 Although the red species' northern limit is linked to the availability of food, the Arctic species' southern range is limited by the presence of the former.Red and Arctic foxes were both introduced to almost every island from the Aleutian Islands to the Alexander Archipelago during the 1830s–1930s by fur companies.The red foxes invariably displaced the Arctic foxes, with one male red fox having been reported to have killed off all resident Arctic foxes on a small island in 1866.