EARED SEALS

Long-nosed Fur Seal (Arctocephalus forsteri)

The Long-nosed Fur Seal (Arctocephalus forsteri) is known traditionally as the New Zealand Fur Seal. However it is also sometimes called the South Australia, Australasian or Antipodean Fur Seal. Because of this, we have made the decision to refer to it as the Long-nosed Fur Seal, which has been proposed for use in recent years. This eliminates any confusion over locations, and is a fitting description. The species is found widely in New Zealand, off the coast of southern Australia, and in Tasmania. They are ‘bear-headed’ seals like all but one of the fur seal species, and described as ‘sea bears’ by naturalists J. R. Forster and his son Georg during Captain Cook’s second voyage. This surname now features in their scientific name. A. forsteri are expanding populations across their range, and thus are categorised as Least Concern. Estimated population size = 200,000.
A. forsteri are moderately large fur seals (males up to 2 m long/ 200 kg, females up to 1.5 m/ 50 kg) with robust bodies. They are sexually dimorphic and the males have heavy chests, thick necks and manes, and large bulbous noses, while the females are smaller and less bulky. Fore and hind flippers are mid length, slender and almost triangular in shape, and heads are small with long faces and tapered, pointed snouts. Hence the name long-nosed. Male sea lions are usually black to dark grey, through to brown or grey-brown, with lighter flecks on the mane. They may show rufous or yellowish colouration around the snout, face or crown. Females are generally paler grey, through to an olive-brown, with tan or cream coloured undersides.
Feeding behaviour:
These fur seals consume cephalopods (mainly squid and some octopus), fish, birds, and crustaceans, and will take on a wide range of species, adapting to what is available and in season. Fish include anchovy, barracuda, cod, flounder, hagfish, lamprey, redbait, filefish, kingfish, lanternfish, and houndshark, and birds include penguins and shearwaters. When foraging, males tend too dive deeper than females, and they will hunt in both the benthos and the water column.
Breeding behaviour:
Sexual maturity – males 8-10 years old/ females 4-6 years old.
Male A. forsteri arrive at breeding colonies in spring (late October), and obtain territories which they vigorously defend throughout the season. The species is polygynous and one male typically has mating rights over 5-8 females, although each female will generally only copulate once per season. There is a 3 month delayed egg implantation period, after which the gestation will commence, lasting 9 months. Females haul out to bear their pups in November, December and January, and the pups are born already quite active, with a velvety black coat which moults to a paler grey-brown one 2-3 months on. After ~10 days the mother will start to forage for short durations at sea, leaving the pup ashore, who will join creches by about 3 weeks old when the females stay away for longer. By 2 months they will enter the water voluntarily, and weaning takes place at approximately 9-10 months old, by which time they will have developed an adult-like pelage and be competent divers. Moulting follows the breeding season in February/ March. Average lifespan for A. forsteri is around 15 years.
There are no subspecies of A. forsteri.

Photos: (1) Laureline Meynier (2, 3) Katharina Peters

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