Pinnipeds - Seals and Sea Lions*

Pinnipeds - Seals and Sea Lions *
Seals, sea lions and walrus are
currently placed in the Suborder
Pinnipedia in the Order Carnivora,
which also includes the bears, dogs,
raccoons, and weasels (including
otters). Three families of living
pinnipeds are recognized, the
Phocidae (earless seals or true
seals), the Otaridae (eared seals or
fur seals and sea lions) and the
Odobenidae (walrus). The word
pinnipedia translates from Latin as
"fin foot," referring to their often large
fin-like flippers. All pinnipeds must
come ashore to breed, give birth and
nurse their young, though some species are at sea for several months at a time while
others return to the shore every day.
Phocid seals include elephant seals, several species of ice seals (some are found in
fresh water lakes) and the harbor seal of temperate coastlines. Monk seals can be
currently found in the Mediterranean Sea and Hawaii, although there is one species
indigenous to the Caribbean Sea that is commonly believed to be extinct. Four phocid
species inhabit the Antarctic ice pack. All of these seals have a vertical undulating
motion when they move on land called "galluphing" because their pelvic bone does not
provide a stable anchor point for the rear flippers to engage the ground for propulsion
and the rear flippers are directed rearward.
The otariids, fur seals and sea lions, are found in temperate colder waters and are
associated in tropical latitudes with cold water upwelling currents. They have external
ear flaps (giving them the distinction of being called "eared seals"). The arm pit or axilla
encloses the forelimbs to about the level of the forearm. In all the pinnipeds, the hind
limbs are enclosed within the body to the level of the ankle. Sea lions and fur seals can
rotate their hind feet forward and therefore use their pelvic bone to propel themselves
forward with considerable speed.
The walruses, odobenids, are currently found in both Pacific and Atlantic Arctic ice pack
areas, but in colonial times they were found as far south as Sable Island off Nova
Scotia. Their mode of locomotion is similar to that in otariids. Under the Marine Mammal
Protection Act walruses are within the jurisdiction of the U.S. Fish and Wildlife Service.
We recommend you visit that agency's Web site for more information.
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Pinnipeds on the Endangered Species List
There are currently four species of pinnipeds in the United States on the endangered
species list. These include the Caribbean monk seal (commonly believed to be extinct),
the Guadalupe fur seal, the Hawaiian monk seal, and the Steller sea lion. The
Caribbean monk seal and the Hawaiian mink seal are listed as endangered, while the
Guadalupe fur seal is listed as threatened. The Steller sea lion is listed as endangered
in the western part of its range, west of 144 deg. W. longitude, but is listed as
threatened east of that longitude.
Commercial
hunting of
seals in the
18th and 19th
century and
in the early
years of this
century
played a
large role in pinniped population declines. Other
factors involved have been coastal development
and competition with man for prey species.
Caribbean Monk Seal: The Caribbean monk seal
was listed as endangered throughout its range on April
10, 1979. The last reliable sighting of a Caribbean monk
seal occurred in 1952. None were seen in aerial
surveys in 1973, and no confirmed sightings have been
reported since then. Many scientists believe that the
species has been extinct since the early 1950s. No
recovery effort is currently being made for this species.
Photo: New York
www.monachus.org
Zoological
Society,
1910,
courtesy
of
Guadalupe Fur Seal: The major cause of the
Guadalupe fur seal's decline was commercial hunting in
the late 1700s and early 1800s, and this species was exterminated in southern
California waters by 1825. Commercial sealing continued in Mexican waters through
1894. Currently the Guadalupe fur seal seems to be expanding its range, with regular
sightings of animals on San Miguel and San Nicolas Islands off the southern California
coast.
Hawaiian Monk Seal: The Hawaiian monk seal was listed as endangered throughout its
range on November 23, 1976. Counts have been made at the atolls, islands, and reefs
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where they haul out in the northwest Hawaiian Islands since the late 1950s. NMFS
estimates that there are approximately 1400 animals remaining. In 1982, the highest
count for all atolls was about 50 percent of the highest counts made in 1957-58. The
Hawaiian monk seal is most abundant on Kure Atoll, Pearl and Hermes Reef, Lisianski
Island, Laysan Island, French Frigate Shoals, Necker Island, and Nihoa Island. This
species is vulnerable to human disturbance on pupping and haulout beaches,
entanglement in marine debris, and incidental take in commercial fisheries, as well as
possible die-offs from disease and naturally occurring biotoxins, male mobbing of
female seals, and shark predation. For more information about Hawaiian monk seals,
including what NMFS is doing to protect them,
visit the NMFS website.
Steller Sea Lions - our Steller sea lion page is
currently being revised. For information about
Steller sea lions, -please visit the NMFS Alaska
Region's page.
For more information about pinnipeds, visit the
NMFS Alaska Region or the NMFS Northwest
Region seal web pages. You may also visit the
NMFS page of FAQs on Pinnipeds.
Photo credits: NMFS file photo, P. Michael Payne, NMFS
AKR, NMFS file photo
* Excerpted from the NMFS Website
Visit NMFS on the Web for current population statistics:
http://www.nmfs.noaa.gov/prot_res/PR2/Stock_Assessment_Program/individual_sars.html
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Northern Elephant Seal
Mirounga angustirostris
Size: Males are typically 15 to 20 feet long and weigh between 2.5 to 4 tons. Females are 11 to 12 feet long
and weigh approximately 1 ton. Male elephant seals are 20 times as heavy as a male harbor seal and up to 3
times as heavy as the female elephant seal.
Appearance: Large (see size). Males have long thick snout. Skin has a gray-brown coloration and has
little hair and no spots. Relatively small fore flippers.
Behavior: Lethargic. Commonly submerges for 20 minutes; is capable of diving to depths in excess of
2,500 feet.
Northern Fur Seal
Callorhinus ursinus
Size: Males are on average a little less than 7 feet in length and can weigh up to 600 pounds. Females and
juveniles can get up to 5 feet in length and weigh up to 135 pounds.
Appearance: Generally gray to black in color. Can be distinguished from the California sea lion by its
much smaller size, more pointed nose and more pronounced ears.
Behavior: The northern fur seal is one of the most oceanic of the pinnipeds. It spends about eight months
of the year at sea without touching land. It is able to sleep at the water surface and might likely survive without
ever coming ashore if it weren't required for breeding. This pinniped does not bark.
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California Sea Lion
Zalophus californianus
Size: Older males grow to 8 feet and 600 pounds; younger males are from 200 to 400 pounds. Females may be up
to six feet in length and weigh up to 200 pounds.
Appearance: Dark brown or black in color. Pointed muzzle. Small cone-shaped ears. Long front and rear
flippers. The forehead of the male has a pronounced crest and is often a lighter color.
Behavior: Loud and gregarious. Acrobatic swimmers.
Guadalupe Fur Seal
Arctocephalus townsendi
Size: Males are between 5 and 6 feet in length and weigh approximately 300 pounds. Females reach a length of
approximately four feet.
Appearance: Dark brown to blackish gray in color. Longer more pointed snout compared to northern fur seals.
Behavior: Has a quiet growl. Are occasionally to rarely sighted in the Channel Islands.
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Harbor Seal
Phoca vitulina
Size: Length to 6 feet. Sexes similar in size and appearance.
Appearance: Grayish, spotted pelt. Large brown eyes. Harbor seal pups are dirty white or gray, and darken to
dark gray or black as they mature.
Behavior: Shy but curious. Often floats in vertical position with head above water; sinks below surface when
alarmed. Can dive to 300 feet for 20 mins. More typically it will dive 3 to 5 minutes before bobbing up to breathe.
Northern (Steller) Sea Lion
Eumetopias jubatus
Size: Males can reach lengths of up to 10 feet and weigh 2,200 pounds. Females are much smaller, at 7 feet
in and 600 pounds.
Appearance: Color varies from a light golden or yellow to brown. Mature males have a thick neck and
yellowish mane. The Steller seal lion is the larger relative of the California sea lion. It can be distinguished
from the California sea lion by its larger size, lighter color, broader head, lack of a prominent forehead crest,
and differences in vocalization.
Behavior: In comparison to the California sea lion the Steller sea lion is relatively silent. When it does
vocalize, rather than barking it makes a low roar.
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PINNIPED BREEDING CYCLES FOR THE
CHANNEL ISLANDS AND SANTA BARBARA AREAS
SPECIES
BREEDING
PUPPING
ELEPHANT SEAL
(E) January to (L) February
(E) January to (E) February
HARBOR SEAL
(E) March to (E) May
(E) February to (E) April
(E) June to (L) July
(L) May to (E) July
CALIFORNIA SEA LION
(E) June to (L) July
(L) May to (E) July
NORTHERN FUR SEAL
(E) June to (L) July
(L) May to (E) July
•GUADALUPE FUR SEAL
(E) June to (L) July
(E) June to (L) July
•STELLAR SEA LION
E= early in the month
L= late in the month
• = Represents the historical pattern of breeding and pupping cycles for these species.
Current data suggest that these species do not breed or pup in the Channel Islands chain any
longer.
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Pinniped & Sea Otter Status Tables
Table 1. Pinnipeds: Otariids
Stock Name
& Size1
Genus & Species
Guadalupe fur seal
(Arctocephalus townsendi )
--7,408
San Miguel Island
9,424
Eastern
47,8852
Northern fur seal
(Callorhinus ursinus )
Steller sea lion
(Eumetopias jubata )
California sea lion
(Zalophus californianus
californianus )
U.S.
237,000 to 244,000
Protected Status4
Protected, depleted and
strategic under MMPA.
Threatened under ESA.
Protected under MMPA
Protected, depleted and
strategic under MMPA.
Threatened under ESA.
Protected under MMPA
Seasonality
Normal Habitat
Summer and fall
Pelagic
May to November
Pelagic
Summer and fall
Coastal
Year-round
Coastal
Table 2. Pinnipeds: Phocids
Stock Name
& Size1
Genus & Species
California Breeding
101,000
California
34,233
Northern elephant seal
(Mirounga angustirostris )
Pacific harbor seal
(Phoca vitulina richardsi )
Protected Status4
Seasonality
Normal Habitat
Protected under MMPA
December to August Coastal and offshore
Protected under MMPA
Year-round
Coastal
Table 3. Carnivores: Mustelids
Genus & Species
Southern sea otter
(Enhydra lutris nereis )
Population Size3
Spring survey
3,026
Protected Status4
Protected, depleted and
strategic under MMPA.
Threatened under ESA.
Seasonality
Year-round
Normal Habitat
Coastal
1. Carretta, et al. 2007. U.S. Pacific Marine Mammal Stock Assessments: 2006. NOAA Technical Memorandum, NOAA-TM-NMFS-SWFSC-398.
2. Angliss, R.R., and R.R. Outlaw. 2007. Alaskan Marine mammal Stock Assessments, 2006. NOAA Technical Memorandum,
NOAA-TM-NMFS-AFSC-168.
3. USGS. 2007. Spring 2007 Mainland California Sea Otter Survey Results. http://www.werc.usgs.gov/otters/ca-surveyspr2007.htm
4. MMPA = Marine Mammal Protection Act;
ESA = Endangered Species Act
Created by: Howorth/ SBMMC
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