Family MUSTELIDAE 



99 



Fig. 64. — Long-tailed weasel. 



slightly bushy. In summer, its fur is a soft brown color except 

 for that on the abdomen and chest, which is whitish, suffused 

 with yellow, and the tip of its tail, which is black. In winter 

 in the northern part of its range, the fur of the long-tailed 

 weasel turns "white" except for the conspicuous black tip of the 

 tail; the fur of the under parts is usually washed with a yel- 

 lowish color. In the southern part of the range of this animal, 

 both brown individuals and white individuals may be found; 

 those which do not become whitish have a winter coat that is 

 thicker than the summer coat and of a different shade of brown. 

 Much additional information is needed regarding the occur- 

 rence of long-tailed weasels in Illinois and the percentage of 

 individuals, if any, that in a particular area turn whitish. 



In size, there is a marked difference between the male and 

 the female of the long-tailed weasel; the male is generally 

 considerably larger than the female. The sex of a weasel speci- 

 men should be determined before a positive identification is 

 attempted. 



Length measurements: adult male, head and body 9i 4— 10i 4 

 inches (235-260 mm.), tail 4i 4 -5i : inches (110-140 mm.), 

 over-all 13^-15^ inches (350-400 mm.), hind foot Hj-2 

 inches (40-50 mm.); adult female, head and body 8*4-914 

 inches (223-235 mm.), tail 3-4 1 4 inches (76-108 mm.), over-all 

 11^-1314 inches (298-338 mm.), hind foot H4-I 1 : inches 

 (31-38 mm.). Weight: adult male 6-10 ounces: adult female 

 3-7 ounces. 



The skull of the long-tailed weasel is much like that of the 

 mink but smaller, less angular, and le^ strongl] ruined. The 



