Caribou - Rangifer tarandus
Caribou - Rangifer tarandus. Photo © Danita Delimont / Getty Images.

Caribou (Rangifer tarandus), also known commonly as reindeer, are members of the deer family that inhabit boreal forests and tundra of North America, Siberia, and Europe. There are four subspecies of caribou and each of the subspecies differs slightly in its coat color and size. Coat color of caribou may be dark brown to nearly white depending on season and subspecies. Woodland caribou have deep brown fur in summer, whereas they have nearly white fur in winter.

Caribou are the only members of the deer family in which both males and females possess antlers. The antlers of male caribou are much larger in size than those of females. Additionally, antler structure varies among the caribou subspecies, with the woodland subspecies having thicker and broader antlers than their barren-ground cousins. Caribou antlers are covered in a fine velvet that males shed each autumn prior to the rut. Caribou rutting season usually occurs in October. The gestation period of caribou is about 228 days and females normally give birth to a single calf in May or June.

The coat of a caribou provides the animal with superb insulation. Such insulation helps caribou survive the frigid arctic winters of its northern forest and tundra habitats. A caribou's consists of two layers: a dense wooly undercoat and a lightweight overcoat. The overcoat consists of long, buoyant, hollow hairs.

This two-layered structure of a caribou's coat helps to trap heat close to the animal's body.

The hooves of caribou are well-adapted for walking in snow. Their hooves change through the seasons. In the summer months, caribou footpads become sponge-like, providing the animal with the extra traction it needs to traverse the soft, thawed tundra ground.

In winter, caribou footpads contract and become more dense, exposing the tough rim of the hoof which is used to slice through ice and snow. This tougher winter hoof also enables caribou to dig their way through the snow to the ground in search of lichen, their primary winter food source.


  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Mammalia
  • Order: Artiodactyla
  • Family: Cervidae
  • Genus: Rangifer
  • Species: Rangifer tarandus
    The species Rangifer tarandus contains the following subgroups:
    • Rangifer tarandus caribou (woodland caribou)
    • Rangifer tarandus groenlandicus (barren-ground caribou)
    • Rangifer tarandus pearyi (Peary caribou)
    • Rangifer tarandus platyrhynchus (Svalbard caribou)

Caribou inhabit a nearly circumpolar range that includes the tundra and boreal forest habitats throughout North America, Northern Europe, Greenland, Siberia, and the Svalbard Archipelago.