The muskox, Ovibos moschatus, is a large, shaggy hoofed mammal that represents a living link to the Ice Age fauna of the Pleistocene epoch. Despite its name, this Arctic ungulate is more closely related to sheep and goats than to true oxen, belonging to the family Bovidae. The species is noted for the musky odor emitted by males during the rutting season, which is the source of the common name. Known to the Inuit as “umingmak,” or “the bearded one,” the muskox is uniquely equipped to survive in one of the planet’s most extreme environments.
Physical Characteristics and the Qiviut Coat
The muskox possesses a stocky, barrel-shaped body set upon short, sturdy legs, which are adaptations for conserving heat in the frigid environment. Adults stand between 1.1 to 1.5 meters (3.6 to 4.9 feet) high at the shoulder, with males typically weighing between 180 and 410 kilograms (400 to 900 pounds). Both sexes sport massive, curved horns that fuse at the base in males to form a thick, bony shield called a “boss”.
The most defining feature of the muskox is its exceptionally dense, two-layered coat, which hangs down almost to the ground and often gives the animal a dark, uniform appearance. The outer layer consists of long, coarse guard hairs that can reach 600 millimeters (nearly 2 feet) in length and serve to shed wind, snow, and rain. This shaggy outer “skirt” protects a finer, insulating undercoat known as qiviut (pronounced “kiv-ee-ute”).
Qiviut is one of the world’s most luxurious and insulating natural fibers, growing as a fine, downy layer beneath the guard hairs. The wool is reputed to be up to eight times warmer than traditional sheep’s wool, offering unparalleled insulation even when wet. Qiviut is naturally shed each spring, and the yearly yield per animal averages around 0.9 kilograms (2 pounds), contributing to its high value and rarity.
Arctic Habitat and Distribution
The muskox is exclusively found in the Arctic Tundra. This habitat is defined by extremely long, cold winters, short growing seasons, permafrost, and low-lying vegetation. They are adapted to conditions where snow cover is typically shallow, allowing them to forage for food during the winter months.
The current natural distribution of the muskox is centered in the Canadian Arctic and Greenland, where strong native populations exist. Historically, the species was extirpated from Alaska in the early 20th century, primarily due to over-hunting. However, successful reintroduction efforts in the 1930s have established thriving populations in Alaska, including on Nunivak Island and the Seward Peninsula.
Reintroduction programs have also established herds in parts of Eurasia, including Siberia, as well as in Norway and Sweden. While they do not undertake long migrations, the herds make seasonal movements, generally preferring wetter, lower river valleys in the short summer months. They move to higher, wind-swept elevations in the winter to avoid deep snow that would impede access to their food sources.
Social Behavior and Defense
Muskoxen live in herds, with group sizes typically ranging from 12 to 24 individuals in winter and slightly smaller in summer. Within the herd, there are separate dominance hierarchies for males and females, with mature animals holding sway over juveniles. The herds are herbivorous, grazing primarily on sparse Arctic vegetation, including grasses, sedges, and dwarf willows.
Their most famous and distinct behavior is their anti-predator defense mechanism. When threatened by predators, primarily Arctic wolves, the herd does not flee but instead rapidly groups together. The adults will quickly form a stationary defensive ring or semi-circle, facing outward toward the threat.
Calves and juveniles are protected in the center of this formation, shielded by the adults’ massive bodies and sharp horns. This tactic allows the herd to stand its ground and present a unified, impenetrable front, conserving energy. While highly effective against natural predators like wolves, this fixed formation historically made muskoxen vulnerable to human hunters equipped with firearms.