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Animals Steller Sea Lion
Steller Sea Lion
Common Name: Steller Sea Lion
Scientific Name: Eumetopias jubatus
Description
Steller's
sea lion,
or northern sea lion, is the largest member of the family
of eared seals - Otariidae. A bull Steller's sea lion
weighs an average of 1,300 pounds and measures approximately
eleven feet long, and a female averages at 600 pounds and
nine feet. They were described and named by German naturalist
Georg Wilhelm Steller who sailed with Vitus Bering on his
voyages to the Bering Sea and North American coast
of the Pacific. Steller's sea lions range from the northern
islands of the Japanese archipelago north to the Bering Straits,
and south along the coast to northern California. Steller's
sea lions are voracious predators, feeding on pollock,
flounder, herring, capelin, Pacific cod, salmon, rockfish,
sculpins, squid and octopus. They are prey only to killer
whales, large sharks, and humans. Early people of the
north Pacific coast depended heavily on them for food, clothing,
and boat coverings. The estimated populations of Steller's
off Alaska declined from 242,000 animals in the early 1970s
to less than half of that now. Their dramatic decline is the
subject of intense study and is probably the result of many
factors including disease, environmental change, natural predation
on juveniles, and the activities of commercial fishing fleets.
Steller's sea lions are listed as a threatened species
under the Endangered Species Act.
Their center of abundance has been in the Aleutian Islands
and Gulf of Alaska where historically nearly three-fourths
of all Steller sea lions inhabiting U.S.
territory were found. Two populations are currently recognized.
The western population, located from Prince William Sound
Alaska westward, has declined by about 85% since the 1970s
for reasons that are poorly understood.
However,
they appear to be related to at least in part to prey availability.
The eastern population, located east of Prince William Sound
appears to be recovering slowly. Steller sea lions haulout
on land to mate, bear their young, nurse, avoid predators,
and rest. The location of rookeries is probably based on proximity
to food sources, protection from terrestrial and marine predators,
topography, surf conditions, and other factors.
Steller
sea lions are generally considered nonmigratory although
some individuals, particularly juveniles and adult males,
may disperse widely outside the summer breeding season. Most
adult sea lions return to their birth site for reproduction.
Range and Habitat
Found along the
rim of the North Pacific Ocean.
Life
20-30 years.
Physical Characteristics
| |
At Birth |
At Maturity |
| Length |
Unknown |
2.3 - 2.8m |
| Weight |
16.23 kg
(31-50 lb) |
263 - 566 kg
(770-1250 lb) |
Other Types of Sea Lions
 Calfornia Sea Lion
Australian Sea Lion
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