The large crest of muscle on the males’
heads paired with the long, narrow snout sets the California
Sea Lion apart from similar species.
Known for their intelligence, playfulness, and
agility, California Sea Lions are found throughout the West
Coast, from Baja California to British Columbia. Their long,
wing-shaped front flippers give them a streamlined figure
when swimming, as well as considerable mobility on land.
Their playful attitude has also been noted when seen blowing
bubbles, surfing, and playing with inanimate objects.
Their crests grow with age and
contribute to the general sexual dimorphism of the species
that is also easily seen in the size difference between the
two genders. While the average male is 7-8 feet in length
and 700-800 pounds, the average female is 6-6.5 feet long
and weighs 250lbs. The uniformly dark brown, tan, or silver
coats of both male and female California Sea Lions are
short, coarse, and lack insulation, causing them to rely on
blubber for warmth. This fur more dark and sleek when wet
and is molted annually.
Feeding and Behavior
California Sea Lions are both social
and vocal creatures; communicating with a series of barks,
grunts, and growls, they feed cooperatively in groups up to
500. They feed mostly on Pacific Hake, sardines, Market
Squid, rockfish, salmon, and anchovy, but the proportions
depend on relative abundance in the area at the time. Their
average foraging trips last between one and two days, but up
to ten if food is scarce. Diving mostly during sunrise and
sunset at an average depth of 110 feet, they take in about
7% of their body weight daily.
Rarely more than 20 miles from land,
Sea lions come ashore throughout the year, mostly
congregating on land during breeding season and migrating
towards prey outside of breeding season. Sandy beaches are
their preferred haul out sites, but they will also climb
rocky bluffs and manmade structures. When breeding, males
fight for space, resulting in evenly spaced territories in
intervals of 35 feet where males often claim up to 14
females. Females give birth once a year between May and
August to single pup. These pups imprint on their mothers at
birth, creating a very strong relationship, and nurse for up
to one year. Most of the breeding takes place in the
California Channel Islands.
Population Threats and Conservation
Sea Lions have been hunted for food,
hides, blubber, and whiskers; two sea lions yielded one
barrel of oil. This killing, however, was banned in the
United States, Mexico, and Canada in the early 1970’s. Since
then, the California Sea Lion has become the most abundant
pinniped in the California Current with a still-growing
population of 240,000 in 2005.
G., Joseph Mortenson, and Sophie Webb. "California Sea
Guide to Marine Mammals of the Pacific Coast: Baja,
California, Oregon, Washington, British Columbia.
Berkeley: University of
California, 2011. 403-12. Print.
Sea Lion (Zalophus Californianus)." NOAA
Fisheries Office of Protected Resources. N.p., 11 June
2013. Web. 07 Oct. 2013.