Elke Wind

Amphibians of the South Coast:
Identification, Habitat Associations, and
Inventory Techniques
Elke Wind
Linda Dupuis
E. Wind Consulting, Nanaimo, B.C.
[email protected]; 250-716-1119
Golder and Associates, Squamish, B.C.
[email protected]
Amphibians of the South Coast
Group
Terrestrial breeding
Stream breeding
Lentic breeding
Common Name
Western Red-backed Salamander
Ensatina
Wandering Salamander
Coastal Tailed Frog
Coast Giant Salamander
Northwestern Salamander
Long-toed Salamander
Rough-skinned Newt
Pacific Treefrog
Western Toad
Red-legged Frog
Oregon Spotted Frog
American Bullfrog
Green Frog
Species
Plethodon vehiculum
Ensatina eschscholtzii
Aneides vagrans
Ascaphus truei
Dicamptodon tenebrosus
Ambystoma gracile
Ambystoma macrodactylum
Taricha granulosa
Hyla regilla
Bufo boreas
Rana aurora
Rana pretiosa
Rana catesbeiana
Rana clamitans
STATUS
Provincial BC listing COSEWIC
S4
Y
NAR
S4
Y
NAR
S4
Y
S3S4
B
SC
T
S2
R
S4S5
Y
NAR
S5
Y
NAR
S4S5
Y
S5
Y
S4
Y
SC
S3S4
B
SC
S1
R
E
SNA
exotic
SNA
exotic
Avoid I.D. Pitfalls
•
Learn the key morphological characteristics of different life stages that
help facilitate rapid, accurate species identification
–
–
–
–
–
–
•
relative body size
toe shape
eye location
webbing
eye mask
specific colour patterns (limited - for some species only)
If possible, take clear photographs from all angles
Morphology
Graphics from Corkran and Thoms 1996
Morphology
Graphics from Corkran and Thoms 1996
Terrestrial-breeding Salamanders
Western
redbacked
salamander,
Wandering
salamander, &
Ensatina
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
‘dainty’ limbs and bodies
Aquatic-breeding Amphibians:
Stream breeding – Coastal Tailed Frog & Coastal Giant Salamander
•
Associated with:
–
–
–
–
Photo: Elke Wind
small, cold mountain streams
step-pool morphology
cobbles
fish generally absent or in low densities
Photo: Elke Wind
Photo: Elke Wind
Coastal Tailed Frog
Terrestrial Form
•
•
•
•
Vertical pupil for life in a
gullies/steep environment
Granular skin
Front claws for climbing
Powerful hind feet for
moving through current
Coastal Tailed Frog egg masses
Strings of beige eggs deposited under large, anchored
boulders
Developmental Stages
Tailed Frog
Aquatic Form
•Speckled
•
•
Flattened profile/streamline
Oral disc for adhering to substrate
• Speckled
• White dot on tail tip
Aquatic-breeding Amphibians:
Stream breeding –Coastal Giant Salamander
Photo: Bill Leonard
Photo: Bill Leonard
Geographic location and habitat are key
Adults – mottled, no costal grooves or paratoid glands
Larva - broad, squarish head/snout; large gills
Photo: Bill Leonard
Aquatic-breeding Amphibians:
Lentic breeding
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Lentic Breeding Sites
Photo: Elke Wind
• Breed in a variety of sites – natural and
artificial
• Small seasonal (temporary, ephemeral)
wetlands are critical
• lack predators (fish, Bullfrogs)
• can be very productive
• have values beyond breeding (foraging,
hydration, cover)
Photo: Elke Wind
Photo: Elke Wind
Aquatic-breeding Amphibians:
Lentic breeding – Salamanders & Newts
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Aquatic-breeding Amphibians:
Lentic breeding - Frogs and Toads
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Exotic Species:
Bullfrog and Green Frog
Photo: Russ Brewer
Photo: Drew Kerr
Photo: Elke Wind
Photo: Elke Wind
Lentic-breeding Amphibians:
Identification
•
Many lentic breeding species lay their eggs in relatively open, shallow,
shoreline waters, attached to or among graminoid vegetation or sticks
– in some cases, it is easiest to identify species, and confirm presence, via egg
surveys (versus surveys for larvae)
•
Beyond morphological differences, you can use a variety of ‘tools’ to help
identify species (e.g., geographic location, elevation, the habitat type,
and the timing of egg laying)
Photo: Elke Wind
Pacific Treefrog
relatively small body size
highly variable colouration
toe pads (rounded discs)
eye mask
Photo: Elke Wind
more rounded snout compared to Rana
sp.
Photo: Elke Wind
Western Toad
Photo: Elke Wind
‘warts’ & paratoid glands
dorsal stripe (often)
short hind legs (crawling)
metamorphs ‘school’
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Red-legged Frog
brown
dorsolateral folds
long, ‘jumping’ hind legs
red legs
coarse green mottling in groin
Photo: Elke Wind
mask
Photo: Elke Wind
Oregon Spotted Frog
dorsolateral folds
spots on back
full webbing between hind toes
upturned eyes
long, ‘jumping’ hind legs
Photo: Bill Leonard
Photo: Bill Leonard
Green Frog and Bullfrog
Photo: Drew Kerr
Photo: Elke Wind
Green Frog
American Bullfrog
SPECIES IDENTIFICATION: Eggs
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
•
Timing/season
•
Shape/size/structure
•
Water body type
•
Attachment/how laid
– early spring versus summer
– string, mass, or individually laid; width of jelly layer
– grape, plum, grapefruit sized
– e.g., creek, ephemeral or permanent wetland
– branch, stick, thin-stemmed graminoid; floating
Photo: Elke Wind
SPECIES IDENTIFICATION - Larvae
Larva (salamanders): Gills visible outside of the body; front legs
develop first; all legs develop outside the body
•
Long-toed salamander
– long gills that taper at tip; bulky looking; emerge early in spring (can be found in
ephemeral waters)
•
Northwestern salamander
– large, bushy gills; can attain a large size; can be observed all year (permanent waters
only)
•
Rough-skinned newt
– small, dainty looking larvae; emerge later in season (can be found in ephemeral
waters)
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Rough-skinned Newt
larva
Photo: Elke Wind
Long-toed
Salamander larva
Photo: Elke Wind
Northwestern
Salamander
larva/neotene
SPECIES IDENTIFICATION - Tadpoles
Tadpoles (frogs and toads): no gills visible; rear legs develop first;
front legs develop inside body
•
Western toad
– black; school; eyes inset
•
Red-legged frog
– brown with gold flecks; eyes inset; high arching tail; attain relatively large size
•
Pacific Treefrog
– grey-brown; pale abdomen; eyes break body outline when viewed from above
Photo: Elke Wind
Photo: Elke Wind
Western toad
tadpole
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Photo: Elke Wind
Red-legged Frog
tadpole (Oregon
Spotted Frog)
Pacific Treefrog
tadpole
Amphibian Inventories
Photo: Elke Wind
•
Main question is usually:
– Do any (listed) amphibian species occur in the area?
•
Follow-up questions:
– Where do they occur?
– Any potential effects of proposed development?
– How can we mitigate effects of development?
• critical habitats present (e.g., breeding ponds)
• landscape context
– next closest potential breeding pond
– connectivity
RISC Lentic and Stream breeding
Amphibian Inventory Techniques
•
Sampling Intensity:
– Presence/not detected
– Relative abundance
•
Survey Techniques:
– There are three basic techniques, depending on your objectives and
the amount of effort you want to put into your surveys. Effort
increases with each technique:
• Call surveys
• Visual surveys
• Trapping (permit required)
Photo: Elke Wind
RISC Lentic and Stream breeding
Amphibian Inventory Techniques
•
Call Surveys
–
–
Effort and cost
•
Limited use on coast (few species have audible call)
Road surveys (e.g., to locate potential breeding sites/wetlands)
Visual Surveys
–
–
Optimize detection (e.g., limited time – look in optimal habitats) or
Follow more systematic design (e.g., search a variety of, or representative, habitat
types; standard sampling areas)
•
•
Time or Area Constrained Surveys (tracking effort allows comparison across time and space)
Trapping
–
–
–
–
Dipnetting
Funnel trapping
Cover boards
Pitfall traps
Photo: Elke Wind
Cost/Benefit of Inventory Techniques
•
Call Surveys
–
–
–
–
•
Visual Surveys
–
–
–
–
•
Calling adult males / breeding(?) (+/-)
Timing – has a narrow window (---)
Confirmed species i.d. (+)
Effort cost low (+)
All life stages (+)
Timing – larger window (+)
Can be biased / have errors (e.g., species i.d.) (-)
Effort/cost relatively low (+)
Trapping
–
–
–
–
Not all life stages (-)
Timing – larger window (+)
Less biased (+)
Time-consuming and costly (---)
Photo: Elke Wind
Lentic Breeding
Visual Survey Inventory Techniques
•
Visual Survey
–
•
belt/transect survey
•
•
•
walk shoreline
paddle
snorkel
•
•
•
•
Adults (active from Feb-Oct.)
Eggs – March/April
Larva – May-Aug.
Metamorphs – July-Sept.
Effort
Photo: Elke Wind
– at least 3 surveys (e.g., 1 per life stage/period mentioned above)
•
Equipment
•
•
•
•
•
•
•
waders and/or boat
polarized sunglasses (preferably conducted on a sunny day)
Ziplock bags/small container
i.d. field guide
hand nets
GPS
map of site
Stream Surveys
•
Visual Survey
–
–
•
Photo: Elke Wind
Effort
–
–
–
•
turn cobbles and rocks, holding hand net
directly below, tadpoles release and fall
into net
scan underside of boulders and stream
banks
area or time constrained
e.g., 20 person-minute search per reach
ideally, multiple reaches per stream
Equipment
•
•
•
•
•
•
rubber boots
hand nets (reinforced)
plastic bucket
habitat description card
GPS
map of site
Photo: Elke Wind
Handling & Disinfection
•
Photo: Elke Wind
Clean gear between sites (watersheds)
– e.g., 4% bleach solution for 15 minutes
– see protocol by Brent Matsuda and included with MOE sampling permits
– Amphibian Disease website = http://www.jcu.edu.au/school/phtm/PHTM/frogs/ampdis.htm
•
Use clean, wet hands at all times (or nitrile gloves – not latex)
– avoid bug dope, moisturizers, etc.
– dampen hands in water
•
Minimize direct handling time
– e.g., put individuals into containers or Ziplocks asap after capture
– release asap
•
Keep animals moist and cool
– place containers on water/in shade during processing
•
Data / Measurements
– site, date, recorder, survey method, weather
– species; size (snout to vent length; total length for salamanders/larvae);
abnormalities; life/developmental stage