WEASELS 



87 



in hollow logs or trees. Furthermore, the weasel is an adept climber and 

 can run up or down the trunks of the smaller trees as readily almost as 

 a tree squirrel. By reason of its structure and capabilities, it is therefore 

 able to prey upon a much larger variety of animals than any other species 

 of carnivore. 



Fig. 9. (a) Sierra Least Weasel; Vogelsang Lake, August 31, 1915. See p. 89. 

 (ft) Mountain Weasel; Ten Lakes, October 8, 1915. See p. 86. (c) Pacific Mink; 

 Merced Lake, August 23, 1915. See p. 89. 



All photographed from freshly taken animals; reproduced about % natural size. 



The body coloration of the weasel is unique among our predatory 

 mammals. It changes abruptly with the seasons, being solidly white in 

 the winter months and brown and yellow in the summer season. The weasel 

 is thus able to hunt the year round, well concealed in its protective color- 

 ation be the season that of blanketing snow or of brown logs on the bare 

 ground. 



In the summer months we found weasels at practically all of our camps 

 in the territory from the 4000-foot contour up to the head of Lyell Canon, 

 at 9800 feet altitude. In Yosemite Valley, in both the winter and summer 

 months, weasels are observed commonly. On December 20, 1914, a 'white' 



