The walrus is a large flippered marine mammal with a discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. The walrus is the only living species in the Odobenidae family and Odobenus genus. This species is subdivided into three subspecies. The Atlantic walrus which lives in the Atlantic Ocean, the Pacific walrus which lives in the Pacific Ocean, and O. r. laptevi, which lives in the Laptev Sea of the Arctic Ocean.
Adult walruses are easily recognized by their prominent tusks, whiskers, and bulkiness. Adult males in the Pacific can weigh more than 4,400 pounds and, among pinnipeds, are exceeded in size only by the two species of elephant seals. Walruses live mostly in shallow waters above the continental shelves, spending significant amounts of their lives on the sea ice looking for benthic bivalve mollusks to eat. Walruses are relatively long-lived, social animals, and they are considered to be a "keystone species" in the Arctic marine regions.
The walrus has played a prominent role in the cultures of many indigenous Arctic peoples, who have hunted the walrus for its meat, fat, skin, tusks, and bone. During the 19th century and the early 20th century, walruses were widely hunted and killed for their blubber, walrus ivory, and meat. The population of walruses dropped rapidly all around the Arctic region. Their population has rebounded somewhat since then, though the populations of Atlantic and Laptev walruses remain fragmented and at low levels compared with the time before human interference.
While some outsized Pacific males can weigh as much as 4,400 pounds, most weigh between 1,800 and 3,700 pounds. An occasional male of the Pacific subspecies far exceeds normal dimensions.
The walrus's body shape shares features with both sea lions and seals.
The Walrus can turn its rear flippers forward and move on all fours. However, its swimming technique is more like that of true seals, relying less on flippers and more on sinuous whole body movements. Also like phocids, it lacks external ears.
The most prominent feature of the walrus is its long tusks. These are elongated canines, which are present in both male and female walruses and can reach a length of 3 feet 3 inches and weigh up to 12 pounds. Tusks are slightly longer and thicker among males, which use them for fighting, dominance and display. The strongest males with the largest tusks typically dominate social groups. Tusks are also used to form and maintain holes in the ice and aid the walrus in climbing out of water onto ice. Tusks were once thought to be used to dig out prey from the seabed, but analyses of abrasion patterns on the tusks indicate they are dragged through the sediment while the upper edge of the snout is used for digging.
Walruses live to about 20–30 years old in the wild.
The rest of the year (late summer and fall), walruses tend to form massive aggregations of tens of thousands of individuals on rocky beaches or outcrops. The migration between the ice and the beach can be long-distance and dramatic.
