Walrus, large marine mammal found in Arctic regions. Walruses range from 2.7 to 3.56 m (8.9 to 11.7 ft) in length and weigh 800 to 1,700 kg (1,800 to 3,700 lbs); males are larger than females. Both the male and female have massive bodies with thick, wrinkled, hairy skin that becomes nearly hairless with age. Their tusks, about 1 m (about 3 ft) long in some males, are used as weapons in fighting and as hooks in climbing on the ice. Although it was once thought that the tusks were also used to rake the ocean bottom for mollusks and shellfish, which constitute the principal food of the Walrus, it is now believed that the sensitive whiskers and fleshy snout play a primary role in detecting and removing prey from the ocean floor. Walruses are highly social animals, congregating in herds—sometimes numbering several thousand animals—on or near the shore or among the ice floes. The bellowing of a herd can be heard for great distances.