reindeer

Reindeer (Rangifer tarandus) are a species of deer native to Arctic, subarctic, and boreal regions of Eurasia and North America. They inhabit tundra and taiga ecosystems and are notable for adaptations to cold environments. The name caribou is used for Northern Hemisphere populations; some classifications treat caribou as a subspecies (R. t. caribou) within Rangifer tarandus.

Reindeer are circumpolar, with wild populations across northern Canada, Alaska, Greenland, Fennoscandia, and Russia. They undertake long seasonal migrations between winter and summer ranges, and some herds travel hundreds of kilometers annually. Predators include wolves and bears, and population dynamics are influenced by climate, forage availability, and human activity such as hunting and habitat disturbance.

Physically, reindeer have thick fur consisting of hollow, air-filled hairs that provide insulation. Both sexes grow antlers, though males typically have larger ones and shed them later in the year. Adults vary in size by sex and subspecies, commonly weighing from about 60 to 300 kilograms. Their hooves are adapted to seasonal conditions: broad and cloven in summer to forage on soft ground, and hard-backed in winter to dig through snow for vegetation.

Diet consists mainly of grasses, herbs, shrubs, and aquatic plants; in winter, lichens become an important food source, including reindeer moss (Cladonia rangiferina). They are social animals, often forming large herds, and calves are typically born in spring and can stand shortly after birth.

Humans have long interacted with reindeer. In parts of northern Eurasia they have been domesticated for centuries, used as draft animals and sources of meat, milk, and hides. Conservation status varies regionally, with some populations stable and others threatened by habitat loss and climate change.