Musk Ox

The musk ox is a large Arctic hoofed mammal, and despite its name it is not an ox at all. It belongs to the subfamily of goat antelopes, which makes it a closer relative of sheep and goats than of cattle; its scientific name, Ovibos moschatus, means musky sheep ox. Musk oxen are a living link to the Ice Age. They crossed into North America from Asia and shared the tundra with woolly mammoths and woolly rhinos, and while most of those giants vanished, the musk ox survived. Adults stand about 1.1 to 1.5 meters at the shoulder. Wild bulls usually weigh about 270 to 400 kg and cows about 180 to 250 kg, though their long coat makes them look even bigger. The skirt of dark guard hair can almost reach the ground. Both sexes carry horns that curve down beside the face and back up at the tips; in bulls the bases meet in a thick shield across the forehead called the boss. The Inuit name, umingmak, means the bearded one.

Musk oxen live on the open Arctic tundra, from the far north of Canada and Greenland to herds that people have moved to Alaska, Russia and Scandinavia. Canada holds most of the world's musk oxen, on Banks and Victoria islands, the other Arctic islands and the mainland of Nunavut and the Northwest Territories, with a herd in northern Quebec started in the 1960s. In Greenland the native herds live in the north and northeast, and a population introduced in the 1960s now thrives around Kangerlussuaq in the west. Alaska's native musk oxen were hunted out in the 1800s; animals from Greenland were taken to Nunivak Island in 1935 and 1936, and their descendants now live on the Seward Peninsula, near Nome and across Arctic Alaska. Russia restocked the Taimyr Peninsula and Wrangel Island in the 1970s. In Norway, the Dovrefjell herd of about 250 comes from animals brought from Greenland after World War II, and a handful crossed into Sweden in 1971. Musk oxen prefer rolling terrain where wind keeps snow shallow, and river valleys and slopes where plants stay reachable through winter.

Food is never guaranteed on the Arctic tundra, and musk oxen have adapted to make the most of whatever plants are available. In summer, they feed on grasses, sedges, willows, and flowering plants, building up fat reserves before the cold sets in. When winter arrives and snow covers the ground, they use their broad, heavy hooves to scrape and dig down to buried mosses, lichens, and dried vegetation. They move constantly between feeding areas rather than exhausting one patch. A fully grown musk ox can consume considerable amounts of plant matter each day to maintain its body heat. Their digestive system extracts as much energy as possible from tough, fibrous plants, which allows them to survive months of cold on relatively sparse forage.

Living in groups is central to how musk oxen survive. Herds typically number between 10 and 30 animals, though larger gatherings can form in summer. When wolves or other predators approach, the adults act fast and with purpose: they arrange themselves in a tight circle facing outward, keeping the calves sheltered at the center. This formation is highly effective against natural predators, though it made hunting by humans dangerously easy in the past. During the rut in late summer and autumn, bulls compete fiercely for the right to mate. Rivals back away from each other, then charge at full speed and collide head to head with tremendous force. These clashes can be heard from a considerable distance. Outside the rut, bulls may live in separate bachelor groups away from the main mixed herd.

Few large mammals are as well equipped for extreme cold as the musk ox. Its coat has two distinct layers working together: a coarse outer layer of guard hairs that repels rain, snow, and wind, and a dense inner wool called qiviut, which is among the warmest natural fibers found anywhere in the world, often described as about eight times warmer than sheep's wool by weight. Qiviut is shed naturally each spring and has long been used by Arctic peoples to make clothing. The hooves are wide and act like snowshoes, spreading the animal's weight across soft ground and providing grip on ice. Thick neck muscles and a reinforced skull absorb the shock of head collisions during the rut, allowing bulls to charge repeatedly without serious injury. Bulls also produce a strong musky odor from glands near the eyes during the breeding season, which is where the species gets its common name.

The story of the musk ox is one of decline followed by a genuine recovery. In the nineteenth and early twentieth centuries, whalers, explorers and fur traders shot whole herds, which was easy because musk oxen stand their ground in a defensive circle instead of running. The species disappeared from Alaska, and numbers in Canada and Greenland fell sharply. Legal protection, starting in Canada in 1917, and the moving of animals to new areas turned things around. A 2019 review of all 55 known populations estimated about 170,000 musk oxen in the world, most of them in Canada, with Greenland second and roughly 4,300 counted in Alaska. The IUCN lists the musk ox as Least Concern. Not every herd is doing well, though: six populations are in decline, including Banks Island, which around the year 2000 held the largest herd on Earth. Climate change brings rain on snow events, when winter rain freezes into a sheet of ice that seals the plants away, and these can kill many animals in a single season. Disease, parasites and grizzly bears also limit some herds.