Walrus

Walrus. The walrus is a large flippered marine mammal with a discontinuous circumpolar distribution in the Arctic Ocean and subarctic seas of the Northern Hemisphere. It is the only living species in the family Odobenidae and genus Odobenus, easily recognized by its long tusks, whiskers, and great bulk. Adult walruses are characterized by prominent tusks and whiskers, with males being larger and bearing longer, thicker tusks than females.

Description and characteristics

The walrus is immediately distinguished by its long ivory tusks, which are actually elongated canine teeth present in both sexes. These formidable tusks can grow over a meter in length in large bulls and are used for dominance displays, fighting, and hauling their massive bodies onto sea ice or rocky shores. Their bodies are covered by a thick layer of blubber, up to 15 cm thick, which provides insulation in frigid waters and energy reserves. The skin is typically brown or cinnamon-colored but can appear almost pink when the animal is warm due to increased blood flow near the skin's surface. They possess hundreds of stiff, sensitive vibrissae (whiskers) on their snout, which are essential for locating bivalve mollusks like clams and mussels on the dark seafloor. The Pacific walrus is generally larger than its Atlantic walrus counterpart, with bulls sometimes exceeding 1,700 kilograms.

Distribution and habitat

Walruses have a discontinuous, circumpolar range across the shallow, productive shelf waters of the Arctic Ocean. The Atlantic walrus population is found from the eastern Canadian Arctic Archipelago, including Hudson Bay and Davis Strait, across Greenland, to the Barents Sea and western Kara Sea. The more numerous Pacific walrus inhabits the seas of the Bering Strait, the Chukchi Sea, and the western Beaufort Sea, with major haul-out sites in Russia and Alaska, such as the Round Island sanctuary. A third, smaller population in the Laptev Sea is sometimes considered a separate subspecies. Their habitat is intrinsically linked to the availability of sea ice over shallow continental shelves, which they use as platforms for resting, giving birth, and nursing, and from which they access their benthic feeding grounds.

Behavior and ecology

Walruses are highly social, gathering in large, often noisy aggregations known as "herds" on ice or land. They are K-selected capital breeders, with females giving birth to a single calf after a gestation of over 15 months, followed by an extended nursing period that may last two years or more. Their diet consists primarily of benthic invertebrates, especially clams, which they locate with their sensitive vibrissae and suction from the seabed using powerful piston-like tongues. Major predators include the polar bear and the orca, with calves being most vulnerable. During the summer, when sea ice retreats, thousands of Pacific walruses, particularly females and calves, are forced to congregate on terrestrial haul-outs along the coasts of Alaska and Chukotka, which can lead to dangerous stampedes.

Relationship with humans

For millennia, walruses have been a vital resource for indigenous Arctic peoples, including the Inuit, Yupik, and Chukchi people. These cultures have utilized virtually every part of the animal for food (muktuk), tools, clothing, and shelter, and their ivory tusks have been carved into intricate artwork. From the era of Norse exploration to the peak of commercial hunting in the 18th and 19th centuries, European and American hunters heavily exploited walrus populations for their blubber (rendered into oil) and ivory, driving some local populations to the brink of extinction. The walrus features prominently in the folklore and spiritual beliefs of northern communities and has become an iconic symbol of the Arctic in global culture.

Conservation

The walrus is currently classified as Vulnerable on the IUCN Red List. The primary modern threat is climate change, which is causing rapid loss of their essential sea ice habitat, particularly in the Chukchi Sea and Bering Sea. Other significant concerns include increased disturbance from oil and gas exploration and shipping traffic in the Arctic, potential overharvesting in some regions, and ocean acidification affecting their shellfish prey. Conservation efforts are coordinated under international agreements like the 1973 Agreement on the Conservation of Polar Bears, which also covers walruses, and through the work of bodies such as the U.S. Fish and Wildlife Service and the IUCN's Species Survival Commission. Sustainable co-management of subsistence hunting with indigenous communities in Alaska and Russia is a critical component of ongoing conservation strategies.

Category:Pinnipeds Category:Arctic fauna Category:Fauna of the Arctic Ocean Category:Mammals described in 1758