INTRODUCTION. 



This work on the Life Histories of North American Birds is based largely 

 upon the collections in the U S. National Museum. It was the wish of the late 

 Prof. Spencer F. Baird that a comprehensive work on this subject should be 

 published, bringing together the great advances in our knowledge made during 

 the past few years. This wish was also shared by Prof. Langley and Dr. Goode, 

 and with their concurrence the present work has been written. 



Since the publication by the Smithsonian Institution in 1857 of an initial 

 volume on North American Oology, by the late Dr. T. M. Brewer — which work 

 was not finished owing to lack of material — and of Baird, Brewer and Ridgway's 

 "History of North American Birds" in 1874, no systematic and comprehensive 

 work on the oology of this country has appeared. Large collections have been 

 brought together during the last three decades, and great advances, only rendered 

 possible by the more general interest that the subject has attracted, have been 

 made. 



It is not intended that this work shall consist merely of descriptions ot nests 

 and eggs. Special attention has been given to the life history, the migratory 

 and breeding ranges, and food of each species. In this connection the latest 

 information, including the field notes made by myself and others and hitherto 

 unpublished, has been freely used. 



Although involving considerably more labor and a certain amount of repeti- 

 tion, I treat each species and subspecies separately, and endeavor to define the 

 "breeding range" of each as accurately as possible. This method is to some 

 extent open to criticism, and especially so where a species is divided into several 

 geographical races between the boundaries of whose ranges a neutral zone exists 

 in which they intergrade. On account of the limited knowledge we possess of 

 many of our birds, I am well aware that the information given under this head is 

 more or less imperfect, but this is irremediable in many instances at present. 



The present volume relates only to land birds. The classification given in 

 the Code and Check List of the American Ornithologists' Union has been followed, 

 and the synonymy and nomenclature used in this list have also been adopted, 

 with the emendations that have been made up to date. 



