Alaska is home to the Rangifer tarandus grantisubspecies of caribou. While other parts of the world use the terms "caribou" and "reindeer" synonymously, in Alaska "reindeer" refers exclusively as Santa's 8 flying reindeer, or domesticated caribous. Caribou in Alaska generally are found in tundra and mountain regions, where there are few trees. However, many herds spend the winter months in the boreal forest areas.
Caribou are large-scale migratory animals and have been known to travel up to 50 miles (80 km) a day. The migratory activities of caribou are usually driven by weather conditions and food availability. Changes in caribou migration can be problematic for Alaska Natives, who depend on Caribou for food.
Caribou in Alaska are abundant; currently there are an estimated 950,000 in the state. The populations of caribou are controlled by predators and hunters (who shoot about 22,000 caribou a year). Though in the 1970s there were worries that oil drilling and development in Alaska would harm caribou populations, they seem to have adapted to the presence of humans, and so far there have been few adverse effects.