SOME ANIMALS OF YUKON TERRITORY 313 



Yukon Territory and Alaska, and in the whole of the 

 Alaska Range. White sheep are always conspicuous on 

 green slopes and pastures. They are inconspicuous on 

 snow, although their stained coats, throughout all the win- 

 ter, spring, and fall, except November, render a strong 

 contrast against the white background. 



The dark sheep, except against a background of sky, 

 are never conspicuous in summer, their color blending 

 well with rocks and green slopes. From a distance they 

 are most easily detected by their light rumps. But in 

 the snow, under nearly all circumstances, they are exceed- 

 ingly conspicuous. 



The sheep of variable color are still less conspicuous, 

 except on snow where they are nearly as conspicuous as 

 the dark sheep. 



All the northern sheep, dark or white, are inconspicu- 

 ous either when feeding among willows, or especially 

 when the surface background is banded or striped with 

 snow, or when bare areas are thickly patched with snow. 

 This applies to the majority of the time in spring, fall, and 

 winter when sheep always seek the wind-swept parts of 

 the mountains to find their food. 



When the dark of evening approaches, both white 

 and dark sheep are usually conspicuous on the sky-line. 

 In the twilight, during the darker hours of the night in 

 summer, the white sheep are very much more con- 

 spicuous below the sky-line than the dark ones. During 

 the night and all through the dark hours of fall and 

 winter, sheep are lying down resting. They move and 

 feed only during the hours of daylight. 



