Walrus

Taxonomy and Evolution

The walrus is a mammal within the order Carnivora and is the only living member of the family Odobenidae. It is one of three lineages in the pinniped suborder, alongside true seals (Phocidae) and eared seals (Otariidae). Recent multigene analysis indicates that odobenids and otariids diverged from phocids 20 to 26 million years ago, while odobenids and otariids separated 15 to 20 million years ago. Genetic evidence suggests all three pinniped groups descended from a caniform ancestor most closely related to modern bears. The walrus family was once highly diverse and widespread, including at least twenty species across several subfamilies. The key distinguishing evolutionary feature of the family was the development of a squirt or suction feeding mechanism, with tusks being a later feature specific to the Odobeninae subfamily, of which the modern walrus is the last relict species. Two subspecies are widely recognized based on fixed genetic differences indicating restricted gene flow: the Atlantic walrus (Odobenus rosmarus rosmarus) and the Pacific walrus (Odobenus rosmarus divergens). Their separation is estimated to have occurred between 500,000 and 785,000 years ago.

Physical Description and Anatomy

The walrus is a massive marine mammal, ranking as the third largest pinniped species after the two elephant seals. Pacific walruses are generally larger than their Atlantic counterparts. While historical records mention outsized Pacific males weighing up to 2,300 kg (5,000 lb), a 2015 review found the maximum reliably verified weight to be 1,883 kg (4,151 lb) for a male measuring 3.8 metres in length. Male Atlantic walruses average about 900 kg (2,000 lb), roughly 10 to 20 percent less than Pacific males. Females are smaller, weighing about two-thirds as much as males, with Atlantic females averaging 560 kg (1,230 lb) and Pacific females averaging 800 kg (1,800 lb). Their bodies are sparsely covered with fur, and their skin is thick, highly wrinkled, and up to 10 cm (4 in) thick around the neck and shoulders of males. Beneath the skin, a blubber layer up to 15 cm (6 in) thick provides critical insulation and energy reserves. Walruses can turn their rear flippers forward to move on land in a manner similar to sea lions, but they swim using sinuous body movements more like true seals. They also lack external ears. Their extraocular muscles are well-developed, allowing them to protrude their eyes and see in both frontal and dorsal directions, though their vision appears best suited for short range.

Tusks, Dentition, and Specialized Features

The walrus's most prominent features are its long tusks, which are elongated canine teeth present in both males and females. Tusks can reach a length of 1 metre (3 ft 3 in) and weigh up to 5.4 kg (12 lb), being slightly longer and thicker in males. They are used for social dominance, fighting, display, and as tools to haul the animal's bulk onto ice and maintain holes in it. Analyses of abrasion patterns indicate they are dragged through sediment while the upper edge of the snout is used for digging prey, not the tusks themselves. The dentition of walruses is highly variable. The maximal number of teeth is 38, but over half are rudimentary and occur with less than 50 percent frequency, resulting in a typical dentition of only 18 teeth. Surrounding the snout is a broad mat of 400 to 700 highly sensitive vibrissae, or whiskers, arranged in 13 to 15 rows. These whiskers, which can grow to 30 cm (12 in) but are often worn shorter, are attached to muscles and supplied with blood and nerves, enabling them to differentiate shapes as small as 3 mm thick and 2 mm wide. Another distinctive feature is an inflatable pharyngeal air sac under the throat, which acts as a flotation bubble, allowing the walrus to bob vertically and sleep in the water. Males also possess a large baculum (penis bone), up to 63 cm (25 in) long, the largest of any land mammal relative to body size.

Life History and Reproduction

Walruses are relatively long-lived, with a lifespan of 20 to 30 years in the wild. The oldest recorded walrus was a captive individual named Slowpoke at SeaWorld Orlando, who lived to be 49. Males reach sexual maturity as early as 7 years but do not typically mate until fully developed at around 15 years of age. Females begin ovulating as early as 4 to 6 years old and reach physical maturity between 10 and 12 years. The breeding season, or rut, occurs from January through April, with peak activity in February. During this time, males dramatically decrease food intake and aggregate in the water around ice-bound groups of estrous females, engaging in competitive vocal displays. Copulation occurs in the water. Walruses exhibit delayed implantation, a strategy common among pinnipeds. The blastula remains in suspended development for the first three to four months of gestation before implanting in the uterus, resulting in a total gestation period of 15 to 16 months. This presumably optimizes the timing of birth to coincide with favourable ecological conditions. Calves are born during the spring migration, from April to June, weighing 45 to 75 kg (99 to 165 lb) at birth and are able to swim immediately. Walrus milk contains higher amounts of fats and protein compared to land animals but lower compared to phocid seals, leading to a slower calf growth rate. Mothers nurse for over a year, and the young can spend up to five years with them. Walruses are the only pinnipeds known to exhibit aquatic suckling. Because ovulation is suppressed until the calf is weaned, females give birth at most every two years, resulting in the lowest reproductive rate of any pinniped.

Ecology: Habitat, Diet, and Social Behaviour

Walruses inhabit shallow waters above continental shelves in the Arctic Ocean and adjacent seas, relying heavily on sea ice as a platform for resting, giving birth, and accessing foraging grounds. They are highly social, often forming massive aggregations of tens of thousands of individuals on rocky beaches or ice floes, particularly in late summer and fall. Their diet consists primarily of benthic invertebrates, especially bivalve molluscs like clams, which they locate on the seafloor using their sensitive vibrissae. They use a powerful suction feeding mechanism, enabled by a unique tongue and palate, to extract the soft tissue from shells. Pacific walruses undertake extensive seasonal migrations, moving north with the receding ice in summer from the Bering Sea into the Chukchi Sea through the Bering Strait, and south again in winter. Their large size and social nature make them a keystone species, influencing the structure of their benthic communities through their foraging activity. Walruses are also known for long-distance vagrancy, with individuals occasionally appearing far south of their normal range in places like Scotland, Ireland, and the Baltic Sea, events that have attracted considerable public attention in recent years.

Population, Distribution, and Conservation Status

The global walrus population is estimated to be approximately 250,000 animals as of 2026. The Pacific subspecies is the more numerous, while Atlantic and Laptev Sea populations remain fragmented and at low levels compared to the time before human interference. Walruses were subjected to intense commercial hunting for their blubber, ivory, leather, and meat throughout the 19th and early 20th centuries, causing rapid population declines across the Arctic. For example, commercial harvesting reduced the Pacific walrus population to between 50,000 and 100,000 by the 1950s and 1960s. Limits on hunting allowed numbers to increase to a peak in the 1970s and 1980s, with aerial censuses in the late 20th century estimating populations above 220,000. However, numbers have subsequently declined again. The primary modern threat is climate change, which is causing rapid loss of the sea ice habitat walruses depend on. This forces them to use terrestrial haul-outs more frequently, which can lead to overcrowding, increased susceptibility to disturbance from humans and predators, and greater calf mortality from stampedes. Conservation efforts focus on sustainable co-management with Indigenous communities, protecting critical habitat, and mitigating human disturbances. Their current conservation status is one of concern due to these cumulative pressures.

Cultural Significance and Historical Interaction

For thousands of years, walruses have been integral to the cultures and survival of Indigenous Arctic peoples across North America and Russia, including Inuit, Inupiat, Yupik, and Chukchi communities. These cultures hunted walrus sustainably for meat, fat (blubber), skin for boat covers and shelters, tusks for tools and art, and bone for implements. Walrus ivory carving remains a vital and celebrated art form. The species also features prominently in myths, stories, and spiritual beliefs. The European and North American commercial hunt, which began in earnest in the 16th century and intensified in the 19th century, had a devastating impact. Walrus were hunted widely for their blubber (rendered into oil), their ivory tusks, and their tough hide. This period of industrial exploitation drove populations to critically low levels before international agreements and national regulations curtailed the hunt. The word 'walrus' itself has a complex etymology, largely deriving from Germanic languages, with the Old Norse 'hrosshvalr' meaning 'horse-whale'. The archaic English word 'morse' for walrus is thought to come from Slavic and ultimately Finno-Ugric languages.

Recent Vagrancy Events and Public Engagement

In recent years, individual vagrant walruses travelling far south of their typical Arctic range have attracted significant international public and media attention. These animals are often tracked due to their recognisable scars and tusk details, and they are frequently given names by the public. A male named Wally was first sighted at Valentia Island, Ireland, in March 2021, then travelled to Wales, western France, Spain, the Isles of Scilly, back to Ireland, and finally to Iceland. A female named Freya, approximately five years old, was sighted in the North Sea from 2019 onwards, appearing in the Netherlands in October 2021, and was shot by Norwegian authorities near Oslo in August 2022 due to public safety concerns. Another female named Stena, estimated to be over 20 years old, travelled from Norway to Denmark, Sweden, Germany, and into the Baltic Sea, reaching Finland in 2022, marking the first record of a walrus in the northern Baltic. She later died from emaciation. A male named Thor, about eight years old, travelled from the Netherlands to France, England, and up the English east coast to Northumberland in late 2022 and early 2023 before returning to Arctic waters. These extraordinary journeys, possibly linked to changing ice conditions and foraging behaviour, have sparked widespread fascination and discussions about wildlife conservation. Public engagement also occurs through events like The Walrus Talks series, which hosted 'The Power of Animals' in Toronto in September 2025.

Questions about Walrus

How much does a walrus weigh and how big can they get?

Walrus size varies significantly by subspecies and sex. Pacific walruses are larger, with males typically weighing between 800 and 1,700 kilograms (1,800-3,700 pounds). The maximum reliably verified weight from a scientific review is 1,883 kg (4,151 lb) for a male measuring 3.8 metres (12 ft 6 in). Atlantic males are smaller, averaging about 900 kg (2,000 lb). Females weigh about two-thirds as much as males. The walrus is the third largest pinniped species overall.

What are the main uses of a walrus's tusks?

Walrus tusks, which are elongated canine teeth found in both sexes, serve several critical functions. They are essential tools for pulling the animal's large body out of the water and onto ice. Males use them extensively for fighting, establishing social dominance, and display, with the strongest males possessing the largest tusks. The tusks are also used to form and maintain holes in ice. Contrary to past belief, they are not primarily used to dig prey from the seabed. Analysis shows tusks are dragged through sediment while the upper snout does the digging.

Where are walruses found and what is their habitat?

Walruses have a discontinuous circumpolar distribution around the North Pole in the Arctic Ocean and subarctic seas. They primarily inhabit shallow waters above continental shelves, which provide access to their benthic prey. They are heavily dependent on sea ice as a platform for resting, breeding, nursing, and as a base for foraging. The Pacific subspecies ranges from the Bering and Chukchi Seas, summering north of the Bering Strait and wintering in the Bering Sea. The Atlantic subspecies is found from eastern Canada (historically as far south as Sable Island) to Greenland and the Russian Arctic.

What is the current global population of walruses?

As of a 2026 estimate, the total world walrus population is about 250,000 animals. The Pacific walrus population constitutes the majority of this number. Populations of the Atlantic walrus remain fragmented and at lower levels than historically, having not fully recovered from past overhunting. Early aerial censuses of Pacific walrus in the 1970s and 1980s estimated populations above 220,000, but numbers have declined since then. Accurate population counts remain challenging due to the animals' remote, vast, and often ice-covered habitat.

How do walruses find and eat their food?

Walruses are specialized suction feeders that primarily eat benthic bivalve molluscs like clams. They locate their prey on the dark seafloor using their highly sensitive whiskers (vibrissae), which can detect objects as small as a few millimetres. Once located, the walrus uses its powerful lips and tongue to create a vacuum, forcibly sucking the soft body of the mollusc right out of its shell. They also consume other invertebrates including worms, snails, and shrimp. They typically feed in relatively shallow waters where their preferred prey is abundant.

Why have walruses been seen so far south in Europe recently?

Recent sightings of individual walruses in Europe, such as in Ireland, the UK, France, and the Baltic Sea, are considered unusual vagrancy events. Walruses have a history of long-distance wandering, with records in Scotland dating back to the 19th century. However, the frequency and high-profile nature of recent incidents may be linked to changing Arctic conditions. The loss of sea ice due to climate change disrupts traditional migration and foraging patterns, potentially causing some individuals, often younger ones, to wander greater distances in search of food or suitable haul-out sites. These vagrants often attract large crowds and media coverage.

Sources: Wikipedia and current public reporting, checked by the Your Space Hamilton desk. Last updated 2026-10-19.