The boreal woodland caribou (Rangifer tarandus caribou; but subject to a recent taxonomic revision. See Reindeer: Taxonomy), also known as Eastern woodland caribou, boreal forest caribou and forest-dwelling caribou, is a North American subspecies of reindeer (or caribou in North America) found primarily in Canada with small populations in the United States. Unlike the Porcupine caribou and barren-ground caribou, boreal woodland caribou are primarily (but not always) sedentary.In their 2012 report entitled "Recovery Strategy for the Woodland Caribou (Rangifer tarandus caribou), Boreal population, in Canada", Environment Canada and SARA refer to the woodland caribou as "boreal caribou". "Woodland Caribou (Rangifer tarandus caribou), Boreal population herein referred to as "boreal caribou", assessed in May 2002 as threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).
The boreal woodland caribou is the third largest of the caribou ecotypes after the Selkirk Mountains caribou and Osborn's caribou (see Reindeer: Taxonomy) and is darker in color than the barren-ground caribou. Valerius Geist, specialist on large North American mammals, described the "true" woodland caribou as "the uniformly dark, small-maned type with the frontally emphasized, flat-beamed antlers" which is "scattered thinly along the southern rim of North American caribou distribution". Geist asserted that "the true woodland caribou is very rare, in very great difficulties and requires the most urgent of attention", but suggests that this urgency is compromised by the inclusion of the Newfoundland caribou, the Labrador caribou, and Osborn's caribou in the Rangifer tarandus caribou subspecies. In Geist's opinion, the inclusion of these additional populations obscures the precarious position of the "true" woodland caribou. A recent revision,Harding LE (2022) Available names for Rangifer (Mammalia, Artiodactyla, Cervidae) species and subspecies. ZooKeys 1119: 117-151. recognizing Labrador and Newfoundland caribou as distinct subspecies of woodland caribou, partially rectifies this problem.
They prefer lichen-rich, mature forests, and mainly live in marshes, bogs, lakes and river regions.
The historic range of the woodland caribou covered over half of present-day Canada, stretching from Yukon to Newfoundland and Labrador. The national meta-population of this sedentary boreal ecotype spans the boreal forest from the Northwest Territories to Labrador (but not Newfoundland). Their former range stretched south into the contiguous United States. By 2019, the last individual in the Lower 48 (a female) was captured and taken to a rehab center in British Columbia, thus marking the extirpation of the caribou in the contiguous U.S.
The boreal woodland caribou was designated as Threatened in 2002 by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Environment Canada reported in 2011 that there were approximately 34,000 boreal woodland caribou in 51 ranges remaining in Canada.(Environment Canada, 2011b). In a joint report by the Canadian Parks and Wilderness Society (CPAWS) and the David Suzuki Foundation, on the status of boreal woodland caribou, it was claimed that "the biggest risk to caribou is industrial development, which fragments their habitat and exposes them to greater predation. Scientists consider only 30% (17 of 57) of Canada's boreal woodland caribou populations to be self-sustaining." Additionally, it was observed that the caribou "... are extremely sensitive to both natural (such as forest fires) and human disturbances, and to habitat damage and fragmentation brought about by resource exploration, road building, and other human activities. New forest growth (following destruction of vegetation) provides habitat and food for other ungulates, which in turn attracts more predators, putting pressure on woodland caribou."
Compared to barren-ground caribou of mainland Canada and Alaska (see Barren-ground caribou), boreal woodland caribou do not form large aggregations and are more dispersed, particularly at calving time. Their seasonal movements are not as extensive. Mallory and Hillis explained how, "In North America, populations of the woodland caribou subspecies typically form small, isolated herds in winter, but are relatively sedentary, and migrate only short distances (50 – 150 km) during the rest of the year."
Evolution See Evolution in main page, Reindeer. Following are excerpts relating to boreal woodland caribou.
Reindeer originated in a Late Pliocene North American-Beringian radiation of New World deer. A frontoparietal skull fragment of Rangifer sp. from the Early Pleistocene of Omsk, Russia dates back to 2.1-1.8 Ma and suggests northern Eurasia as a center of reindeer origin.Bondarev AA, Tesakov AS, Simakova AN, Dorogov AL (2017) Reindeer (Rangifer) from Early Pleistocene of the south of Western Siberia (in Russian). In: Bogdanov AA, others (Eds) Integrative palaeontology: development prospects for geological objectives, material of the LXIII session of the Palaeontological Society, April, 3-7, 2017. Sankt-Peterburg, 173-175. Its pedicles (antler bases), unlike modern reindeer, are inclined backward and set parallel to each other, demonstrating the primitive morphology for archaic cervids. The oldest North American Rangifer fossil is from the Yukon, 1.6 million years before present (BP).Harington CR (2011) Pleistocene vertebrates of the Yukon Territory. Quaternary Science Reviews 30: 2341-2354.
Rangifer "evolved as a mountain deer, ...exploiting the subalpine and alpine meadows...".Geist V (1998) Deer of the world: their evolution, behavior, and ecology. Stackpole Books, Mechanicsburg, Pennsylvania, 421 pp. Rangifer originated 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.Croitor R (2018) Plio-Pleistocene deer of Western Palearctic: taxonomy, systematics, phylogeny. Institute of Zoology of the Academy of Sciences of Moldova, Chișinău, 142 pp.
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). 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. For this reason, forest-adapted reindeer and caribou could not survive in tundra or polar deserts. Genetic research confirms this, documenting almost no introgression (interbreeding) of woodland caribou into barren-ground caribou and very few the other way. This is evidence of reproductive isolation, a hallmark of species definitions.
In North America, DNA analysis shows that woodland caribou (originally Cervus tarandus caribou Gmelin 1788) diverged from primitive ancestors of tundra/barren-ground caribou, not during the last glacial maximum, 26,000–19,000 years ago as previously assumed, but in the Middle Pleistocene around 357,000 years ago.Yannic G, Pellissier L, Ortego J, Lecomte N, Couturier S, Cuyler C, Dussault C, Hundertmark KJ, Irvine RJ, Jenkins DA, Kolpashikov L, Mager K, Musiani M, Parker KL, Røed KH, Sipko T, Þórisson SG, V.Weckworth B, Guisan A, Bernatchez L, Côté SD (2013) Genetic diversity in caribou linked to past and future climate change. Nature Climate Change 4: 132-137. Horn R, Marques AJD, Manseau M, Golding B, Klütsch CFC, Abraham K, Wilson PJ (2018) Parallel evolution of site-specific changes in divergent caribou lineages. Ecology and Evolution 8: 6053-6064. At that time, modern tundra caribou had not even evolved. Woodland caribou are likely more related to extinct forest caribou subspecies 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.Croitor R (2022) Paleobiogeography of Crown Deer. Earth 3: 1138-1160. For this reason (in addition to molecular data showing lack of shared haplotypes and great genetic distance, as well as morphological and ecological differences) woodland caribou cannot be conspecific with barren-ground caribou because they do not share a direct common ancestor.
Molecular data also revealed that the four western Canadian montane ecotypes shared a common ancestor with modern barren-ground/tundra reindeer and caribou, but distantly, having diverged 120,000–130,000 years ago. They are subspecies of the Arctic caribou (R. arcticus).
The name caribou was probably derived from the Mi'kmaq word xalibu or qalipu meaning "the one who paws".
The caribou design on the Royal Canadian Mint quarter was first used in 1937.
Nomenclature The boreal woodland caribou (Rangifer tarandus caribou; but subject to a recent taxonomic revision. See Reindeer: Taxonomy) is also referred to as the woodland caribou, woodland caribou (boreal group) and forest-dwelling caribou.
The Mi'kmaq people referred to caribou as xalibu or qalipu which means "the one who paws". The word "caribous" was first published in print in the 1610 publication on the history of New France by Marc Lescarbot. Lescarbot partially based his writing on his expedition to 1606–1607 to Acadia where he encountered the Mi'kmaq people. Silas Tertius Rand included the term kaleboo in his Mi'kmaq-English Dictionary in 1888.
Species and subspecies description According to the 2019 Species at Risk Act (SARA), while caribou and reindeer were the same species — Rangifer tarandus — there are differences. The term "Caribou" refers to the "various subspecies present in North America" and the term "reindeer" is used to describe the "domesticated, semi-domesticated or wild subspecies found in Eurasia." Some reindeer have been introduced to North America. Woodland caribou, a rather large subspecies, is a medium-sized ungulate which inhabits boreal and subarctic environments and exhibits "tremendous variation in ecology, genetics, behavior and morphology". A distinctive characteristic of all caribou is large crescent-shaped hooves that change shape with the season and that are adapted to walking in snow-covered and soft ground such as swamps and peat lands and assist in digging through snow to forage on lichens and other ground vegetation. The subspecies ecotype, boreal woodland caribou, have a shoulder height of approximately 1.0-1.2 m shoulder height and weigh 110–210 kg (242–462 lbs).
Both male and female boreal woodland caribou have antlers during part of the year, although some females may have only one antler or no antlers at all (Boreal Caribou ATK Reports, 2010–2011). On the males these grow so quickly each year that velvety lumps in March can become a rack measuring more than a metre in length by August. Antlers of boreal woodland caribou are flattened, compact, and relatively dense. Boreal woodland caribou antlers are thicker and broader than those of the barren-ground caribou and their legs and heads are longer.