Climate change isn't only affecting polar bears in the Arctic. Muskoxen are one of the few creatures that depend on cold, dry winters in the Arctic to survive.
Photo credit: Nansen Weber For many of you returning from a week at Arctic Watch, the word muskox is likely met with blank stares among friends and family. While some may have heard of the animal, they often don’t have any idea what this prehistoric mammal might look like. Visually, a muskox is the smaller and shaggier cousin to the bison. A muskox is to a bison as a shetland pony might be to a horse. Highly specialized with their long shaggy hair and insulating undercoat, muskoxen are designed to live in the arctic environment. While they are the largest arctic mammal, the muskox weighs in at an average of 360lbs whereas the bison can weigh upwards of 2000lbs. Despite the visual similarities, the muskox is taxonomically unique as one of the few remaining prehistoric species that continue to roam the land today. Inhabiting the Arctic for many thousands of years, muskoxen are native to Canada and Northern Greenland, and now inhabit a circum-Arctic distribution after having been introduced to other Arctic regions.
Bull muskoxen have a thick “plate” on their foreheads. The plate is easily distinguishable from females and is used to bang heads during rutting season as males compete for breeding rights. Photo credit: Nansen Weber
Subsisting off a diet of sedges, grasses and arctic willow during the summer’s short growing season, muskoxen survive through the harsh winter months by uncovering moss and lichen under the snow. However, with recent changes in temperature around the world, but most prevalent in the north, climate change threatens the availability of food for muskoxen during the winter. A recent study published in Scientific Reports found that muskoxen are vulnerable to rapid climate change in the Arctic. Not only is the Arctic experiencing more drastic environmental changes, but on average the polar region is warming at twice the global rate. Warming temperatures have meant more days of winter rain which researchers suggest provides a strong link to the overall health of muskoxen. It is believed that when the temperature returns back to sub zero following a winter rain, the freezing temperatures create a layer of ice which prevents muskoxen from accessing their critical food source. Muskoxen have a thick undercoat in their fur called Qiviut (the warmest wool on earth) - this warm baselayer acts like a down jacket during the winter months. Freezing rain can soak this layer of fur and at times, cause muskox to die due to an inabillity to retain body heat.
Photo credit: Nansen Weber
The recent study pointed to the prevalence of undersized calves during years of frequent winter rain as a likely consequence. The concern is that undersized calves are at greater risk of dying prematurely or simply cannot mature quickly enough to maintain a stable population. Females will generally only have one calf every other year and may not even calve during especially harsh winters. Because muskoxen have a low reproductive rate, small environmental changes can lead to population decline.
Photo credit: Nansen Weber
Muskoxen’s meager diet means they already live within a thin energy balance and as a result, are extremely vulnerable to predation and human interference. This is because additional stress cause animals to increase their heart rates and metabolism which unnecessarily burns energy they need to survive. At Arctic Watch we strive to view wildlife in a manner that is not only safe for our guests but also respects the long term health of the animals we interact with. By keeping a courteous distance and carrying binoculars, we can continue to have intimate interactions with our resident muskoxen herd for years to come.
An Arctic Watch guest photographs a herd of muskoxen near Arctic Watch. Photo credit: Nansen Weber