The distribution of the genus is limited by the character of the mountain ranges, rather than any other consideration, and too much emphasis cannot be placed on the fact, that of all our North American animals the white goat is the only one absolutely confined to precipitous peaks and ridges, which even the mountain sheep seldom approach.
The extreme north and south ranges of Oreamnos in the main Rockies present several problems of great interest. The southern limit is clearly marked by a change in the formation and ruggedness of the mountains themselves, which, together with climatic conditions, and the lack of water in summer on the mountain tops, are sufficient to account for the absence of these animals much south of their present limit. A very different condition prevails in the north. At the extreme northern limit which is about 63° 30´, the mountains begin to lose their height but are still of considerable size and quite rugged enough to provide a suitable home for Oreamnos. White sheep are found all through these mountains, up to the very coast of the Arctic Ocean and westward through the Romanzoff Mountains in northern Alaska. These sheep are certainly not better equipped to resist arctic cold than are the goat, so we must seek for some cause other than climatic or topographical conditions. There must be some unknown and unfavorable condition of food supply which prevents Oreamnos from reaching the extreme north. This is perhaps the most interesting and difficult of the problems affecting the distribution of the genus.
Along the Pacific coast of the United States the mountains are not sufficiently precipitous to attract the goat, and consequently that animal is found only at some distance inland, but in northwestern British Columbia and southern Alaska, the Rockies approach the coast in stupendous chains, which swing westward through the Mt. St. Elias range. Through all this country the goat occupies the coast region from Prince William Sound south nearly to the American border. They are not found in any of the adjacent islands.
SEVEN MOUNTAIN GOAT KIDS
CAPTURED NEAR BANFF, ALBERTA, 1904, FOR THE NEW YORK ZOOLOGICAL SOCIETY.
Along these coast ranges goat are much more numerous than in the main Rockies, owing probably to the presence of forests high up in the mountains and in close contact with the cliffs where the goat lives, together with a copious supply of water. At all events the conditions are certainly favorable. North of Skagway goat do not extend inland much beyond the summit of the coast range, and do not again occur until the main Rockies are reached, hundreds of miles to the east. The goat in these eastern mountains are, in all likelihood, specifically distinct from the coast goat, as practically all the other mammals of these two distinct faunal areas are separate species.
LEGENDARY DISTRIBUTION.