MOUNTAIN CARIBOU } Rangifer tarandus caribou
ETYMOLOGY: The word caribou comes from French explorers of eastern North America who derived it from the Micmac Indian term xalibu , meaning the “one who paws.” This is a reference to the caribou’s wide hooves, which make it possible to walk in deep snow.
DESCRIPTION: Mountain caribou are the largest subspecies of caribou, with males approaching 600 pounds and females 300. Members of the deer family, caribou are distinguished by their large, splayed hooves, broad muzzles, long legs, and distinctive amber-colored antlers. Their color ranges from a deep chocolate brown in summer to a grayish tan during spring, while they simultaneously sport a whitish underbelly, neck and rump.
HABITAT: The Selkirk population of caribou favors old-growth spruce-fir and cedar-hemlock forests.
RANGE: Extirpated from nearly the entire United States, mountain caribou now comprise an extremely small population that inhabits the Selkirk Mountains of northeastern Washington and northern Idaho. Caribou are also found throughout Canada’s portion of the range.
MIGRATION: Mountain caribou gather in small herds of four to 50 individuals. They do not participate in extensive migrations like their northern cousins, instead moving up and down the Selkirk Mountains to correspond with the changing seasons. Their territories range between 20 and 60 miles.
BREEDING: Caribou are polygamous creatures with males defending up to 10 females with calves. Female caribou become sexually mature at three years of age. Breeding takes place in early to mid-October, and following a gestation period of seven months, single calves are born in the late spring. Calf mortality is high, often approaching 50 percent.
LIFE CYCLE: Caribou generally live between eight and 15 years.
FEEDING: Although caribou eat a wide variety of foods, winter foraging is limited almost exclusively to ground and arboreal lichens. Caribou in the Selkirk population eat lichens for up to six months of the year. They feed extensively on huckleberry leaves, Sitka valerian, boxwood, and smooth woodrush in the spring and summer.
THREATS: Mountain caribou face threats from habitat loss, industrial logging, wildfires, collisions with motor vehicles, poaching and genetic problems associated with their small population size. Snowmobiles, which are able to travel through remote areas at high speeds, drive the few remaining woodland caribou away from critical habitat and pose a serious threat to the caribou.
POPULATION TREND: In the United States, mountain caribou were reduced to an isolated population of 100 individuals by the 1950s. This population continued to decline until 1983, when only 26 caribou remained. Current estimates put their numbers at about 35 individuals without any increases for some time. Fewer than 1,700 caribou survive north of the border in Canada.