Dall sheep
| Dall sheep | |
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| Dall ram at the Alaska Zoo in Anchorage, Alaska | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Synapsida |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Family: | Bovidae |
| Subfamily: | Caprinae |
| Genus: | Ovis |
| Species: | O. dalli |
| Binomial name | |
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Ovis dalli Nelson, 1884 |
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| Subspecies | |
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The Thinhorn sheep (Ovis dalli) is a species of sheep native to northwestern North America, ranging from white to slate brown in colour and having curved yellowish brown horns. There are two subspecies: the nominate Dall sheep or Dall's sheep and the more southern subspecies, Stone sheep (also spelled Stone's sheep) (Ovis dalli stonei), which is a slaty brown with some white patches on the rump and inside the hind legs.
Research has shown the use of these subspecies designations are questionable. Complete colour integradation occurs between white and dark morphs of the species with intermediately coloured populations, called Fannin sheep (Ovis dalli fannini), found in the Pelly Mountains and Ogilvie Mountains of Yukon Territory. DNA evidence has shown no molecular division along current subspecies boundaries, although evidence from nuclear DNA may provide some support. Also at the species level, current taxonomy is questionable because hybridization between Ovis dalli and Ovis canadensis has been recorded in recent evolutionary history.
The latter half of the Latin name dalli is derived from William Healey Dall (1845–1927), an American naturalist. The common name Dall sheep or Dall's sheep is often used to refer to the species Ovis dalli. An alternative use of common name terminology is that thinhorn sheep refers to the species Ovis dalli, while Dall's sheep and Stone's sheep refer to subspecies Ovis dalli dalli and Ovis dalli stonei, respectively.
The sheep inhabit the subarctic mountain ranges of Alaska, the Yukon Territory, the Mackenzie Mountains in the western Northwest Territories, and central and northern British Columbia. Dall sheep are found in relatively dry country and try to stay in a special combination of open alpine ridges, meadows, and steep slopes with extremely rugged ground in the immediate vicinity, to allow escape from predators that cannot travel quickly through such terrain.
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Wikipedia