Some would consider America’s least known large mammal an Arctic antihero. That mammal is the muskox (Ovibos moschatus), and despite its low profile, it survived the last ice age, unlike woolly mammoths, saber-toothed cats, and other prehistoric animals.
“People may think Pleistocene relics exist only in museums or that animals with a highly ordered social structure like elephants exist only in Africa, but actually they exist here in the American wild,” said Dr. Joel Berger, WCS senior scientist.
Although doing well in the Canadian Archipelago and a few mainland sites, musk oxen disappeared from Arctic Alaska 150 years ago. Today’s persisting populations were re-introduced and they currently experience strong interacting effects of climate change, predation by grizzly bear and by humans, and food limitation.
Muskoxen are the earth's only remaining Arctic obligate large herbivore and they subsist on a diet of lichen, mosses and roots - supplemented somewhat by flowers and grasses in the summer months - that they often have to dig through snow to graze upon. Their name is partly a misnomer as they are not actually related to oxen, though males do emit a musky odor during mating season. They are thought to be most closely related to sheep and goats. The species was once distributed throughout the arctic worldwide, but today only inhabits Arctic North America, Greenland and pockets of Siberia and Scandinavia - the latter two sites where they were introduced.
Unlike their Pleistocene cohorts, muskox are not terribly large animals. Adult males usually are roughly four feet tall and weigh in at 600-700 pounds. Having survived thousands of years in their hostile environment, they are exceptionally well adapted to the cold with their long, shaggy coats that are actually comprised of two layers. The underlayer of fur is shed at the end of winter.
Muskoxen are herd animals, but as more is understood about the species, scientists are also finding that they have a highly ordered social structure like elephants, with groups of up to 30 often led by one matriarch. The animals use cooperative techniques to defend themselves against predators and when confronted will form a circle with the young in the middle and horns facing outward.
Dr. Berger, who has been studying musk oxen in Alaska since 2006, is looking into various factors responsible for the animals’ ability to thrive in some areas, hold stable population numbers in others, and decline in still others. He and his partners are currently evaluating the impacts of changing climate, species interactions, and nutrition to musk oxen population dynamics and distribution in western Alaska.
These studies are integral to informing future conservation efforts for muskoxen and other large at-risk Arctic species.