Family VESPERTILIONIDAE 



81 



der patches light brown. The female is of a slightly paler color 

 than the male. This bat is of medium size, the ears are short 

 and rounded, and the tail membrane is fully furred on the top 

 surface. 



Length measurements: head and body 21/^ inches (55 mm.); 

 tail \\/2-2\4, inches (40-55 mm.) ; over-all 3^-4i4 inches 

 (95-110 mm.) ; hind foot about V^ inch (8-10 mm.) ; ear from 

 notch about Y2 inch (10-13 mm.). 



The skull is 12.8-14.2 mm. (about V? inch) in length. Dental 

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



Life History. — In Illinois the red bat is an early spring and 

 late fall migrant and a common summer resident. In the late 

 spring, a female red bat with one or two young attached may be 

 found on leaves of trees, on the ground, or on house porches; 

 the mother may be so undernourished and the young so large 

 that she cannot become air-borne. 



Bats of this species are solitary and spend the daytime of 

 "summer" months beneath bark, under leaves, or in cracks of 



Fig. 57. — A family of young red bats hanging with heads down 

 from the branch of a tree (as viewed from directly below). 



