Their color ranges from chocolate brown in males to a lighter, golden brown in females.

Males may reach 1,000 lbs. (more often 850 lbs., or 390 kg) and seven feet (2.1 m) in length.

Females grow to 220 lbs. (110 kg) and up to six feet (1.8 m) in length.

They have a "dog-like" face, and at around five years of age, males develop a bony bump on top of their skull called a sagittal crest. The top of a male's head often gets lighter with age.

These members of the otariid or walking seal family have external ear flaps and large flippers that they use to "walk" on land.

The trained "seals" in zoos and aquariums are usually California sea lions.

They breed mainly on offshore islands, ranging from southern California's Channel Islands south to Mexico, although a few pups have been born on Año Nuevo and the Farallon Islands in central California.

There is a distinct population of California sea lions at the Galapagos Islands.

A third population in the Sea of Japan became extinct, probably during World War II.

They are sometimes seen porpoising, or jumping out of the water, presumably to speed up their swimming.

Sea lions have also been seen "surfing" breaking waves.

California sea lions are opportunistic eaters, feeding on squid, octopus, herring, rockfish, mackerel, and small sharks.

In turn, sea lions are preyed upon by Orcas (killer whales) and great white sharks.

They nurse for at least five to six months and sometimes over a year.

Mothers recognize pups on crowded rookeries through smell, sight, and vocalizations. Pups also learn to recognize the vocalizations of their mothers.

Breeding takes place a few weeks after birth.

Males patrol territories and bark almost continuously during the breeding season.

The current population is approximately 200,000.