The reindeer or caribou (Rangifer tarandus) is a species of deer with circumpolar distribution, native to Arctic, subarctic, tundra, boreal, and mountainous regions of Northern Europe, Siberia, and North America. It is the only representative of the genus Rangifer. More recent studies suggest the splitting of reindeer and caribou into six distinct species over their range.
Reindeer occur in both migratory and sedentary populations, and their herd sizes vary greatly in different regions. The tundra subspecies are adapted for extreme cold, and some are adapted for long-distance migration.
Reindeer vary greatly in size and color from the smallest, the Svalbard reindeer (R. (t.) platyrhynchus), to the largest, Osborn's caribou (R. t. osborni). Although reindeer are quite numerous, some species and subspecies are in decline and considered vulnerable. They are unique among deer (Cervidae) in that females may have antlers, although the prevalence of antlered females varies by subspecies.
Reindeer are the only successfully semi-domesticated deer on a large scale in the world. Both wild and domestic reindeer have been an important source of food, clothing, and shelter for Arctic people from prehistorical times. They are still herded and hunted today. In some traditional Christmas legends, Santa Claus's reindeer pull a sleigh through the night sky to help Santa Claus deliver gifts to good children on Christmas Eve.
Names follow international convention[1] before the recent revision[2] (see Reindeer#Taxonomy below). Reindeer / caribou (Rangifer) vary in size from the smallest, the Svalbard reindeer (R. (t.) platyrhynchus), to the largest, Osborn's caribou (R. t. osborni). They also vary in coat color and antler architecture.
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.[3] Of the eight subspecies classified by Harding (2022) into the Arctic caribou (R. arcticus), the migratory mainland barren-ground caribou of Arctic Alaska and Northern Canada (R. t. arcticus), summer in tundra and winter in taiga, a transitional forest zone between boreal forest and tundra; the nomadic Peary caribou (R. t. pearyi) lives in the polar desert of the high Arctic Archipelago and Grant's caribou (R. t. granti also called the Porcupine caribou) lives in the western end of the Alaska Peninsula and the adjacent islands; the other four subspecies, Osborn's caribou (R. t. osborni), Stone's caribou (R. t. stonei), the Rocky Mountain caribou (R. t. fortidens) and the Selkirk Mountains caribou (R. t. montanus) are all montane. The extinct insular Queen Charlotte Islands caribou (R. t. dawsoni), lived on Graham Island in Haida Gwaii (formerly known as the Queen Charlotte Islands).
The boreal woodland caribou (R. t. caribou), lives in the boreal forest of northeastern Canada: the Labrador or Ungava caribou of northern Quebec and northern Labrador (R. t. caboti), and the Newfoundland caribou of Newfoundland (R. t. terranovae) have been found to be genetically in the woodland caribou lineage.
In Eurasia, both wild and domestic reindeer are distributed across the tundra and into the taiga. Eurasian mountain reindeer (R. t. tarandus) are close to North American caribou genetically and visually, but with sufficient differences to warrant division into two species. The unique, insular Svalbard reindeer inhabits the Svalbard Archipelago. The Finnish forest reindeer (R. t. fennicus) is spottily distributed in the coniferous forest zones from Finland to east of Lake Baikal: the Siberian forest reindeer (R. t. valentinae, formerly called the Busk Mountains reindeer (R. t. buskensis) by American taxonomists) occupies the Altai and Ural Mountains.
Male ("bull") and female ("cow") reindeer can grow antlers annually, although the proportion of females that grow antlers varies greatly between populations. Antlers are typically larger on males. Antler architecture varies by species and subspecies and, together with pelage differences, can often be used to distinguish between species and subspecies (see illustrations in Geist, 1991[4] and Geist, 1998).[5]
About 25,000 mountain reindeer (R. t. tarandus) still live in the mountains of Norway, notably in Hardangervidda.[6] In Sweden there are approximately 250,000 reindeer in herds managed by Sámi villages.[7] Russia manages 19 herds of Siberian tundra reindeer (R. t. sibiricus) that total about 940,000.[8] The Taimyr herd of Siberian tundra reindeer is the largest wild reindeer herd in the world,[9] [10] varying between 400,000 and 1,000,000; it is a metapopulation consisting of several subpopulations — some of which are phenotypically different[11] — with different migration routes and calving areas.[12] [13] The Kamchatkan reindeer (R. t. phylarchus), a forest subspecies, formerly included reindeer west of the Sea of Okhotsk which, however, are indistinguishable genetically from the Jano-Indigirka, East Siberian taiga and Chukotka populations of R. t. sibiricus.[14] Siberian tundra reindeer herds have been in decline but are stable or increasing since 2000.
Insular (island) reindeer, classified as the Novaya Zemlya reindeer (R. t. pearsoni) occupy several island groups: the Novaya Zemlya Archipelago (about 5,000 animals at last count, but most of these are either domestic reindeer or domestic-wild hybrids), the New Siberia Archipelago (about 10,000 to 15,000), and Wrangel Island (200 to 300 feral domestic reindeer).
What was once the second largest herd is the migratory Labrador caribou (R. t. caboti) George River herd in Canada, with former variations between 28,000 and 385,000. As of January 2018, there are fewer than 9,000 animals estimated to be left in the George River herd, as reported by the Canadian Broadcasting Corporation.[15] The New York Times reported in April 2018 of the disappearance of the only herd of southern mountain woodland caribou in the contiguous United States, with an expert calling it "functionally extinct" after the herd's size dwindled to a mere three animals.[16] After the last individual, a female, was translocated to a wildlife rehabilitation center in Canada, caribou were considered extirpated from the contiguous United States.[17] The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) classified both the Southern Mountain population DU9 (R. t. montanus) and the Central Mountain population DU8 (R. t. fortidens) as Endangered and the Northern Mountain population DU7 (R. t. osborni) as Threatened.[18]
Some species and subspecies are rare and three subspecies have already become extinct: the Queen Charlotte Islands caribou (R. t. dawsoni) from western Canada, the Sakhalin reindeer (R. t. setoni) from Sakhalin and the East Greenland caribou from eastern Greenland,[19] [20] although some authorities believe that the latter, R. t. eogroenlandicus Degerbøl, 1957, is a junior synonym of the Peary caribou.[21] [22] Historically, the range of the sedentary boreal woodland caribou covered more than half of Canada[23] and into the northern states of the contiguous United States from Maine to Washington. Boreal woodland caribou have disappeared from most of their original southern range and were designated as Threatened in 2002 by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Environment and Climate Change Canada reported in 2011 that there were approximately 34,000 boreal woodland caribou in 51 ranges remaining in Canada (Environment Canada, 2011b), although those numbers included montane populations classified by Harding (2022) into subspecies of the Arctic caribou. Siberian tundra reindeer herds are also in decline, and Rangifer as a whole is considered to be Vulnerable by the International Union for Conservation of Nature (IUCN).
Charles Hamilton Smith is credited with the name Rangifer for the reindeer genus,[24] which Albertus Magnus used in his Latin: De animalibus, fol. Liber 22, Cap. 268: "Dicitur Rangyfer quasi ramifer". This word may go back to the Sámi word Sami languages: raingo. Carl Linnaeus chose the word tarandus as the specific epithet, making reference to Ulisse Aldrovandi's Latin: Quadrupedum omnium bisulcorum historia fol. 859–863, Cap. 30: De Tarando (1621). However, Aldrovandi and Conrad Gessner[25] thought that rangifer and tarandus were two separate animals.[26] In any case, the tarandos name goes back to Aristotle and Theophrastus.
The use of the terms reindeer and caribou for essentially the same animal can cause confusion, but the ICUN clearly delineates the issue: "Reindeer is the European name for the species of Rangifer, while in North America, Rangifer species are known as Caribou."[27] The word reindeer is an anglicized version of the Old Norse words Norse, Old: hreinn ("reindeer") and Norse, Old: dýr ("animal") and has nothing to do with reins.[28] The word caribou comes through French, from the Mi'kmaq Mi'kmaq; Micmac: qalipu, meaning "snow shoveler", and refers to its habit of pawing through the snow for food.[29]
Because of its importance to many cultures, Rangifer and some of its species and subspecies have names in many languages. Inuvialuit of the western Canadian Arctic and Inuit of the eastern Canadian Arctic, who speak different dialects of the Inuit languages, both call the barren-ground caribou Inuktitut: tuktu.[30] [31] [32] The Wekʼèezhìi (Tłı̨chǫ) people, a Dene (Athapascan) group, call the Arctic caribou Dogrib: Ɂekwǫ̀ and the boreal woodland caribou Dogrib: tǫdzı.[33] The Gwichʼin (also a Dene group) have over 24 distinct caribou-related words.
Reindeer are also called Kalaallisut; Greenlandic: tuttu by the Greenlandic Inuit[34] and Icelandic: hreindýr, sometimes Icelandic: rein, by the Icelanders.
The "glacial-interglacial cycles of the upper Pleistocene had a major influence on the evolution" of Rangifer species and other Arctic and sub-Arctic species. Isolation of tundra-adapted species Rangifer in Last Glacial Maximum refugia during the last glacial – the Wisconsin glaciation in North America and the Weichselian glaciation in Eurasia – shaped "intraspecific genetic variability" particularly between the North American and Eurasian parts of the Arctic.[35]
Reindeer / caribou (Rangifer) are in the subfamily Odocoileinae, along with roe deer (Capreolus), Eurasian elk / moose (Alces), and water deer (Hydropotes). These antlered cervids split from the horned ruminants Bos (cattle and yaks), Ovis (sheep) and Capra (goats) about 36 million years ago.[36] 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.[37] Rangifer "evolved as a mountain deer, ...exploiting the subalpine and alpine meadows...". Rangifer originated in the Late Pliocene and diversified in the Early Pleistocene, a 2+ million-year period of multiple glacier advances and retreats. Several named Rangifer fossils in Eurasia and North America predate the evolution of modern tundra reindeer.
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. They include a broad, high muzzle to increase the volume of the nasal cavity to warm and moisten the air before it enters the throat and lungs, bez tines set close to the brow tines, distinctive coat patterns, short legs and other adaptations for running long distances, and multiple behaviors suited to tundra, but not to forest (such as synchronized calving and aggregation during rutting and post-calving).[38] As well, many genes, including those for vitamin D metabolism, fat metabolism, retinal development, circadian rhythm, and tolerance to cold temperatures, are found in tundra caribou that are lacking or rudimentary in forest types.[39] [40] For this reason, forest-adapted reindeer and caribou could not survive in tundra or polar deserts. The oldest undoubted Rangifer fossil is from Omsk, Russia, dated to 2.1-1.8 Ma.[41] The oldest North American Rangifer fossil is from the Yukon, 1.6 million years before present (BP).[42] A fossil skull fragment from Süßenborn, Germany, R. arcticus stadelmanni,[43] (which is probably misnamed) with "rather thin and cylinder-shaped" antlers, dates to the Middle Pleistocene (Günz) Period, 680,000-620,000 BP.[44] Rangifer fossils become increasingly frequent in circumpolar deposits beginning with the Riss glaciations, the second youngest of the Pleistocene Epoch, roughly 300,000–130,000 BP. By the 4-Würm period (110,000–70,000 to 12,000–10,000 BP), its European range was extensive, supplying a major food source for prehistoric Europeans.[45] North American fossils outside of Beringia that predate the Last Glacial Maximum (LGM) are of Rancholabrean age (240,000–11,000 years BP) and occur along the fringes of the Rocky Mountain and Laurentide ice sheets as far south as northern Alabama; and in Sangamonian deposits (~100,000 years BP) from western Canada.[46]
A R. t. pearyi-sized caribou occupied Greenland before and after the LGM and persisted in a relict enclave in northeastern Greenland until it went extinct about 1900 (see discussion of R. t. eogroenlandicus below). Archaeological excavations showed that larger barren-ground-sized caribou appeared in western Greenland about 4,000 years ago.[47]
The late Valerius Geist (1998) dates the Eurasian reindeer radiation dates to the large Riss glaciation (347,000 to 128,000 years ago), based on the Norwegian-Svalbard split 225,000 years ago.[48] Finnish forest reindeer (R. t. fennicus) likely evolved from Cervus [Rangifer] geuttardi Desmarest, 1822, a reindeer that adapted to forest habitats in Eastern Europe as forests expanded during an interglacial period before the LGM (the Würmian or Weichsel glaciation);. The fossil species geuttardi was later replaced by R. constantini, which was adapted for grasslands,[49] 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. 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. Likewise in North America, DNA analysis shows that woodland caribou (R. caribou) diverged from primitive ancestors of tundra / barren-ground caribou not during the LGM, 26,000–19,000 years ago, as previously assumed, but in the Middle Pleistocene around 357,000 years ago.[50] [51] At that time, modern tundra caribou had not even evolved. Woodland caribou are likely more related to extinct North American forest caribou than to barren-ground caribou. For example, the extinct caribou Torontoceros [Rangifer] hypogaeus, had features (robust and short pedicles, smooth antler surface, and high position of second tine) that relate it to forest caribou.[52]
Humans started hunting reindeer in both the Mesolithic and Neolithic Periods, and humans are today the main predator in many areas. Norway and Greenland have unbroken traditions of hunting wild reindeer from the Last Glacial Period until the present day. 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. These can, with some certainty, be dated to the Migration Period, although it is not unlikely that they have been in use since the Stone Age.
Cave paintings by ancient Europeans include both tundra and forest types of reindeer.
A 2022 study of ancient environmental DNA from the Early Pleistocene (2 million years ago) Kap Kobenhavn Formation of northern Greenland identified preserved DNA fragments of Rangifer, identified as basal but potentially ancestral to modern reindeer. This suggests that reindeer have inhabited Greenland since at least the Early Pleistocene. Around this time, northern Greenland was warmer than the Holocene, with a boreal forest hosting a species assemblage with no modern analogue. These are among the oldest DNA fragments ever sequenced.[53] [54]
Carl Linnaeus in 1758 named the Eurasian tundra species Cervus tarandus, the genus Rangifer being credited to Smith, 1827.
Rangifer has had a convoluted history because of the similarity in antler architecture (brow tines asymmetrical and often palmate, bez tines, a back tine sometimes branched, and branched at the distal end, often palmate). Because of individual variability, early taxonomists were unable to discern consistent patterns among populations, nor could they, examining collections in Europe, appreciate the difference in habitats and the differing function they imposed on antler architecture. Comparative morphometrics, the measurement of skulls, is often seen as more objective than description of differences of color or antler patterns, but actually confounds genetic variance with epistatic and statistical variance as well as compounded environment-based variance.
For example, woodland caribou males, rutting in boreal forest where only a few females can be found, collect harems and defend them against other males, for which they have short, straight, strong, much-branched antlers, beams flattened in cross-section, designed for combat — and not too large, so as not to impede them in forested winter ranges.
By contrast, modern tundra caribou (see Evolution above) have synchronized calving as a predator-avoidance strategy, which requires large rutting aggregations. Males cannot defend a harem because, while he was busy fighting, they would disappear into the mass of the herd. Males therefore tend individual females; their fights are infrequent and brief. 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. Their bez tines are set low, just above the brow tine, which is vertically flattened to protect the eyes while the buck "threshes" low brush, a courtship display.[55] The low bez tines help the wide flat brow tines dig craters in the hard-packed tundra snow for forage, for which reason brow tines are often called "shovels" in North America and "ice tines" in Europe. The differences in antler architecture reflect fundamental differences in ecology and behavior, and in turn deep divisions in ancestry that were not apparent to the early taxonomists.
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. Geist calls these "nuptial" characteristics: sexually selected characters that are highly conserved and diagnostic among subspecies.
Towards the end of the 19th century, national museums began sending out biological exploration expeditions and collections accumulated. Taxonomists, usually working for the museums, began naming subspecies more rigorously, based on statistical differences in detailed cranial, dental and skeletal measurements than antlers and pelage, supplemented by better knowledge of differences in ecology and behavior. From 1898 to 1937, mammalogists named 12 new species (other than barren-ground and woodland, which had been named earlier) of caribou in Canada and Alaska, and three new species and nine new subspecies in Eurasia, each properly described according to the evolving rules of zoological nomenclature, with type localities designated and type specimens deposited in museums (see table in Species and subspecies below).[56]
In the mid-20th century, as definitions of "species" evolved, mammalogists in Europe[57] and North America[58] made all Rangifer species conspecific with R. tarandus, and synonymized most of the subspecies. Alexander William Francis Banfield's often-cited A Revision of the Reindeer and Caribou, Genus Rangifer (1961),[59] eliminated R. t. caboti (the Labrador caribou), R. t. osborni (Osborn's caribou — from British Columbia) and R. t. terranovae (the Newfoundland caribou) as invalid and included only barren-ground caribou, renamed as R. t. groenlandicus (formerly R. arcticus) and woodland caribou as R. t. caribou. However, Banfield made multiple errors, eliciting a scathing review by Ian McTaggart-Cowan in 1962.[60] Most authorities continued to consider all or most subspecies valid; some were quite distinct. In his chapter in the authoritative 2005 reference work Mammal Species of the World, referenced by the American Society of Mammalogists, English zoologist Peter Grubb agreed with Valerius Geist, a specialist on large mammals, 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. These subspecies were retained in the 2011 replacement work Handbook of the Mammals of the World Vol. 2: Hoofed Mammals. Most Russian authors also recognized R. t. angustirostris, a forest reindeer from east of Lake Baikal.[61]
However, since 1991, many genetic studies have revealed deep divergence between modern tundra reindeer and woodland caribou.[62] [63] [64] [65] Geist (2007) and others continued arguing that the woodland caribou was incorrectly classified, noting that "true woodland caribou, the uniformly dark, small-maned type with the frontally emphasized, flat-beamed antlers", is "scattered thinly along the southern rim of North American caribou distribution". He affirms that the "true woodland caribou is very rare, in very great difficulties and requires the most urgent of attention."[66]
In 2011, noting that the former classifications of Rangifer tarandus, either with prevailing taxonomy on subspecies, designations based on ecotypes, or natural population groupings, failed to capture "the variability of caribou across their range in Canada" needed for effective subspecies conservation and management, COSEWIC developed Designatable Unit (DU) attribution, an adaptation of "evolutionary significant units".[67] The 12 designatable units for caribou in Canada (that is, excluding Alaska and Greenland) based on ecology, behavior and, importantly, genetics (but excluding morphology and archaeology) essentially followed the previously named subspecies distributions, without naming them as such, plus some ecotypes. Ecotypes are not phylogenetically based and cannot substitute for taxonomy.[68]
Meanwhile, genetic data continued to accumulate, revealing sufficiently deep divisions to easily separate Rangifer back into six previously named species and to resurrect several previously named subspecies. Molecular data showed that the Greenland caribou (R. t. groenlandicus) and the Svalbard reindeer (R. t. platyrhynchus), although not closely related to each other, were the most genetically divergent among Rangifer clades; that modern (see Evolution above) Eurasian tundra reindeer (R. t. tarandus and R. t. sibiricus) and North American barren-ground caribou (R. t. arcticus), although sharing ancestry, were separable at the subspecies level; that Finnish forest reindeer (R. t. fennicus) clustered well apart from both wild and domestic tundra reindeer and that boreal woodland caribou (R. t. caribou) were separable from all others.[69] [70] Meanwhile, archaeological evidence was accumulating that Eurasian forest reindeer descended from an extinct forest-adapted reindeer and not from tundra reindeer (see Evolution above); since they do not share a direct common ancestor, they cannot be Biological specificity#conspecific|conspecific. Similarly, woodland caribou diverged from the ancestors of Arctic caribou before modern barren-ground caribou had evolved, and were more likely related to extinct North American forest reindeer (see Evolution above). Lacking a direct shared ancestor, barren-ground and woodland caribou cannot be conspecific.
Molecular data also revealed that the four western Canadian montane ecotypes are not woodland caribou: they share a common ancestor with modern barren-ground caribou / tundra reindeer, but distantly, having diverged > 60,000 years ago[71] [72] — before the modern ecotypes had evolved their cold- and darkness-adapted physiologies and mass-migration and aggregation behaviors (see Evolution above). 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[73] Murie, 1935 and Anderson 1946, among others) R. t. stonei, R. t. montanus, R. t. fortidens and R. t. osborni, respectively,[74] [75] and this phylogeny was confirmed by genetic analysis.
DNA also revealed three unnamed clades that, based on genetic distance, genetic divergence and shared vs. private haplotypes and alleles, together with ecological and behavioral differences, may justify separation at the subspecies level: the Atlantic-Gaspésie caribou (COSEWIC DU11), an eastern montane ecotype of the boreal woodland caribou, and the Baffin Island caribou.[76] Neither one of these clades has yet been formally described or named.
Jenkins et al. (2012) said that "[Baffin Island] caribou are unique compared to other Barrenground herds, as they do not overwinter in forested habitat, nor do all caribou undertake long seasonal migrations to calving areas." It also shares a mtDNA haplotype with Labrador caribou, in the North American lineage (i.e., woodland caribou).[69] Røed et al. (1991)[62] had noted:
Among Baffin Island caribou the TFL2 allele was the most common allele (p=0.521), while this allele was absent, or present in very low frequencies, in other caribou populations (Table 1), including the Canadian barren-ground caribou from the Beverly herd. A large genetic difference between Baffin Island caribou and the Beverly herd was also indicated by eight alleles found in the Beverly herd which were absent from the Baffin Island samples.Jenkins et al. (2018) also reported genetic distinctiveness of Baffin Island caribou from all other barren-ground caribou; its genetic signature was not found on the mainland or on other islands; nor were Beverly herd (the nearest mainly barren-ground caribou) alleles present in Baffin Island caribou, evidence of reproductive isolation.
These advances in Rangifer genetics were brought together with previous morphological-based descriptions, ecology, behavior and archaeology to propose a new revision of the genus.
| Species (6-species taxonomy) | width=12.5% | Subspecies | width=12.5% | Common name | width=13% | Sedentary / migratory | width=14.5% | Range | width=13.5% | Weight of male | width=14.5% | Type locality / specimen | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| R. tarandus (Linnaeus, 1758) reindeer or caribou | R. arcticus Richardson, 1829 Barren-ground caribou | R. t. arcticus or R. a. articus (Richardson, 1829) | barren-ground caribou | migratory | the High Arctic islands of Nunavut and the Northwest Territories, Canada and western Greenland (except for the southwestern region) | "Fort Enterprise, Winter Lake, Mackenzie District, N.W.T., Canada" given by Allen 1908; Neotype no. 22066 (for the species) | ||||||||||||||||||
R. t. arcticus or R. a. arcticus (Richardson, 1829) | Porcupine caribou (an ecotype of the barren-ground caribou) | migratory | the same as for the subspecies | |||||||||||||||||||||
| R. t. fortidens or R. a. fortidens (Hollister, 1912) | Rocky Mountain caribou | short migrations: summers in alpine forest and winters in lowland forest | the Canadian Rocky Mountains | "Largest of the caribou, exceeding in measurements the largest specimens of Rangifer osborni and Rangifer montanus." | "head of Moose Pass branch of the Smoky River, Alberta (north-east of Mount Robson)"; USNM No. 174505 | |||||||||||||||||||
| R. t. granti or R. a. granti (Allen, 1902) | Grant's caribou | sedentary (makes short movements to seasonal habitats)[77] | the western end of the Alaska Peninsula and the adjacent islands | "Western end of Alaska Peninsula, opposite Popoff Island, Alaska"; AMNH no. 17593 | ||||||||||||||||||||
R. t. montanus or R. a. montanus (Seton-Thompson, 1899) | Selkirk Mountains caribou | twice-yearly altitudinal movements | the Columbia Mountains (specifically the Selkirk, Purcell and Monashee Mountains) in British Columbia, Canada and Washington, Idaho and Montana, United States | no data | "Illecillewaet watershed, near Revelstoke, Selkirk Range, B. C."; NMC no. 232 | |||||||||||||||||||
R. t. osborni or R. a. osborni (Allen, 1902) | Osborn's caribou | short migrations: summers in alpine forest and winters in lowland muskeg | British Columbia, Canada | males up to | "Cassiar Mountains, British Columbia; AMNH no. 15714 | |||||||||||||||||||
R. t. pearyi or R. a. pearyi (Allen, 1902) | Peary caribou | an island population that makes local movements both within and among islands | the High Arctic islands (except for Baffin Island) of Nunavut and the Northwest Territories, Canada | smallest North American subspecies: males average | "Ellesmere Land [Ellesmere Island], N. Lat. 79⁰"; AMNH no. 19231|-|R. t. stonei or R. a. stonei (Allen, 1901)|Stone's caribou|altitudinal movements|the mountains of southern Alaska and the southeastern Yukon|no data|"Kenai Peninsula, Alaska"; AMNH no. 16701|-| rowspan="3" |R. caribou (Gmelin, 1788) woodland caribou| R. t. caribou or R. c. caribou (Gmelin, 1788) ||boreal woodland caribou || sedentary (makes short movements to seasonal habitats) ||the boreal forests of northeastern Canada||males average, up to |Type locality amended to "eastern Canada" (Miller Jr. 1912); NMC Neotype no. 4800|-| R. t. caboti or R. c. caboti (G. M. Allen, 1914)||Labrador caribou or Ungava caribou|| migratory (except for the Torngat Mountain population DU10)|| northern Quebec and northern Labrador, Canada|no data|"Thirty miles north of Nachvak [Torngat Mountains], northeast coast of Labrador", MCZ No. 15,372|-| R. t. terranovae or R. c. terranovae (Allen, 1896)||Newfoundland caribou|| ||Newfoundland, Canada ||139.6 kg (3 adult males)[78] |"Grand Lake, Newfoundland"; AMNH 11775|-| rowspan="2" |R. fennicus Lönnberg, 1909 forest reindeer| R. t. fennicus or R. f. fennicus (Lönnberg, 1909) ||Finnish forest reindeer || migratory ||northwestern Russia and Finland[79] |||"Torne District [in [[Enontekiö]]], Finnish Lappland"; NR No. 4661, Stockholm|-|R. t. valentinae or R. f. valentinae (Flerov, 1933)|| Siberian forest reindeer|| altitudinal migration || the Ural Mountains, Russia and the Altai Mountains, Mongolia||no data|"Head of Chulyshman River, North-Eastern Altai, Siberia"; skin ZMASL no. 22599, skull no. 10214|-|R. groenlandicus (Borowsky, 1780)| R. groenlandicus or R. t. groenlandicus (Borowsky, 1780) ||Western Greenlandic Caribou or reindeer|sedentary|four small areas in southwestern Greenland[80] |no data|"Greenland"|-|R. platyrhynchus (Vrolik, 1829) Svalbard reindeer| R. platyrhynchus or R. t. platyrhynchus (Vrolik, 1829) ||Svalbard reindeer || an island population that makes local movements both within and among islands ||the Svalbard Archipelago of Norway||smallest of the reindeer; has extremely short legs|"Spitzbergen"; Neotype no. M2625, Oslo|-| rowspan="4" |R. tarandus (Linnaeus, 1758) tundra reindeer or mountain reindeer|R. t. pearsoni (Lydekker, 1903)||Novaya Zemlya reindeer|| an island population that makes local movements both within and among islands ||the Novaya Zemlya and New Siberia Archipelagoes of Russia and Wrangel Island, Russia||no data|"Island of Novaya Zemlya"; type specimen "In the possession of H. J. Pearson, Esq., Bramcote, Nottinghamshire, England" (Flerov, 1933).|-|R. t. phylarchus (Hollister, 1912)|| Kamchatkan reindeer|| ||restricted to the Kamchatka Peninsula, Russia, after those reindeer west of the Sea of Okhotsk were found to actually be R. t. sibiricus||no data|"Southeastern Kamchatka [Kamchatka]"; USNM No. 21343|-|R. t. sibiricus (Murray, 1866)|| Siberian tundra reindeer|| long-distance migrations||Siberia, Russia, Franz Josef Land during the Holocene from >6400–1300 cal. BP (from where it has been extirpated)[81] ||no data|"Siberia. ...eastward of the River Lena"; Type specimen of sibiricus unknown; however, Jacobi (1931) deposited a type specimen of "asiaticus" in the Museum of Leningrad (ZMASL), Buturlin coll. no. 240-1908|-| R. t. tarandus (Linnaeus, 1758)||mountain reindeer or Norwegian reindeer|| migratory ||the Arctic tundra of the Fennoscandian Peninsula in Norway and the Austfirðir in Iceland (where it has been introduced)[82] ||no data|Scandinavia|}Abbreviations:
The table above includes, as per the recent revision, R. t. caboti (the Labrador caribou (the Eastern Migratory population DU4)), and R. t. terranovae (the Newfoundland caribou (the Newfoundland population DU5)), which molecular analyses have shown to be of North American (i.e., woodland caribou) lineage; and four mountain ecotypes now known to be of distant Beringia-Eurasia lineage (see Taxonomy above). The scientific name Tarandus rangifer buskensis Millais, 1915 (the Busk Mountains reindeer) was selected as the senior synonym to R. t. valentinae Flerov, 1933, in Mammal Species of the World but Russian authors do not recognize Millais and Millais' articles in a hunting travelogue, The Gun at Home and Abroad,[83] seem short of a taxonomic authority. The scientific name groenlandicus is fraught with problems. Edwards (1743)[84] illustrated and claimed to have seen a male specimen ("head of perfect horns...") from Greenland and said that a Captain Craycott had brought a live pair from Greenland to England in 1738. He named it Capra groenlandicus, Greenland reindeer. Linnaeus,[85] in the 12th edition of Systema naturae, gave grœnlandicus as a synonym for Cervus tarandus. Borowski[86] disagreed (and again changed the spelling), saying Cervus grönlandicus was morphologically distinct from Eurasian tundra reindeer. Baird[87] placed it under the genus Rangifer as R. grœnlandicus. It went back and forth as a full species or subspecies of the barren-ground caribou (R. arcticus) or a subspecies of the tundra reindeer (R. tarandus), but always as the Greenland reindeer / caribou. Taxonomists consistently documented morphological differences between Greenland and other caribou / reindeer in cranial measurements, dentition, antler architecture, etc.[88] [89] Then Banfield (1961) in his famously flawed revision, gave the name groenlandicus to all the barren-ground caribou in North America, Greenland included, because groenlandicus pre-dates Richardson's[90] R. arctus. However, because genetic data shows the Greenland caribou to be the most distantly related of any caribou to all the others (genetic distance, FST = 44%, whereas most cervid (deer family) species have a genetic distance of 2% to 5%)--as well as behavioral and morphological differences—a recent revision returned it to species status as R. groenlandicus. Although it has been assumed that the larger caribou that appeared in Greenland 4,000 years ago originated from Baffin Island (itself unique; see Taxonomy above), a reconstruction of LGM glacial retreat and caribou advance (Yannic et al. 2013) shows colonization by NAL lineage caribou more likely. Their PCA and tree diagrams show Greenland caribou clustering outside of the Beringian-Eurasian lineage. The scientific name R. t. granti has a very interesting history. Allen (1902) named it as a distinct species, R. granti, from the "western end of Alaska Peninsula, opposite Popoff Island" and noting that: Rangifer granti is a representative of the Barren Ground group of Caribou, which includes R. arcticus of the Arctic Coast and R. granlandicus of Greenland. It is not closely related to R. stonei of the Kenai Peninsula, from which it differs not only in its very much smaller size, but in important cranial characters and in coloration. ...The external and cranial differences between R. granti and the various forms of the Woodland Caribou are so great in almost every respect that no detailed comparison is necessary. ...According to Mr. Stone, Rangifer granti inhabits the " barren land of Alaska Peninsula, ranging well up into the mountains in summer, but descending to the lower levels in winter, generally feeding on the low flat lands near the coast and in the foothills...As regards cranial characters no comparison is necessary with R. montanus or with any of the woodland forms."Osgood and Murie (1935), agreeing with grantis close relationship with the barren-ground caribou, brought it under R. arcticus as a subspecies, R. t. granti. Anderson (1946) and Banfield (1961), based on statistical analysis of cranial, dental and other characters, agreed. But Banfield (1961) also synonymized Alaska's large R. stonei with other mountain caribou of British Columbia and the Yukon as invalid subspecies of woodland caribou, then R. t. caribou. This left the small, migratory barren-ground caribou of Alaska and the Yukon, including the Porcupine caribou herd, without a name, which Banfield rectified in his 1974 Mammals of Canada [91] by extending to them the name "granti". 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." But Skal 1982 had included specimens from the eastern end of the Alaska Peninsula and the Kenai Peninsula, the range of the larger Stone's caribou. Later, geneticists comparing barren-ground caribou of Alaska with those of mainland Canada found little difference and they all became the former R. t. groenlandicus (now R. t. arcticus). R. t. granti was lost in the oblivion of invalid taxonomy until Alaskan researchers sampled some small, pale caribou from the western end of the Alaska Peninsula, their range enclosing the type locality designated by Allen (1902) and found them to be genetically distinct from all other caribou in Alaska.[92] [93] Thus, granti was rediscovered, its range restricted to that originally described. Stone's caribou (R. t. stonei), a large montane type, was described from the Kenai Peninsula (where, apparently, it was never common except in years of great abundance), the eastern end of the Alaska Peninsula, and mountains throughout southern and eastern Alaska.[94] It was placed under R. arcticus as a subspecies, R. t. stonei, and later synonymised as noted above. The same genetic analyses mentioned above for R. t. granti resulted in resurrecting R. t. stonei as well. The Sakhalin reindeer (R. t. setoni), endemic to Sakhalin, was described as Rangifer tarandus setoni Flerov, 1933, but Banfield (1961) brought it under R. t. fennicus as a junior synonym. The wild reindeer on the island are apparently extinct, having been replaced by domestic reindeer. Some of the Rangifer species and subspecies may be further divided by ecotype depending on several behavioral factors – predominant habitat use (northern, tundra, mountain, forest, boreal forest, forest-dwelling, woodland, woodland (boreal), woodland (migratory) or woodland (mountain), spacing (dispersed or aggregated) and migration patterns (sedentary or migratory).[95] [96] [97] North American examples of this are the Torngat Mountain population DU10, an ecotype of R. t. caboti; a recently discovered and unnamed clade between the Mackenzie River and Great Bear Lake of Beringian-Eurasian lineage, an ecotype of R. t. osborni;[98] the Atlantic-Gaspésie population DU11, an eastern montane ecotype of the boreal woodland caribou (R. t. caribou);[99] [100] the Baffin Island caribou, an ecotype of the barren-ground caribou (R. t. arcticus); and the Dolphin-Union "herd", another ecotype of R. t. arcticus.[101] The last three of these likely qualify as subspecies, but they have not yet been formally described or named. Physical characteristicsNaming in this and following sections follows the taxonomy in the authoritative 2011 reference work Handbook of the Mammals of the World Vol. 2: Hoofed Mammals. AntlersIn most cervid species, only males grow antlers; the reindeer is the only cervid species in which females also grow them normally.[102] Androgens play an essential role in the antler formation of cervids. The antlerogenic genes in reindeer have more sensitivity to androgens in comparison with other cervids.[103] [104] There is considerable variation among species and subspecies in the size of the antlers (e.g., they are rather small and spindly in the northernmost species and subspecies), but on average the bull's antlers are the second largest of any extant deer, after those of the male moose. In the largest subspecies, the antlers of large bulls can range up to in width and in beam length. They have the largest antlers relative to body size among living deer species. Antler size measured in number of points reflects the nutritional status of the reindeer and climate variation of its environment.[105] [106] The number of points on male reindeer increases from birth to 5 years of age and remains relatively constant from then on. "In male caribou, antler mass (but not the number of tines) varies in concert with body mass."[107] [108] While antlers of male woodland caribou are typically smaller than those of male barren-ground caribou, they can be over across. They are flattened in cross-section, compact and relatively dense. Geist describes them as frontally emphasized, flat-beamed antlers. Woodland caribou antlers are thicker and broader than those of the barren-ground caribou and their legs and heads are longer. Quebec-Labrador male caribou antlers can be significantly larger and wider than other woodland caribou. Central barren-ground male caribou antlers are perhaps the most diverse in configuration and can grow to be very high and wide. Osborn's caribou antlers are typically the most massive, with the largest circumference measurements.[109] The antlers' main beams begin at the brow "extending posterior over the shoulders and bowing so that the tips point forward. The prominent, palmate brow tines extend forward, over the face." The antlers typically have two separate groups of points, lower and upper. Antlers begin to grow on male reindeer in March or April and on female reindeer in May or June. This process is called antlerogenesis. Antlers grow very quickly every year on the bulls. As the antlers grow, they are covered in thick velvet, filled with blood vessels and spongy in texture. The antler velvet of the barren-ground caribou and the boreal woodland caribou is dark chocolate brown. The velvet that covers growing antlers is a highly vascularised skin. This velvet is dark brown on woodland or barren-ground caribou and slate-grey on Peary caribou and the Dolphin-Union caribou herd. Velvet lumps in March can develop into a rack measuring more than a in length by August.[110] When the antler growth is fully grown and hardened, the velvet is shed or rubbed off. To Inuit, for whom the caribou is a "culturally important keystone species", the months are named after landmarks in the caribou life cycle. For example, amiraijaut in the Igloolik region is "when velvet falls off caribou antlers." Male reindeer use their antlers to compete with other males during the mating season. Butler (1986) showed that the social requirements of caribou females during the rut determines the mating strategies of males and, consequently, the form of male antlers.[111] In describing woodland caribou, which have a harem-defense mating system, SARA wrote, "During the rut, males engage in frequent and furious sparring battles with their antlers. Large males with large antlers do most of the mating." Reindeer continue to migrate until the bulls have spent their back fat.[112] [113] By contrast, barren-ground caribou males tend individual females and their fights are brief and much less intense; consequently, their antlers are long, and thin, round in cross-section and less branched and are designed more for show (or sexual attraction) than fighting. In late autumn or early winter after the rut, male reindeer lose their antlers, growing a new pair the next summer with a larger rack than the previous year. Female reindeer keep their antlers until they calve. In the Scandinavian and Arctic Circle populations, old bulls' antlers fall off in late December, young bulls' antlers fall off in the early spring, and cows' antlers fall off in the summer. When male reindeer shed their antlers in early to mid-winter, the antlered cows acquire the highest ranks in the feeding hierarchy, gaining access to the best forage areas. These cows are healthier than those without antlers.[114] Calves whose mothers do not have antlers are more prone to disease and have a significantly higher mortality. Cows in good nutritional condition, for example, during a mild winter with good winter range quality, may grow new antlers earlier as antler growth requires high intake. According to a respected Igloolik elder, Noah Piugaattuk, who was one of the last outpost camp leaders,[115] caribou (tuktu) antlers According to the Igloolik Oral History Project (IOHP), "Caribou antlers provided the Inuit with a myriad of implements, from snow knives and shovels to drying racks and seal-hunting tools. A complex set of terms describes each part of the antler and relates it to its various uses". Currently, the larger racks of antlers are used by Inuit in Inuit art as materials for carving. 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". PeltThe color of the fur varies considerably, both between individuals and depending on season and species. Northern populations, which usually are relatively small, are whiter, while southern populations, which typically are relatively large, are darker. This can be seen well in North America, where the northernmost subspecies, the Peary caribou, is the whitest and smallest subspecies of the continent, while the Selkirk Mountains caribou (Southern Mountain population DU9) is the darkest and nearly the largest,[116] only exceeded in size by Osborn's caribou (Northern Mountain population DU7). The coat has two layers of fur: a dense woolly undercoat and a longer-haired overcoat consisting of hollow, air-filled hairs. |