Arctocephalus forsteri

(Lesson, 1828) - New Zealand fur seal

Distinctive Characteristics

New Zealand fur seals have rather generic southern fur seal features. The muzzle is moderately long, flat, and pointed, with a fleshy, somewhat bulbous nose that extends past the mouth and ends in nostrils that point ahead with a slight down angle. In adults, the vibrissae are cream to white and of medium length, reaching to about the ear. The flippers are of medium length, with the characteristic hindflipper toe configuration. The ears are long and prominent. The head of pups is rounded in profile. Adult males develop a mane of elongated, coarse guard hairs, which cover a thickened neck, chest, and shoulders. The nose is larger and more bulbous in adult males than in females.

Adult males are dark brownish grey above and paler below. In paler animals, the tops of the flippers are usually a contrasting darker brown. There is a grizzling of white, which creates a silvery sheen on dry animals. The muzzle is paler, grey to rusty tan. So, too, are the ear pinnae and the area around their insertions. Adult females are generally paler on the underside of the neck and chest. Pups are blackish, except for a whitish muzzle. They moult to adult pelage at 2 to 3 months.

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

Can be confused with

New Zealand fur seals share their range with a number of other otariids, including Antarctic, subantarctic, and Australian fur seals, and Hooker's and Australian sea lions. Shape of the head and muzzle, presence of a dense underfur, coloration, size and prominence of ear pinnae, and length of the toes on the hindflipper readily distinguish New Zealand fur seals from both sea lions. Separating the fur seal species is more difficult and may be problematic for subadults and females. Generally, note the length of the muzzle and size of the nose, coloration (especially of the front of the body), prominence and coloration of the ear pinnae, and relative lengths of the flippers.

Size

Adult males are up to 2 m and 120 to 200 kg, females 1.5 m and 30 to 50 kg. Pups average 3.3 to 3.9 kg and 40 to 55 cm at birth.

Geographical Distribution

New Zealand fur seals are distributed in 2 geographically isolated populations. In New Zealand, they occur around both the North and South Islands, with rookeries south and west to all of New Zealand's subantarctic islands. They are present, but do not breed, on Macquarie Island. A separate population also occurs on offshore islands in southern and western Australia. New Zealand fur seals prefer rocky habitat with shelter, particularly on locations more exposed to wind and weather; they readily enter vegetation. Little is known of distribution at sea, although they apparently prefer waters of the continental shelf and slope.

Biology and Behaviour

Breeding occur from mid-November to January. Most pups are born from late November to mid-December. The number of animals ashore at rookeries declines rapidly in January. New Zealand fur seals are considered non-migratory. At sea they actively groom and raft in a variety of postures.

New Zealand fur seals appear to feed mainly at night. Diet includes a wide variety of pelagic near-surface fishes and squids, and benthic prey, particularly octopuses. They occasionally feed on penguins and other marine birds.

Exploitation

Prehistoric hunting was pursued by native peoples of Australia and New Zealand. Commercial sealing by Europeans was carried out in earnest in the early 19th Century and the population of these fur seals in New Zealand, Australia and the subantarctic was drastically reduced and whole colonies were wiped out. There have been sporadic culls as numbers rebounded in the 20th Century. At present, New Zealand fur seals are protected throughout their range by New Zealand and Australian laws. Threats today include entanglement in fishing gear and debris and the potential depletion of their food resource base due to intensive commercial harvesting of fish and squid.

IUCN Status

Insufficiently known.

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