Caribou (Rangifer tarandus), which are also known as reindeer in Europe and Asia, are a type of deer indigenous to the northern regions of North America, Greenland, Asia and Europe, and are a well-known component of the story of Santa Claus. There are 9 subspecies of caribou, most of which represent the only types of deer where both sexes grow antlers.
The size of caribou depends largely on sex and subspecies. Female reindeer usually weigh between 170-260lbs, with males ranging from 200-700lbs; both sexes are between 33 and 59 inches tall at the shoulders. Compared to their body size, caribou have extremely large antlers. Males can possess racks up to 39 inches in width and 53 inches in beam length. The only deer with larger antlers is the moose. All species of caribou have insulated, double-layer coats with the color of the coat depending upon species and habitat.
Caribou are migratory animals, and venture farther each year than any other terrestrial mammal; sometimes over 3000 miles in a year. The herds during these migrations can contain up to 500,000 animals. Reindeer are very capable at covering ground, with an average traveling distance of 12-34 miles per day. They are excellent sprinters as well, and can run at speeds up to 50mph. Water is frequently and easily traversed on migration routes, as reindeer can swim at speeds in excess of 6mph.
Caribou and reindeer are ruminants, and eat primarily tundra grass in the summer. In the winter, lichen is their main food source, but they have also been known to consume leaves, seeds, eggs, and small rodents.
Reindeer and caribou mate from September to November during their autumn migration. During this time, males will become very competitive, locking antlers in great contests to push the challenger away. Those who win these challenges are able to mate with 15-20 females. Calves are born six months after mating, and will be dependent on their mothers until the following autumn. Young calves are the most frequently preyed upon caribou, and must survive being hunted by golden eagles, wolverines, and bears. Adult caribou must worry about these threats as well, but face a much larger predatory danger from wolves and humans.
Reindeer have been hunted by native peoples since nearly the beginning of human history. Their meat and fur is a staple in northern tribal life, where most species are still actively hunted. In Europe and Asia some reindeer have been partially domesticated for centuries, and they are often used as draught animals.
- Caribou hooves change with the season. They are wider and softer in the spring to allow more traction, and harder in the winter to dig into ice and frozen ground.
Alaska Department of Fish and Game