Family MUSTELIDAE 97 



of the woods, alone." The fisher is chiefly arboreal and in- 

 habits timbered swamps or woods near water. It feeds on vari- 

 ous mammals, including mice and porcupines, and on birds. The 

 subspecies in Illinois was Alartes pennanti pennanti (Erxleben). 

 The species now has a range from Labrador, Nova Scotia, and 

 northern New York to northern British Columbia, with south- 

 ern extensions to Yellowstone National Park and to central 

 California. 



MUSTELA RIXOSA (Bangs) 

 Least Weasel 



Description. — The least weasel, fig. 63, as the name implies, 

 is the smallest of our weasel-like mammals and also the smallest 

 known American carnivore. It has a slender body (only about 

 114 inches in diameter) and a stubby tail about a fourth as long 

 as the body. Its body is as long as that of an adult Norway 

 rat, but is much slimmer. The least weasel has two coats or 

 two "colors" each year, an entirely white coat and a summer 

 coat that is dark brown above and whitish beneath. The tail 

 is of uniform color, whether white or brown, and does not have 

 a conspicuous black tip, although the tip may have a few darker 

 hairs. The upper sides of the feet are white in summer as well 

 as in winter. 



Length measurements: adult male, head and body 6-7}/^ 

 inches (153-191 mm.), tail \yi-\]/2 inches (28.0-37.5 mm.), 

 over-all 7^-9 inches (188-230 mm.), hind foot about J^ inch 



Fig. 63. — Least weasel. 



