Family: Odobenidae, Walruses view all from this family

Description Upper canines form large tusks, up to 40" (1 m) long in Pacific bull, 14" (35 cm) in Atlantic bull; cow's tusks shorter, more curved. Nearly hairless body may be yellowish, reddish, pink, or brown to almost white. Muzzle covered with about 400 bristles up to 12" (30 cm) long. No external tail. Short, round head. Fore flippers lack nails. Atlantic race: L male 8'2"-11'10" (2.5-3.6 m); female 7'7"-9'6" (2.3-2.9 m); Wt male 1,650 lb (750 kg), female 1,250 lb (570 kg). Pacific race larger: Wt male 3,300 lb (1,500 kg), female 2,200 lb (1,000 kg).

Similar Species No other aquatic carnivore has tusks.

Breeding Mates January-February; 1 calf born mid-April to mid-June of following year. Newborn weighs 100-150 lb (45-68 kg).

Habitat Along continental shelf of northern seas, especially edge of pack ice; usually in water less than 60' (18 m) deep.

Range Atlantic race: Arctic seas around Greenland south to Hudson Bay. Pacific race migratory: generally in Chukchi Sea off ne Siberia in summer, Bering Sea off sw Alaska in winter.

Discussion A sociable animal, the Walrus gathers in a mixed herd of up to 2,000 bulls, cows, and calves when feeding and migrating, as well as when hauled out on ice floes, although the sexes sometimes segregate during the nonbreeding season. An ungainly creature, the Walrus spends more time out of the water than other aquatic carnivores, sunbathing and resting on ice and beaches for long periods. Individuals in the herd compete for the best basking spots. This animal will dive immediately if it scents humans. It sometimes sleeps at sea, hanging vertically in the water, held up by a pair of inflatable air sacs in the neck. Today the Walrus spends most of its time on pack ice, but some evidence indicates that before disturbance by humans, it lived more on islands and rocky shores. An excellent swimmer, this mammal uses its hind flippers alternately for propulsion. It can travel about 15 mph (25 km/h) and is able to dive to 300 feet (90 m) and remain submerged for almost half an hour. During deep dives, blood flows from the skin to the internal organs, leaving the skin pale; after the animal surfaces, its heartbeat is unusually rapid at first, with the increased blood flow gradually restoring the skin to its usual color. Walruses use their tusks to defend themselves against predators, including local people in kayaks. Tusk size is important in helping bulls establish dominance. Tusks are also used as grappling hooks to help the animal haul out onto ice or remain anchored to it. The Walrus generally feeds in early morning, foraging along the sandy sea bottom using its tusks as sled runners and the highly sensitive bristles on its face to search for prey. Mollusks, especially clams, and crustaceans are its chief foods. The animal uses its dome-shaped mouth like a vacuum cleaner to suck the meat from the shells, which are then discarded. A Walrus can eat as many as 3,000 to 6,000 clams at a single feeding. Softshell crabs, shrimp, worms, and a few fish supplement the diet. An adult requires about 100 pounds (45 kg) of food daily, but may go without food for a week at times. The bull sometimes preys on seals, grabbing a victim with his fore flippers and stabbing it with his tusks. Walruses have been known to eat small whales, probably ones that are already dead. These polygamous animals court at sea and are thought to mate underwater. The bull does not form a harem, but performs an elaborate courtship display, adding a sound that resembles pealing church bells to his ordinary bellows and grunts. Males remain in the water about 23 to 33 feet (7-10 m) apart, apparently defending their territories, and may engage in courtship battles in which tusks are sometimes broken. Unlike the seals, the female Walrus does not mate in the same year she gives birth, but waits until the following year. The Pacific female is sexually mature at 8 years, with the first birth occurring at 10. The male is mature at 10, but apparently is unable to compete successfully for mates until he is about 15. Walruses live up to 40 years. The female Walrus usually nurses in the water, in an upright position, with the young hanging upside down. The young remains with its mother for about two years, nursing most of the time, until its tusks emerge and it can forage for itself. The calf often rides on its mother's back while she swims, holding on with its flippers. A cow is fiercely protective and will charge a Polar Bear to defend her calf. If a Walrus is attacked, neighboring animals will come to its defense, and injured herd mates will be helped from the water onto ice.