California sea lion  Zalophus californianus

California sea lions can often be seen hauling out on the shore, buoys or docks. They have broad fore flippers, a narrow snout and external ears. Often when hauled out they defend their territories with aggressive physical displays and vocalizations which sound like dog barks and growls.

Range

California sea lions are migratory and live in the coastal waters of the North Pacific from Vancouver Island south to Mexico.  California sea lions are becoming more abundant in Washington and Oregon State and can sometimes be seen at most sites along The Whale Trail.

Biology

Male California sea lions have a robust body while females and juveniles are more slender. Males have a broad forehead with a sagittal crest, and their fur is medium to dark brown when dry.  Females are slightly lighter in color.  Pups are born dark and lighten over a couple months.  Their gestation period is ten months and pups are usually weaned by six months of age although some may nurse for up to one year.  They eat over fifty species of fish, squid, octopus, and mollusks.

Social Structure and Behavior

California sea lions use their fore flippers to propel themselves through the water, and can rotate their hind limbs forward in order to “walk” upon the land.  Another common behavior exhibited by sea lions is “sailing” where they hold their flippers above the water motionless for a long period of time.  This behavior regulates their body temperature. 

Adults are usually solitary except during the breeding season from May to July.  Males are polygamous, establishing breeding territories that may include up to fourteen females. 

California sea lions feed mainly in upwelling areas on a variety of prey such as squid anchovies, mackerel, rockfish, and sardines. They also take fish from commercial fishing gear, sport-fishing lines, and at fish passage facilities at dams and rivers.

Current and Historical Threats

The population of California sea lions is growing steadily and is estimated at around 20,000.  Causes of death include natural causes, disease, trauma and interactions with humans (fishing gear, gunshots).

Learn More!

Books:

California Sea Lion: Fast & Smart! (Blink of An Eye: Superfast Animals), 2010

Sea Lion by Caroline Arnold and Richard Hewett, 1994

Sea Lions (Early Bird Nature) by Frank J. Staub, 2000

Links:

http://www.marinemammalcenter.org/learning/education/pinnipeds/casealion.asp

http://animals.nationalgeographic.com/animals/mammals/california-sea-lion.html

http://www.nmfs.noaa.gov/pr/species/mammals/pinnipeds/californiasealion.htm

Sources

http://www.marinemammalcenter.org/learning/education/pinnipeds/casealion.asp

http://animals.nationalgeographic.com/animals/mammals/california-sea-lion.html

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Facts

Length

Adult ♂ : 7 ft (2.1 m)

Adult ♀ : 6 ft (1.8 m)

Birth Length :36 in (1 m)

Weight

Adult ♂ : 850 pounds (390 kg)

Adult ♀ : 220 pounds (110 kg)

Birth Weight : 15lbs (6.8 kg)

Life Expectancy

15+ years

Photos

The Whale Trail is a nonprofit organization in partnership with
Partners NOAA Seattle Aquarium People for Puget Sound Washington Department of Fish and Wildlife The Whale Museum National Marine Sanctuaries