A large
marine mammal inhabiting open water at the edge of the Arctic ice pack, the walrus,
Odobenus rosmarus, is closely related to the seal but forms its own family, the
Odobenidae. Walruses lack external ears and have long tusks, a thick, wrinkled, nearly
hairless skin except for long bristles on the cheek pads, and reversible hind flippers
that facilitate locomotion over ice. They grow to enormous size: males may be 3.7 m (12
ft) long and weigh up to about 1,400 kg (3,000 lb); females are only slightly smaller.
Walruses
use their tusks to climb up onto the ice, to stir up clams and other bottom shellfishes,
and in fighting. Most walruses live in herds, and in the late winter and spring they drift
along on large floating ice fields.
Female walruses have one calf every other year, in April or early May; the calf may stay
with the mother for two years. Some walruses live for up to 40 years. Long a source of
food, ivory, blubber-oil fuel, and hides to Eskimos, walrus populations have been greatly
reduced by hunting.