IN THE ARCTIC THERE ARE SOME ANIMALS THAT ARE ENDEMIC TO COLD LANDS AND OTHERS THAT, COMPARED TO THEIR COUSINS FROM LOWER LATITUDES, HAVE ADAPTED TO THE ENVIRONMENT THEY LIVE IN. BELOW ARE SOME SIGNIFICANT EXAMPLES OF MAMMALS THAT INHABIT THE ARCTIC.

POLAR BEAR (Ursus maritimus)

Main characteristics: It is the largest of all bear species. It has a long neck and a relatively smaller head compared to other bears like the brown or black bear. Its fur is white, though in summer it can appear yellowish. Females become sexually mature at 5–6 years of age. Mating occurs in April/May, but the egg is only fertilized in autumn and the cub is born in December. Newborns are very small (around 600 g) but grow quickly, reaching 10–12 kg when they leave the den in March/April. Cubs stay with their mother for about 2.5 years to learn how to hunt seals. Only pregnant females hibernate in dens; other polar bears remain active throughout the winter. Their favorite prey is the ringed seal, though they also hunt other types of seals, walruses, belugas, narwhals, and even ducks. If food is scarce, they can fast for up to 8 months. They are excellent swimmers and can cover long distances in water.
Male size: length 230–260 cm; weight 400–800 kg.
Distribution: Because sea ice distribution is highly variable, polar bears are not very territorial and move frequently. They mainly live near the edge of the polar ice pack where prey is more accessible. They are found throughout the Arctic.

ARCTIC FOX (Alopex lagopus)

Main characteristics: It is the only fox species adapted to the harsh Arctic climate. To survive in this environment, it has developed unique physical traits: smaller ears and nose, and shorter legs compared to its southern relatives. Its fur also changes with the seasons and geography. In the North Atlantic, it is pure white in winter and turns grayish-brown in summer. In the North Pacific, it varies by habitat: on the coasts, it is blue-gray in winter and dark blue-gray or dark brown in summer; inland, it resembles the North Atlantic type. Its thick, warm fur insulates it from temperatures as low as –70°C. Nocturnal by nature except during the Arctic summer, it hunts seabirds and small mammals, and scavenges leftovers from predators like polar bears. It was commonly bred in the past for its fur.
Male size: length 83–110 cm; weight 3.2–9.4 kg.
Distribution: Found across all Arctic continents and islands. Its northern range is limited by food availability, and its southern range by the presence of red foxes, which outcompete and drive them away.

WALRUS (Odobenus rosmarus)

Main characteristics: A large, pinkish seal with tusks—these are actually elongated canine teeth. Its snout is covered in whiskers known as vibrissae. Their color ranges from pink to dark reddish-brown, as they regulate their body temperature by adjusting blood flow to the skin. There are two distinct subspecies: the Atlantic walrus (smaller and with rounder snouts) and the Pacific walrus (larger). Males are larger and have thicker skin on their neck and shoulders. Tusks are used mainly for defense and intimidation. Walruses feed on bottom-dwelling sea creatures, primarily mollusks, but also crabs, anemones, shrimp, mussels, fish, octopuses, and occasionally young seals.
Male size: length 250–350 cm; weight 600–2000 kg.
Distribution: Found throughout the Arctic. Important breeding areas include northern Greenland, Svalbard, Franz Josef Land, Novaya Zemlya, Laptev Sea, Bering Sea, Chukchi Sea, and Baffin Island.

MUSKOX (Ovibos moschatus)

Main characteristics: A bovine with long, dark brown winter hair that nearly touches the ground, covering a soft undercoat similar to cashmere. Males are larger than females and have massive, curved horns growing from a heavy forehead; females have smaller, less imposing horns. They feed on seeds, grasses, and shrubs. Typically found in mixed-sex groups, although some males prefer a solitary life in summer. When threatened by predators, adults form a defensive circle with calves in the center, presenting a barrier of sharp horns. Females give birth to a single calf in April/May after a 34-week gestation. In summer, they prefer grassy tundra with low precipitation, and in winter, they favor windswept areas where vegetation remains exposed.
Male size: length 200–260 cm; weight 200–400 kg (some up to 600 kg).
Distribution: Found in Alaska, Greenland, and parts of Russia.

REINDEER OR CARIBOU (Rangifer tarandus)

Main characteristics: A stocky deer species living in the far north. Both males and females have antlers; male antlers are larger and more palm-shaped, while females’ are smaller and less so. Antler color and size vary by subspecies. Their habitat ranges from the boreal forest—where they grow largest—to the high Arctic islands, where they are smaller, with shorter limbs and ears, and lighter coloring. They feed on grasses, mosses, and lichens. Reindeer live in herds and migrate long distances to find food in the tundra. In Europe and Russia, they are domesticated and used by humans, which is not the case in North America.
Male size: length 160–220 cm; weight 80–150 kg.
Distribution: Found throughout nearly all Arctic regions.