See text, traditionally 1, but possibly up to 6 The reindeer or caribou[a] (Rangifer tarandus)[5] is a species of deer with circumpolar distribution, native to Arctic, subarctic, tundra, boreal, and mountainous regions of Northern Europe, Siberia, and North America.

The North American range of caribou extends from Alaska through the Yukon, the Northwest Territories and Nunavut throughout the tundra, taiga (boreal forest) and south through the Canadian Rocky Mountains.

[50] The Eurasian clade of Odocoileinae (Capreolini, Hydropotini and Alcini) split from the New World tribes of Capreolinae (Odocoileini and Rangiferini) in the Late Miocene, 8.7–9.6 million years ago.

Archaeologists distinguish "modern" tundra reindeer and barren-ground caribou from primitive forms – living and extinct – that did not have adaptations to extreme cold and to long-distance migration.

[56] A fossil skull fragment from Süßenborn, Germany, R. arcticus stadelmanni,[57] (which is probably misnamed) with "rather thin and cylinder-shaped" antlers, dates to the Middle Pleistocene (Günz) Period, 680,000-620,000 BP.

[58] The fossil species geuttardi was later replaced by R. constantini, which was adapted for grasslands,[63] in a second immigration 19,000–20,000 years ago when the LGM turned its forest habitats into tundra, while fennicus survived in isolation in southwestern Europe.

[58] R. constantini was then replaced by modern tundra / barren-ground caribou adapted to extreme cold, probably in Beringia, before dispersing west (R. t. tarandus in the Scandinavian mountains and R. t. sibiricus across Siberia) and east (R. t. arcticus in the North American Barrenlands) when rising seas isolated them.

In the non-forested mountains of central Norway, such as Jotunheimen, it is still possible to find remains of stone-built trapping pits, guiding fences and bow rests, built especially for hunting reindeer.

[citation needed] Their antlers are thin, beams round in cross-section, sweep back and then forward with a cluster of branches at the top; these are designed more for visual stimulation of the females.

Similarly, working on museum collections where skins were often faded and in poor states of preservation, early taxonomists could not readily perceive differences in coat patterns that are consistent within a subspecies, but variable among them.

In his chapter in the authoritative 2005 reference work Mammal Species of the World,[7] referenced by the American Society of Mammalogists, English zoologist Peter Grubb agreed with Valerius Geist, a specialist on large mammals,[14][60] that these subspecies were valid (i.e., before the recent revision): In North America, R. t. caboti, R. t. caribou, R. t. dawsoni, R. t. groenlandicus, R. t. osborni, R. t. pearyi, and R. t. terranovae; and in Eurasia, R. t. tarandus, R. t. buskensis (called R. t. valentinae in Europe; see below), R. t. phylarchus, R. t. pearsoni, R. t. sibiricus and R. t. platyrhynchus.

Before Banfield (1961), taxonomists using cranial, dental and skeletal measurements had unequivocally allied these western montane ecotypes with barren-ground caribou, naming them (as in Osgood 1909[85] Murie, 1935[86] and Anderson 1946,[87] among others) R. t. stonei, R. t. montanus, R. t. fortidens and R. t. osborni, respectively,[86][87] and this phylogeny was confirmed by genetic analysis.

The late Valerius Geist (1998), in the only error in his whole illustrious career, re-analyzed Banfield's data with additional specimens found in an unpublished report he cites as "Skal, 1982", but was "not able to find diagnostic features that could segregate this form from the western barren ground type."

Iqaluit-based Jackoposie Oopakak's 1989 carving, entitled Nunali, which means "place where people live", and which is part of the permanent collection of the National Gallery of Canada, includes a massive set of caribou antlers on which he has intricately carved the miniaturized world of the Inuit where "Arctic birds, caribou, polar bears, seals, and whales are interspersed with human activities of fishing, hunting, cleaning skins, stretching boots, and travelling by dog sled and kayak...from the base of the antlers to the tip of each branch".

[140] In 1913, Dugmore noted how the woodland caribou swim so high out of the water, unlike any other mammal, because their hollow, "air-filled, quill-like hair" acts as a supporting "life jacket".

CCHE is present in animals like reindeer, fox and moose living in extreme conditions of cold or hot weather as a mechanism for retaining the heat in (or out of) the body.

"Specifically, loud knee-clicking is discovered to be an honest signal of body size, providing an exceptional example of the potential for non-vocal acoustic communication in mammals.

It is thought that this ability helps them to survive in the Arctic, because many objects that blend into the landscape in light visible to humans, such as urine and fur, produce sharp contrasts in ultraviolet.

[155] The tapetum lucidum of Arctic reindeer eyes changes in color from gold in summer to blue in winter to improve their vision during times of continuous darkness, and perhaps enable them to better spot predators.

[186] There is also some evidence to suggest that on occasion, especially in the spring when they are nutritionally stressed,[187] they will feed on small rodents (such as lemmings),[188] fish (such as the Arctic char (Salvelinus alpinus)), and bird eggs.

[citation needed] Tormenting insects keep caribou on the move, searching for windy areas like hilltops and mountain ridges, rock reefs, lakeshore and forest openings, or snow patches that offer respite from the buzzing horde.

[148] Changes in climate and habitat beginning in the 20th century have expanded range overlap between white-tailed deer and caribou, increasing the frequency of infection within the reindeer population.

Professor Marco Musiani of the University of Calgary said in a statement that "The woodland caribou is already an endangered subspecies in southern Canada and the United States...[The] warming of the planet means the disappearance of their critical habitat in these regions.

The reindeer has an important economic role for all circumpolar peoples, including the Sámi, the Swedes, the Norwegians, the Finns and the Northwestern Russians in Europe, the Nenets, the Khanty, the Evenks, the Yukaghirs, the Chukchi and the Koryaks in Asia and the Inuit in North America.

[225] Reindeer herding has been vital for the subsistence of several Eurasian nomadic indigenous peoples living in the circumpolar Arctic zone such as the Sámi, Nenets, and Komi.

Millais (1915),[97] for example, shows a photograph (Plate LXXX) of an "Okhotsk Reindeer" saddled for riding (the rider standing behind it) beside an officer astride a steppe pony that is only slightly larger.

"[6]Both Aristotle and Theophrastus have short accounts – probably based on the same source – of an ox-sized deer species, named tarandos, living in the land of the Bodines in Scythia, which was able to change the colour of its fur to obtain camouflage.

[38] A deer-like animal described by Julius Caesar in his Commentarii de Bello Gallico (chapter 6.26) from the Hercynian Forest in the year 53 BC is most certainly to be interpreted as a reindeer:[38][241] There is an ox shaped like a stag.

During World War II, the Soviet Army used reindeer as pack animals to transport food, ammunition and post from Murmansk to the Karelian front and bring wounded soldiers, pilots and equipment back to the base.

Contemporary Canadian artist Brian Jungen, of Dane-zaa First Nations ancestry, commissioned an installation entitled "The ghosts on top of my head" (2010–11) in Banff, Alberta, which depicts the antlers of caribou, elk and moose.