“Caribou and reindeer are the same species; “caribou” is usual in North America and “reindeer” in Eurasia.”
The caribou, also called reindeer, is a circumpolar deer built for Arctic and subarctic life, with migratory herds, lichen winter diets, and antlers on both sexes.
By An Nguyen · Updated
Rangifer tarandusArtiodactylaCervidae
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Core article
A closer look at habitat, diet, behavior, reproduction, and conservation.
Across wind-scoured Arctic plains, the caribou (Rangifer tarandus) travels in herds that can run into the thousands. Called reindeer in Eurasia, this circumpolar member of the deer family Cervidae is built for polar and subarctic life — hollow insulating hair, snowshoe hooves, and a winter diet centered on lichens. It is the only living species in the genus Rangifer, and caribou and reindeer are one and the same animal.
Adults stand about 3 to 5 feet at the shoulder and weigh 180 to 400 pounds, bulls heavier than cows, with size varying widely by subspecies — stocky Svalbard reindeer at one end, tall broad-antlered North American bulls at the other. The coat combines dense underfur with hollow guard hairs that trap air for insulation and buoyancy in water, and a specialized nasal chamber warms frigid air before it reaches the lungs. Broad, concave hooves spread the animal's weight on soft snow and dig feeding craters. Uniquely among living deer, both sexes can grow antlers: bulls shed soon after the autumn rut, while pregnant cows often keep theirs through winter to defend feeding craters. Several subspecies and ecotypes exist, from migratory barren-ground herds of open tundra to sedentary woodland caribou of the boreal forest.
Caribou range across Arctic and subarctic tundra, alpine plateaus, and boreal forest edges in Canada, Alaska, Greenland, northern Scandinavia, Russia, and parts of Iceland. Summer ranges favour green vegetation and insect-clearing winds; winter ranges shift to lichen-rich snow country or sheltering woodland. Big migratory herds like the Porcupine and Western Arctic move between calving grounds and winter quarters along routes used for millennia, sharing the land with musk oxen, arctic foxes, and, on some coasts, polar bears, while forest-edge caribou overlap ranges where moose browse willow thickets.
Caribou are herbivores. In the short Arctic summer they eat willow and birch leaves, sedges, grasses, forbs, and mushrooms as plants green up; in winter they rely heavily on lichens — including "reindeer lichen" — scraped from beneath the snow, plus woody shrubs and dried plants. Hooves and nose clear the feeding craters, and a ruminant gut ferments the fibre. Seasonal nutrition is critical: cows need condition for pregnancy and milk, and calves must build fat before freeze-up. Competition with other grazers is usually low, but ice crusts that seal lichen under a hard layer can bring starvation.
Caribou are highly social for much of the year, feeding, resting, and moving together so more eyes watch for predators on open ground — chiefly wolves, with bears, wolverines, and golden eagles taking calves. In the autumn rut, bulls spar with antlers for mating access; outside it, groups mix sexes and ages. They keep contact with soft calls between cows and calves, along with scent and posture. In midsummer, swarms of mosquitoes and warble flies can drive whole herds onto windy ridges and lingering snow patches for relief.
Mating peaks in autumn so calves arrive in late spring or early summer after seven to eight months' gestation. Twins are rare; most cows raise a single calf, and newborns stand and follow within hours — essential when the herd keeps moving. Cows nurse through summer while calves learn migration routes and feeding skills, with survival highest when insect pressure eases and predators are thinly spread. Wild caribou often live 10 to 15 years, cut short by predation, hard winters, collisions, and disease in some herds.
Globally Rangifer tarandus is Vulnerable, reflecting roughly a 40% drop in abundance over about three generations in the mid-2010s assessment, with further regional losses since. Trends vary by herd — some migratory groups stay large while many woodland and southern herds have shrunk. The pressures include climate-driven icing that locks away winter forage, industrial roads and mining that fragment ranges, higher predation near disturbed forest, overharvest in places, and parasites boosted by warmer summers. Conservation focuses on protecting calving grounds and migration corridors, limiting development footprints, and supporting Indigenous stewardship of the herds.
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Artiodactyla
Family
Cervidae
Genus
Rangifer
Species
R. tarandus
Caribou and reindeer are the same species; “caribou” is usual in North America and “reindeer” in Eurasia.
Unlike other deer, both males and females can grow antlers.
Hollow guard hairs trap air for warmth and help animals float while swimming.
Some herds migrate hundreds of miles between calving grounds and winter ranges.
In winter they scrape feeding craters through snow to reach lichens.
Broad, concave hooves act like snowshoes on soft tundra and ice.
Select a question to reveal the answer.
Yes. They are one species (*Rangifer tarandus*). “Caribou” is the common North American name for wild herds; “reindeer” is the usual name in Europe and Siberia, including many herded herds.
They live across Arctic and subarctic regions of North America, Greenland, northern Europe, and Siberia. Habitats include open tundra, boreal forest edges, and alpine Arctic slopes.
Caribou are herbivores. In summer they eat willows, sedges, grasses, and leafy plants. In winter they rely heavily on lichens scraped from under snow, plus shrubs and other woody browse.
Many herds move between rich summer calving grounds and winter ranges with better lichen and shelter. Migration reduces insect harassment, follows plant green-up, and spreads grazing across huge landscapes.
A baby caribou is called a calf. Calves are usually born in late spring or early summer and can walk soon after birth.
Yes. Females can grow antlers, unlike most other deer. Pregnant cows may keep antlers into winter and spring to defend feeding spots before calves are born.
Globally the species is listed as Vulnerable on the IUCN Red List after large long-term declines. Some local herds are stable, while others are Threatened or Endangered under national laws.
Moose are larger, more solitary forest browsers with palmate antlers in males only. Caribou form herds, often migrate long distances, and can grow antlers in both sexes.
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