different species in many extended areas, from the Arctic coast south 

 to the pampas of Argentina. Supplementing these investigations is 

 the work of hundreds of volunteer ornithologists and bird students 

 throughout the United States and Canada, who each year, spring and 

 fall, forward to the Service reports on the migrations as observed in 

 their respective localities. Added to the mass of data thus assembled 

 is a rapidly growing recovery file of marked individuals. These data, 

 together with other carded records gleaned by the Fish and Wildlife 

 Service from a vast literature, constitute a series of files that now con- 

 tain well over 3,000,000 entries, easily the greatest existing accumulation 

 of information pertaining to the distribution and movements of North 

 American birds. Not only do the facts thus assembled form the basis 

 of regulatory action for the protection of the birds, but they also make 

 it possible to publish scientific accounts of the ranges and migrations 

 of the different species. They furnish the basis of this bulletin. 



The several important bird-protective measures adopted by State 

 and Federal Governments, particularly those having as their objectives 

 the conservation of the migratory song, insectivorous, and game species, 

 can be effective only if they have intelligent public support. To 

 increase such support, information must be more generally available 

 on that little understood but universally fascinating subject of bird 

 migration. A brief presentation of facts on the migratory habits of 

 the birds scientifically gathered by the Fish and Wildlife Service over 

 many years, will be helpful to bird-study classes, to conservation or- 

 ganizations, and to farmers and others individually interested in the 

 welfare of the birds. 



In addition to his original investigations in the field and in the files 

 of the Fish and Wildlife Service, the author has made free use of the 

 writings of many other students of the subject. To all of these grateful 

 acknowledgment is made. 



