Muskox

Name and taxonomy

The scientific name is Ovibos moschatus. Ovibos is Latin for sheep-ox, and moschatus refers to the musky smell of a rutting bull. The English name comes from that smell too. Inuit call the animal umingmak, and the Woods Cree names mean ugly moose and ugly bison.

The muskox is a bovid in the tribe Caprini, the sheep and goats, and sits in a subtribe of its own, Ovibovina. Two subspecies are named: the barren-ground muskox of Canada and the slightly smaller white-faced muskox of Greenland. Mitochondrial DNA shows only small differences between populations, and some authors treat the species as a single form.

Evolution and relatives

The muskox's closest living relatives are the gorals of Central and East Asia, not the takin, which resembles it by convergence. Its line arose in the temperate forests of Asia and moved out onto the grasslands in the Pliocene. Early relatives with high, sheep-like horns spread through Siberia, and the shrub-ox Euceratherium crossed to North America two million years ago. The giant muskox Praeovibos reached Alaska a million years ago and may be the direct ancestor of Ovibos.

Modern muskoxen appeared in Germany almost a million years ago and reached Britain in the Mindel glaciation. Today's animals descend from a wave that crossed from Siberia between 200,000 and 90,000 years ago. Only a few large Ice Age mammals survive in North America today, and the muskox stands beside the bison and the pronghorn among them. The last European herd died out in Sweden 9,000 years ago, and the last Asian one on the Taymyr about 2,700 years ago.

Appearance

The muskox is a blocky animal with a broad head, a short neck, a humped shoulder and short stout legs. It stands 1.1 to 1.5 metres at the withers. Females measure 135 to 200 centimetres long and males 200 to 250 cm. Adults average 285 kilograms and range from 180 to 410 kg, and a zoo animal has reached 650 kg. The tail is only about 10 cm long and hides under the fur.

The coat is a mix of black, grey and brown. Long guard hairs hang like a skirt almost to the ground, and older animals grow a mane on the shoulders. A lighter saddle of shorter hair marks the middle of the back, and the legs and muzzle are pale. Beneath the guard hairs grows qiviut, a dense underwool that the animal sheds each spring. Rare white muskoxen have been seen in the Queen Maud Gulf Bird Sanctuary.

Both sexes carry amber horns that sweep down beside the face and hook up at sharp tips. A bull's horns meet across the forehead in a boss 15 to 20 cm thick, which takes the shock of a head-on charge. A cow's horns are thinner and lack the boss. Bulls are about 25 percent larger than cows.

Habitat and range

The native range covers the Arctic tundra of northern Canada, from the mainland barrens to Banks and Ellesmere Islands, and north-east Greenland. Muskoxen once lived from Point Barrow in Alaska to north-east Manitoba, but Alaska lost its herds in the late 1800s. Greenland stock restored them to Nunivak Island in the 1930s, and from there to the Seward Peninsula and northern Alaska. Russia released animals on the Taymyr Peninsula and Wrangel Island in 1974 and 1975, and Norway's Dovrefjell herd seeded a Swedish one in 1971.

The muskox lives north of the tree line on tundra where the snow stays shallow. In summer it grazes wet river valleys, sedge meadows and coastal plains. In winter it climbs to wind-swept ridges where the snow blows off the forage. It survives cold that reaches minus 80 degrees Celsius with wind chill.

Summer home ranges in Alaska average 223 square kilometres and shrink to 27 to 70 in winter. Tagged animals have moved 120 to 130 km, though most herds shift only locally with the seasons. GBIF holds records from 18 countries, a count that includes zoos and introductions.

Diet and feeding

The muskox is a grazer first. Sedges and grasses make up most of the diet, and on the Taymyr grasses supply 47 to 86 percent of the year's food. Willows and forbs matter in summer and autumn, and willow is rich in nitrogen. In winter it turns to willow, dwarf birch, roots, moss and lichen, whatever it can dig from under the snow.

Feeding fills most of the winter day, because the animal must keep its fat reserves up. A cow will not come into heat after a hard winter, so the breeding rate follows the food. Deep snow costs energy to dig through, which is why herds seek shallow snow. Calves take adult food within weeks of birth but nurse for about a year.

Behaviour and social life

Muskoxen live in herds of 8 to 20 in summer and 12 to 24 in winter. Winter groups of 60 or more have been recorded. They hold no territories but mark their trails with the glands in front of the eyes. Males and females each have their own rank order by age, and dominant animals take the best grazing. Animals shift between herds, so membership is loose.

In the rut a dominant bull drives the other males out and holds a harem of six or seven cows and their young. Rivals roar, swing their heads, paw the ground and rub their face glands on their legs. Then they back off about 20 metres, lower their heads and crash together on the horn bosses. They repeat the charge until one gives up, and the fights are rarely fatal. Beaten bulls form bachelor groups or wander alone and rejoin the herd when danger appears.

Outside the rut the pregnant cows lead. They decide how far the herd travels each day and where it beds. When wolves come, the adults turn outward in a ring or a line with the calves behind them. A big adult may charge out to hook or trample a wolf. The muskox can run at up to 60 kilometres per hour, but it overheats quickly, so it stands and fights instead.

Communication and senses

Calves bleat, and the call deepens with age into the roars and rumbles of adults, which carry a long way. Adults grunt and snort at one another, at their calves and at intruders. A cow calls her calf with a bray.

Scent does much of the work in the rut. A bull urinates on his forelegs and dribbles urine as he displays, and the rank smell spreads through the belly fur. The gland secretion smells light and sweet, and analysis found benzaldehyde and a series of lactones. Bulls also walk sideways to show their bulk and horn the ground to throw up turf.

Reproduction and life cycle

The rut begins in late June or July and mating takes place in August and September. A bull taps a cow with his foreleg to calm her before mating. Pregnancy lasts about eight to nine months, or 235 to 245 days by one account. Most calves arrive from mid-April to early June, into temperatures as low as minus 30 degrees Celsius.

A cow bears one calf of about 10 kilograms, and twins are very rare. Within 45 minutes the calf is standing and nursing, and within hours it can keep up with the herd. It shelters under its mother's skirt of hair through the first winter. Calves nurse for 10 months to a year and grow up to 0.5 kg a day. The bond with the mother weakens after two years.

Cows first calve at about three years and may calve until 18, usually in alternate years. Bulls mature at three to four years but cannot win a harem until about six to eight. Life expectancy is 12 to 20 years, and a captive animal reached 27.4. Cows outlive bulls, whose rut wears them out, and worn molars end most long lives.

Predators and threats

The Arctic wolf is the main predator and may cause half of all muskox deaths. Grizzly bears, polar bears and wolverines take calves and weak adults. The defensive ring works against a single wolf, but a pack can probably hold the herd in place and pick off a calf.

Hard winters kill calves and old animals, and rain that freezes over the forage can starve a whole herd. Norway's herd lost 29 animals to a measles outbreak in 2004. Small scattered herds, as in Greenland, are exposed to local swings in climate. Trains on the Dovre railway kill a few animals each year.

Population and conservation

The IUCN lists the muskox as Least Concern. The world population is put at 80,000 to 125,000, with about 47,000 on Banks Island alone. Overhunting in the 1800s emptied Alaska and cut the Canadian herds, and hunting quotas since the late 1900s have driven the recovery.

Reintroductions have restored the species across its old range and beyond. Alaska began in 1930 with 34 animals from East Greenland and now holds about 4,000. Wrangel Island held about 1,100 by 2019 and the Taymyr 11,000 to 14,000. Quebec's herd, released from a failed farm between 1973 and 1983, reached about 1,400 by 2003. Norway's Dovrefjell herd numbered about 300 in 2012.

In Greenland most herds live inside national parks and reserves and are fully protected. In Alaska hunters draw permits by lottery. The Pleistocene Park team on the Kolyma released six animals in 2010 to test whether hunting, not climate, ended the Siberian herds.

Relationship with humans

Arctic peoples hunted the muskox for meat, hide and horn for thousands of years, and Inuit hunters still take it under quota. Market hunting in the 1800s came close to wiping it out. The animal is not aggressive, but a person who crowds it can be attacked. A 73-year-old man died in Norway in 1964. A court officer died near Nome, Alaska, in December 2022 while chasing a group from his dog kennel.

Qiviut is the muskox's gift to people. The underwool is finer than cashmere, insulates eight times better than sheep's wool, and does not shrink in water. It is combed from farmed animals or gathered during the spring moult, never sheared. In 2016 a gram of raw fibre cost about 1.2 dollars, and a scarf about 275 dollars.

Farms in Alaska raise the animal for wool, and the Oomingmak cooperative, founded by Alaska Native women in the late 1960s, has about 200 members. The Large Animal Research Station in Fairbanks keeps about 40 muskoxen for research. A Quebec farm set up in 1967 to build an Inuit qiviut trade was closed. The province wanted wild herds for hunting instead.

In culture and myth

In Inuit tradition, the animal is umingmak, the bearded one, and its name lives on in the Oomingmak cooperative and the community of Umingmaktok. In Woods Cree tradition, the names mâthi-môs and mâthi-mostos call it the ugly moose and the ugly bison. In Alaska Native tradition, qiviut knitting has become a village craft and a source of income since the 1960s.

Norwegian railway workers found two fossil vertebrae on Dovrefjell in 1913, and the find inspired the first muskox release in the world in 1925. In Russia, the muskox appears to serve as a symbol of the Pleistocene Park project, which aims to rebuild the Ice Age grassland. The Ice Age defensive ring is thought to have evolved against wolves, and it is often cited as an image of solidarity.