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“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.
Rangifer tarandusArtiodactylaCervidae
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Core article
A closer look at habitat, diet, behavior, reproduction, and conservation.
Across wind-polished Arctic plains, the caribou (Rangifer tarandus) travels in herds that can number in the thousands. Also called reindeer in Eurasia, this circumpolar deer is built for polar and subarctic life: hollow insulating hair, snowshoe-like hooves, and a winter diet centered on lichens. It belongs to the deer family Cervidae and is the only living species in the genus Rangifer.
Caribou and reindeer are one species. Several subspecies and ecotypes exist — from migratory barren-ground herds of the open tundra to more sedentary woodland forms of boreal forest. Genetic and fossil evidence places Rangifer among cervids that expanded with Ice Age landscapes across the northern Northern Hemisphere.
They share the Cervidae family with moose, yet they filled a different niche: open-country grazing and long migrations rather than deep forest browsing. In Eurasia, some populations have been herded for centuries by Indigenous peoples; in North America, wild caribou remain the common form of the same species.
Adults usually stand about 3 to 5 feet (0.9 to 1.5 m) at the shoulder and weigh roughly 180 to 400 pounds (80 to 180 kg), with bulls heavier than cows. Body length often falls between about 5 and 7 feet (1.5 to 2.1 m). Size varies by subspecies — Svalbard reindeer are short and stocky, while some North American bulls grow tall frames and broad antlers.
The coat mixes dense underfur with hollow guard hairs that trap air for insulation and buoyancy. Broad, concave hooves spread on soft snow and dig feeding craters. A heat-conserving nasal chamber warms cold air before it reaches the lungs. Uniquely among living deer, both sexes can grow antlers; bulls typically shed earlier after the rut, while pregnant cows may keep antlers longer to defend winter forage.
Caribou inhabit Arctic and subarctic tundra, alpine plateaus, and boreal forest edges across Canada, Alaska, Greenland, northern Scandinavia, Russia, and parts of Iceland. Summer ranges often favor insect-relieving winds and green vegetation; winter ranges shift toward lichen-rich snowscapes or woodland cover.
Large migratory herds such as the Porcupine and Western Arctic herds move between calving grounds and winter quarters along routes used for millennia. Neighbors on these landscapes include musk oxen, arctic foxes, and polar bears along some coasts. Forest-edge caribou may overlap ranges where moose browse wetlands and willow thickets.
Caribou are herbivores. In the brief Arctic summer they eat willows, birches, sedges, grasses, forbs, mushrooms, and other leafy growth timed to plant green-up. In winter they depend heavily on lichens — including “reindeer lichen” — scraped from under snow, plus woody shrubs and remaining dried plants.
Hooves and noses clear feeding craters. A ruminant digestive system ferments fibrous forage. Seasonal nutrition matters: cows need body condition for pregnancy and milk, and calves must pack on fat before freeze-up. Competition with other grazers is usually low, but ice crusts that seal lichen under a hard layer can cause starvation.
Most caribou are highly social for at least part of the year. Herds travel, feed, and rest together, which improves predator detection on open ground. Wolves are major predators; bears, wolverines, and golden eagles take calves.
During the autumn rut, bulls spar with antlers for breeding access. Outside the rut, groups may mix sexes and ages. Communication includes soft contact calls among cows and calves, scent cues, and posturing during competition. Insect harassment from mosquitoes and warble flies can force herds onto windy ridges or snow patches in midsummer.
Mating peaks in autumn so calves arrive in late spring or early summer after about seven to eight months of gestation. Twins are uncommon; most cows raise a single calf. Newborns stand and follow within hours — essential when the herd must keep moving.
Cows nurse through summer while calves learn migration routes and feeding skills. Survival is highest when insect pressure is manageable and predators are scattered across large ranges. Wild lifespan often spans roughly 10 to 15 years, shortened by predation, harsh winters, vehicle collisions, and disease in some herds.
(Population and conservation trend data sourced from the IUCN Red List of Threatened Species)
Globally Rangifer tarandus is classified as Vulnerable, reflecting roughly a 40% abundance decline over about three generations in the mid-2010s assessment, with continued regional losses since then. Trends differ by herd: some migratory groups remain large, while many woodland and southern herds have shrunk.
Threats include climate-driven icing events that lock winter forage, industrial roads and mining that fragment ranges, elevated predation near disturbed forests, overharvest in some areas, and parasites amplified by warmer summers. Conservation work focuses on protecting calving grounds and migration corridors, managing development footprints, and supporting Indigenous stewardship of herds.
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.
The caribou (*Rangifer tarandus*) is a member of the deer family Cervidae. In Eurasia the same species is usually called reindeer. It is adapted to polar and subarctic landscapes.
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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