Rangifer tarandus
(Woodland Caribou )

Description:
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 antlers. 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).

Range:
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.

Habitat:
Caribou are found in arctic tundra , the subarctic taiga (scrub forest and open muskeg ), mature coniferous forests, semi-open and open bogs, rocky ridges with jack pine, and riparian zones. They are most often found where lichens are 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.

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

Ecology:
Caribou are primarily diurnal , but their feeding periods are crepuscular . They are gregarious as in the tundra , 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 caribou 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 had stabilized at about 50 animals. In the northern tundra wolves 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 .

Reproduction:
They breeds mostly in October. Gestation lasts about 7 ˝ to 8 months. Cows bear usually 1, sometimes 2, young in May and June. Calves are precocious in 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 bulls attempt to establish harems of 12 to 15 cows and expend a lot of energy thrashing about and even battling other bulls.

Conservation:

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.