How Birds Are Named. 



The study of the distribution of birds and the mapping of their 

 natural life-areas are also intimately connected with this recognition 

 by name of their geographical variations, but into this phase of the 

 subject we will not enter. 



Since it is evident that a bird may vary much or little, according to 

 the governing conditions and its tendency to respond to them, no 

 fixed rule can be laid down which shall decide just what degrees of 

 difference are deserving a name. It follows, therefore, that in some cases 

 ornithologists do not agree upon a bird's claim to subspecific rank. 



In North America, however, questions of this kind are referred to a 

 committee of seven experts of the American Ornithologists' Union, 

 and their decision establishes anomeclature, which is accepted as the 

 standard by other American ornithologists and which has been adopted 

 in this volume. 



Foreign birds of wholly accidental occurrence, most of which have been 

 found in North America but once or twice, are included in the systematic 

 list of North America birds, but are not described or figured in the body 

 of the book, where their presence would tend to convey an erroneous im- 

 pression of their North American status. Furthermore, records of the 

 presence of birds so rare as these can be properly based on only the 

 capture of specimens. 



In the preparation of the following pages both author and artist have 

 had full access to the collections of the American Museum of Natural 

 History, and they are also glad to acknowledge their indebtednesss to 

 William Brewster of Cambridge, Massachusetts, to Robert Ridgway, 

 Curator of Birds in the United States National Museum, and to C. 

 Hart Merriam, Chief of the Biologic Survey, for the loan of specimens 

 for description and illustration. 



