California sea lion
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.
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.
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.
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.
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).
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