Ovibos moschatus
muskox

Ovibos moschatus is a circumpolar species native to Canada, Greenland, and up until the late 1800's, Alaska. The species was reintroduced to Alaska from animals captured in Greenland in the 1930's. Muskox have also been introduced into Russia, Svalbard, Norway, and Siberia. Some herds have also found their own way from Norway into Sweden. ("Muskox ( Ovibos moschatus )", 1995; Groves, 1997)

Ovibos moschatus lives north of the tree line on the arctic tundra. Summers have a very short growing seasons of three to four months with lush and abundant vegetation. Winters are long and very cold with little precipitation and harsh winds. There is little vegetation in winter and shallow snow. ("Muskox ( Ovibos moschatus )", 1995; Gray, 1990; Groves, 1997; Woodward, 1997)

Many of the physical characteristics of O. moschatus can be attributed to arctic adaptations. Musk oxen have barrel-shaped bodies with short legs, and their entire bodies are covered with fur except for the small area between the nostrils and lips. Both sexes have cream-colored horns with black tips that grow together at the center of the head, drop down along side of head, then curve up to form sharp hooks. These horns grow with age. The tail is short (5 to 10 cm) and is entirely covered and hidden under the fur. Fur can be divided into two types: guard hair and qiviut (pronouced kiv-ee-Ute). Guard hairs are the continuously growing dark hairs that create the characteristic long, shaggy coat. This portion of the pelage can grow long enough to brush the ground on older muskoxen. This long hair is sometimes refered to as a skirt. The guard hairs act as protection against wind and precipitation, as well as insects. Qiviut is the insulating winter coat of muskoxen. It begins growing in the fall and is shed out through the guard hair in the spring. The back is marked by a lighter colored patch of brown or cream where the guard hairs are shorter. This is refered to as the saddle. Legs of these animals are white. Older adult muskoxen sometimes develop a large mane of fur that sits on the shoulders. (Gray, 1990; Groves, 1997; Rowell, 1990)

Subspecies include barren ground muskoxen, Ovibos moschatus moschatus, which are native to Canada and were native to Alaska until extirpation in the late 1800's. White-faced muskoxen, Ovibos moschatus wardi, are native to Greenland and have been introduced to many locations. Ovibos moschatus wardi tends to be slightly smaller than O. moschatus moschatus, but distinction between the two is based mostly on location of the animal. The two subspecies can interbreed. (Gray, 1990; Groves, 1997)

Calves are born in the early spring with very short guard hair and nubs where the horns will begin growing soon after. They are also born with a layer of baby qiviut and over the harsh winter are dependent on the cows for both additional body warmth and protection from the elements by standing in the skirt. (Groves, 1997)

Female weight ranges from 180 to 275 kg, with an average of 250 kg. Head and body length can vary from 135 to 200 cm. Muskoxen typically stand 120 cm at the shoulders. Females grow horns, but lack the extra thickness of a horn boss at the base of the horns. Hook size typically matches that of males. Ovibos moschatus has an udder with four teats, also covered in fur. (Gray, 1990; Groves, 1997; Rowell, 1990)

Males typically weigh an average of 320 kg, with a range of 300 to 400 kg. The combined head and body length varies from 200 to 250 cm. Males have a large horn boss, which is an extra thickness of the base of their horns at the top of the skull, that is between 15 and 20 cm thick. This feature protects them during mating behaviors that include headbutting. (Gray, 1990; Groves, 1997; Rowell, 1990)

Ovibos moschatus lives in very harsh climates and harsh winters may cause death for young calves as well as older adults. Females typically live 15 to 18 years though some older than 20 years have been recorded in the wild and in captivity. Males typically only live 10 to 12 years, as the breeding season is very strenuous. Adult muskoxen typically die through the inability to properly digest food because of excessive wear on molar teeth, or as a result of predation. ("Muskox ( Ovibos moschatus )", 1995; Gray, 1990; Groves, 1997; Rowell, 1990)

Ovibos moschatus is a social species and much of the behavior is based on the harem breeding system. Muskoxen live in herds as small as 5 animals during the summer, and may join with other small groups to form herds as large as 60 individuals in the winter. These larger groups help provide for protection from both the elements and predators. Other advantages of such a large herd size are that during the long winters, it is easier for a lost muskox to locate a large heard in the dark than a few individuals. Also, younger animals may have the advantage of grazing more food supplies that have been uncovered under the snow. Most herds average between 10 and 20 animals. ("Muskox ( Ovibos moschatus )", 1995; Gray, 1990; Groves, 1997; Rowell, 1990)

Muskoxen have many arctic adaptations to the cold (such as short legs, thick fur, and high body fat), that limit their mobility. Though muskoxen can run as fast as 25 miles per hour, they can easily overheat. For this reason, O. moschatus is generally slow moving and has very short migrations within the home range. However, under certain conditions (weather permitting), muskoxen calves as well as adults will play. This play can include chasing and king of the mountain. (Gray, 1990; Groves, 1997; Reynolds, Wilson, and Klein, 2001; Rowell, 1990)

The social hierarchy in the herd is based upon dominance. Dominance among males is typically determined during the breeding season, and sometimes throughout the year through headbutting and chasing, as well as grunting and bellows. Sometimes males are forced out of the herds during the breeding season. Among females, dominance is determined by age and size, with the larger, older females typically exerting dominance over younger, smaller, females through pushing, shoving, and chasing. Calves are generally lowest in the hierarchy, although they determine dominance amongst themselves through chasing, mounting, and play. Generally, the higher the dominance status of the muskox, the better its food supply and breeding rights. (Gray, 1990; Groves, 1997; Rowell, 1990)

Home Range

Home ranges for muskoxen in Alaska are reported to be very large in the summer, averaging 223 square kilometers, and much smaller in the winter and calving seasons, ranging from 27 to 70 square kilometers. Muskoxen will typically stay in areas near water during summer months and then move to higher ground areas where wind will blow off much of the snow covering food supplies during the winter. (Reynolds, Wilson, and Klein, 2001)

Ovibos moschatus has very interesting vocal abilities. Calves, when communicating with cows or each other, bleat. The pitch of the bleat lowers with maturity. Adults have deeper voices that sound closer to roars and rumbles that can be heard long distances. Adults also grunt and snort at each other, at calves, and at other animals. Pushing and shoving, as well as chasing and stomping, are used to communicate dominance. (Gray, 1990; Groves, 1997; Rowell, 1990)

Much of the non-vocal communication among muskoxen occurs during the breeding season when males compete for dominance and breeding rights. Males have very strong-smelling urine and urinate on their front legs and dribble urine during displays as warnings to competitors. They will also use a gland near each eye to mark objects by rubbing their faces against the item to be marked. Bulls also swing their heads, walk sideways, and horn the ground to gather chunks of earth to make themselves look larger. (Gray, 1990; Groves, 1997; Rowell, 1990)

Muskoxen are generalized grazers. As calves, they are dependent upon the milk of their mothers for up to 1 year. Within weeks of birth, they begin incorporating the adult foods into their diet. In the summer months, the diet inculdes grasses, leafy plants, sedges, mosses, shrubs, herbs, and generally any vegetation available. The fecal matter of the animals at this time is very moist and still has high levels of nutrients available. In the winter months, the diet of muskoxen changes to willow, dwarf birch stems, roots, mosses, lichen, and any vegetation they can locate under or above the snow. The fecal matter during these months is very dry and has very few nutrients left after the animals have digested the food. (Gray, 1990; Groves, 1997; Rowell, 1990)

The known predators of O. moschatus are polar bears, brown bears, and wolves. When faced with a predator coming head on, muskoxen line up with their heads down and horns facing the attacker. The calves are generally located behind the adults. When attacked by multiple predators, the herd creates a circle with horns pointed out and calves in the center of the herd. Larger adults may charge out to attack a predator. When a predator approaches the herd, the muskoxen attempt to headbutt or hook that predator with their horns. Muskoxen have been known to throw and trample wolves. As O. moschatus is adapted to arctic life, these animals can overheat easily and cannot run faster than wolves or bears long enough to escape from them. They therefore tend to stay in the circle formation as long as possible. (Gray, 1990; Groves, 1997; Rowell, 1990)

Ovibos moschatus is herbivorous, and consumes plant life. It also provides a food source for arctic scavengers, wolves, polar bears, and brown bears. Muskoxen may help to disperse seeds as they graze. (Gray, 1990; Groves, 1997; Rowell, 1990)

There are no known adverse affects of O. moschatus on humans.

One of the arctic adaptations of muskoxen is the winter coat of underwool, called qiviut (pronounced "kiv-ee-Ute"). Qiviut is an Alaskan native word that has adapted many spellings. The wool is finer than cashmere and eight times warmer than wool. When collected from the few domestic muskox herds, it can be bought by companies or individuals to make garments, and can be sold raw. The rarity of the fiber and the garments makes it very valuable. Managers of 'domesticated' herds supply qiviut to companies and co-operations for use in making garments. A main producer of these garments is the Musk Ox Producer's Co-Operative. (Applied Microsystems and Inc., 1996; Chambers, 1993)

Research is also performed at the Large Animal Research Station at the University of Alaska Fairbanks on nutrition and arctic adaptations which can be applied to wildlife conservation, biology, and many other aspects. LARS has a captive herd of approximately 40 muskoxen. (Groves, 1997)

In some areas, including Alaska, current laws allow hunting if the hunter is selected through a periodic lottery system, though laws vary across locations and countries. There are domestic herds of muskoxen that can be used for meat, though the qiviut of the animal is much more valuable and continually produced. (Groves, 1997)

Though herds of O. moschatus native to Alaska and parts of Europe were driven to extinction through hunting pressures and climate fluctuations in the late 1800's, the species has been successfully reintroduced from suviving populations in Canada and Greenland and is doing well, currently numbering greater than 60,000 world wide. Ovibos moschatus is currently not listed as a threatened species. (Gray, 1990; Groves, 1997; Reynolds, Wilson, and Klein, 2001; Rowell, 1990)

Muskoxen actually have no musky smell. During the breeding season, the urine the males spray on themselves and the ground is rather pungent, but O. moschatus lacks a true musk gland. Also, it wasn't until recent genetic studies that it was discovered that the closest relatives to muskoxen are members of the Caprinae subfamily. It was previously suggested, based on appearance, that its closest members were cows, bison, or buffalo. (Groves, 1997; Rowell, 1990)