Reindeer are just domesticated caribou, and the animals themselves see no difference. In fact, a herders nightmare is to have his reindeer hear the call of the wild and join a migrating herd of caribou. Reindeer, which have changed very little during thousands of years of domestication, are raised for meat, milk, and hides. They also are used as beasts of burden. Reindeer are able to pack up to 90 pounds and pull 450 pounds of cargo over great distances.
Reindeer are well suited for the Arctic cold.
Their outer guard hair is hollow to help trap air for insulation and for buoyancy. These creatures of the north are excellent swimmers and able to negotiate rough running water. They have even been known to swim in the Arctic Ocean. Herds of up to 200,000 animals have been reported traveling in mass on average 22 miles per day. Some herds will travel as much 400 miles between ranges.