PREFACE 



Frederick C. Lincoln's classic work on the "Migration of Birds" 

 first appeared in 1935. It was revised in 1950 and has been out of print 

 for several years, after selling over 140,000 copies. Unfilled requests 

 by many individuals, clubs, and institutions prompted the Office of 

 Conservation Education (now the Office of Public Affairs) in the U.S. 

 Fish and Wildlife Service to petition another update for reissue. This 

 publication incorporates the results gathered by research biologists 

 in the U.S. Fish and Wildlife Service to meet these requests. 



Lincoln's original intent was to present to the American public a 

 summary of the facts on bird migration as they existed in the early 

 1930's. He wrote with a style that made the topic fascinating to the 

 young and old, to the educated and uninformed, and to the ardent 

 observer as well as the backyard watcher. An attempt has been made 

 to retain this style, while incorporating material from often highly 

 technical research efforts. Much of the content and organization of 

 the original publication has been maintained, but new sections were 

 added to incorporate recent concepts and techniques. Other concepts, 

 known to be inconsistent with present knowledge, have been deleted. 

 Because graphics are of utmost importance in this type of 

 publication, most of the original figures were preserved and, where 

 appropriate, new illustrations have been added. 



Since the previous edition, tremendous progress has been made in 

 researching and understanding bird migration; along with this 

 increased effort has come a substantial increase in the literature 

 devoted to the subject. Emphasis was given to reviewing literature 

 pertaining to migration studies conducted in North America after 

 1950, but a number of examples from the European literature have 

 been included to emphasize similarities and differences in migration 

 throughout the world. Because extensive author citations tend to 

 disrupt the flow of thought, they were kept to a minimum in the text. 

 However, this publication is essentially a review of the literature on 

 the subject as it existed in the early 1970's, and a rather extensive 

 bibliography has been included to cover all the papers quoted in the 

 text as well as the many used but not specifically cited. The 

 bibliography, then, is primarily intended for those interested in 

 pursuing the subject further. 



