Caribou, or reindeer, are herding deer of the far north. They can be found in tundra today, but in earlier times they also inhabited forests. These are the only deer in which females as well as males are antlered, although those of the males are much larger. Reindeer will migrate long distances in vast herds to find food or return to their calving grounds. They rut in early winter, and give birth in early summer. The calves can keep up with the herd almost as soon as they are born. Reindeer have been domesticated for meat, milk, hides, antlers, and as beasts of burden.