Walrus — facts, diet, habitat & conservation

The walrus is an Arctic giant built around two tools: a pair of tusks it uses to climb out of the ocean, and a set of whiskers so sensitive it can hunt in total darkness by touch alone.

Overview

Walruses live in the shallow, ice-covered seas of the Arctic, where the water is no more than about 80 m deep and the seabed is thick with clams. They spend roughly a third of their time in the water, feeding, and the rest hauled out in tightly packed herds on sea ice or, increasingly, on beaches — herds that can number in the tens of thousands. There are two subspecies, the larger Pacific walrus and the Atlantic walrus.

Physical characteristics

A big male Pacific walrus weighs over 1,500 kg, most of it blubber — a layer up to 15 cm thick that insulates the animal and stores energy. The skin is deeply wrinkled and, in males, covered in tubercle “bosses” around the neck and shoulders, like natural armour for fighting.

Both sexes grow tusks, elongated upper canine teeth that keep growing for life and can exceed a metre in old males. The tusks are used for hauling out onto ice, for keeping breathing holes open, and as a display and weapon in the contests males have over females — not, despite the popular image, for digging up food.

Males also have inflatable air sacs in the neck. They act as flotation aids, letting a walrus sleep upright in the water, and as resonating chambers that produce the bell-like, gong-like underwater calls males make during the breeding season.

Feeding

A foraging walrus dives to the seabed and roots through the sediment with its snout, using its mystacial vibrissae — 400 to 700 short, coarse, extraordinarily sensitive whiskers — to locate buried clams, cockles, and other molluscs by feel. It seals its lips over a shell and uses its muscular tongue as a piston to draw a powerful suction that pulls out the soft body, discarding the shell. A walrus can process several thousand clams in one feeding bout and eats around 3–6% of its body weight a day.

Reproduction and life cycle

Females give birth to a single calf, usually on the ice, after a 15–16 month pregnancy that includes delayed implantation. Calves nurse for over a year and often stay with the mother for two or three, riding on her back in the water. Because females breed only every two to three years, walrus populations recover slowly from losses.

Threats and conservation

The walrus is listed as Vulnerable. The overriding concern is sea-ice loss:

Walruses need ice as a resting platform close to their shallow feeding grounds. As Arctic summer ice retreats over deep water, animals are forced to gather on coastal land in enormous, dangerous haul-outs where a single disturbance — an aircraft, a polar bear, a boat — can trigger a stampede that tramples calves by the hundred.
Longer swims between land and food strain adults and separate mothers from calves.
Subsistence hunting by Arctic Indigenous communities is managed and generally sustainable, but industrial disturbance from expanding Arctic shipping and oil and gas exploration adds pressure, along with the risk of an oil spill in walrus habitat.

Walrus: common questions

What do walruses use their tusks for?

Mainly for hauling themselves out of the water onto ice — the scientific name Odobenus means "tooth-walker." They also use them to keep breathing holes open, to establish dominance among males, and as weapons. They do not use them to dig up food, which is a common misconception.

How does a walrus find clams on the dark seabed?

With its whiskers. A walrus's face carries hundreds of thick, stiff bristles that are among the most sensitive touch organs of any mammal. Dragging its snout through the mud, it detects buried clams by feel, then clamps its lips over the shell and uses its powerful piston-like tongue to create a vacuum that sucks the clam's body straight out.

Why do walruses turn pink?

When a walrus is warm — basking on ice or land in the sun — blood rushes to the skin surface to shed heat, and the animal flushes a rosy pink or reddish-brown. In cold water, blood is pulled away from the skin to conserve heat, and the walrus looks pale grey, almost white.

Are walruses affected by climate change?

Directly and severely. Walruses rest on sea ice between dives to the seabed. As summer ice retreats past the shallow feeding grounds, tens of thousands are forced to crowd onto land haul-outs instead, where stampedes triggered by disturbance crush calves, and the round trip to food becomes exhausting.