THE NATURAL HISTORY SURVEY. 



The Board of Managers of The Natural History Survey takes 

 pleasure in presenting the sixth of its publications. It is the 

 second relating to the fauna of the area and is devoted to the 

 Birds of Chicago and vicinity. 



The Chicago Area includes all of Cook and Du Page Counties, 

 the nine north townships of Will County and a portion of Lake 

 County, Indiana. This territory is about fifty miles square and 

 is very varied in character, consisting of numerous swamps, 

 lakes, creeks and rivers, besides a considerable forest-covered 

 area. 



It is a notable avifaunal locality, since it lies on the border 

 between the eastern and western ranges of many species, where 

 much intergradation occurs. It is also notable as being in the 

 path of the Mississippi Valley migration, which accounts in a 

 large measure for the number of species recorded and also for 

 their individual abundance. 



This report has been prepared by Mr. Frank Morley Woodruff, 

 Assistant to the Curator of the Academy, who has devoted many 

 years to the study of the avian life of the vicinity of Chicago. 

 Mr. Woodruff has enlisted the aid of all local ornithologists, 

 besides some residing at a greater distance, and the Board wishes 

 to express its appreciation of their valuable assistance, acknowl- 

 edgement of which has been made by Mr. Woodruff in the text. 



Finally, it is again a pleasure to make mention of the patrons 

 of The Natural History Survey, whose generosity has tended so 

 much to its success and enables the Survey to make another 

 contribution to the advancement of Science. 



