These are the largest of the sea lions and will sometimes kill other pinnipeds.

Life span
30 years.

Statistics
Males (bulls): 3m, 1000kg. Females (cows): 2m, 300kg.

Physical description
Steller's sea lions are the largest of the sea lions. They are born with a dark brown coat that becomes a reddish-brown as they develop into adults.

Distribution
Steller's sea lions inhabit the cooler waters of the North Pacific. They are divided into two stocks - the western population (Gulf of Alaska, Bering Sea, Russia and Japan), and the eastern population (California, British Columbia and south east Alaska).

Diet
Steller's sea lions feed near the shore on squid, octopus and fish, such as herring, mackerel and salmon.

Behaviour
They have also been known to hunt northern fur seal pups and harbour seals. They are hunted by sharks and killer whales. Steller's sea lions are known to make dives of 400m in search of food.

Males are polygamous and territorial on land. They defend the boundaries of their territories with ritual threat displays to other males.

Reproduction
The females give birth to one pup that is nursed for at least a year, sometimes for up to three years. After nine days of giving birth, the females may spend 1-3 days in the sea - feeding, and then will return to her young for a further few hours.

She will carry out this ritual until the pup is a month old, and will be able to join her in the sea.

Conservation status
Steller's sea lions are on the 2000 IUCN Red List as Endangered. The western population has been decreasing in numbers. This may be due to declining fish stocks.

Since 1990, no-trawl buffer zones of 10 nautical miles (N.M.) and 20 N.M. around various Steller's sea lion rookeries have been established by the U.S. Sea lions are killed annually for subsistence by Aleutians in Alaska.