Subantarctic Fur Seal
Encyclopedia
The subantarctic fur seal (Arctocephalus tropicalis) is a fur seal
found in the southern parts of the Indian and Atlantic Oceans. It was first described by Gray in 1872 from a specimen recovered in northern Australia—hence the inappropriate tropicalis specific name.
s. The largest breeding colonies are on Gough Island
in the south Atlantic and Île Amsterdam
in the southern part of the Indian Ocean. Breeding grounds are also found at Marion Island in the Prince Edward Islands
(where there is an overlap with Antarctic fur seals), Crozet Islands
and the Macquarie Island
. Where grounds overlap, the subantarctic species can be identified by the orange colour on the chest.
There are about 300,000 of the species alive today, probably substantially down from when they were first discovered in 1810, as they were hunted for their pelts throughout the 19th century. Populations are recovering rapidly, though, in most areas whilst under the protection of the Convention for the Conservation of Antarctic Seals
. A small population on Heard Island is endangered. Unlike the Antarctic fur seal, whose genetic variation is low due to hunting making all but one breeding colony extinct by 1900, the diversity amongst subantarctic specimens remains high.
Fur seal
Fur seals are any of nine species of pinnipeds in the Otariidae family. One species, the northern fur seal inhabits the North Pacific, while seven species in the Arctocephalus genus are found primarily in the Southern hemisphere...
found in the southern parts of the Indian and Atlantic Oceans. It was first described by Gray in 1872 from a specimen recovered in northern Australia—hence the inappropriate tropicalis specific name.
Description
The subantarctic fur seal is medium-sized compared with other fur seals. Males grow to 2 m and 160 kg, whereas females are substantially smaller—1.4 m and 50 kg. Both sexes have a distinctive creamy-orange chest and face. The belly is more brownish. Males have a dark grey to black back. The female's is a lighter grey. Pups are black at birth, but molt at about three months old. The snout is short and flat. The flippers are short and broad. Subantarctic fur seals live for about 20–25 years.Distribution
Subantarctic fur seals are geographically widespread. As their name implies, they generally breed in more northerly locations than the Antarctic fur sealAntarctic Fur Seal
The Antarctic fur seal is one of eight seals in the genus Arctocephalus, and one of nine fur seals in the subfamily Arctocephalinae. As its name suggests, the Antarctic fur seal is distributed in Antarctic waters. Around 95% of the world population breeds at the Island of South Georgia...
s. The largest breeding colonies are on Gough Island
Gough Island
Gough Island , also known historically as Gonçalo Álvares or Diego Alvarez, is a volcanic island in the South Atlantic Ocean. It is a dependency of Tristan da Cunha and part of the British overseas territory of Saint Helena, Ascension and Tristan da Cunha...
in the south Atlantic and Île Amsterdam
Île Amsterdam
New Amsterdam, Amsterdam Island, or Île Amsterdam is a French island in the Indian Ocean located at . It is part of the French Southern and Antarctic Lands.- History :...
in the southern part of the Indian Ocean. Breeding grounds are also found at Marion Island in the Prince Edward Islands
Prince Edward Islands
The Prince Edward Islands are two small islands in the sub-antarctic Indian Ocean that are part of South Africa. The islands, named Marion Island and Prince Edward Island, are located at ....
(where there is an overlap with Antarctic fur seals), Crozet Islands
Crozet Islands
The Crozet Islands are a sub-antarctic archipelago of small islands in the southern Indian Ocean. They form one of the five administrative districts of the French Southern and Antarctic Lands.-Geography:...
and the Macquarie Island
Macquarie Island
Macquarie Island lies in the southwest corner of the Pacific Ocean, about half-way between New Zealand and Antarctica, at 54°30S, 158°57E. Politically, it has formed part of the Australian state of Tasmania since 1900 and became a Tasmanian State Reserve in 1978. In 1997 it became a world heritage...
. Where grounds overlap, the subantarctic species can be identified by the orange colour on the chest.
There are about 300,000 of the species alive today, probably substantially down from when they were first discovered in 1810, as they were hunted for their pelts throughout the 19th century. Populations are recovering rapidly, though, in most areas whilst under the protection of the Convention for the Conservation of Antarctic Seals
Convention for the Conservation of Antarctic Seals
The Convention for the Conservation of Antarctic Seals is part of the Antarctic Treaty System. It was signed at the conclusion of a multilateral conference in London on February 11, 1972...
. A small population on Heard Island is endangered. Unlike the Antarctic fur seal, whose genetic variation is low due to hunting making all but one breeding colony extinct by 1900, the diversity amongst subantarctic specimens remains high.
Further reading
- Wynen, Louise P. et al. "Postsealing genetic variation and population structure of two species of fur seal (Arctocephalus gazella and A. tropicalis)". Molecular EcologyMolecular ecologyMolecular ecology is a field of evolutionary biology that is concerned with applying molecular population genetics, molecular phylogenetics, and more recently genomics to traditional ecological questions...
. Vol. 9. (2000). pp. 299–314.