Galapagos fur seal (Arctocephalus galapagoensis)

Also known as: Galapagos Islands fur seal
Synonyms: Arctocephalus australis galapagoensis, Arctophoca galapagoensis
  
French: Arctocéphale Des Galapagos
Spanish: Oso Marino De Las Galápagos
KingdomAnimalia
PhylumChordata
ClassMammalia
OrderCarnivora
FamilyOtariidae
GenusArctocephalus (1)
SizeMale length: up to 150 cm (2)
Female length: up to 130 cm (2)
Average male weight: 64 kg (3)
Average female weight: 27 kg (3)

The Galapagos fur seal is classified as Endangered (EN) on the IUCN Red List (1) and listed on Appendix II of CITES (4).

The scientific name of the Galapagos fur seal (Arctocephalus galapagoensis) comes from Greek words meaning ‘bear headed’ (3), and with its short, pointed muzzle, small, button-like nose and fairly large eyes (5), this marine mammal does indeed bear a resemblance to its land-dwelling, carnivorous ancestors (3).

The coat of the Galapagos fur seal varies from dark brown to dark grey, with light-tipped, longer guard hairs that give a grizzled appearance (3) (6). Male Galapagos fur seals also have a mane of slightly longer hairs, from the top of the head to the shoulders (5). Both the muzzle and the fur on the underside is paler (3), with females and subadults having a pale greyish-tan chest and rusty-tan belly (5). The skin on the flippers is blackish (6).

Galapagos fur seal pups have a blackish-brown coat, sometimes with greyish or whitish margins around the mouth and nose (5).

The Galapagos fur seal is endemic to the Galapagos Islands (3), where it is widely distributed. The main colonies occur on the western islands of the archipelago, with Isla Fernandina and Isla Isabela holding the largest populations (2).

A colony of Galapagos fur seals has also recently been found on Isla Foca, northern Peru, possibly having moved there due to rising sea temperatures (7).

When ashore, the Galapagos fur seal prefers rocky areas where it can seek shelter from the sun under ledges and between large boulders (5).

On the rocky shores of the Galapagos Islands, six to ten Galapagos fur seals may occupy an area of about 100 square metres (8). Grouping together in this manner may be largely due to the rarity of suitable rocky sites, but it also has the benefit of making females less vulnerable to predation or harassment (9). Breeding males establish larger territories, of around 200 square metres, which encompass a number of females (8).

The breeding season of the Galapagos fur seal lasts from mid-August to mid-November (5), when the cooler temperatures mean less heat stress and a greater availability of prey (8). A peak of births occurs in the last week of September or the first week of October (5), when females give birth to a single pup that has been carried for eight to twelve months (3). For the first five to ten days, the female will stay with the newborn, but after this period she alternates one to three days of feeding at sea with one to two days ashore with the pup. The pup is nursed for two to three years, sometimes even longer (8).

Just eight days after giving birth, the female Galapagos fur seal mates again (8). Being a polygynous mammal, one male may mate with between six and sixteen females within his territory (9). The rough terrain and large size of the male’s territory means that it can be difficult to successfully defend all the females within the area, and a rival male may sometimes invade and mate with a female (8). Defending a territory with threats and fighting can be tiring work, so the male Galapagos fur seal can often be seen cooling off in the sea at midday (8).

Although all female Galapagos fur seals mate shortly after giving birth, only a small percentage will give birth the following year if they are still feeding a pup. If a pup is born to a female that is still feeding a pup from the previous year, the newborn often starves, or is occasionally killed by the older sibling (8). Females mature at three to four years of age, while males become territorial breeding bulls between seven and ten years old (2).

While the Galapagos fur seal is capable of diving to much greater depths, it mainly undertakes short dives to between 10 and 50 metres (2) (3), where it feeds on a variety of fish and small squid (2) (5).

During the 19th century, the Galapagos fur seal was severely impacted by the large-scale commercial seal hunting that was rampant at the time (3) (8). By the early 20th century, the Galapagos fur seal was believed to be extinct, until a small colony was discovered in 1932-33 (8). Since then, and following the end of extensive seal hunting (3), numbers have increased substantially (8), and the Galapagos fur seal is no longer exploited (2).

Today, the spread of feral dogs on the Galapagos Islands may jeopardise the future of some of the fur seal colonies (2).

The Galapagos fur seal is fully protected by the Galapagos National Park Service under Ecuadorean law (2). It will also benefit from the management of the Galapagos Islands and the surrounding waters as a national park and marine reserve (5) (10). As one of the first sites to be designated a Natural World Heritage Site (10), the recognition of the Galapagos’ incredible and unique ecosystem will hopefully ensure the preservation of the islands’ fauna and flora for generations to come.

Find out more about the conservation of the Galapagos fur seal and its habitat:

More information on the Galapagos fur seal:

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

  1. IUCN Red List (November, 2008)
    http://www.iucnredlist.org/
  2. 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, Gland, Switzerland.
  3. 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, London.
  4. CITES (April, 2008)
    http://www.cites.org/
  5. Jefferson, T.A., Leatherwood, S. and Webber, M.A. (1993) Marine Mammals of the World. Food and Agriculture Organisation of the United Nations, Rome.
  6. Clark, T.W. (1975) Arctocephalus galapagoensis. Mammalian Species, 64: 1-2.
  7. Organization for Research and Conservation of Aquatic Animals (ORCA) (November, 2011)
    http://www.orca.org.pe/
  8. Nowak, R.M. (1999) Walker’s Mammals of the World. Johns Hopkins University Press, Baltimore, Maryland.
  9. Bowen, W.D., Beck, C.A. and Austin, D.A. (2002) Pinniped ecology. In: Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (Eds.) Encyclopedia of Marine Mammals. Academic Press, London.
  10. UNEP-WCMC: Galapagos National Park and Marine Reserve (May 2008)
    http://www.unep-wcmc.org/medialibrary/2011/06/28/62f3bab1/Galapagos%20Islands.pdf