Family VESPERTILIONIDAE 



81 



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

 than the male. This bat is of medium size, tlu* ears art- >hort 

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

 surface. 



Length measurements: head and body 2i * inches (55 mm.); 

 tail li/>-2i/6 inches (40-55 mm.); over-all 3j4-4]4 inches 

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

 notch about )/> inch (10-13 mm.). 



The skull is 12.8-14.2 mm. (about \ _> 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 behm 



