Musk Ox, Arctic Circle

The musk ox is a fascinating creature, having roamed the Earth for at least 600,000 years, rubbing shoulders with sabre-toothed tigers and woolly mammoths during the Ice Age. Its scientific name, Ovibos moschatus, meaning "musky sheep-ox", hints at its somewhat surprising family ties. Despite its bulky, bovine look, the musk ox is more closely related to sheep and goats than bison or cattle.

Musk oxen are relics of the Pleistocene epoch (2.6 million to 11,700 years ago), a period marked by repeated glaciations and many now-extinct megafauna. During this time, musk oxen roamed far beyond their current Arctic range, with fossils found as far south as Spain, Texas and California. Some 200,000 years ago, they crossed the Bering Land Bridge into North America, at a time when what is now the Bering Sea was once solid land, connecting Asia and North America. As the climate warmed and glaciers retreated, their range shrank, and today, they are confined to the cold tundra of Greenland, northern Canada, and Alaska, with a few reintroduced populations in Norway and Siberia. While many prehistoric animals went extinct as the planet warmed, the musk ox endured.

Built for extremes, the musk ox is a quiet survivor of the Arctic tundra, largely due to its remarkable coat, a two-layered system that works like a built-in parka. Long, coarse guard hairs form the outer layer, hanging almost to the ground like a shaggy curtain. These shield the body from wind and moisture, helping to repel snow and rain before they can reach the skin. Beneath this is a dense, downy underwool called qiviut that traps warmth so efficiently that snow can rest on its back without melting. Combined with a slow, energy-efficient metabolism and a robust build, this insulation allows musk oxen to conserve heat and survive in the Arctic climate.

Calves are born in late spring after an eight-month gestation, arriving just in time to take advantage of the short Arctic summer. Within a few hours of birth, they're already on their feet, keeping pace with the herd. Though their coats are not yet as thick as those of adults, they’re born with a soft layer of insulating underwool that offers some protection against the cold. At first, their fur is a lighter brown, almost beige or tan, but as they grow, it darkens into a deep brown, almost black coat of the adults, often with lighter brown or greyish undertones. 

Both males and females grow horns, though the curve and size differ. These horns appear as small nubs at just a few months old. Over time, these horns curve downward and then up into sharp points, forming a protective shield across the forehead. In bulls, the horns grow thick and rounded, meeting toward the centre to form a solid shield used in dramatic head-to-head clashes for mating rights. These battles can be loud and forceful but rarely lethal, with the thick skull and horn base absorbing much of the impact.

Musk oxen are herbivores that graze on the sparse vegetation of the tundra. In summer, their diet includes grasses, sedges, and flowering plants. In winter, they dig through snow with their hooves and noses to reach mosses, lichens, and roots. Their four-chambered stomachs ferment and break down these tough Arctic plants, extracting every possible bit of nutrition from a landscape that offers little.

Once heavily threatened in the 19th and 20th centuries due to overhunting and habitat loss, musk oxen are now listed as a species of Least Concern, with numbers recovering in many regions thanks to conservation and reintroduction efforts. However, challenges persist with climate change and shifting weather patterns. They also contend with a few natural predators, such as wolves and polar bears, though their strong horns and herd defence strategies help them ward off attacks.