The Northern Fur Seal, Callorhinus ursinus, is an eared seal. It is the only species in the genus Callorhinus. It is found in the north Pacific Ocean.

Physical description

The Northern Fur Seal, has substantial physical differences compared to its cousins: its head is smaller, snout shorter and the hindflippers are the largest of any eared seal. The "fingers" on the hindflippers are conspicous by their length. Males are substantially larger (2m, 270kg) and darker-coloured (the pelage is dark brown or black) than the female (1.5m, 60kg, light brown to grey). Males live for up to 20 years, and females 25.

Northern Fur breeding grounds are fairly densely packed, though activities at sea are generally solitary. Pups are weaned in October. They enter the water and start heading south towards the end of November. Individuals return to the breeding grounds in May. Males aggressively establish their territory and herd females into it. Males are polygynous with each breeding season. June is birthing month. Having said with their pups for the first eight to ten days of their life, females then begin foraging trips lasting about a week. These trips last for about four months before weaning.

Fur Seals eat a mixture of pelagic fish and squid.

Range

The Northern Fur Seal is found in the north Pacific - its southernmost reach is a line that runs roughly from the southern tip of Japan to the southern tip of Baja California, the Sea of Okhotsk and the Bering Sea. The largest breeding colonies are the Pribilof Islands and Commander Islands in the Bering Sea. Breeding also occcurs on Robben Island in the Sea of Okhotsk, islands around the north of Japan and San Miguel Island off California.

There are estimated to be around 1.2m Northern Fur Seals across the range. The other fur seal found in the northern hemisphere is the Guadalupe Fur Seal - the two species' ranges overlap in the north-east Pacific.

Hunting

Northern Fur Seals have been a staple food of native Russian and Alaskan Inuit peoples for thousands of years. It also provides a fine pelt. Indeed its genus name comes from the Greek for "beautiful hide".

More substantial harvests beginning in the eighteenth century lead to a decrease in numbers. A multi-national agreement of 19xx ended hunting of seals at sea with the proviso that a managed take at the Pribilof islands could take its place. Commercial hunting ended completely in 1984, however a subsistence hunt continues - around 1,500 animals are taken each year.

References

• Randall R. Reeves, Brent S. Stewart, Phillip J. Clapham and James A. Powell (2002). National Audubon Society Guide to Marine Mammals of the World. Alfred A. Knopf, Inc. ISBN 0375411410.