Species of medium-sized, common American deer that covers a huge range from the Arctic Circle in western Canada to 18 degrees south of the Equator in Peru and Bolivia. The white-tailed deer get its name from the long white hair on the underside of the tail and rump, which is evident during flight. The white-tailed deer predates the Ice Ages and is the oldest extant deer species. It became abundant only after the last glaciation when the indigenous Ice Age fauna of the Americas became extinct and competitive and predation pressures were lifted. Its high speed in running, its legendary skills at hiding, and its ability to move silently reflect severe pressure from extinct American Ice Age predators. Although the white-tailed deer of North and South America are currently classified as one species (with several subspecies), genetic research indicates that these deer are further apart than are white-tailed and black-tailed deer in North America so their classification is likely to change in the future.