Walruses are famous for their tusks and are the only pinnipeds (true seals, sea lions and fur seals) that have them. These can grow up to 1m in length, and males tend to have larger tusks than females.

Statistics
Males (bulls): 4m, 1600kg, Females (cows): 2.6m, 1250kg.

Physical description
Both males and females bear large tusks, as well as stiff bristles called vibrissae that form a moustache. Their skin can be 4cm thick and the blubber beneath can reach 15cm in thickness.

Walruses lack external ears and their hind limbs can be rotated underneath their bodies to aid locomotion on land.

Distribution
Walruses inhabit the ice-floes in the shallower waters of the Arctic. They move south in the winter as the ice expands and north in the summer as the ice recedes.

Diet
Their main diet consists of snails, mussels, echinoderms (starfish, urchins and sea cucumbers) and crabs. Occasionally they will feed on fish, seals and young whales; holding them down on the ice with their flippers and tearing with their tusks.

Behaviour
Walruses are rapid, efficient swimmers and can reach speeds of up to 35 km/hr, although on average they swim at speeds of 7 km/hr. They are good divers and forage at depths of up to 90m.

Walruses live in large herds, sometimes with more than 2000 individuals. The larger bulls have the biggest harems of cows that they will defend from other amorous males.

Bulls use a variety of tactics to attract females including male-male combat and vocal displays. The males also communicate underwater with a series of whistles, sharp clicks, and bell-like sounds.

Reproduction
Mating is thought to occur underwater, and cows give birth to a single, well-developed calf. Walruses can live for up to 40 years.

Conservation status
Humans have exploited walruses for years. They have been harvested for their meat, skin and ivory tusks by native people. Although northern cultures are allowed to hunt walruses for subsistence living, poachers still kill them illegally for their ivory. The 2000 IUCN Red Data list categorises the subspecies O.r. laptevi as Data Deficient, as there is not enough reliable data to determine its conservation status.