SOURCES OF INFORMATION AND ACKNOWLEDG- 

 MENTS. 



While the literature relating to raptorial birds is widely scattered, 

 a few outstanding sources of information deserve special mention. 

 Dr. B. H. Warren, in his Birds of Pennsylvania, 1888, deals particu- 

 larly with the birds of prey from an economic standpoint, giving re- 

 ports on the contents of many stomachs. The Life Histories of 

 North American Birds, 1892, by Captain Charles Bendire, relates 

 the habits of raptorial birds in a manner both interesting and thor- 

 ough. Dr. A. K. Fisher's Hawks and Owls of the United States, 

 1893, is widely known in ornithological literature, and is a classic in 

 its field. Dr. R. M. Anderson's Birds of Iowa, 1907, is the most 

 notable contribution to Iowa ornithology and has proved invalu- 

 able as a reference. Certain publications, dealing with the birds of 

 nearby states, have yielded valuable data. Among these are History 

 of the Birds of Kansas, 1891, by N. S. Goss; Birds of Minnesota, 

 1892, by Dr. P. L. Hatch ; A Preliminary Catalogue of the Birds of 

 Missouri, 1907, Otto Wldmann ; A Preliminary Reviezv of the Birds 

 of Nebraska, 1909, by L. Bruner, R. H. Wolcott and M. H. Swenk, 

 and Dr. C. B. Cory's Birds of Illinois and Wisconsin, 1912. Dr. Paul 

 Bartsch, at present Curator of Marine Invertebrates in the Na- 

 tional Museum, Washington, D. C., in 1899 compiled The Literature 

 of Iowa Birds, which is as yet in manuscript form. He has gen- 

 erously permitted me to use this material, and as much of it as re- 

 lates to birds of prey is included in the bibliography herewith pub- 

 lished. Dr. T. C. Stephens, of Morningside College, Sioux City, 

 no less generously placed in my hands bibliographic data relative to 

 the more recent literature of Iowa Raptores. 



Dr. T. C. Stephens, Professor H. F. Wickham, Professor J. H. 

 Scott, Dr. F. A. Stromsten, Mr. Dayton Stoner, Professor Charles 

 Reuben Keyes, of Mt. Vernon, and Mrs. B. H. Bailey have generous- 

 ly given their time and by their criticisms and suggestions have as- 

 sisted in arranging the subject matter of this book. Dr. C. B. Cory, 

 of the Field Museum, Chicago ; Mr. Robert Ridgway, and Mr. H. C. 

 Oberholser, of Washington, D. C., have determined the identifica- 



