investigations are made by the U.S. Fish and Wildlife Service, an 

 arm of the Interior Department, charged by Congress under the 

 Migratory Bird Treaty Act, with the duty of protecting those species 

 that in their yearly journeys, pass back and forth between the United 

 States and other countries. 



For more than three-quarters of a century the Fish and Wildlife 

 Service and its predecessor, the Biological Survey, have been 

 collecting data on the important details of bird migration. Scientists 

 have gathered information concerning the distribution and seasonal 

 movements of many species throughout the New World, from the 

 Canadian archipelago south to the Argentine pampas. Supplement- 

 ing these investigations is the work of hundreds of U.S. and 

 Canadian university personnel and volunteer birdwatchers, who 

 report on the migrations and status of birds as observed in their 

 respective localities; while others place numbered bands on the legs 

 of birds to determine their movements from one place to another. 

 These data, stored in field notes, computer cards, scientific journals, 

 and on magnetic tape constitute an enormous reservoir of 

 information pertaining to the distribution and movements of North 

 American birds. It is the purpose of this publication to summarize 

 these data and present the more important facts about that little 

 understood but universally fascinating subject of bird migration. 

 The U.S. Fish and Wildlife Service is grateful to the many persons 

 who have contributed their knowledge so that other people, be they 

 bird study classes, conservation organizations, or just individuals 

 interested in the welfare of the birds, may understand and enjoy this 

 precious resource as well as preserve it for generations to come. 



