Introduction

The Order Pinnipedia is related to the Carnivora and was formerly classified within that Order. It includes three Families: the Otariidae or eared seals, including fur seals and sea lions; the Odobenidae, including the Atlantic and Pacific walruses; and the Phocidae or true seals, including the Phocinae (northern species) and the Monachtinae (Antarctic ice breeding seals and the elephant seals).

Of seven species of seal considered here, three (elephant seal and two species of fur seal) tend to be sub-Antarctic in distribution, but penetrate further south, particularly in the maritime Antarctic. The other four (Weddell, Ross, crabeater, leopard) are primarily fast ice or pack ice animals. The Weddell (at South Georgia only) and leopard seals also have sub-Antarctic populations. In elephant and fur seals, the males are much larger than the females; in the other species the females are slightly larger than the males (Laws, 1984). There is no sexual dimorphism of colour or pattern. The elephant and fur seals are grey brown, lighter ventrally but with no patterned markings (except small, lighter scars); the other species are all strikingly marked with spots, stripes or blotches, particularly when freshly moulted. Juvenile and adult coats are similar; pups of elephant and fur seals are born with uniform black fur or lanugo; in other species the newborn coat is mottled greyish brown (Weddell), pale ‘milk coffee’ coloured (crabeater) or strongly patterned like the adult (leopard, Ross).