The muskox is an ancient herbivore with an ancestry that can be traced back 90,000 years in North America. During the last ice age, muskoxen roamed the ice-free Beringian steppes with the long extinct wooly mammoth, woolly rhino, and mastodon. Today’s tundra muskox, number between100,000 and 150,000 worldwide. Although it resembles a bison, the muskox is more closely related to sheep and goats. Its closest relative in North America is, in fact, the mountain goat.
The majority of the worldwide population of muskoxen lives in wild herds in the Northwest Territories and Nunavut. The muskox was eliminated from the northern Yukon and Alaska in the mid-1800s, largely as a result of hunting. In recent years, however, a small population of 150-200 animals has wandered onto the Yukon North Slope from a reintroduced muskox population in Alaska.
Muskoxen are herd animals and form tight family bonds. Muskox herds vary in size, partly depending on the season. They tend to be larger in winter, numbering up to 50 animals, when sites with good forage are harder to find, and smaller during the rut, when the bulls compete with each other for access to cows. When a member of the herd is threatened, the adults may form a ring, protecting the young and weak. If the herd is small, they may form a line abreast with the vulnerable herd members behind the line. A muskox bull, in particular, will charge anything it perceives as a threat, but issues a warning first by rubbing the scent gland near it's eye against the ground or it's foreleg.
As one of its adaptations to life in the cold, the muskox has fine under-layer of fur called qiviut. Qiviut is 8 times warmer than sheep wool and finer than cashmere.It makes a high quality and expensive yarn.