
PREFACE 
This report is the outcome of a cooperative venture, For 
more than a quarter of a century, professional and amateur ornitholo- 
gists (especially the latter) have been banding birds on a gigantic 
scale = North America. These banders laid the foundation of this 
researcne 
Since 1922, the U. S. Fish and Wildlife Service (formerly 
the Bureau of Biological Survey) has issued bird bands and kept the 
records. The clerical work in routinely accepting each letter about 
the discovery of a dead banded bird and converting this report onto 
an IBM record card takes about 19 minutes; many letters take even 
longer. Thus, in full cooperation with the Canadian Government, the 
Fish and Wildlife Service has erected an invaluable superstructure 
for ornithological research. Their investment in this report is very 
large. 
My studies of the North American banding files were made 
possible from August 1, 196, to December 31, 1947, by a fellowship 
of the John Simon Guggenheim Memorial Foundation, to which I want to 
extend my very sincere thanks. The project was carried out with the 
mich-appreciated advice of Dr. Josselyn Van Tyne of the University 
of Michigan. Most of the work was done at the Patuxent Research 
Refuge (Laurel, Maryland) of the Fish and Wildlife Service. J. W. 
Aldrich, Clarence Cottam, F. C. Lincoln, A. L. Nelson, and G. A. 
Swanson, officials of the Service at that time, were unfailing in 
their encouragement and assistance. Other biologists then at Patuxent, 
D. Le Allen, L. M. Dargan, L. M. Llewellyn, J. P. Linduska, A. C. 
Martin, Neil Hotchkiss, R. E. Stewart, and W. H. and Lucille Stickle, 
helped me in less direct but much-appreciated ways. In the banding 
office, C. S. Robbins introduced me to the record files, and throughout 
my stay Mrs. Lois Smith Horn cheerfully and patiently advised me on 
clerical problems that were constantly arising. Others whe helped 
clarify banding data were F. A. Carpenter, M. C. Hammond, A. S. 
Hawkins, C. M. Herman, H. A. Hochbaum, E. R. Jones, C. S. Jung, F. C. 
Lincoln, E. A. McIlhenny, A. G. Niss, R. H. Norr, M. D. Pirnie, W. H. 
Ransom, LeRoy Wilcox, C. S. Williams, and V. T. Wilson. 
The final preparation of the report was greatly aided by the 
University of Wisconsin. I am indebted to the late Professor Aldo 
Leopold who encouraged me to continue the study as a Department of 
Wildlife Management project, and to Miss Patricia Murrish and Miss 
Ruth L. Hine who typed innumerable drafts and carried out check calcu- 
lations. 
R. P. Allen, J. T. Emlon, Jr., A. S. Hawkins, Irving Kassoy, 
J. C. Neess, R. A. McCabe, L. K. Sowls, A. W. Stokes, and D. R. Thompson 
were kind enough to read various chapters as the report was in prepara- 
tion. 
