These intelligent and social animals congregate in large groups on land (called colonies) and smaller groups in the water (called rafts). Breeding areas are called rookeries. (Classification: Suborder Pinnipedia, Family Otariidae, Subfamily Otariinae, Genus Zalophus, Species californianus)

Anatomy: The California sea lion has a thick layer of blubber (fat), short, thick fur that is dark brown to buff-colored, and a dog-like head. Males (called bulls) are darker and bigger than females. Males also have a thick furry mane around the neck. Bulls weigh up to 850 pounds (380 kg) and are up to 8 feet (2.5 m) long. Females weigh up to 250 pounds (115 kg) and are up to 6.5 feet (2 m) long. The whiskers (called vibrissae) help the seal's sense of touch. The nostrils are closed in the resting state. The sea lion has small external ears and a good sense of hearing. It also has keen eyesight but no color vision.

Diet: Sea lions are carnivores (meat-eaters); they eat fish, squid, octopi, crabs, clams, and lobsters. Seals don't chew their food. They swallow it in large chunks. They can crush the shells of crustaceans and mollusks with their flat back teeth.

Predators: Sea lions are hunted by killer whales (orcas) and some sharks.