Science, Tech, Math › Animals & Nature Arctic Wolf or Canis lupus arctos Share Flipboard Email Print The Arctic wolf is easy to recognize because of its distinct white coat. Photo © John Knight / Getty Images. Animals & Nature Mammals Amphibians Birds Habitat Profiles Reptiles Wildlife Conservation Insects Marine Life Forestry Dinosaurs Evolution View More By Laura Klappenbach Ecology Expert M.S., Applied Ecology, Indiana University Bloomington B.S., Biology and Chemistry, University of Illinois at Urbana-Champaign Laura Klappenbach, M.S., is a science writer specializing in ecology, biology, and wildlife. our editorial process Laura Klappenbach Updated May 09, 2018 The Arctic wolf (Canis lupus arctos) is a subspecies of the grey wolf that inhabits the Arctic regions of North America and Greenland. Arctic wolves are also known as polar wolves or white wolves. Appearance Arctic wolves are similar in build to other grey wolf subspecies. They are slightly smaller in size than other grey wolf subspecies and have smaller ears and a shorter nose. The most prominent difference between arctic wolves and other grey wolf subspecies is their all-white coat, which remains white throughout the year. Arctic wolves have a coat of fur that is specially adapted to the extreme cold climate in which they live. Their fur consists of an outer layer of fur that grows thick when the winter months arrive and an inner layer of fur that forms a waterproof barrier close to the skin. Adult Arctic wolves weigh between 75 and 125 pounds. They grow to lengths of between 3 and 6 feet. Arctic wolves have sharp teeth and powerful jaws, characteristics fitting for a carnivore. Arctic wolves can eat large quantities of meat which enables them to survive for the sometimes long periods between prey captures. Climate and Ecosystem Arctic wolves have not been subjected to the intense hunting and persecution that other grey wolf subspecies have. This is due to the fact that arctic wolves inhabit regions that are largely unpopulated by humans. The greatest threat to Arctic wolves is climate change. Climate change has caused a cascade of effects throughout Arctic ecosystems. Climate variations and extremes have altered the composition of Arctic vegetation which has, in turn, had a negative impact on populations of herbivores in the Arctic. This, in turn, has affected populations of Arctic wolf who rely on herbivores for prey. The diet of Arctic wolves consists primarily of muskox, Arctic hares, and caribou. Arctic wolves form packs that can consist of just a few individuals to as many as 20 wolves. The size of the pack varies based on the availability of food. Arctic wolves are territorial but their territories are often large and overlap with the territories of other individuals. They mark their territory with urine. Arctic wolf populations are present in Alaska, Greenland, and Canada. Their greatest population density is in Alaska, with smaller, sparser populations in Greenland and Canada. Arctic wolves are thought to have evolved from a lineage of other canids about 50 million years ago. Scientists believe that Arctic wolves were isolated in very cold habitats during the Ice Age. It was during this time that they developed the adaptations necessary to survive in the extreme cold of the Arctic. Classification Arctic wolves are classified within the following taxonomic hierarchy: Animals > Chordates > Vertebrates > Tetrapods > Amniotes > Mammals > Carnivores > Canids > Arctic wolf References Burnie D, Wilson DE. 2001. Animal. London: Dorling Kindersley. 624 p.