Mammals
Dall Sheep
Ovis dalli · also called Dall's sheep, white sheep
Against a backdrop of snow-covered peaks in remote Alaska, a Dall sheep’s entirely white coat renders it almost invisible from a distance, a specialised camouflage shared by no other wild sheep species on Earth.
Overview
The Dall sheep, Ovis dalli, is the only entirely white wild sheep species in the world, native to alpine mountain habitat across a range of Alaska and northwestern Canada. Its distinctive snow-white coat, amber-coloured curling horns, and preference for some of North America’s most remote mountain terrain make it one of the more visually striking and geographically isolated large mammals found on the continent.
Camouflage perfected for a white world
Where the related bighorn sheep blends into brown rock and dry grassland, the Dall sheep has instead evolved to disappear entirely against snow, its pure white coat a specialised adaptation to a genuinely different kind of mountain habitat.
Status
Least Concern, widespread and stable across suitable alpine mountain habitat throughout Alaska and northwestern Canada.
Dall Sheep: common questions
Why is the Dall sheep entirely white?
This species is the only wild sheep species with an entirely white coat, a colouration that provides effective camouflage against the snow and pale rock typical of the northern alpine habitat it occupies across Alaska and northwestern Canada, helping it avoid detection by predators.
How can you tell a Dall sheep from a bighorn sheep?
Coat colour and horn shape are the clearest distinguishing features, since the Dall sheep is entirely white with thinner, more tightly curled amber-coloured horns, while the bighorn sheep has a darker brownish coat and thicker, more massive curled horns.
Why does the Dall sheep live in such remote terrain?
This species occupies some of the most remote and rugged alpine terrain found in North America partly because that inaccessible, steep habitat offers effective protection from ground-based predators, an advantage supported by the species' specialised hooves suited to navigating such difficult terrain confidently.
Do Dall sheep stay in mixed groups year-round?
No, outside of the breeding season, this species typically segregates into separate groups of males and groups of females with young, coming together mainly during the autumn breeding period, a social pattern shared with several related mountain sheep and goat species.