INTBODUCTION 3 



Academy of Natural Sciences, Philadelphia; the Jonathan Dwight, 

 Jr., collection in the American Museum of Natural History, New York 

 City ; and the Museum of Comparative Zoology, Harvard College, 

 Cambridge. To all of these institutions and their officers we express 

 our appreciation of the spirit of cordial cooperation they have shown. 

 In response to our direct request a great many persons have 

 furnished specific information. Wherever such information has been 

 used it has been credited to the individual contributor. Much use has 

 been made of Ljanan Belding's manuscript Water Birds of the Pacific 

 District, now on deposit in the Bancroft Library of the University of 

 California. The field observations of the three present co-authors and 

 of W. P. Taylor and R. H. Beck have been taken from the note books 

 of these persons on file in the California Museum of Vertebrate 

 Zoology. All of these various sources of information are referred 

 to in the text as "MS." 



The hearty cooperation of the California Fish and Game Commis- 

 sion has been of great assistance in assembling data. Much new 

 material has been obtained by means of circular letters to the com- 

 mission's deputies, as in the cases of the Mourning Dove and Valley 

 Quail. Mr. Ernest Schaeffle, former secretary of the commission, 

 assisted us in a multitude of ways both official and personal. 



Finally, Mr. Harry S. Swarth, curator of birds in the California 

 Museum of Vertebrate Zoology, has read the entire proof of the book, 

 and by reason of his extensive knowledge of western birds has been 

 able to make important corrections and improvements. 



It was found necessary arbitrarily to set a date beyond which no 

 new information should be incorporated into our manuscript. This 

 date was fixed at June 30, 1916. "Work done subsequently, and up to 

 the time of going to press, consisted solely in revision. 



The list of "literature cited" at the end of the book must not be 

 taken as a complete bibliography of the subject ; it contains titles only 

 of those articles or books from which material is actually taken either 

 indirectly or by quotation. 



Many of our readers will probably disapprove of our frequent 

 use of direct quotations. In defense of this practice we urge the 

 greater accuracy thereby obtained. Experience has taught us that 

 rewording an account often leads unintentionally to a perversion of 

 the original author's exact meaning, and we believe that scientific 

 accuracy of fact should take precedence over smoothness of diction or 

 an appearance of originality. We also recognize the fact that inter- 

 polation of citations in the text mars its typographical appearance ; 

 but their presence makes verification possible, and, together with the 

 list of articles and books under the heading "literature cited," they 

 serve to assist those readers who are interested in following the sub- 



