Rangifer tarandus
(Woodland Caribou )

Order: Artiodactyla
Order Description: Hoofed Mammals or Ungulates
Family: Cervidae
Family Description: Deer, Elk, Moose, Caribou

Caribou have variably brown hair on their back with a whitish neck and mane. The belly, rumpand underside of their tail are whitish. They have a large-appearing snout with short ears. Their rounded hooves contain large, soft pads in the summer, but the pads shrink and become hardened during the winter. A unique feature among the deer family (Cervidae) is that both sexes of caribou have antlersClick word for definition. The antlers of bulls are larger, semi-palmated with tines or points and they have a fairly large, flattened brow tine projecting forward over the forehead, referred to as a “shovel” by some observers. Antlers of cows are spindly appearing and not as long, and they lack a brow tine. Males weight between 275 and 600 pounds (115-275 kg), and females between 150 to 300 pounds (64-135 kg).

Historically the woodland caribou was found as far south as central Idaho, through the Great Lakes area and northern New England. Wild populations currently exist in Alaska, Canada, northeastern Washington, and extreme northern Idaho in the Selkirk mountains. The northern Idaho population, currently endangered, has been supplemented by transplants from Canada.

Caribou are found in arctic tundra Click word for definition, the subarctic taiga Click word for definition(scrub forest and open muskeg Click word for definition), mature coniferous forests, semi-open and open bogs, rocky ridges with jack pine, and riparian Click word for definitionzones. They are most often found where lichens Click word for definitionare common. In Idaho, they occupy high-elevation open forests in winter, moves to more mature stands of timber with high lichen density for spring calving, then to shallower slopes with greater understory cover in summer, and finally to lower-elevation forests with denser overstories in fall. Northern populations migrate long distances between summer and winter habitat.

Caribou rely heavily on lichens Click word for definitionin the winter, but throughout the summer they eat leaves, buds and bark of trees and shrubs, grasses, sedges, forbs Click word for definition, mushrooms, and terrestrial Click word for definitionand arboreal Click word for definitionlichens Click word for definition(found in tree branches). ArborealClick word for definitionlichens are probably a most important winter food in northern Idaho. In summer, they move to new areas to find new plant growth.

Caribou are primarily diurnal Click word for definition, but their feeding periods are crepuscular Click word for definition. They are gregarious Click word for definitionas in the tundra Click word for definition, they are usually found in bands of 10-50, or in loose herds of up to a 1000. The sexes may segregate seasonally. In May females form herds after fawning. Tundra Click word for definitioncaribou may travel extensively in the summer in an attempt to avoid bothersome insects. Caribou often incur high calf losses, mostly due to predation. Survival of calves to 1 year is usually only 10 to 15%. In Idaho, grizzly bears, mountain lions, and humans are predators. The transplanted Idaho population is experiencing high levels of predation from mountain lions. As of 1995, the population in the Selkirks ecosystem Click word for definitionhad stabilized at about 50 animals. In the northern tundra Click word for definitionwolves are a major predator. Caribou are excellent swimmers as their hollow, insulative hair provides great buoyancy. They can run for short bursts at over 40 mph, and they can move steadily for long periods of time during seasonal migrations Click word for definition.

They breeds mostly in October. Gestation Click word for definitionlasts about 7 ˝ to 8 months. Cows bear usually 1, sometimes 2, young in May and June. Calves are precocious Click word for definitionin that they are able to stand about 30 minutes after birth, run a bit after 90 minutes and keep up with the herd after their first day of life. They are about 11 pounds at birth and begin to eat solid food after two weeks. During the rut Click word for definitionbulls attempt to establish harems Click word for definitionof 12 to 15 cows and expend a lot of energy thrashing about and even battling other bulls.

Status: Protected nongame species
Global Rank: G5
State Rank: S1

Important State References:
U.S. Fish and Wildlife Service. 1993. Recovery plan for woodland caribou in the Selkirk Mountains. Portland, OR. 71 pp.

Information written by Donald Streubel,© 2000
Map image provided by
Stephen Burton,© 2000
Design by Ean Harker©1999, 2000.