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STELLER OR NORTHERN SEA LION
Eumetopias jubatus
meaning of Latin name: having a broad forehead and mane
DESCRIPTION:
Steller or northern sea lions are sometimes confused with California
sea lions, but are much larger and lighter in color. Males may grow
to 11 feet (3.25 m) in length and weigh almost 2,500 pounds (1120
kg). Females are much smaller, and may grow to nine feet (2.9 m)
in length and weigh 1,000 pounds (350 kg). Steller sea lions are
light tan to reddish brown in color. They have a blunt face and
a boxy, bear-like head. Adult males do not have a visible sagittal
crest (the bump on the top of their heads) as is seen in adult male
California sea lions. Stellers have a bulky build and a very thick
neck, which resembles a lion's mane, hence the name "sea lion."
RANGE/HABITAT:
Stellers are found throughout the North Pacific Rim from Japan to
central California. Unlike California sea lions, Stellers tend to
remain off shore or haul out in unpopulated areas. Breeding occurs
along the North Pacific Rim from Año Nuevo Island in central
California to the Kuril Islands North of Japan, with the greatest
concentration of rookeries (breeding grounds) in the Gulf of Alaska
and Aleutian Islands.
MATING AND BREEDING: Pups are born on offshore islands from
mid-May to mid-July, and weigh 35-50 pounds (16-23 kg). Mothers
stay with pups for one to two weeks before hunting at sea. Then
they spend roughly equal amounts of time hunting and nursing pups
on land. Pups usually nurse for a year, but some continue to nurse
for up to three years. Mating occurs 10-14 days after the pups are
born. Dominant mature males maintain territories for one to two
months and mate with many females. During the breeding season, males
do not eat.
BEHAVIOR:
Steller sea lions eat a variety of fishes, invertebrates, and occasionally
other pinnipeds. Known predators are killer whales (orcas) and white
sharks.
STATUS:
The current population of Steller sea lions is about 40,000, with
about 500 living in California. However, there is great concern
about this population, which has dropped by 80% in the last 30 years.
In 1997, the western stock in Alaska was listed as endangered and
the eastern stock of the Continental United States and Canada was
listed as threatened. Reasons for this decline are not known. However,
researchers believe that a decline in the fish they eat is the biggest
cause. The decline of fish could be due to increasing commercial
fisheries in the Gulf of Alaska. Drowning, entanglement in nets,
and gunshot are all possible reasons for the Stellers' decline.
Stellers are protected under the Marine Mammal Protection Act, which
forbids the killing, harming, or harassing of any marine mammal,
as well as the Endangered Species Act. With this federal protection,
there is hope for the recovery of the Steller sea lion population.
AT THE MARINE MAMMAL CENTER: The Marine Mammal Center has
not rescued many Steller sea lions because they haul out on offshore
rocks. Most Steller sea lions that The Center rescues are orphaned
pups. In addition, Stellers are susceptible to many of the same
diseases as California sea lions, such as leptospirosis and San
Miguel sea lion virus. Because of their threatened status, Steller
sea lions released from The Center are fitted with a satellite tag.
This has enabled us to track their movements. To date, the three
Steller pups released, Artemis, Mozart, and Bethoven, have thrived
in the wild; foraging and hauling out with other Steller sea lions.
May be reprinted for scientific and educational purposes
Revised 1/01
Learn more about the following:
Harbor Seal
Northern
Elephant Seal
California
Sea Lion
Northern Fur
Seal
Guadalupe
Fur Seal
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