Southern fur seals
Scientific Classification Kingdom: Anamalia (Animals) |
The Southern fur seals (scientific name: Arctocephalus) are a genus of eight species of fur seals (there are nine species of fur seals in total). The genus is part of the family of Eared seals, which includes fur seals and sea lions. The eights species are:
- South American fur seal (Arctocephalusaustralis)
- New Zealand fur seal (also Antipodean fur seal, Australasian fur seal, Black fur seal, and South Australian fur seal.) (Arctocephalusforsteri)
- Galápagos fur seal (Arctocephalusgalapagoensis)
- Antarctic fur seal (also Kerguelen fur seal) (Arctocephalusgazella)
- Juan Fernandez fur seal (Arctocephalusphilippii)
- South African fur seal (also Cape fur seal, Australian fur seal, Brown fur seal , Giant fur seal, Tasmanian fur seal, and Afro-Australian Fur Seal) (Arctocephaluspusillus)
- Guadalupe fur seal (Also Lower Californian fur seal) (Arctocephalustownsendi)
- Subantarctic fur seal (also Amsterdam fur seal) (Arctocephalustropicalis)
Contents
Physical Appearance
Fur seals (Southern fur seals comprise eight of nine fur seal species) differ from the true seals in having small external earflaps and hind flippers that can be turned to face forwards. Together with strong front flippers, this gives them extra mobility on land and an adult fur seal can move extremely fast across the beach if it has to. They also use their front flippers for swimming, whereas true seals use their hind flippers.
Like other Eared seals, the malesareconsiderably larger than the female, in some instances, up to five times as large. This makes them among the most sexually dimorphous mammals.
Reproduction
South fur seals are polygynous, meaning that males will establish territories (often created and protected through fighting or shows of aggression) within which they establish a harem and breed witha number of females (the range varies with species). Males will come ashore and establish their territories at the beginning of the mating season.
Females typically arrice a few weeks after the males and select their mates for the coming season. Before mating, the females will first give birth to a pup conceived during the mating season of the prior year. Mating occurs typically 6-12 days after the birth of the pup.
The fertilised egg within the female fur seal undergoes a three - four month period of delayed implantation. This ensures that that the developing pup will be born at the right time the following year when the animals return to their breeding grounds.
Females will nurse their young for anything from seven months to three years.
Distribution
Southern fur seals are, as their name suggests primarily found in the southern hemisphere. One of the eightspecies, the Guadalupe fur seal,is found in the northern hemisphere,and a second, the Galapagos fur seal, is found on the equator.
- South American fur seal - Coast of South America from southern Peru to Southern Brazil, Falkland Islands, South Georgia
- New Zealand fur seal- South Island, New Zealand, the Bounty Islands,the coast of southwestern Australia
- Galapagos fur seal- Galapagos Islands
- Antarctic fur seal - Seasonally ice-free islands south of the convergence in theSouthern Ocean
- Juan Fernandez fur seal- Juan Fernandez Islands off the coast of Chile
- South African fur seal-Coast of Namibia and western/southern South Africa, southwest coast of Australia
- Guadalupe fur seal - Isla de Guadalupe, off the coast of Baja California, Mexico (breeding, non-breedinf observe farther south and north)
- Subantarctic fur seal- islands just north of the convergence/Southern Ocean
Conservation Status
The Southern fur seals were heavily hunted up to the end of the nineteenth century, at which point many of the species were close (and in some cases thought be) extinct. As their name suggests, their primary value was for their skins and the thick underfur. They were also exploited for their oil andmeat. Most of these species have, under legal protection, made a significant recovery. At this time, only the Galapagos fur sealis considered endangered.
- South American fur seal Least Concern
- New Zealand fur seal Least Concern
- Galapagos fur seal Endangered
- Antarctic fur sealLeast Concern
- Juan Fernandez fur sealNear Threatened
- South African fur seal Least Concern
- Guadalupe fur seal Near Threatened
- Subantarctic fur seal Least Concern
Further Reading
- Arctocephalus, Encyclopedia of Life (accessed April 5, 2009)
- Arctocephalus,Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey, 2008, Animal Diversity Web (accessed April 5, 2009)
- Seal Conservation Society (accessed April 5, 2009)
- The Pinnipeds: Seals, Sea Lions, and Walruses, Marianne Riedman, University of California Press, 1991 ISBN: 0520064984
- Encyclopedia of Marine Mammals, Bernd Wursig, Academic Press, 2002 ISBN: 0125513402
- Marine Mammal Research: Conservation beyond Crisis, edited by John E. Reynolds III, William F. Perrin, Randall R. Reeves, Suzanne Montgomery and Timothy J. Ragen, Johns Hopkins University Press, 2005 ISBN: 0801882559
- Walker's Mammals of the World, Ronald M. Nowak, Johns Hopkins University Press, 1999 ISBN: 0801857899
- Arctocephalus, MarineBio.org (accessed April 5, 2009)