Like eared seals, walruses can turn their hind limbs forward and thus use all four
                        limbs in moving when ashore. Male walruses, which are larger than the females,
                        average about 3 m (about 10 ft) in length and weigh more than 900 kg (more than
                        2000 lb). Both the male and female have a massive body with thick, wrinkled, nearly
                        hairless skin. Both have a relatively small head with no external ears, a broad,
                        bristled muzzle, and enormously elongated upper canine teeth forming heavy tusks.
                        The tusks, approximately 1 m (approximately 3 ft) long in some males, are used to
                        rake the ocean bottom for mollusks and shellfish, which constitute the principal food
                        of the walrus; they are also used as weapons in fighting and as hooks in climbing
                        on the ice. The Pacific walrus differs from the Atlantic subspecies in that its nostrils
                        are more laterally located and are not visible when the animal is viewed from the
                        front. 

                        Walruses are highly social animals, congregating in herds?sometimes numbering
                        more than 100 animals?on or near the shore or among the ice floes. The bellowing
                        of a herd can be heard for great distances. Walruses are gentle unless attacked;
                        the whole herd will come to the defense of a member in danger. Polar bears are the
                        chief natural predator of the walrus, and humans hunt the animal for its valuable
                        ivory tusks and for its flesh and blubber. Excessive hunting has reduced the world
                        population sharply.