Musk Ox have inhabited Arctic regions for thousands of years, and their long-shaggy hair is well adapted to the brutal climate and well-known for its insulation qualities, 8 times that of sheep's wool. The name Musk Ox is derived from the strong odur emitted by the bulls during the mating (or rutting) season. This image was taken at Dovrefjell National Park, Norway where the animals were reintroduced in 1947. Musk Ox are known for their destinctive defence behaviour when under-threat; the bulls and cows will face outwards to form a stationary ring around the calves making a formidable challenge to most predators.