INTRODUCTION 



This is the eighth in a series of bulletins of the United States 

 National Museum on the life histories of North American birds. 

 Previous numbers have been issued as follows : 



107. Life Histories of North American Diving Birds, August 1, 

 1919. 



113. Life Histories of North American Gulls and Terns, August 

 27, 1921. 



121. Life Histories of North American Petrels, Pelicans and their 

 Allies, October 19, 1922. 



126. Life Histories of North American Wild Fowl, May 25, 1923. 



130. Life Histories of North American Wild Fowl, June 27, 1925. 



135. Life Histories of North American Marsh Birds, March 11, 

 1927. 



142. Life Histories of North American Shore Birds, December 31, 

 1927. 



The same general plan has been followed, as explained in previous 

 bulletins, and the same sources of information have been utilized. 

 The classification and nomenclature adopted by the American Orni- 

 thologists' Union, in its latest check list and its supplements, have 

 been followed, mainly, with such few changes as, in the author's 

 opinion, will be, or should be, made to bring the work up to date and 

 in line with recent advances in the science. 



The main ranges are as accurately outlined as limited space will 

 permit; the normal migrations are given in sufficient detail to indi- 

 cate the usual movements of the species; no attempt has been made to 

 give all the records, for economy in space, and no pretence at complete 

 perfection is claimed. Many published records, often repeated, have 

 been investigated and discarded; many apparently doubtful records 

 have been verified; some published records, impossible to either 

 verify or disprove, have been accepted if the evidence seemed to 

 warrant it. 



The egg dates are the condensed results of a mass of records taken 

 from the data in a large number of the best egg collections in the coun- 

 try, as well as from contributed field notes and from a few published 

 sources. They indicate the dates on which eggs have been actually 

 found in various parts of the country, showing the earliest and latest 

 dates and the limits between which half the dates fall, the height of 

 the season. 



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