First described in 1751, the Steller
Sea Lion is named for naturalist George Wilhelm Steller, a
German naturalist serving on a Russian expedition. The
largest member of eared seal family, and adult male Steller
Sea Lion reaches 9-12 feet in length and weighs up to 2,500
pounds. Their size, along with a large, muscular neck and
thick mane, differentiate the males from females, who are
generally two to three times smaller than the male Steller
Sea Lion. These sea lions have a uniformly blond or reddish
coat that holds its color when wet and lightens with age.
Molting of the fur takes place annually – in spring or summer
for females and in later months for males.
Steller Sea Lions at Fort Ross, by Joe Mortenson
Fort Ross Steller Sea Lion Rock - map and photos
Steller Sea Lions typically range from
Southern California to Japan, with the Aleutian Islands as
the main breeding center. Breeding season, the peak
abundance for these sea lions on shore, occurs from the
middle of June into early July. During this time, males fast
to keep in defense of semiaquatic territories up to 20 feet
in diameter and guard up to 30 females. Although males
become sexually mature between ages 3-8, they rarely are
large enough to defend territories before the age of nine or
ten. While the nursing of the pups usually lasts 32-44
weeks, females have been known to arrive for breeding with
the previous year’s pup, nursing the newborn and older at
the same time.
Feeding and Behavior
Steller Sea Lions generally stay
between the coast and the continental shelf but have been
seen as far as 300 miles from shore. While their main diet
consists of many fish and squid, they also eat crustaceans
and mammals like harbor seals and sea otters. Steller Sea
Lions are generally considered non-migratory, though they
have been known to travel long distances to find prey; males
often hunt alone, whereas females and young form small
Entering the endangered species list,
the Steller Sea Lion population has declined steadily since
the 1940’s, with a decline as large as 50%. These sea lions
have been hunted for food, hides, blubber, fur, and more
recently to reduce competition with fisheries. Although
protective zones of 20 mile buffers around haul out sites
have been designated for their critical habitat, the
population is thought to be still declining, possibly due to
overfishing. Other threats to the species include
pollutants, interaction with fishing gear, and the
continuation of hunting despite illegality.
Sarah G., Joseph Mortenson, and Sophie Webb. "Steller Sea
Guide to Marine Mammals of the Pacific Coast: Baja,
California, Oregon, Washington, British Columbia.
Berkeley: University of
California, 2011. 392-403. Print.
Sea Lion (Eumetopias Jubatas)." NOAA
Fisheries Office of Protected Resources. N.p., 11 June
2013. Web. 07 Oct. 2013.