The Reindeer and the Caribou are the same species, known scientifically as Rangifer tarandus. This deer species is native to the Arctic, subarctic, tundra, and boreal regions across the globe. The difference in common names is based primarily on geography and lifestyle, not a split in species. Differences in size, build, and behavior result from centuries of separation and, in one group, human management.
The Core Distinction: Nomenclature and Range
The name “Caribou” is reserved for the wild, non-domesticated populations found throughout North America, including Alaska, Canada, and Greenland. The term originates from the Mi’kmaq word xalibu, meaning “the one who paws” or “scratcher,” referring to the animal’s habit of digging for food under the snow. All Rangifer tarandus in North America exist only as wild animals.
In contrast, “Reindeer” is the term used for populations across Eurasia, specifically Northern Europe and Siberia. While wild reindeer herds exist there, the name most often refers to the semi-domesticated animals herded by indigenous peoples for thousands of years.
Physical Differences and Adaptations
Caribou are generally larger, leaner, and possess longer legs, an adaptation beneficial for long-distance travel. A large bull caribou can weigh over 600 pounds, making it significantly heavier than a typical domesticated reindeer bull. Reindeer, especially those under human management, are often stockier, shorter-legged, and more compact, requiring less energy expenditure for less migratory movement.
Both sexes of Rangifer tarandus grow antlers, a unique trait within the deer family. Wild caribou tend to have larger, taller, and more sprawling antlers, while domesticated reindeer often have shorter, more compact antlers. This difference is influenced by selective breeding and diet. Reindeer also often possess a thicker, denser fur coat compared to caribou, though both animals have hollow guard hairs for insulation.
Behavioral Differences (Wild vs. Domesticated)
The most significant behavioral distinction results from the presence or absence of domestication. Caribou are renowned for undertaking some of the longest terrestrial migrations on Earth, covering thousands of kilometers annually between their winter and calving grounds. This necessitates large, cohesive herds that move constantly across the vast tundra and boreal forest.
Reindeer, especially those in managed herds, exhibit drastically different behavior due to their relationship with humans. They are non-migratory or have significantly shorter migration routes, often moving under the guidance of herders. Domestication has made these reindeer more tolerant of human presence, whereas wild caribou remain skittish and avoid people. Their diet also differs, as domesticated reindeer may receive supplemental feed while wild caribou forage extensively for lichens and sedges.