GENERAL INFORMATION 23 



In the year 1904, and again in 1905, a circular letter was directed 

 to various parts of the state, requesting that such hawks and owls 

 as should be shot by hunters, farmers and others, be sent to Coe 

 College, where the contents of the stomachs might be examined. 

 The data thus obtained were of sufficient interest to warrant a com- 

 pilation of these, together with other findings ; and at the suggestion 

 of Dr. G. F. Kay, State Geologist, they have here taken the form 

 of a bulletin of the Iowa Geological Survey. The literature of rap- 

 torial birds, particularly such as relates to Iowa, the collections of 

 the various museums, both public and private, and the observations 

 of many friends have all yielded valuable information. The final 

 impetus necessary to the completion of the work was given by the 

 opportunity to spend a year in continuous residence at the State Uni- 

 versity of Iowa, where Professor C. C. Nutting, head of the De- 

 partment of Zoology, to whom I am deeply indebted for criticism 

 and direction, placed within easy access the facilities of the Uni- 

 versity. 



GENERAL INFORMATION. 



a. The classification, in the following pages follows that of the 

 American Ornithologists' Union Check-List, 1910, with the excep- 

 tion of a subspecies of the Broad-winged Hawk (B. platypterus 

 Vieillot), hitherto undescribed. 



b. The number appearing at the left of the name of each species 

 is a serial number pertaining to this work alone, the number at the 

 right is the number given to that species or subspecies in the A. O. 

 U. Check-List. 



c. The first common name is t,he one generally accepted ; if it is 

 followed by others, these are names of more or less local character. 



d. The field characters are to assist in the identification of the 

 species at a distance, whether by its size, color, flight, feeding habits, 

 or characteristic haunts. 



e. The description is of use either with the bird in hand or 

 viewed at close range, and gives the general coloration above and 

 below ; the italics emphasize special marks of identification. 



/. The measurements are averages, representing neither maxi- 

 mum nor minimum, but the limits between which most specimens 

 will range. 



g. In general, the range or distribution given pertains to the 

 United States; in special cases the distribution in Iowa and re- 

 marks as to abundance are afterwards noted. 



