The walrus has played a prominent role in the cultures of many indigenous Arctic peoples, who have hunted it for meat, fat, skin, tusks, and bone.

It has rebounded somewhat since, though the populations of Atlantic and Laptev walruses remain fragmented and at low levels compared with the time before human interference.

[6] For example, the Old Norse word hrosshvalr means 'horse-whale' and is thought to have been passed in an inverted form to both Dutch and the dialects of northern Germany as walros and Walross.

[11] The coincidental similarity between morse and the Latin word morsus ('a bite') supposedly contributed to the walrus's reputation as a "terrible monster".

Fixed genetic differences between the Atlantic and Pacific subspecies indicate very restricted gene flow, but relatively recent separation, estimated at 500,000 and 785,000 years ago.

[17] These dates coincide with the hypothesis derived from fossils that the walrus evolved from a tropical or subtropical ancestor that became isolated in the Atlantic Ocean and gradually adapted to colder conditions in the Arctic.

[20] Fossils known from San Francisco, Vancouver, and the Atlantic US coast as far south as North Carolina have been referred to glacial periods.

[21] An isolated population in the Laptev Sea was considered by some authorities, including many Russian biologists and the canonical Mammal Species of the World,[3] to be a third subspecies, O. r. laptevi (Chapskii, 1940), but has since been determined to be of Pacific walrus origin.

These are elongated canines, which are present in both male and female walruses and can reach a length of 1 m (3 ft 3 in) and weigh up to 5.4 kg (12 lb).

[36] This lower fat content in turn causes a slower growth rate among calves and a longer nursing investment for their mothers.

[38] Because ovulation is suppressed until the calf is weaned, females give birth at most every two years, leaving the walrus with the lowest reproductive rate of any pinniped.

[39] 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.

[30][40] The majority of the population of the Pacific walrus spends its summers north of the Bering Strait in the Chukchi Sea of the Arctic Ocean along the northern coast of eastern Siberia, around Wrangel Island, in the Beaufort Sea along the northern shore of Alaska south to Unimak Island,[41] and in the waters between those locations.

[56] The Atlantic walrus once ranged south to Sable Island, off of Nova Scotia; as late as the 18th century, they could be found in large numbers in the Greater Gulf of St. Lawrence region, sometimes in colonies of 7-8,000 individuals.

[58][59] In April 2006, the Canadian Species at Risk Act listed the populations of northwestern Atlantic walrus in Québec, New Brunswick, Nova Scotia, Newfoundland and Labrador as having been eradicated in Canada.

[62] Even though walruses can dive to depths beyond 500 meters, they spend most of their time in shallow waters (and the nearby ice floes) hunting for bivalves.

[66] In June 2022, a single walrus was sighted on the shores of the Baltic Sea - at Rügen Island, Germany, Mielno, Poland and Skälder Bay, Sweden.

[67][68][69] In July 2022, there was a report of a lost, starving walrus (nicknamed as Stena) in the coastal waters of the towns of Hamina and Kotka in Kymenlaakso, Finland,[70][71] that, despite rescue attempts, died of starvation when the rescuers tried to transport it to the Korkeasaari Zoo for treatment.

[64] The walrus has a diverse and opportunistic diet, feeding on more than 60 genera of marine organisms, including shrimp, crabs, priapulids, spoon worms, tube worms, soft corals, tunicates, sea cucumbers, various mollusks (such as snails, octopuses, and squid), some types of slow-moving fish, and even parts of other pinnipeds.

[77] The walrus sucks the meat out by sealing its powerful lips to the organism and withdrawing its piston-like tongue rapidly into its mouth, creating a vacuum.

[78] Walruses at the Tierpark Hagenbeck were easily able to suck the five-pound metal plug out of the bottom of their pool, at a water depth of 1.1 metres.

It disturbs (bioturbates) the sea floor, releasing nutrients into the water column, encouraging mixing and movement of many organisms and increasing the patchiness of the benthos.

The polar bear often hunts the walrus by rushing at beached aggregations and consuming the individuals crushed or wounded in the sudden exodus, typically younger or infirm animals.

[94] Commercial walrus harvesting is now outlawed throughout its range, although Chukchi, Yupik and Inuit peoples[95] are permitted to kill small numbers towards the end of each summer.

[96] The meat, often preserved, is an important winter nutrition source; the flippers are fermented and stored as a delicacy until spring; tusks and bone were historically used for tools, as well as material for handicrafts; the oil was rendered for warmth and light; the tough hide made rope and house and boat coverings; and the intestines and gut linings made waterproof parkas.

An estimated four to seven thousand Pacific walruses are harvested in Alaska and in Russia, including a significant portion (about 42%) of struck and lost animals.

Thinner pack ice over the Bering Sea has reduced the amount of resting habitat near optimal feeding grounds.

[103][104] Analysis of trends in ice cover published in 2012 indicate that Pacific walrus populations are likely to continue to decline for the foreseeable future, and shift further north, but that careful conservation management might be able to limit these effects.

Both in Chukotka and Alaska, the aurora borealis is believed to be a special world inhabited by those who died by violence, the changing rays representing deceased souls playing ball with a walrus head.

Although Carroll accurately portrays the biological walrus's appetite for bivalve mollusks, oysters, primarily nearshore and intertidal inhabitants, these organisms in fact comprise an insignificant portion of its diet in captivity.