82 Order CHIROPTERA 



trees, or even among tall weeds and shrubs. It is thought that 

 the coloration of the red bat, particularly the dusting or frosting 

 of white, enables it to remain better hidden in less protected 

 places than some other bats. 



The long, narrow wings of the red bat make it an excellent 

 flyer and an adept insect catcher. Sometimes members of this 

 species start foraging beneath the branches of trees even before 

 the sun has gone down, but normally they become active about 

 twilight. They feed on insects around trees and other objects, 

 including cribs containing corn that is heavily infested with 

 grain moths. 



On one occasion in eastern Illinois, several red bats were at- 

 tracted by the watery appearance of freshly tarred roads, or by 

 insects caught in the tar, and were trapped in the sticky material. 

 At Starved Rock State Park in Illinois, a red bat and a blue 

 jay were captured together, the bat fastened by its teeth to the 

 side of the jay's head; the bird was nearly exhausted, but the bat 

 appeared neither exhausted nor hurt. 



The red bat frequently migrates southward in groups. It is 

 not known whether the "summer" residents of extreme southern 

 Illinois migrate out of the state or whether they overwinter 

 there. 



Distribution. — The red bat is common over all of Illinois 

 during the summer months. The subspecies in this state is 

 Lasiurus borealis borealis (Miiller). The range of the red bat 

 includes most of the North American continent from extreme 

 southern Canada to Panama. Apparently not in the range is a 

 broad, irregular area that extends from central Mexico through 

 New Mexico into British Columbia and includes part of eastern 

 California and all of Oregon, Washington, and Idaho. 



NYCTICEIUS HUMERALIS (Rafinesque) 

 Evening Bat 



Description. — The evening bat appears to be a miniature of 

 the big brown bat; it is bronze or chocolate-brown, except for 

 blackish ears, wings, and tail membrane. The wingspread is 

 about 10 inches, and the length of each forearm is less than 

 \y% inches (40 mm.). 



Length measurements: head and body X^-ly? inches (46-62 

 mm.) ; tail \y^-\y^ inches (34—42 mm.) ; over-all 3]/s-4]/s inches 



