The reindeer (Rangifer tarandus), also known as the caribou in North America, is a species of deer with circumpolar distribution, native to Arctic, subarctic, tundra, boreal, and mountainous regions of northern Europe, Siberia, and North America. This includes both sedentary and migratory populations. It is the only representative of the genus Rangifer. Herd size varies greatly in different geographic regions.
DNA analysis indicates that reindeer were independently domesticated in Fennoscandia and Western Russia (and possibly Eastern Russia). Reindeer have been herded for centuries by several Arctic and sub-Arctic peoples, including the Sámi, the Nenets and the Yakuts. They are raised for their meat, hides and antlers and, to a lesser extent, for milk and transportation. Reindeer are not considered fully domesticated, as they generally roam free on pasture grounds. In traditional nomadic herding, reindeer herders migrate with their herds between coastal and inland areas according to an annual migration route and herds are keenly tended. However, reindeer were not bred in captivity, though they were tamed for milking as well as for use as draught animals or beasts of burden. Domesticated reindeer are shorter-legged and heavier than their wild counterparts. In Scandinavia, management of reindeer herds is primarily conducted through siida a traditional Sámi form of cooperative association.