They can also be seen in sub arctic boreal forests during migration where they take refuge in windy coastal areas from flies and mosquitoes. Caribou habitats include arctic tundra regions, sub arctic boreal forests and mountainous habitats.

Caribous are herbivores and their preferred diet is tundra plant matter including leaves, twigs, moss and lichen known as reindeer moss. When food is abundant, an adult caribou can eat as much as 5 – 6 kilograms of food per day. When the caribou eats, the food goes down to the caribous first stomach, where it is mashed into small pieces called cud and stored to eat at the caribous next meal. Because caribous can eat large quantities of food they increase their internal heat production to prevent them from freezing in extreme weather conditions.

Caribou undertake one of the most grueling animal migrations of any other terrestrial mammal. Herds of thousands of animals complete a round migration journey of over 5,000 kilometres (3,100 miles) visiting spring calving areas and summer and winter feeding grounds. During migration, herds of cows (female caribou) leave several weeks before the males, who follow with yearling calves from the previous birthing season.

Mating season occurs in autumn as aforementioned. Males fight for access to females. Two males will lock their antlers together and try to push each other away. The most dominant males can collect as many as 15 – 20 females to mate with. A male will stop eating during this time and lose much of its body reserves.