The semi-domesticated reindeer (Rangifer tarandus) and the wild caribou of North America and Greenland are the same species. Reindeer are farmed in many countries. In northern Scandinavia and Russia the herds freely roam over areas up to 8000 square km. The reindeer herders are dependent on the animal for survival, using it for milk and meat, transport, and clothing. They even use the tendons and sinews for sewing.The caribou's annual migration is a spectacular 9000km journey on foot across the vast Canadian tundra, with temperatures varying from 86 to minus 40 degrees Fahrenheit. Its wide-splaying hoofs provide support across snow, act as paddles when swimming, and are essential tools for digging under snow for lichen.