What Are Walrus Tusks For? Hauling Out, Fighting and Display

What are walrus tusks made of?

The tusks of the walrus are its upper canine teeth, the same teeth that form the fangs of a dog or a bear. Instead of stopping when they reach adult size, they keep growing from open roots for most of the walrus’s life. They are made of dentine, a hard, dense material known as walrus ivory, covered at first by a thin layer of enamel that soon wears away.

Calves are born with no visible tusks. The tusks start to show during the first couple of years and then lengthen year after year, so in general, the older the walrus, the longer its tusks. At the same time, the tips wear down and often chip or break, especially in fights, so very old walruses can have shorter, blunter tusks than walruses in their prime.

Apart from the tusks, a walrus has few teeth. Most of the rest are simple, flat cheek teeth, and many are tiny or missing. Walruses do not chew their prey; they suck it into the mouth, so they do not need a full set of teeth.

Using tusks to haul out onto the ice

Getting a walrus that weighs a ton or more out of the water and onto a slippery ice floe is hard work. Walruses often hook their tusks over the edge of the ice and use them like ice picks, pulling with the neck while pushing with the flippers. This habit gave the walrus its scientific name. Odobenus comes from Greek words meaning “tooth” and “walk”, so the walrus is the “tooth-walker”.

Walruses also use their tusks to work at thin ice. They can chip at the edges of breathing holes to keep them open and push or break thin ice to make an opening. A resting walrus in the water can even hang from the edge of a floe by its tusks, keeping its head above the surface while it dozes.

Tusks as status symbols

The most common use of walrus tusks is social. Walruses live in crowded herds with a pecking order, and tusk size is one of the main signals of rank, along with body size and age. The Alaska Department of Fish and Game describes how two males meeting each other raise and turn their heads sideways to show off their tusks. The walrus with the smaller tusks usually backs down without a fight.

Females use their tusks in the same way. On a packed haul-out, they jab and threaten their neighbors to claim a better resting place on the ice or beach.

Fighting during the breeding season

In winter, males compete for access to groups of females gathered on the pack ice. When two males have tusks of similar size and display does not settle the matter, they fight. They stab and hook at each other with downward blows of the tusks, causing bruises, cuts and punctures. Adult bulls carry many scars on the neck and shoulders, where their skin is up to about 10 cm (4 in) thick and covered in tough bumps called bosses that act like armor.

This is the main reason males have bigger tusks than females. A male’s tusks are longer, thicker and straighter, and they help decide which bulls get to breed. Males rarely win the chance to mate until they are about 15 years old, by which time their tusks and bodies are near full size.

Defense against polar bears and orcas

Tusks are also weapons against predators. Adult walruses have only two natural enemies, the polar bear and the orca. A polar bear usually avoids attacking a healthy adult walrus, because a walrus can wound a bear badly with its tusks, especially if the fight moves into the water. Bears target calves and weak animals instead, often by charging a herd and catching stragglers.

Mothers use their tusks to protect their calves, and when a group is threatened, adults may gather around the young.

Myth: walruses do not dig with their tusks

It seems logical that a walrus would use its tusks to plow up clams from the seafloor, and older books often say so. But the evidence says otherwise. Studies of the wear on walrus tusks show scratches consistent with the tusks being dragged through the mud as the walrus moves along the bottom, not with digging. The real work is done by the snout, the sensitive whiskers, jets of water squirted from the mouth, and sometimes a waving flipper. How walruses find and eat their prey is explained in What do walruses eat?

How long are walrus tusks?

Walrus tusks can reach about 1 m (3.3 ft) long and weigh up to about 5.4 kg (12 lb) each in the biggest males, but most are much shorter, often around 50 cm (20 in). Pacific walruses usually have longer tusks than Atlantic walruses.

Walrus tusks compared with other tusks

Tusks have evolved several times in mammals, from different teeth. Elephant tusks are upper incisors, as explained in Do Asian elephants have tusks? The narwhal’s spiral tusk is usually a single left canine that grows straight out through the upper lip, mainly in males, as described in What is a narwhal tusk? Walruses are unusual because both sexes have a pair of large tusks.

Walrus ivory has been carved by Arctic peoples for thousands of years, and in medieval Europe it was used for luxury objects such as the 12th-century Lewis Chessmen. Today, international trade in walrus ivory is controlled under CITES.