Fur Seals Eared Seals and Sea Lions: Otariidae

Physical characteristics: California sea lions have a torpedo-like body, with flippers for swimming and moving on land. Males have brown or black fur, a bulky upper body, and a thick mane over the shoulders. A crest, or a distinctive bump on the forehead, is topped with blonde or light brown hair. They weigh as much as 772 pounds (350 kilograms). Females are much lighter, weighing up to 220 pounds (100 kilograms), and are tan in color.

Geographic range: California sea lions live in the Pacific Ocean along central Mexico to southern California. In between breeding seasons, males migrate, travel, to feeding sites off Oregon, Washington, and British Columbia, Canada.

Habitat: California sea lions breed on sandy, gravel, or rocky beaches.

California sea lions are the fastest marine carnivore and can swim up to 25 miles (40 kilometers) per hour. (Phillip Colla/Bruce Coleman Inc. Reproduced by permssion.)

Diet: California sea lions are opportunistic feeders, eating whatever is available. They feed mainly on squid and octopuses, but also consume fish, including anchovies, salmon, rockfish, and small sharks. They eat at all hours of the day. They typically swallow small prey whole in water but take bigger prey to land to shake them into small pieces. Males prey on northern fur seal pups and small true seals.

Behavior and reproduction: California sea lions are active the whole day. They are the fastest marine carnivore and can swim up to 25 miles (40 kilometers) per hour. They often swim in groups, covering large distances by porpoising, leaping over water. They also rest together on the water surface in a horizontal position called rafting.

Breeding season lasts from May through July. Bulls wait for the pregnant cows to come ashore before establishing territories. After giving birth to one pup, mothers nurse their young, then forage at sea, sometimes taking the newborn with them. Three or four weeks later, mating occurs in the water. Mothers recognize their pup by sound and smell. A pup may nurse for a whole year at the rookery. The males leave for the ocean soon after breeding.

California sea lions and people: California sea lions are most familiar as talented performers in marine parks and circuses. Some fishermen consider them pests because they steal fish from nets. Sea lions have been trained by the U.S. Navy to detect suspicious swimmers and divers near military ships and ports because they have excellent underwater directional hearing and low-light vision and are able to make repeated deep dives. A sea lion can approach an intruder without being heard. Using its flippers, it will clamp a handcuffs-like device carried in its mouth onto the person's leg, allowing sailors to apprehend the suspect. The U.S. Navy has normally relied on sea lions to recover practice mines undersea.

Conservation status: The California sea lion is not a threatened species. ∎