385 



birds of northern Illinois pastures, 80 per cent, of those of central 

 Illinois, and 64 per cent, of those of southern Illinois. Besides the 

 five species already mentioned, these were the flicker, the robin, the 

 mourning-dove, the red-headed woodpecker, and the red-winged 

 blackbird. 



One general impression made by this preliminary examination of 

 the present bird population of the State of Illinois is that of a re- 

 markable flexibility and tenacity of the associate and ecological re- 

 lationships of birds in the face of revolutionary changes in their en- 

 vironment. Apart from the results of the introduction of the English 

 sparrow, and the direct destruction of game birds and birds of prey, 

 the main effect of human occupation seems to have been the with- 

 drawal of most of the prairie birds from the area devoted to Indian 

 corn, and their concentration in pastures, meadows, and fields of 

 small grain — situations which most nearly resemble their original 

 habitat. 



