98 Order CARNIVORA 



(23 mm.) : adult female, head and body 5-7l4 inches (127-184 

 mm.), tail 1-1)4 inches (25-33 mm.), over-all b-yiSyj inches 

 (170-217 mm.), hind foot about ^^i inch (19-21 mm.). Weight 

 (adult) : about 2 ounces. 



The skull is small (30.5-33.0 mm., or about 1)4 inches, long) 

 and delicate. Dental formula: I 3/3, C 1/1, Pm 3/3, M 1/2. 



Life History. — The least weasel commonly lives in a den 

 about 6 inches below ground. It may appropriate the nest cavity 

 and nest of a meadow vole. V^ery little is known of its breeding 

 habits, but they are probably similar to those of the long-tailed 

 weasel. 



The least weasel can go many places that mice can go and 

 consequently preys on them to a considerable extent. A few least 

 weasels may be exceedingly valuable in controlling meadow voles 

 and white-footed mice in fields. In Ohio, one storehouse of a 

 least weasel contained nearly a hundred discarded skins of 

 meadow voles. Probably during the summer it preys exten- 

 sively on the readily available insects. 



Signs. — Tracks of the least weasel are like those of other 

 weasels but smaller and without tail marks. The toe marks 

 rarely show. The usual gait of this weasel is a bound. The 

 long prints of the hind feet, which lead in the bound, are between 

 •j4 and 1 inch long, whereas those of the long-tailed weasel arc 

 between li/4 and 2 inches long. 



Droppings of this weasel are packed with mouse fur and great 

 numbers of insect parts. 



Distribution. — The least weasel, uncommon in Illinois, is 

 known to occur only in the northern three or four tiers of 

 counties except in the eastern part of the state, where it extends 

 south into Champaign County. The subspecies in Illinois is 

 Mustela rixosa allegheniensis (Rhoads). The range of the spe- 

 cies includes an area that extends from the St. Lawrence River 

 northwestward to northern Alaska, with extensions southward 

 to northern Montana, southern Nebraska, central Illinois, and 

 along the Appalachians to North Carolina, fig. 59. 



MUSTELA FRENATA Lichtenstein 



Long-Tailed Weasel 



Description. — The long-tailed weasel, fig. 64, is a slender ani- 

 mal ; its length is accentuated by the long, slim tail, which is 



