Fur Seals Eared Seals and Sea Lions: Otariidae

Physical characteristics: Antarctic fur seals have a thick waterproof underfur and an overcoat of long guard hairs. Bulls, adult males, are dark brown or charcoal-gray. A long mane of hair protects bulls when fighting over breeding territories. Bulls measure about 6 feet 7 inches (2 meters) long and weigh up to 440 pounds (200 kilograms). Adult females, cows, are smaller in size, about 4 feet 5 inches (1.4 meters) long and weigh up to 110 pounds (50 kilograms). They are gray, with cream-colored throat and chest.

Geographic range: Antarctic fur seals live in the Southern Ocean surrounding Antarctica. They breed on the islands south of, or close to, the Antarctic polar front. About 95 percent breed on South Georgia in the South Atlantic Ocean.

Habitat: Antarctic fur seals live in the open seas and congregate on land to breed, molt, and rest.

Antarctic fur seal pups stay on land for about four months. Growing seals stay at sea for several years, returning only when they're ready to mate. (© Paul A. Souders/Corbis. Reproduced by permission.)

Diet: Antarctic fur seals are the only otariids that feed mainly on krill. They sometimes consume fish, squid, and birds.

Behavior and reproduction: Antarctic fur seals are solitary, alone, at sea, usually foraging at night. Adult and subadult males congregate on land to molt. Cows may assemble in herds but do not socialize. Growing seals stay at sea for several years, only returning to their birthplaces to mate for the first time.

In late October, bulls arrive at rookeries to claim territories. They quarrel, sometimes biting one another. Males fast, go without food, for as long as two months while protecting their territory. In November, cows arrive, choose a bull's territory, and give birth to a single pup conceived the previous year. A bull has an average of eleven to sixteen cows in his territory. At birth, the pup vocalizes with its mother. After nursing for a week to ten days, the cow mates with the territorial bull. The female then feeds at sea for up to six days. A returning mother calls out to her pup who answers back. After smelling the pup to make sure it is hers, and then nurses for three or more days. The periodic foraging and nursing lasts about four months. In April, all seals leave for the sea, each going its own way.

Antarctic fur seals and people: Once hunted almost to extinction for their fur, meat, and blubber, these seals are currently protected by international agreements and by the islands where they breed.

Conservation status: The Antarctic fur seal is not a threatened species. ∎