Caribou are wild, elk-like animals that live above the tree lined arctic regions of North America and Greenland where they feed on lichen. Migrating great distances, these strong swimmers travel across wide rushing rivers and frozen Artic Ocean ice. They have unique hair that traps air for good insulation as well as provide buoyancy in water. Both cow and bull Caribou grow characteristically long antlers up to 4 feet wide. They are larger than reindeer.