Arctocephalus pusillus

(Schreber, 1776) - Australian fur seal

Distinctive Characteristics

These are the largest fur seals. The head is large and wide, and the muzzle is robust (the most “sea lion-like” of any fur seal). The muzzle is pointed and flat to slightly upturned, most conspicuously in subadult males. It extends well past the mouth and ends in a bulbous fleshy nose (more heavily developed in males). The ear pinnae are long and prominent. The vibrissae are moderately long, regularly reaching past the ears.

Adults are greyish to brown; South African seals are generally darker than those from Australia. The guard hairs have a grizzled appearance. Males initially darken with age. Then as adults, the mane becomes light coloured. Females can also be lighter in the chest region, but less so than in males. The muzzle, lower jaw, and face are paler. The tops of the flippers are very dark. The ear pinnae and their insertions are frequently paler. Adult females and subadults are paler below, especially on the chest and underside of the neck. Pups are blackish, with variable hints of silver overall. They first moult at 4 to 5 months to an olive grey coat. As juveniles, they moult a year later into a silvery grey coat.

The dental formula is I 3/2, C 1/1, PC 6/5.

Can be confused with

South African and Australian fur seals share their range with a number of vagrant or wandering otariid species. Of these, they may be confused with Antarctic, subantarctic, and New Zealand fur seals, and Australian sea lions. The most important features are overall size, coloration, head and muzzle size and shape, proportional length of flippers, and size and prominence of ear pinnae. Differentiating subadult and female fur seals may be very difficult. The Australian race of this fur seal should be readily separable from the Australian sea lion.

Size

Adult males are up to 2.3 m long and weigh 200 to 360 kg, females to 1.8 m and 41 to 120 kg. Newborns are about 60 to 70 cm and 4.5 to 7 kg (South African) or 80 cm and 12.5 kg (Australian).

Geographical Distribution

South African fur seals (A. p. pusillus) are found along the south and southwestern coasts of Africa from South Africa to Angola. Australian fur seals (A. p. doriferus) are found along the coast and continental shelf and slope waters from Victoria, along southern New South Wales, including Tasmania, and the islands of Bass Strait. They range up to 160 km offshore. On land, they have a decided preference for rocky habitat.

Biology and Behaviour

Breeding is from late October to the beginning of January. The peak is in the first week of December, although there is some variation between colonies. At sea, these seals are found alone or in small groups of up to 15 animals, and often in huge rafts or herds adjacent to rookeries. They adopt a variety of postures while resting in the water, including the “jug-handle.” These fur seals also purposely entangle themselves in rafts of kelp, possibly using the kelp as an anchor and for camouflage. When traveling rapidly, they sometimes porpoise. Neither of the populations is migratory; they move more locally within their restricted ranges.

These fur seals are opportunistic feeders that take a wide variety of prey, including pelagic, mid-water, and benthic animals, such as schooling and solitary fish, cephalopods, and crustaceans. They can dive to at least 200 m and are thought to feed most often during the day.

Exploitation

Commercial sealing began off southern Africa in the early 17th Century, and in the late 18th Century off Australia. By the late 19th Century both populations had been severely depleted. At about this time fur seals became partially protected in Australia, with hunting fully halted there in the 1970s. The government in South Africa took control and managed the sealing in the late 19th Century; however, it continues to this day.

IUCN Status

Insufficiently known.

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