Arctic deer ( Rangifer tarandus ) of the tundra, taiga, and forests, native to North America and northern Eurasia from Scandinavia to eastern Siberia.
Both sexes have antlers. Caribou stand 2.3–4.6 ft (0.7–1.4 m) tall at the shoulder and weigh up to 660 lbs (300 kg); domesticated races are about the size of donkeys. They are usually grayish or brownish with lighter underparts but may be whitish or nearly black. Their herds are famous for their seasonal migration between summer and winter ranges. Their staple winter food is a lichen , popularly called reindeer moss, which they reach by scraping the snow away with their feet. In summer they also eat grasses and saplings. See also reindeer .