Southern fur seals

Scientific Classification

Kingdom: Anamalia (Animals)
Phylum:--- Chordata
Class:------ Mammalia (Mammals)
Order:-------- Carnivora (Carnivores)
Family:-------- Otariidae (Eared Seals)
Genus:--------- Arctocephalus Species:-------- 8 species

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:

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 males are considerably larger than the female, in some instances, up to five times as large. This makes them among the most sexually dimorphous mammals.

 
caption South American fur seal. Source: Wikipedia
caption New Zealand Fur Seal. Source: Petr Baum/BioLib/Encyclopedia of Life
 
 
caption Antarctic Fur Seal. Source: José Luis Orgeira/WoRMS/Encyclopedia of Life
 
caption South African fur seal. Source: Petr Baum/BioLib/Encyclopedia of Life
 
caption Guadalupe fur seal. Source:NOAA
 
caption Sub Antarctic fur seal. Source:Yan Ropert-Coudert/WoRMS/Encyclopedia of Life
 
caption Source: Collection Georges Declercq/WWF/Encyclopedia of Life
  

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 with a 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 eight species, the Guadalupe fur seal, is found in the northern hemisphere, and a second, the Galapagos fur seal, is found on the equator. 

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 and meat. Most of these species have, under legal protection, made a significant recovery. At this time, only the Galapagos fur seal is considered endangered.

Further Reading 

  1. Arctocephalus, Encyclopedia of Life (accessed April 5, 2009)
  2. 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)
  3. Seal Conservation Society (accessed April 5, 2009)
  4. The Pinnipeds: Seals, Sea Lions, and Walruses, Marianne Riedman, University of California Press, 1991 ISBN: 0520064984 
  5. Encyclopedia of Marine Mammals, Bernd Wursig, Academic Press, 2002 ISBN: 0125513402
  6. 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
  7. Walker's Mammals of the World, Ronald M. Nowak, Johns Hopkins University Press, 1999 ISBN: 0801857899 
  8. Arctocephalus, MarineBio.org (accessed April 5, 2009)
Glossary

Citation

Life, E. (2010). Southern fur seals. Retrieved from http://www.eoearth.org/view/article/156195

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