Despite a paucity of images, I’ve decided to write about the caribou for Critter Post 3. Caribou are an integral part of life in the Arctic and we were lucky enough to see one on the shore of the Beaufort Sea on Alaska’s North Slope – quite the sight, the lone antlered creature on the vast tundra. He was too far away to photograph, so for Critter Post 3 I’m using a couple of images taken on our trip to Denali National Park.
Caribou is the name given to all North American populations of Rangifer tarandus, also known as reindeer. The caribou we’ve seen are barren-ground caribou, living on the tundra. There are also boreal woodland caribou. The barren-ground caribou have the largest migration of any land mammal, roaming 1,200 kilometers in a season from birthing grounds to feeding grounds. Bull caribou weigh 400-600 pounds and the cows average about 200 pounds. Both males and females grow antlers, which is unique in the deer family. The whole species is listed as Vulnerable by the IUCN Red List due to a 40% decline in global population over the last 25 years.
Range and Habitat:
The species is circumpolar in boreal forest and tundra, although it is only called ‘caribou’ in North America and Greenland.
Caribou have a four-chambered stomach that allows them to digest tough plant matter – lichens, sedges, grasses, and the leaves of willow and birch trees.
Humans, wolves, bears, mountain lions, lynx, and coyotes. Arctic Native cultures have long relied on caribou for food and clothing.
Mating usually occurs in early fall (September/October) and calves are born the following spring (May/June). During the rut (mating season), the males have frequent battles, sparring with their antlers. Survival rate for the calves is 30-50%, but the calves are able to travel with their mothers within an hour of birth.
Caribou fur is well-adapted to the cold Arctic climate, with a dense woolly undercoat and an outer coat of hollow guard hairs. Caribou hooves adapt to the season: in summer they become larger and spongier for better traction on the wet tundra; in winter their footpads shrink and become harder, enabling the animals to dig in the snow for lichen.