This deer is found in Arctic tundra, forests, and mountains in Russia, Northern China, Canada, Alaska, and Scandinavia. Some reindeer migrate in huge herds from the coastal Arctic to the tundra. The Reindeer (also called the Caribou) is a medium-sized member of the deer family. Reindeer are strong runners and very good swimmers. Reindeer have a life span of about 10 years in the wild. The reindeer is about 4 feet (1.2 m) tall at the shoulder and is about 6 feet (1.8 m) long. Unlike most other types of deer, both bulls (males) and cows (females) have antlers. The antlers are shed each year and regrow. Reindeer have very wide hooves, a broad muzzle, and thick brown fur. The thick fur traps air, which insulates the reindeer from the cold and helps the reindeer float in water.