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Rangifer tarandus Linnaeus
Caribou; Reindeer
Family: Cervidae
Species account author: David Shackleton
Extracted from the Hoofed Mammals of British Columbia
Introduction to the Mammals of BC

Photograph

© Ian Gardiner     (Photo ID #5815)

Map

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Distribution of Rangifer tarandus in British Columbia.
(Click on the map to view a larger version.)
Source: Hoofed Mammals of British Columbia by David Shackleton © Royal BC Museum

Introduction


The Caribou is a distinctive and familiar mammal species. Two subspecies of caribou are recognized in British Columbia 1) Dawson's Caribou, which is now extinct and 2) Woodland Caribou. The Woodland Caribou is found in boreal forests and mountain regions from northern BC to southeastern BC. Three populations or ecotypes of this subspecies are recognized 1) northern mountain population, boreal population, and southern mountain population. All are of conservation concern (BCCDC 2012). The three ecotypes differ in habit, habitat, behaviour, and distribution (BCCDC 2012). For example, the northern mountain population and the boreal population feed on ground lichens, while the southern mountain population feeds on arboreal lichens (BCCDC 2012).

Both male and female caribou have antlers, unlike other deer species where only the males have antlers. Antlers on females, though, are smaller than on males.

Species Information

Caribou shows variation in antler and body size throughout its wide distribution across the Northern Hemisphere where it inhabits montane, boreal, subarctic and arctic habitats. In B.C., Woodland Caribou is a moderately large deer with long, slender legs and large, semicircular hooves, each with a prominent dew claw just above it. The rather blunt, square nose is covered by short hair, and the ears are short, broad and not pointed. Body colour varies from light brown to almost chocolate-brown in summer, and light grey or brown in winter, sometimes becoming bleached even lighter by the end of winter. The neck is usually lighter coloured than the rest of the body, and females can also show some areas of lighter grey-brown just behind the shoulders. Males sometimes have a light, horizontal flank stripe above a darker belly band. The face is generally dark from the top of head to the nose, although the lower cheeks may be lighter, especially in older males. The white tail is relatively short, and is surrounded by a medium-sized light or white rump patch. There is a noticeable thin band of white hairs (called socks) running above the upper edge of each main hoof. Adult males develop a mane of longer hairs along the underside of the neck as far back as the chest, and during the rut, both the light neck and mane contrast strongly with the darker body.

When walking or running, Caribou make a characteristic clicking sound. This is caused by small tendons stretching over bone protuberances (sesamoid bones) in their feet. Skin glands in Caribou include antorbital, caudal, and on the hind feet, tarsal and interdigital.

Caribou is unique among the world’s deer, because females regularly develop antlers. Although there is variation among the subspecies and among individuals, male Caribou antlers generally consist of a long oval-shaped main beam that rises up and back from the head before curving forward again to form a clear “C” shape when viewed from the side. The brow tine is often palmated and vertically oriented with small points along the edge, with often one brow tine larger than the other. The second tine may be branched into small points, and in some individuals may be palmated. The first two tines point forward. The third, if present, is located in the middle of the main beam and projects backwards; it is short, unpalmated and unbranched. The end of the main beam is usually moderately palmated, with points along the upper edge. Adult female antlers are much smaller and simpler in structure than those of adult males, being about the same size as those of one- and two-year-old males. Female antlers also lack the large, vertically palmated first tine that adult males have. Unlike other deer species in British Columbia, Caribou may grow short spiked antlers, less than 300 mm long, in their first year. The surface of the main beam of Caribou antlers is much smoother than in other deer, and the impressions of major blood vessels can often be traced along its length.

A Caribou has small upper canines, that rarely project beyond the maxilla of the skull or the gum of the live animal. Upper incisors are absent and the lower incisors and canines are small and peglike. The molars have a simplified selenodont enamel pattern. A small extension of the maxilla prevents the premaxilla from meeting the nasal bone, and the anterior nasal opening is large. There is a moderately deep antorbital depression on the lachrymal bone in front of the orbit, and the pedicels are located well back on the skull so that they are partially on the frontal and parietal bones.

Identification and Subspecies Information

Two subspecies of Caribou have been recognized in British Columbia.

Subspecies: Woodland Caribou (Rangifer tarandus caribou)

Three populations of this subspecies are found in BC (there are 52 across Canada), representing three ecotypes (Mountain Caribou, Boreal Woodland Caribou, and Northern Woodland Caribou). All are of conservation concern.

Subspecies Description

Woodland Caribou, a medium to large deer, is the largest of all Caribou. Males can weigh as much as 300 kg and females up to 130 kg, but there are few weights available for this deer in the province. Woodland Caribou is also the darkest subspecies of any in the world. The body is usually a dark, almost chocolate brown, as is the face, belly and legs.

Woodland Caribou has the heaviest antlers of all Caribou, although they are not the longest, and their spread is often narrower. Though Woodland Caribou have the general antler plan of the species, their antlers do vary: they can be short, heavy and strongly palmated, or long with only a slightly palmated terminal section.

Measurements

total length: male: 2,327 mm (2,060-2,980) n = 15; female: 2,007 mm (1,760-2,200) n = 70
tail vertebrae: male: 177 mm (130-220) n = 10; female: 142 mm (50-220) n = 51
hind foot: male: 548 mm (430-660) n = 10; female: 528 mm (380-660) n = 48
ear: male: 149 mm (130-160) n = 6; female: 143 mm (120-160) n = 15
shoulder: male: 1,384 mm (1,245-1,580) n = 14; female: 1,222 mm (1,030-1,390) n = 43
chest male: 1,447 mm (1,390-1,530) n = 12; female:1,277 mm (1,180-1,440) n = 75
weight: male: ? (181-272 kg) n = ?; female: ? (91-1)

Range:

In British Columbia, Woodland Caribou inhabit boreal forests and mountain regions. The Northern ecotype is spread over a large area extending north and west of Prince George that can be roughly divided into two sections. The smaller part runs from around Kleena Kleene, northwest through the Hazelton Mountains and Tweedsmuir Park as far as the Nass River to the west of Mount Weber, and also extends over parts of the western Nechako Plateau. The larger section extends across much of northern British Columbia: its northern boundary is the Yukon border; the western edge is the southern St Elias Mountains and the east slopes of the Coast Mountains to about 56° 50’ latitude, through the Skeena Mountains onto the northeastern part of the Nechako Plateau east and northeast of Babine Lake; and the eastern boundary is the east slopes of the Rocky Mountains. The Boreal ecotype occurs at low densities from the eastern flanks of the Rockies as far as the Alberta border, except for a small area around Fort St John where there are no Caribou.

The range of the Mountain ecotype extends from its northern limit just south of Prince George to the international border, although recent work suggests that the northern boundary may be north of Prince George at Mount Mortifee in the Misininchinka Ranges. In the Rocky Mountains, the range extends from north of Mount Robson, south to the central Rockies west of Mount Columbia. These Caribou are also found on the east side of the Fraser River through the Quesnel Highlands south of Prince George, through the Monashee Mountains to Whatshan Lake, and also through the Columbia and Purcell mountains south to about Kitchener. In the Selkirk Mountains, Mountain Caribou occur as far south as Kaslo and the east side of northern Lower Arrow Lake, then there is a break in their distribution until it begins again in the southern Purcell Mountains, where it mixes with populations from northwestern Washington and northeastern Idaho.

A readily accessible viewing area for Woodland Caribou is at the top of the Salmo-Creston Pass, along Highway 3. They are often seen there in spring seeking salt on the road, and also in summer travelling through the area. Back-country visitors may also observe Caribou in Well’s Gray Provincial Park, Spatsizi Plateau Wilderness Provincial Park and Mount Revelstoke National Park.

Subspecies: Dawson's Caribou (Rangifer tarandus dawsoni) --

Extinct in British Columbia

Subspecies Description

Dawson’s Caribou is now extinct. There are only five museum specimens in the world, and none of the skulls are complete. All available materials, including skins and mounts, are in poor condition. From these specimens, researchers have come up with an uncertain description. It was a small Caribou, standing about one metre at the shoulder. Its body appears to have been mouse-grey, darker on top of the head and face, with a lighter neck and belly, a short mane, and probably without the clear brown-and-white markings found in other subspecies. The antlers were poorly developed, lacking the typical Caribou palmation, and it is uncertain if females possessed them.

Measurements

total length: male: 1,910 mm n = 1; female: 1,550 mm n = 1
tail vertebrae: male: 110 mm n = 1
hind foot: male: 385 mm n = 1;
shoulder: male: 1,050 mm n = 1
skull length: male: 350 mm (est.) n = 1

Range

Dawson’s Caribou is known with certainty to have lived only on the plateau around Virago Sound on the northern end of Graham Island in the Queen Charlotte archipelago, although an unverified skull was reported to have been found near a glacier at the mouth of the Skeena River on the mainland. Even on Graham Island, it was rarely seen, and the last three specimens were collected from a group of four in 1908. Dawson’s Caribou most probably became extinct either shortly after 1910 or in the early 1920s, although there were reports of tracks as late as 1935. The ancestors of these Caribou were most likely trapped on the Queen Charlotte Islands at the end of the last ice age when sea levels rose and cut off access to the mainland.

Biology

Identification

The Woodland Caribou is larger than the White-tailed Deer and the Mule Deer, but smaller than the Elk and the Moose. It also differs in body coloration from all other deer. Key features for identifying Caribou are the light-coloured neck and mane, and contrasting darker body, the short white tail and rump patch, and the white ring of hairs at the top of the hooves. The nose and upper lip are also blunt and square.

Caribou is the only species of deer in which females and, sometimes, young of the year normally grow antlers. Relative to their body size, the antlers of adult male Woodland Caribou are the largest of all the province’s deer, and their shape is unique. The long C-shaped main beam, the vertically oriented and palmated brow tines, the second tine often branched, and the palmated terminal branch are key distinguishing characters separating antlered male Caribou from other antlered deer. The deer with the most similar antlers is the Elk, but the lower tines of its antlers are never palmated; instead, they are sharply pointed. The surface of Elk antlers is also much rougher than that of Caribou.

For identifying skulls, Caribou and Elk are the only deer species in the province with upper canines. But Caribou canines are much smaller than those of Elk, and are pointed and rarely project beyond the maxilla or gum. Furthermore, in the Caribou skull, the premaxilla does not touch the nasal bone, and it has an angular profile when viewed from above, unlike the round shape of Elk. The incisors of Caribou are small and round, rather than flat with sharp tips (spadelike) as in most other deer. Also, the Caribou is only one of three species in which the vomer divides the posterior nares, but neither of the other two species – White-tailed Deer and Mule Deer – have upper canines, and their skulls are smaller. The Caribou’s anterior nasal opening is large in lateral view, so the anterior region of the skull (between the nasals and the upper tooth row) is characteristically deep. Finally, the antler pedicels are not wholly on the frontal bones but encroach onto the parietals, unlike other deer.

The Caribou’s hooves are large relative to its body and they create a rounded track with the impressions of the large dew claws often seen just behind hooves, even where track impressions are not deep. Caribou tracks may resemble those of Bison or Domestic Cattle in terms of size and general shape, but Caribou tracks are more rounded and sausage-shaped, and show their larger dew claws. The tracks of the other two show the dew claws only if the animal’s foot has sunk deeply in soft ground. The clicking sound that Caribou make with their feet when they walk or trot is also unique to the species.
Reproduction

Except for the Boreal ecotype, Woodland Caribou females in B.C. move and disperse to high elevations, around the treeline, to give birth, probably in an attempt to reduce predation by wolves and bears on their vulnerable young. A single young is born usually in late May or early June after a gestation period of about 228 days. Newborn Caribou weigh between 5 and 12 kg, depending on the mother’s nutrition during pregnancy. Their coat is brown, often with a dark dorsal stripe, but lacks spots. Woodland Caribou females usually give birth away from their herd. Their young are followers; within a few hours after birth, the neonate is capable of following its mother. Caribou reach sexual maturity at 16 to 28 months of age, with most females giving birth for the first time around their third birthday.
Diet

Woodland Caribou eat a wide range of forages, including grasses, forbs and browse in summer, and lichens in winter. The most commonly eaten arboreal lichens grow on coniferous trees, and include Common Witch’s Hair and various species of horsehair and beard lichens. Caribou will feed on these either as they grow on standing or wind-thrown trees, or as litter blown to the ground. The ecotypes that feed primarily on terrestrial lichens in winter commonly eat lichens such as reindeer lichens, including Cladina and Cetraria species. The importance of lichens in the Caribou’s winter diet is probably reflected in their tooth structure. Caribou incisors are relatively smaller and less spatulate in shape, and the enamel ridges of the cheek teeth are less convoluted than in other B.C. deer, probably because lichens are easily cropped and less abrasive than other forages.
Age determination and life expectancy

Calf mortality is often high, but if they survive this vulnerable period, Caribou can live for 8 to 10 years, some for more than 15 years. A Caribou’s age can be determined by tooth succession up to about 2.5 years old, and by cementum annuli counts using incisor teeth for older individuals. Adult males and females can be distinguished by antler and skull measurements, while the shorter dentary (lower jaw) length of yearling males separates them from adult females.
Predators and other mortality factors

Predation is probably the primary cause of death. In general, the main predator of Woodland Caribou is the Wolf, but the Cougar is a significant predator in the southern Selkirk Mountains. Wolverines, Grizzly Bears and Black Bears also prey on Woodland Caribou, and in some areas, avalanches can be a major cause of death. As stated earlier, Wolf predation along with lichen distribution and snow conditions seem to explain much of the Mountain and Northern ecotypes’ seasonal migrations and habitat use. Not only do high-elevation forests provide abundant arboreal lichens, but the Caribou face fewer predators there. Wolves prefer to remain at lower elevations in winter, where they can easily hunt deer and, especially, Moose. In B.C., Caribou diseases have received little research. The parasite Besnoitia tarandi has been found in Caribou during hunter surveys, but does not seem to cause significant problems. Bot and Caribou Warble flies may be a problem for individual Caribou, but do not appear to have significant impacts on populations.
Social Organization, Groupomg AND Behaviour

Woodland Caribou usually live in small groups of 4 to 6 animals, but they sometimes form larger groups of 20 to 25 in late winter at high elevations. Older males often live in all-male groups. Woodland Caribou usually show fidelity to seasonal ranges and calving areas, but sometimes may use different areas from one year to the next, and seasonal range sizes can also vary, even within a population.

Biologists are uncertain why Caribou are the only species in which females grow antlers. The most likely explanation is that they help females compete with males for food in late winter. Unlike other deer in B.C., adult male Caribou shed their antlers soon after the rut, so that by November only young males, calves and females still have antlers and may keep them as late as May. (But large males in the Northern ecotype may retain their antlers until December.)

The large antlers of adult males are relatively light and are used as much for display as for fighting. During the rut, males will first use their antlers in displays and threats, but if these do not succeed, they may use them to fight. A typical fight involves shoving and wrestling, with each rival trying to gore the other; injuries and deaths can occur. Males also use their antlers to thrash bushes, perhaps as a displacement activity, or as an advertisement or signal to other males in the vicinity. Male Caribou in the rut are said to perform a behaviour called bush-gazing, standing motionless while staring fixedly at the distance. Also in the rut, they perform hock-urination.

The first signs of the rut in B.C. usually begins in late September and continues through mid October when mating occurs. Woodland Caribou form harems in the mating season, with one large adult male guarding a group of adult females from other males. Males herd females using a head-up threat posture to keep them from wandering off. The harem male constantly checks each female’s urine for signs of oestrus by lip-curling. Caribou courtship is believed to be relatively simple compared to other ungulates.

Habitat


Biologists in British Columbia recently divided the province’s Woodland Caribou into three ecotypes – Northern, Boreal and Mountain – based primarily on their winter diet and annual movement patterns. Snowfall appears to play a major role in these divisions, with Mountain Caribou having to cope with higher snow accumulations and generally more rugged mountain systems than either of the other two ecotypes. But the picture can be complicated by annual variation in snowfall.

The Northern ecotype inhabits the mountains in western and northern B.C. These Caribou generally migrate twice each year, descending to low elevations in fall or early winter depending upon timing and extent of snowfall. They winter at low elevations in Lodgepole Pine or Black Spruce forests where low snowfall allows them to feed mainly on terrestrial lichens, as well as some arboreal lichens, before moving back to higher elevations in late spring and summer. But they may also winter at higher elevations on open windswept ridges, where they feed on exposed terrestrial lichens before descending to low elevations again in spring to feed on early-growing plants. Females almost always move to high elevations for the calving period, while males may remain at low elevations longer. The Northern ecotype uses the Englemann Spruce-Subalpine Fir, Montane Spruce, Sub-Boreal Pine-Spruce, Spruce-Willow-Birch, and Boreal White and Black Spruce biogeoclimatic zones.

The Boreal ecotype of Woodland Caribou, included by some biologists in the Northern ecotype, occupies the flatter landscapes found in the Boreal White and Black Spruce Zone forests of northeastern B.C. and also feeds on terrestrial lichens in winter. But in contrast to Caribou of the Northern ecotype, they are relatively sedentary and live at low densities in smaller, more dispersed groups.

The Mountain ecotype, inhabits the mountain regions of southeastern B.C. In winter, because deep snow buries terrestrial foods, these Caribou feed almost entirely on arboreal lichens at high elevations. Other important foods for the Mountain ecotype are False Box, an evergreen shrub that is eaten in late fall and early winter in the Selkirk and Monashee mountains, and the needles of conifers that are consumed along with arboreal lichens. Animals of this ecotype often make four vertical migrations each year, moving down in early winter, back up to higher elevations in late winter, down once more to low elevations in spring and returning to high elevations for the summer. Although there is regional variation in habitat use, these migration patterns correspond to use of three biogeoclimatic zones: Interior Cedar Hemlock, Englemann Spruce – Subalpine Fir, and Alpine Tundra Parkland.

Predators (Wolves and Cougars), snow conditions and the availability of arboreal lichens appear to be the major determinants of habitat use by the Mountain and Northern ecotypes, especially in winter. These Caribou attempt to avoid predation by inhabiting subalpine forests well above the valley floor where Wolves prefer to remain in winter. At the same time, the availability and quantity of arboreal lichens is greater in these high elevation forests. Although the snow is deeper at these high elevations, it commonly forms a crust on top that can support more weight. Snow crusting combined with the Caribou’s large foot surface (created by its large hooves and dew claws) helps to keep Caribou from sinking too deeply into the snow. This allows them to travel and feed with relative ease, and as the snow pack increases, they can reach arboreal lichens growing higher up in the trees. For the other two ecotypes, the large hooves are an added advantage for pawing through snow to expose the terrestrial lichens beneath.

Taxonomy


Reindeer is the common name used in Europe and Asia to describe Caribou, and also refers to the domesticated form. The type specimen for Caribou comes from Lapland in Sweden, the type locality for Woodland Caribou is Quebec City, Quebec, and for Dawson’s Caribou it is Virago Sound, Graham Island, Queen Charlotte Islands. Cowan and Guiguet, in The Mammals of British Columbia (1965), recognized two species of Caribou in British Columbia: the Arctic Caribou (Rangifer tarandus), with two subspecies – Osborn’s Caribou (Rangifer tarandus osborni) and Mountain Caribou (Rangifer tarandus montanus) – and the extinct Dawson’s Caribou (Rangifer dawsoni). In his 1961 revision of Rangifer, Banfield recognized six subspecies in North America, only two of which occurred in B.C. He included Dawson’s Caribou as a subspecies of Rangifer tarandus, and combined Osborn’s and Mountain Caribou into a single subspecies – the Woodland Caribou (Rangifer tarandus caribou). Ongoing genetic studies using mitochondrial and nuclear DNA from Caribou across North America will soon shed more light on the relationships between the populations, and should lead to a revision of Caribou taxonomy.

Remarks


Nothing is known of the natural history of the extinct Dawson’s Caribou. The information on natural history (habitat, diet, social organization, grouping and behaviour, reproductive data, age determination and life expectancy, and predators and other mortality factors) applies only to Woodland Caribou.

The generic name Rangifer is from the French rangifère, which means “reindeer”. “Reindeer” originates from reino, the Laplander word for this animal. The specific name tarand(r)us is from the Latin and Greek for the fabled reindeer that could change its colour, and Caribou is a Micmac word meaning “shoveller”, because of the way these deer paw through the snow to feed. Dawson’s Caribou is named after G.M. Dawson, an early director of the Geological Survey of Canada and the first scientist to describe the animal.

Reindeer are found on a few game farms in B.C., and because they are the same species as wild Caribou, hybridization is possible should any domestic forms escape from captivity.

Status Information

Scientific NameOrigin StatusProvincial StatusBC List
(Red Blue List)		COSEWIC
Rangifer tarandusNativeS3?No StatusNot Listed
Rangifer tarandus dawsoniNativeSXExtinctXX (May 1984)
Rangifer tarandus pop. 1NativeS1RedE (May 2014)
Rangifer tarandus pop. 14NativeS2?RedT (Nov 2014)
Rangifer tarandus pop. 15NativeS2S3BlueSC (May 2014)
Rangifer tarandus pop. 18NativeS1S2RedE (Dec 2014)



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