South American fur seal (Arctocephalus australis )

Description

South American fur seal fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

South American fur seal description

The South American fur seal is a relatively stocky fur seal with a moderately long, flat-topped, pointed muzzle, a noticeable forehead, creamy white whiskers and prominent ears ^{(2) (6)}. The genus name, Arctocephalus, derives from the Greek for ‘bear-headed’, and the facial characteristics do indeed reflect the terrestrial carnivore ancestry of these seals ⁽⁷⁾. Male and female South American fur seals differ in appearance, the male being considerably larger and heavier than the female, with a mane of long hairs over the thick neck and shoulders ^{(2) (3) (6) (7)}. Adult males are blackish-grey in colour, sometimes with a slightly grizzled appearance, while females and immature males are dark brown to greyish-black, with paler underparts ^{(2) (3) (4) (6) (8)}. The fur on top of the flippers is usually quite dark ⁽²⁾. Pups are born with black fur, attaining adult colouration after around three to four months ^{(2) (3) (6) (7) (8)}. Like all fur seals, the coat of this species is characterised by its soft, dense layer of underfur beneath the short, thick, relatively stiff outer layer of hairs ^{(3) (6) (7) (9)}.

The South American fur seal is generally split into two subspecies, with Arctocephalus australis australis of the Falkland Islands reported to be slightly larger than Arctocephalus australis gracilis of mainland South America ^{(1) (3) (6)}. However, the validity of these subspecies is debated ^{(1) (4)}. The South American fur seal produces a variety of calls, including barks, whimpers, guttural threats, growls and, in females, a high-pitched wail, used to call to the pup ^{(1) (10)}.

Also known as

southern fur seal.

Synonyms

Arctophoca australis.

French

Otarie À Fourrure Australe.

Spanish

Oso Marino Austral.

Size

Male length: up to 1.9 m ^{(2) (3)}

Female length: up to 1.4 m ^{(2) (3)}

Male weight: 120 - 200 kg ^{(2) (3)}

Female weight: 30 - 90 kg ^{(3) (4)}

South American fur seal biology

The South American fur seal breeds between mid-October and mid-January, although the exact timing of births varies between colonies ^{(2) (3) (6) (7)}. Males are territorial, occupying breeding territories that average around 50 square metres, and driving away rival males with threatening calls and displays. Disputes can escalate into fights, sometimes resulting in serious wounds and scars ^{(2) (3) (6)}. Successful males will mate with a number of females ^{(6) (9)}, whereas non-territorial bachelor males will gather on separate beaches where no females are present ^{(3) (9)}. The female South American fur seal gives birth to a single pup each year, and mates again just a week or so after giving birth. However, the new embryo does not begin development for another three to four months, giving a total gestation period of about a year ^{(3) (4) (6) (7)}.

After giving birth and then mating again, the female South American fur seal begins to make foraging trips out to sea, alternating these with time spent ashore nursing the pup ^{(8) (9)}, which is relocated using a combination of vocalisations and scent ^{(3) (9)}. The pup, which measures around 60 to 65 centimetres at birth ^{(2) (6) (8)}, is not weaned until around eight months old, although it may continue to suckle for up to two years ^{(3) (6) (7)}, particularly if conditions have been poor ⁽⁸⁾. Females will often nurse a newborn at the same time as the previous year’s young ⁽³⁾. When food is scarce, the survival rate of pups may be quite low, and many are also swept away by storms or killed by adult male South American sea lions (Otaria flavescens), or by orcas (Orcinus orca) or sharks ^{(4) (8)}. Young females usually give birth for the first time at four years old, while males do not mature until around seven years ^{(1) (3) (4) (6)}, but are unlikely to hold a territory until at least eight years old ⁽⁸⁾. Female South American fur seals have been recorded living for nearly 30 years ⁽³⁾.

Although the seasonal movements of male and juvenile South American fur seals are not well known, most females remain near the breeding grounds throughout the year ^{(2) (6) (8)}. The diet of this species includes a variety of fish, crustaceans, cephalopods (such as squid), gastropods and other marine invertebrates ^{(2) (3) (4) (7) (8)}. Most hunting is done at night ^{(3) (8)}, and individuals may dive to around 30 metres for up to 3 minutes, although dives to 170 metres for up to 7 minutes have also been recorded ^{(1) (3) (8)}. At sea, the South American fur seal is often seen travelling or resting in groups, spending much time grooming when resting at the surface ^{(1) (2)}.

South American fur seal range

As its common name suggests, the South American fur seal occurs along both the Atlantic and Pacific coasts of South America, with a discontinuous distribution from Peru to Chile and from southern Brazil to Tierra del Fuego, and around the Falkland Islands ^{(1) (2) (3) (4) (7)}. Most of the population is concentrated on the coast of Uruguay ⁽¹⁾, and the species is also occasionally recorded outside of its normal range, in Colombia and in the Juan Fernández Islands, off the coast of Chile ^{(1) (6) (9)}. A. a. gracilis is found around the mainland, while A. a. gracilis occurs in the Falkland Islands ^{(1) (4) (6) (7)}.

South American fur seal habitat

This species breeds on land, with colonies generally found on rocky coasts, in caves, on ledges above the shoreline, or in areas strewn with boulders ^{(1) (3) (4) (9)}. The areas used by colonies generally need some shade as well as easy access to the ocean or to tidal pools ^{(1) (3)}. The South American fur seal’s distribution at sea is not well known, but it is thought to mainly use waters around the coast and over the continental shelf and slope, although it sometimes ranges to more than 600 kilometres offshore ^{(1) (2) (9)}.

South American fur seal status

Classified as Least Concern (LC) on the IUCN Red List ⁽¹⁾ and listed on Appendix II of CITES ⁽⁵⁾.

South American fur seal threats

The South American fur seal has a large population which is believed to be increasing, and is not currently considered at risk of extinction. However, it faces a number of threats, and the status of some local populations may be of concern ⁽¹⁾. This species has the longest continuous record of human exploitation of any fur seal, having long been hunted for its fur, skin and oil. Commercial hunting began as early as 1515 and continued until very recently in Uruguay ^{(1) (2) (4) (6) (7) (8)}. Some illegal poaching still continues, particularly in Peru ^{(1) (2) (4) (8)}, and the population in the Falkland Islands, which was greatly reduced by sealers in the late 19^thcentury, has yet to fully recover ^{(3) (7)}.

Further threats to the South American fur seal include accidental entanglement in fishing gear, pollution, oil spills, illegal exploitation as bait for the king crab fishery (although this is now likely to be decreasing), and a reduction in prey as a result of intensive commercial fishing ^{(1) (2) (4) (6) (8)}. The South American fur seal can also be severely impacted by El Niño events, which affect ocean currents, reducing food availability and causing the deaths of large numbers of adults and pups. This natural phenomenon has had its most serious effects on the populations in Peru ^{(1) (8)}. The presence of tourists may also affect the South American fur seal’s behaviour at breeding colonies, and such disturbance may need to be monitored ⁽¹¹⁾.

South American fur seal conservation

International trade in South American fur seals should be regulated under its listing on Appendix II of the Convention on International Trade in Endangered Species (CITES) ⁽⁵⁾, and the species is also legally protected and managed in most of the countries in which it occurs ⁽¹⁾. The South American fur seal has also been given protection by the establishment of a number of reserves and protected areas ⁽¹⁾, and studies into the responses of seals to tourist groups have suggested measures such as fences to limit human disturbance ⁽¹¹⁾. It has been recommended that South American fur seals in the Pacific should be given particular conservation attention, as the Peruvian and northern Chilean populations may qualify for a more threatened status ⁽¹⁾.

ARKive is supported by OTEP, a joint programme of funding from the UK FCO and DFID which provides support to address priority environmental issues in the Overseas Territories, and Defra

Find out more

To find out more about the South American fur seal and its conservation, see:

• Seal Conservation Society:
  http://www.pinnipeds.org/
• Jefferson, T.A., Leatherwood, S. and Webber, M.A. (1993) FAO Species Identification Guide. Marine Mammals of the World. FAO, Rome. Available at:
  http://nlbif.eti.uva.nl/bis/marine_mammals.php?menuentry=inleiding

For more information on conservation in the Falkland Islands, see:

• Falklands Conservation:
  http://www.falklandsconservation.com/
• UK Overseas Territories Conservation Forum - The Falkland Islands:
  http://www.ukotcf.org/territories/falkland.htm

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Glossary

Carnivore

An organism that feeds on flesh. The term can also be used to refer to a mammal in the order Carnivora.

Cephalopod

From the Greek for ‘head-foot’, a class of molluscs that occur only in marine habitats. All species have grasping tentacles, and either an internal or external shell. Includes nautiloids, cuttlefish, squids, octopuses, and extinct ammonites and belemnites.

Continental shelf

A region of relatively shallow water, not usually deeper than 200 metres, surrounding each of the continents.

Crustaceans

Diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, woodlice and barnacles.

El Niño

A natural phenomenon that happens every 4 to 12 years, and lasts for several months, when upwelling of cold, nutrient-rich water does not occur. This causes the warming of ocean surface water off the western coast of South America and causes die-offs of plankton and fish. It also affects Pacific jet stream winds, altering storm tracks and creating unusual weather patterns in various parts of the world.

Gastropods

A group of molluscs that have a well-defined head, an unsegmented body and a broad, flat foot. They can possess a single, usually coiled shell or no shell at all. Includes slugs, snails and limpets.

Genus

A category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.

Gestation

The state of being pregnant; the period from conception to birth.

Invertebrates

Animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.

Subspecies

A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.

Territorial

Describes an animal, a pair of animals or a colony that occupies and defends an area.

Territory

An area occupied and defended by an animal, a pair of animals or a colony.

References

1. IUCN Red List (September, 2010)
   http://www.iucnredlist.org/
2. Jefferson, T.A., Leatherwood, S. and Webber, M.A. (1993) FAO Species Identification Guide. Marine Mammals of the World. FAO, Rome. Available at:
   http://nlbif.eti.uva.nl/bis/marine_mammals.php?menuentry=inleiding
3. Nowak, R.M. (1991) Walker’s Mammals of the World. The Johns Hopkins University Press, Baltimore and London.
4. Reijnders, P., Brasseur, S., van der Toorn, J., van der Wolf, P., Boyd, I., Harwood, J., Lavigne, D. and Lowry, L. (1993) Seals, Fur Seals, Sea Lions, and Walrus. Status Survey and Conservation Action Plan. IUCN/SSC Seal Specialist Group, IUCN, Gland, Switzerland and Cambridge, UK. Available at:
   http://data.iucn.org/dbtw-wpd/edocs/1993-034.pdf
5. CITES (September, 2010)
   http://www.cites.org/
6. Macdonald, D.W. (2006) The Encyclopedia of Mammals. Oxford University Press, Oxford.
7. Arnould, J.P.Y. (2002) Southern fur seals, Arctocephalus spp. In: Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (Eds.) Encyclopedia of Marine Mammals. Academic Press, San Diego, California.
8. Seal Conservation Society - South American Fur Seal (Arctocephalus australis) (September, 2010)
   http://www.pinnipeds.org/species/samfursl.htm
9. Eisenberg, J.F. and Redford, K.H. (2000) Mammals of the Neotropics. Volume 3. The Central Neotropics: Ecuador, Peru, Bolivia, Brazil. University of Chicago Press, Chicago.
10. Phillips, A.V. and Stirling, I. (2001) Vocal repertoire of South American fur seals, Arctocephalus australis: structure, function, and context. Canadian Journal of Zoology, 79(3): 420-437.
11. Cassini, M.H., Szteren, D. and Fernández-Juricic, E. (2004) Fence effects on the behavioural responses of South American fur seals to tourist approaches. Journal of Ethology, 22: 127-133.