Methods
Not applicable or effective.
Identification
Weasels belong to the Mustelidae family, which also includes mink, martens,
fishers, wolverines, badgers, river otters, black-footed ferrets, and four species of skunks. Although members of
the weasel family vary in size and
color (Fig. 1), they usually have long,
slender bodies, short legs, rounded
ears, and anal scent glands. A weasel’s
hind legs are barely more than half as
long as its body (base of head to base
of tail). The weasel’s forelegs also are
notably short. These short legs on a
long, slender body may account for
the long-tailed weasel’s (Mustela
frenata) distinctive running gait. At
every bound the long body loops
upward, reminding one of an inchworm.
In the typical bounding gait of the
weasel, the hind feet register almost, if
not exactly, in the front foot impressions, with the right front foot and
hind feet lagging slightly behind. The
stride distance normally is about 10
inches (25 cm).
Male weasels are distinctly larger than
females. The long-tailed and shorttailed (M. erminea) weasels have a
black tip on their tails, while the least
weasel (M. nivalis) lacks the black tip
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-119
Fig. 2. Identification of the weasels.
Range
Three species of weasels live in North
America. The most abundant and
widespread is the long-tailed weasel.
Some that occur in parts of Kansas,
Oklahoma, Texas, and New Mexico
have a dark “mask” and are often
called bridled weasels. The short-tailed
weasel occurs in Canada, Alaska, and
the northeastern, Great Lakes, and
northwestern states, while the least
weasel occurs in Canada, Alaska, and
the northeastern and Great Lakes
states (Fig. 3).
Least weasel, Mustela nivalis
— 8 inches long; 2 1/2 ounces in weight
— short tail without black tip
— white feet
Short-tailed weasel, M. erminea
— 13 inches long; 6 ounces in weight
— black tip on tail
— white feet
Habitat
18-inch ruler
Long-tailed weasel, M. frenata
— 16 inches long; 12 ounces in weight
— black tip on tail
— brown feet
(Fig. 2). The long-tailed weasel sometimes is as long as 24 inches (61 cm).
The short-tailed weasel is considerably
smaller, rarely longer than 13 inches
(33 cm) and usually weighing between
3 and 6 ounces (87 and 168 g). Just as
its common name implies, the least
weasel is the smallest, measuring only
7 or 8 inches (18 to 20 cm) long and
weighing 1 to 2 1/2 ounces (28 to 70 g).
Many people assume the least weasel
is a baby weasel since it is so small.
a
b
Fig. 3. Range of the (a) long-tailed weasel, (b) short-tailed weasel, and (c) least weasel in North America.
C-120
Some authors report finding weasels
only in places with abundant water, although small rodents, suitable as food,
were more abundant in surrounding
habitat. Weasels are commonly found
along roadsides and around farm
buildings. The absence of water to
drink is thought to be a limiting factor
(Henderson and Stardom 1983).
A typical den has two surface openings about 2 feet (61 cm) apart over a
burrow that is 3 to 10 feet (0.9 to 3 m)
long. Other weasel dens have been
found in the trunk of an old uprooted
oak, in a bag of feathers, in a threshing
machine, in the trunk of a hollow tree,
in an old mole run, a gopher burrow,
and a prairie dog burrow (Henderson
and Stardom 1983).
c
Weasel population densities vary with
season, food availability, and species.
In favorable habitat, maximum
densities of the least weasel may
reach 65 per square mile (169/km2);
the short-tailed weasel, 21 per square
mile (54/km2); and the long-tailed
weasel, 16 to 18 per square mile (40 to
47/km2). Population densities fluctuate considerably with year-to-year
changes in small mammal abundance,
and densities differ greatly among
habitats.
Fig. 4. Weasels are efficient killers, preying on mice as well as on pocket gophers, birds, and other
animals.
Food Habits
The weasel family belongs to the order
Carnivora. With the exception of the
river otter, all members of the weasel
family feed primarily on insects and
small rodents (Fig. 4). Their diet consists of whatever meat they can obtain
and may include birds and bird eggs.
As predators, they play an important
role in the ecosystem. Predators tend
to hunt the most abundant prey,
turning to another species if the numbers of the first prey become scarce. In
this way, they seldom endanger the
long-term welfare of the animal populations they prey upon.
Long-tailed weasels typically prey on
one species that is continually available. The size of the prey population
varies from year to year and from season to season. At times, weasels will
kill many more individuals of a prey
species than they can immediately eat.
Ordinarily, they store the surplus for
future consumption, much the same as
squirrels gather and store nuts.
Pocket gophers are the primary prey of
long-tailed weasels. In some regions
these gophers are regarded as nuisances because they eat alfalfa plants
in irrigated meadows and native
plants in mountain meadows where
livestock graze. Because of its predation on pocket gophers and other
rodents, the long-tailed weasel is
sometimes referred to as the farmer’s
best friend. This statement, however, is
an oversimplification of a biological
relationship.
Weasels prefer a constant supply of
drinking water. The long-tailed weasel
drinks up to 0.85 fluid ounces (26 ml)
daily.
General Biology,
Reproduction, and
Behavior
Weasels are active in both winter and
summer; they do not hibernate.
Weasels are commonly thought to be
nocturnal but evidence indicates they
are more diurnal in summer than in
winter.
Home range sizes vary with habitat,
population density, season, sex, food
availability, and species (Svendsen
1982). The least weasel has the smallest
home range. Males use 17 to 37 acres
(7 to 15 ha), females 3 to 10 acres (1 to
4 ha). The short-tailed weasel is larger
than the least weasel and has a larger
home range. Male short-tailed weasels
use an average of 84 acres (34 ha), and
females 18 acres (7 ha), according to
snow tracking.
The long-tailed weasel has a home
range of 30 to 40 acres (12 to 16 ha),
and males have larger home ranges in
summer than do females. The weasels
appear to prefer hunting certain
coverts with noticeable regularity but
rarely cruise the same area on two consecutive nights.
Weasels, like all mustelids, produce a
pungent odor. When irritated, they
discharge the odor, which can be detected at some distance (Jackson 1961).
Long-tailed weasels mate in late summer, mostly from July through
August. Females are induced
ovulators and will remain in heat for
several weeks if they are not bred.
There is a long delay in the implantation of the blastocyst in the uterus, and
the young are born the following
spring, after a gestation period averaging 280 days. Average litters consist of
6 young, but litters may include up to
9 young. The young are blind at birth
and their eyes open in about 5 weeks.
They mature rapidly and at 3 months
of age the females are fully grown.
Young females may become sexually
mature in the summer of their birth
year.
Damage and Damage
Identification
Occasionally weasels raid poultry
houses at night and kill or injure domestic fowl. They feed on the warm
blood of victims bitten in the head or
neck. Rat predation on poultry usually
differs in that portions of the body
may be eaten and carcasses dragged
into holes or concealed locations.
Legal Status
All three weasels generally are considered furbearers under state laws, and a
season is normally established for fur
harvest. Check local and state laws
before undertaking weasel control
measures.
C-121
Damage Prevention and
Control Methods
Exclusion
Weasels can be excluded from poultry
houses and other structures by closing
all openings larger than 1 inch (2.5 cm).
To block openings, use 1/2-inch (1.3cm) hardware cloth, similar wire
mesh, or other materials.
Trapping
Weasels are curious by nature and are
rather easily trapped in No. 0 or 1 steel
leghold traps. Professional trappers in
populated areas use an inverted wooden
box 1 or 2 feet (30 or 60 cm) long, such as
an apple box, with a 2- to 3-inch (5- to 8cm) round opening cut out in the lower
part of both ends (Fig. 5). Dribble a trail
of oats or other grain through the box.
Mice will frequent it to eat the grain and
weasels will investigate the scent of the
mice. A trap should be set inside the box,
directly under the hole at each end of the
box. Keep the trap pan tight to prevent
the mice from setting off the trap.
Alternatively, make a hole in only one
end of the box and suspend a fresh meat
bait against the opposite end of the box.
Set the trap directly under the bait.
Trap sets in old brush piles, under outbuildings, under fences, and along stone
walls are also suggested, since the
weasel is likely to investigate any small
covered area. Trap sets should be protected by objects such as boards or tree
limbs to protect nontarget wildlife.
Weasels can also be captured in live
traps with fresh meat as suitable bait.
If trapping to alleviate damage is to be
conducted at times other than the
designated season, the local wildlife
agency representative must be notified.
Economics of Damage
and Control
Svendsen (1982) writes:
“Overall, weasels are more of an
asset than a liability. They eat quantities of rats and mice that otherwise
would eat and damage additional
crops and produce. This asset is
partially counter-balanced by the
fact that weasels occasionally kill
C-122
Fig. 5. A trap set within a wooden box can successfully catch weasels without catching
larger nontarget species.
beneficial animals and game species. The killing of domestic poultry
may come only after the rat population around the farmyard is diminished. In fact, rats may have
destroyed more poultry than the
weasel. In most cases, a farmer lives
with weasels on the farm for years
without realizing that they are even
there, until they kill a chicken.”
Acknowledgments
Figures 1, 2, and 4 adapted by Jill Sack Johnson
from “Weasel Family of Alberta” (no date), Alberta
Fish and Wildlife Division, Alberta Energy and
Natural Resources, Edmonton (with permission).
Figure 3 adapted from Burt and Grossenheider
(1976) by Jill Sack Johnson.
Figure 5 adapted from a publication by the US
Fish and Wildlife Service.
For Additional
Information
Burt, W. H., and R. P. Grossenheider. 1976. A
field guide to the mammals, 3d ed.
Houghton Mifflin Co., Boston. 289 pp.
Fitzgerald, B. M. 1977. Weasel predation on a
cyclic population of the montane vole
(Microtus montanus) in California. J. An. Ecol.
46:367-397.
Glover, F. A. 1942. A population study of
weasels in Pennsylvania. M.S. Thesis,
Pennsylvania State Univ. University Park.
210 pp.
Hall, E. R. 1951. American weasels. Univ. Kansas
Museum Nat. Hist. Misc. PubL. 4:1-466.
Hall, E. R. 1974. The graceful and rapacious
weasel. Nat. Hist. 83(9):44-50.
Hamilton, W. J., Jr. 1933. The weasels of New
York. Am. Midl. Nat. 14:289-337.
Henderson, F. R., and R. R. P. Stardom. 1983. Shorttailed and long-tailed weasel. Pages 134-144 in
E. F. Deems, Jr. and D. Purseley, eds. North
American furbearers: a contemporary reference. Internatl. Assoc. Fish Wildl. Agencies
Maryland Dep. Nat. Resour.
Jackson, H. H. T. 1961. Mammals of Wisconsin.
Univ. Wisconsin Press, Madison. 504 pp.
King, C. M. 1975. The home range of the weasel
(Mustela nivalis) in an English woodland. J.
An. Ecol. 44:639-668.
MacLean, S. F., Jr., B. M. Fitzgerald, and F. A.
Pitelka. 1974. Population cycles in arctic
lemmings: winter reproduction and
predation by weasels. Arctic Alpine Res. 6:112.
Polderboer, E. B., L. W. Kuhn, and G. O.
Hendrickson. 1941. Winter and spring habits
of weasels in central Iowa. J. Wildl. Manage.
5:115-119.
Quick, H. F. 1944. Habits and economics of New
York weasel in Michigan. J. Wildl. Manage.
8:71-78.
Quick, H. F. 1951. Notes on the ecology of
weasels in Gunnison County, Colorado. J.
Mammal. 32:28-290.
Schwartz, C. W. and E. R. Schwartz. 1981. The
Wild mammals of Missouri, rev. ed. Univ.
Missouri Press, Columbia. 356 pp.
Svendsen, G. E. 1982. Weasels. Pages 613-628 in
J. A. Chapman and G. A. Feldhamer, eds.,
Wild mammals of North America: biology,
management, and economics. The Johns
Hopkins Univ. Press, Baltimore, Maryland.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
William J. Paul
District Supervisor
USDA-APHISAnimal Damage Control
Grand Rapids, Michigan 55744
WOLVES
Philip S. Gipson
Unit Leader
Kansas Cooperative Fish and Wildlife
Research Unit
Division of Biology
Kansas State University
Manhattan, Kansas 66506-3501
Fig. 1. Adult gray wolf, Canis lupus
Damage Prevention and
Control Methods
Exclusion
Net wire fences.
Electric fences.
Cultural Methods
Frightening
Shooting
Livestock guarding dogs.
Use predator calls or voice howling to
lure wolves into rifle range.
Flashing lights and siren devices.
Toxicants
None are registered.
Trapping
Aerial hunting from a helicopter or
fixed-wing aircraft.
Hunting seasons for legal fur harvest.
Other Methods
Proper disposal of dead livestock
carcasses.
No. 4, 14, 114, or 4 1/2 Newhouse
leghold traps, No. 4 or 7 McBride
traps, Braun wolf trap.
Use a dart gun to chemically immobilize wolves from a helicopter.
Do not allow calving or lambing on
remote, wooded pastures.
Thompson 4xx or 5xx snares,
Gregerson No. 14 wolf snare.
Pen small flocks of sheep at night or
bring near buildings.
Long-range land-use planning should
take into account potential conflicts
between wolves and livestock.
Trapping seasons for legal fur harvest.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
Great Plains Agricultural Council
Wildlife Committee
C-123
1970s, biologists captured the last few
red wolves for captive breeding before
the species was lost to hybridization.
The red wolf was considered extinct in
the wild until 1987, when reintroductions began.
Identification
Two species of wolves occur in North
America, gray wolves (Canis lupus)
and red wolves (Canis rufus). The common names are misleading since individuals of both species vary in color
from grizzled gray to rusty brown to
black. Some gray wolves are even
white. The largest subspecies of the
gray wolf are found in Alaska and the
Northwest Territories of Canada.
Adult male gray wolves typically
weigh 80 to 120 pounds (36.3 to 54.4
kg), and adult females 70 to 90 pounds
(31.8 to 40.8 kg). Although males
rarely exceed 120 pounds (54.4 kg),
and females 100 pounds (45.4 kg),
some individuals may weigh much
more. Gray wolves vary in length from
about 4.5 to 6.5 feet (1.4 to 2 m) from
nose to tip of tail and stand 26 to 36
inches (66 to 91.4 cm) high at the
shoulders (Mech 1970).
Red wolves are intermediate in size
between gray wolves and coyotes.
Typical red wolves weigh 45 to 65
pounds (20.4 to 29.5 kg). Total length
ranges from about 4.4 to 5.4 feet (1.3 to
1.6 m) (Paradiso and Nowak 1972).
Wherever wolves occur, their howls
may be heard. The howl of a wolf
carries for miles on a still night. Both
gray wolves and red wolves respond
to loud imitations of their howl or to
sirens.
Range
During the 1800s, gray wolves ranged
over the North American continent as
far south as central Mexico. They did
not inhabit the southeastern states,
extreme western California, or far
western Mexico (Young and Goldman
1944). In the late 1800s and early 1900s,
wolves were eliminated from most
regions of the contiguous United
States by control programs that incorporated shooting, trapping, and poisoning. Today, an estimated 55,000
gray wolves exist in Canada and 5,900
to 7,200 in Alaska. In the contiguous
United States, the distribution of the
gray wolf has been reduced to approximately 3% of its original range.
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Fig. 2. Current range of the gray wolf (light) and
red wolf (dark) in North America.
Minnesota has the largest population
of wolves in the lower 48 states, estimated at 1,550 to 1,750. A population
of wolves exists on Isle Royale in Lake
Superior, but the population is at an
all-time low of 12 animals. In recent
years, wolves have recolonized
Wisconsin, the Upper Peninsula of
Michigan, northwestern Montana,
central and northern Idaho, and northern Washington. A few isolated gray
wolves may also exist in remote areas
of Mexico.
Current efforts to reestablish gray
wolves are being conducted in northwestern Montana, central Idaho, the
Greater Yellowstone area, and northern Washington (USFWS 1987). Recovery through natural recolonization is
likely in northwestern Montana, central Idaho, and northern Washington.
Due to Greater Yellowstone’s geographic isolation from areas with
established wolf populations, recovery
there would likely require the reintroduction of wolves into Yellowstone
National Park.
Red wolves originally occurred from
central Texas to Florida and north to
the Carolinas, Kentucky, southern Illinois, and southern Missouri (Young
and Goldman 1944). Years of predator
control and habitat conversion had, by
1970, reduced the range of the red wolf
to coastal areas of southeastern Texas
and possibly southwestern Louisiana.
When red wolf populations became
low, interbreeding with coyotes
became a serious problem. In the mid-
Red wolf recovery attempts have been
made on Bulls Island near Charleston,
South Carolina, and on Alligator River
National Wildlife Refuge in eastern
North Carolina (Phillips and Parker
1988). The Great Smoky Mountains
National Park in western North
Carolina and eastern Tennessee is also
being considered as a red wolf
reintroduction area. The goal of the
red wolf recovery plan is to return red
wolves to nonendangered status by
“re-establishment of self-sustaining
wild populations in at least 2 locations
within the species’ historic range”
(Abraham et al. 1980:14).
Habitat
Gray wolves occupy boreal forests and
forest/agricultural edge communities
in Minnesota, northern Wisconsin, and
northern Michigan. In northwest
Montana, northern Idaho, and northern Washington, wolves inhabit
forested areas. In Canada and Alaska,
wolves inhabit forested regions and
alpine and arctic tundra. In Mexico,
gray wolves are limited to remote
forested areas in the Sierra Madre
Occidental Mountains.
The last areas inhabited by red wolves
were coastal prairie and coastal
marshes of southeastern Texas and
possibly southwestern Louisiana.
These habitats differ markedly from
the diverse forested habitats found
over most of the historic range of red
wolves.
Food Habits
Mech (1970) reported that gray wolves
prey mainly on large animals including white-tailed deer, mule deer,
moose, caribou, elk, Dall sheep, bighorn sheep, and beaver. Small mammals and carrion make up the balance
of their diet. During the 1800s, gray
wolves on the Great Plains preyed
mostly on bison. As bison were eliminated and livestock husbandry
established, wolves commonly killed
livestock.
Red wolves in southern Texas fed primarily on small animals such as nutria,
rabbits, muskrats, and cotton rats
(Shaw 1975). Carrion, wild hogs,
calves, and other small domestic animals were also common food items.
General Biology,
Reproduction, and
Behavior
Gray wolves are highly social, often
living in packs of two to eight or more
individuals. A pack consists of an
adult breeding pair, young of the year,
and offspring one or more years old
from previous litters that remain with
the pack. The pack structure of gray
wolves increases the efficiency of
wolves in killing large prey. Red
wolves may be less social than gray
wolves, although red wolves appear to
maintain a group social structure
throughout the year.
Each wolf pack has a home range or
territory that it defends against intruding wolves. Packs maintain their territories by scent marking and howling.
On the tundra, packs of gray wolves
may have home ranges approaching
1,200 square miles (3,108 km2). In forested areas, ranges are much smaller,
encompassing 40 to 120 square miles
(104 to 311 km2). Some wolves leave
their pack and territory and become
lone wolves, drifting around until they
find a mate and a vacant area in which
to start their own pack, or wandering
over large areas without settling. Extreme movements, of 180 to 551 miles
(290 to 886 km), have been reported.
These movements were probably of
dispersing wolves. The home ranges of
red wolves are generally smaller than
those of gray wolves. Red wolf home
ranges averaged 27.3 square miles (71
km2) in southern Texas (Shaw 1975).
Wild gray wolves usually are sexually
mature at 22 months of age. Breeding
usually takes place from early February through March, although it has
been reported as early as January and
as late as April. Pups are born 60 to 63
days after conception, usually during
April or May. Most litters contain 4 to
7 young.
Courtship is an intimate part of social
life in the pack. Mating usually occurs
only between the dominant (alpha)
male and female of the pack. Thus,
only 1 litter will be produced by a pack
during a breeding season. All pack
members aid in rearing the pups.
Dominance is established within days
after gray wolf pups are born. As pups
mature, they may disperse or maintain
close social contact with parents and
other relatives and remain members of
the pack.
Little is known about reproduction in
red wolves, but it appears to be similar
to that of gray wolves. Red wolves
may breed from late December to
early March. Usually 6 to 8 pups are
produced.
Damage and Damage
Identification
The ability of wolves to kill cattle,
sheep, poultry, and other livestock is
well documented (Young and
Goldman 1944, Carbyn 1983, Fritts et
al. 1992). From 1975 through 1986 an
average of 21 farms out of 7,200 (with
livestock) in the Minnesota wolf range
suffered verified losses annually to
wolves (Fritts et al. 1992). In more recent years, 50 to 60 farms annually
have been affected by wolf depredations in Minnesota. Domestic dogs and
cats are also occasionally killed and
eaten by gray wolves.
In many instances, wolves live around
livestock without causing damage or
causing only occasional damage. In
other instances, wolves prey on livestock and cause significant, chronic
losses at individual operations. In Minnesota, wolf depredation on livestock
is seasonal, most losses occurring
between April and October, when livestock are on summer pastures. Livestock are confined to barnyards in the
winter months, and therefore are less
susceptible to predation.
Cattle, especially calves, are the most
common livestock taken. Wolves are
capable of killing adult cattle but seem
less inclined to do so if calves are available. Attacks usually involve only one
or two cattle per event. Depredation
on sheep or poultry often involves surplus killing. In Minnesota, wolf attacks
on sheep may leave several (up to 35)
individuals killed or injured per night.
Attacks on flocks of domestic turkeys
in Minnesota have resulted in nightly
losses of 50 to 200 turkeys.
Wolf attacks on livestock are similar to
attacks on wild ungulates. A wolf
chases its prey, lunging and biting at
the hindquarters and flanks. Attacks
on large calves, adult cattle, or horses
are characterized by bites and large
ragged wounds on the hindquarters,
flanks, and sometimes the upper
shoulders (Roy and Dorrance 1976).
When the prey is badly wounded and
falls, a wolf will try to disembowel the
animal. Attacks on young calves or
sheep are characterized by bites on the
throat, head, neck, back, or hind legs.
Wolves usually begin feeding on livestock by eating the viscera and hindquarters. Much of the carcass may be
eaten, and large bones chewed and
broken. The carcass is usually torn
apart and scattered with subsequent
feedings. A wolf can eat 18 to 20
pounds (8.1 to 9 kg) of meat in a short
period. Large livestock killed by
wolves are consumed at the kill site.
Smaller livestock may be consumed at
the kill site in one or two nights or they
may be carried or dragged a short distance from the kill site. Wolves may
carry parts of livestock carcasses back
to a den or rendezvous sites. Wolves
may also carry off and bury parts of
carcasses.
Wolves and coyotes may show similar
killing and feeding patterns on small
livestock. Where the livestock has been
bitten in the throat, the area should be
skinned out so that the size and spacing of the tooth holes can be examined.
The canine tooth holes of a wolf are
about 1/4 inch (0.6 cm) in diameter
while those of a coyote are about 1/8
inch (0.3 cm) in diameter. Wolves usually do not readjust their grip in the
C-125
throat area as coyotes sometimes do;
thus, a single set of large tooth holes in
the throat area is typical of wolf depredation. Coyotes will more often leave
multiple tooth holes in the throat area.
Attacks on livestock by dogs may be
confused with wolf depredation if
large tracks are present, especially in
more populated areas. Large dogs
usually injure and kill many animals.
Some dogs may have a very precise
technique of killing, but most leave
several mutilated livestock. Unless
they are feral, they seldom feed on the
livestock they have killed.
Wolves are attracted to and will scavenge the remains of livestock that have
died of natural causes. Dead livestock
in a pasture or on range land will attract wolves and increase their activity
in an area. It is important to distinguish between predation and scavenging. Evidence of predation includes
signs of a struggle and hemorrhaging
beneath the skin in the throat, neck,
back, or hindquarter area.
Tracks left by wolves at kill sites are
easily distinguishable from those of
most other predators except large
dogs. Wolf tracks are similar to coyote
tracks but are much larger and reveal a
longer stride. A wolf’s front foot is
broader and usually slightly longer
than its rear foot. The front foot of the
Alaskan subspecies is 4 to 5 inches
(10.2 to 12.7 cm) long (without claws)
and 3 3/4 to 5 inches (9.5 to 12.7 cm)
wide; the rear foot is 3 3/4 to 4 3/4
inches (9.5 to 12.1 cm) long and 3 to 4
1/2 inches (7.6 to 11.4 cm) wide (Murie
1954) (Fig. 3). Track measurements of
the eastern subspecies of gray wolf
found in Minnesota and Wisconsin are
slightly smaller. The distance between
rear and front foot tracks of a wolf
walking or trotting on level ground
varies between 25 and 38 inches (63.5
to 96.5 cm). When walking, wolves
usually leave tracks in a straight line,
with the rear foot prints overlapping
the front foot prints. In deep snow,
wolves exhibit a single-file pattern of
tracks, with following wolves stepping
in the tracks of the leading wolf.
Wolf tracks are similar to the tracks of
some large breeds of dogs but are genC-126
Gray Wolf
4 1/2"
3 1/2"
Coyote
2 1/2"
2"
Fig. 3. Gray wolf and coyote silhouettes and track measurements of each.
erally larger and more elongated, with
broader toe pads and a larger heel
pad. Dog tracks are rounder than wolf
tracks, and the stride is shorter. When
walking, dogs leave a pattern of tracks
that looks straddle-legged, with the
rear prints tending not to overlap the
front prints. Their tracks appear to
wander, in contrast to the straight-line
pattern of wolf tracks.
Scats (droppings) left in the vicinity of a
kill site or pasture may be useful in
determining wolf depredation. Wolf scats
are usually wider and longer than
coyote scats. Scats 1 inch (2.5 cm) or
larger in diameter are probably from
wolves; smaller scats may be from
wolves or coyotes. Wolf scats frequently
contain large amounts of hair and bone
fragments. An analysis of the hair contained in scats may indicate possible
livestock depredation. Since wolves
feed primarily on big game, their scats
are not as likely to contain the fine fur
or the small bones and teeth that are
often found in coyote scats.
During hard winters, gray wolves may
contribute to the decline of populations of deer, moose, and caribou in
northern areas (Gauthier and Theberge
1987). Studies in Minnesota (Mech and
Karns 1977), Isle Royale (Peterson
1977), and Alaska (Gasaway et al.
1983, Ballard and Larsen 1987) indicate
that predation by wolves, especially
during severe winters, may bring
about marked declines in ungulate
populations. It appears that after ungulate populations reach low levels,
wolves may exert long-term control
over their prey populations and delay
their increase.
Legal Status
All gray wolves in the contiguous 48
states are classified as “endangered”
except for members of the Minnesota
population, which are classified as
“threatened.” The maximum penalty
for illegally killing a wolf is imprisonment of not more than 1 year, a fine of
not more than $20,000, or both. The
classification of the wolf in Minnesota
was changed from “endangered” to
“threatened” in April 1978. This
classification allows a variety of
management options, including the
killing of wolves that are preying on
livestock by authorized federal or state
personnel. In Canada and Alaska, gray
wolves are considered both furbearers
and game animals and are subject to
sport harvest and control measures
regulated by province or state
agencies.
Red wolves are classified as “endangered” in the United States. This classification restricts control of red wolves
to authorized federal or state damage
control personnel, who may capture
and relocate red wolves that are preying on livestock.
Damage Prevention and
Control Methods
Exclusion
Fences may help prevent livestock
losses to wolves. Exclude wolves with
well-maintained woven-wire fences
that are 6 to 7 feet (1.8 to 2.1 m) high.
Install electrically charged wires along
the bottom and top of woven-wire
fences to increase their effectiveness.
Several antipredator fencing designs
are available (Thompson 1979,
Dorrance and Bourne 1980, Linhart et
al. 1984).
Cultural Methods
Livestock carcasses left in or near pastures may attract wolves and other
predators to the area and increase the
chances of depredation. Remove and
properly dispose of all dead livestock
by rendering, burying, or burning.
Calves and lambs are particularly vulnerable to predators, and cows are
vulnerable while giving birth. Confine
cows and ewes to barnyard areas during calving and lambing season if possible or maintain them near farm
buildings. Hold young livestock near
farm buildings for 2 weeks or longer,
before moving them with the herd to
pastures or rangeland. As newborns
mature they are better able to stay
with their mothers and the herd or
flock, and are less likely to be killed by
wolves.
Nighttime losses of sheep to wolves
can be reduced by herding the sheep
close to farm buildings at night or putting them in pens where possible.
If wolf depredation is suspected, livestock producers should observe their
livestock as often as possible. Frequent
observation may be difficult in large
wooded pastures or on large tracts of
open rangeland. The more often livestock are checked, however, the more
likely that predation will be discovered. Frequent checks will also help
the operator determine if any natural
mortality is occurring in the herd or
flock, and if any livestock thought to
be pregnant are barren and not producing. The presence of humans near
herds and flocks also tends to decrease
damage problems.
ably most effective in small, open pastures, around penned livestock, or in
situations where other lethal methods
may not be acceptable. They can also
provide short-term protection from
wolves while other control methods
are initiated.
Frightening
Trapping
Livestock guarding dogs have been
used for centuries in Europe and Asia
to protect sheep and other types of
livestock. The dogs are bonded socially
to a particular type of livestock. They
stay with the livestock without harming them and either passively repel
predators by their presence or chase
predators away. Livestock guarding
dogs are currently being used by producers in the western United States to
protect sheep and other livestock from
coyotes and bears. They have been
used in Minnesota to protect sheep
from coyotes and cattle from wolves.
The most common breeds of dogs
used in the United States are the
Anatolian shepherd, Great Pyrennees,
Komondor, Akbash dogs, Kuvasz,
Maremma, and Shar Plainintez. Livestock guarding dogs should be viewed
as a supplement to other forms of
predator control. They usually do not
provide an immediate solution to a
predator problem because time must
be spent raising puppies or bonding
the dogs to the livestock they protect.
Green et al. (1984) and Green and
Woodruff (1990) discuss proper methods for selecting and training livestock
guarding dogs and reasonable expectations for effectiveness of guarding
dogs against predators. Consult with
USDA-APHIS-ADC personnel for additional information.
Control of damage caused by wolves
is best accomplished through selective
trapping of depredating wolves. Another method is to classify wolves as
furbearers and/or game animals and
encourage sport harvest to hold wolf
populations at acceptable levels. The
Alberta Fish and Wildlife Division has
used this approach successfully in
Canada, where gray wolves are classified as furbearers. A similar approach
was proposed by the Minnesota Department of Natural Resources in 1980
and 1982 to help control the expanding
wolf population in Minnesota, but it
was ruled illegal because of the wolf’s
“threatened” status in Minnesota.
Strobe light/siren devices (Electronic
Guard [USDA-APHIS-ADC]) may be
used to reduce livestock depredation
up to 4 months. Such devices are prob-
Toxicants
None are registered for wolves in the
United States.
Fumigants
None are registered for wolves in the
United States.
Steel leghold traps, Nos. 4, 14, 114, and
4 1/2 Newhouse or Nos. 4 and 7
McBride are recommended for capturing wolves. Nos. 4 and 14 Newhouse
traps and the No. 4 McBride trap are
routinely used for research and depredation-control trapping of wolves in
Minnesota. Some wolf trappers feel
that Nos. 4 and 14 Newhouse traps are
too small for wolves. Where larger
subspecies of the gray wolf exist, use
the No. 4 1/2 Newhouse, No. 7
McBride, or the Braun wolf trap.
Set traps at natural scent posts where
wolves urinate and/or defecate along
their travel routes. Make artificial scent
posts by placing a small quantity of
wolf urine, lure, or bait on weeds,
clumps of grass, low bushes, log ends,
or bones located along wolf travel
routes. Place traps near the carcasses
of animals killed or scavenged by
C-127
wolves, at trail junctions, or at water
holes on open range. Set snares
(Thompson 4xx or 5xx, Gregerson No.
14) at holes in or under fences where
wolves enter livestock confinement
areas, or where wolves create trails in
heavy cover.
Use traps and snares that are clean and
free of foreign odor. Remove grease
and oil from new traps and snares, set
them outside until slightly rusted, and
then boil them in a solution of water
and logwood trap dye. Wear gloves
when handling traps and snares to
minimize human odor. While constructing the set, squat or kneel on a
clean canvas “setting cloth” to minimize human odor and disturbance at
the site. Traps may be either staked or
attached to a draghook. A trap that is
staked should have about 4 feet (1.2 m)
of chain attached to it. A trap with a
draghook should have 6 to 8 feet (1.8
to 2.4 m) of chain attached.
Shooting
Where legal, local wolf populations
can be reduced by shooting. Call
wolves into rifle range using a predator call or by voice howling.
Aerial hunting by helicopter or fixedwing aircraft is one of the most efficient canid control techniques
available where it is legal and acceptable to the general public. Aerial hunting can be economically feasible when
losses are high and the wolves responsible for depredation can be taken
quickly. When a pack of wolves is
causing damage, it may be worthwhile
to trap one or two members of the
pack, outfit them with collars containing radio transmitters and release
them. Wolves are highly social and by
periodically locating the radiotagged
wolves with a radio receiver, other
members of the pack may be found
and shot. The wolves wearing radio
collars can then be located and shot.
This technique has been used effectively by the Alaska Department of
Fish and Game.
Other Methods
In situations where lethal control of
depredating wolves may not be
authorized (USFWS 1987), aerial huntC-128
ing by helicopter can be used to dart
and chemically immobilize depredating wolves so that they can be relocated from problem areas. Some recent
wolf control actions in Montana have
used this technique.
Long-range land-use planning should
solve most conflicts between livestock
producers and wolves. When wolves
are present in the vicinity of livestock,
predation problems are likely to
develop. Therefore, care should be
taken in selecting areas for reestablishing wolf populations to assure that
livestock production will not be threatened by wolves.
Acknowledgments
Information contained in the sections on identification, habitat, food habits, and general biology are adapted from Mech (1970). The manual,
Methods of Investigating Predation of Domestic
Livestock, by Roy and Dorrance was very helpful
in developing the section on wolf damage identification. Recommendations for preventing or
reducing wolf damage were developed in association with Dr. Steven H. Fritts. We would also
like to thank Scott Hygnstrom for reviewing this
chapter and providing many helpful comments.
Figure 1 from Schwartz and Schwartz (1981).
Figure 2 adapted from Schwartz and Schwartz
(1981) by Jill Sack Johnson.
Figure 3 adapted from a Michigan Department
of Natural Resources pamphlet.
Economics of Damage
and Control
For Additional
Information
Wolves can sometimes cause serious
economic losses to individual livestock
producers. Minnesota, Wisconsin, and
Montana have established compensation programs to pay producers for
damage caused by wolves. In recent
years, $40,000 to $45,000 has been paid
annually to Minnesota producers for
verified claims of wolf damage. Control of depredating wolves is often economically feasible, but it can be timeconsuming and labor intensive. If
wolves can be trapped, snared, or shot
at depredation sites, the cost is usually
low.
Abraham, G. R., D. W. Peterson, J. Herring, M.
A. Young, and C. J. Carley. 1980. Red wolf
recovery plan. US Fish Wildl. Serv.,
Washington, DC. 22 pp.
Deer, moose, and other ungulates have
great economic and aesthetic value,
but wolves have strong public support. Thus, wolf control is often highly
controversial. Where wolves are the
dominant predator on an ungulate
species and prey numbers are below
carrying capacity, a significant reduction in wolf numbers can produce increases in the number of ungulate prey
(Gasaway et al 1983, Gauthier and
Theberge 1987) and therefore sometimes can be economically justified.
When control programs are terminated, wolves may rapidly recover
through immigration and reproduction (Ballard et al. 1987). Therefore,
wolf control must be considered as an
acceptable management option (Mech
1985).
Ballard, W. B., and D. G. Larsen. 1987.
Implications of predator-relationships to
moose management. Swedish Wildl. Res.
Suppl. 1:581-602.
Ballard, W. B., J. S. Whitman, and C. L. Gardner.
1987. Ecology of an exploited wolf
population in south-central Alaska. Wildl.
Mono. 98. 54 pp.
Carbyn, L. N., ed. 1983. Wolves in Canada and
Alaska: their status, biology, and
management. Can. Wildl. Serv. Rep. 45,
Ottawa. 135 pp.
Dorrance, M. J., and J. Bourne. 1980. An
evaluation of anti-coyote electric fencing.
J. Range Manage. 33:385-387.
Fritts, S. H., W. J. Paul, L. D. Mech, and D. P.
Scott. 1992. Trends and management of
wolf-livestock conflicts in Minnesota. US
Fish Wildl. Serv. Resour. Publ. 181.,
Washington, DC. 27 pp.
Gasaway, W. C., R. O. Stephenson, J. L. David,
P. K. Shepherd, and O. E. Burris. 1983.
Interrelationships of wolves, prey, and man
in interior Alaska. Wildl. Mono. 84. 50 pp.
Gauthier, D. A., and J. B. Theberge. 1987. Wolf
predation. Pages 120-127 in M. Novak, J. A.
Baker, M. E. Obbard, and B. Mallach, eds.
Wild furbearer management and
conservation in North America. Ont.
Minist. Nat. Resour., Toronto.
Green, J. S., and R. A. Woodruff. 1990. Livestock
guarding dogs: protecting sheep from
predators. US Dep. Agric. Info. Bull. 588.
31 pp.
Green, J. S., R. A. Woodruff, and T. T. Tueller.
1984. Livestock guarding dogs for predator
control: costs, benefits, and practicality.
Wildl. Soc. Bull. 12:44-50.
Linhart, S. B., J. D. Roberts, and G. J. Dasch. 1982.
Electric fencing reduces coyote predation
on pastured sheep. J. Range Manage.
35:276-281.
Linhart, S. B., R. T. Sterner, G. J. Dasch, and J. W.
Theade. 1984. Efficacy of light and sound
stimuli for reducing coyote predation upon
pastured sheep. Prot. Ecol. 6:75-84.
Mech, L. D. 1970. The wolf: the ecology and
behavior of an endangered species. The
Natural History Press, Doubleday, New
York. 384 pp.
Mech, L. D. 1985. How delicate is the balance of
nature? Natl. Wildl., February-March:54-58.
Mech, L. D., and P. D. Karns. 1977. Role of the
wolf in a deer decline in the Superior
National Forest. US Dep. Agric. For. Serv.
Res. Rep. NC-148. 23 pp.
Murie, O. J. 1954. A field guide to animal
tracks. The Riverside Press, Cambridge,
Massachusetts. 374 pp.
Paradiso, J. L., and R. M. Nowak. 1972. A report
on the taxonomic status and distribution of
the red wolf. US Dep. Inter. Special Sci. Rep.
Wildl. 145. 36 pp.
Peterson, R. O. 1977. Wolf ecology and prey
relationships on Isle Royale. US Natl. Park
Serv. Sci. Mono. 11. 210 pp.
Phillips, M. K., and W. T. Parker. 1988. Red wolf
recovery: a progress report. Conserv. Biol.
2:139-141.
Roy, L. D., and M. J. Dorrance. 1976. Methods
of investigating predation of domestic
livestock. Alberta Agric. Plant Ind. Lab.,
Edmonton. 54 pp.
Schwartz, C. W., and E. R. Schwartz. 1981. The
wild mammals of Missouri, rev. ed. Univ.
Missouri Press, Columbia. 356 pp.
Shaw, J. H. 1975. Ecology, behavior, and
systematics of the red wolf (Canis rufus).
Ph.D. Diss. Yale Univ. 99 pp.
Thompson, B. C. 1979. Evaluation of wire
fences for coyote control. J. Range Manage.
32:457-461.
US Fish and Wildlife Service. 1987. Northern
Rocky Mountain wolf recovery plan. US Fish
Wildl. Serv., Denver, Colorado. 119 pp.
Young, S. P., and E. A. Goldman. 1944. The
wolves of North America. Parts 1 and 2.
Dover Publ. Inc., New York. 636 pp.
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
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