Caribou are circumpolar members of the deer family, and the only deer species in which both sexes have antlers. The oldest known caribou fossil was found near Fort Selkirk in the Yukon and was dated as 1.6 million years old. Bone and antler tools found in the Old Crow Basin confirm that caribou have been important to the livelihood of humans in the Yukon for at least 12,000 years. They remain so today.
Most of the Yukon’s caribou are barren-ground caribou, like the Porcupine Caribou herd estimated at 123,000 animals, that migrates across the northern Yukon. The territory also has 20 small, isolated herds of woodland, or mountain caribou, totaling about 25,000 animals. Woodland caribou are found throughout the boreal forest and many herds are listed as species at risk in Canada. Both kinds of caribou survive mainly on lichens in winter, although they broaden their diets in summer to include a variety of grasses, sedges, willows, and mushrooms.
Woodland caribou, found at the Preserve, are larger than barren-ground caribou and travel shorter distances. They spend most of the year in small groups that move between the boreal forest and the open mountain habitats where they travel in summer to escape insects. In recent years, the melting of ice patches high in the mountains of the southern Yukon has revealed the accumulated droppings of thousands of years of caribou generations, along with the beautifully-preserved artifacts of the people who hunted them.
Caribou are well adapted to surviving extreme northern temperatures. Their bodies are compact. Appendages that stick out, such as muzzles, ears and tails, are thick, round and heavily furred. Their hair is hollow, which adds to its insulating value and also makes the caribou more buoyant when swimming across lakes and rivers. Their large hooves act like snowshoes to help them to travel over soft snow or boggy ground. They are experts at digging beneath the snow for food. The clicking sound made by moving caribou is caused by the tendons slipping over the bones in their feet.