Introduction xxii 
to embody much information derived both from his notes 
and from what he has told me from his own experiences. 
Mr. Edward R. Warren has also helped me in many cases 
with specimens and information, and has kindly allowed 
me to make use of several MSS. lists of birds drawn up 
by him, especially those made in various places in 
Gunnison county. 
To Judge Junius Henderson and to the authorities of 
the State University of Colorado, I am indebted for the 
use of the invaluable notes kept during many years of 
collecting by the late Mr. Dennis Gale, of Gold Hill, 
Boulder co. 
All the information we have in regard to the breeding 
of a large number of species of Colorado birds is to be 
found in these note-books, which have been most 
carefully arranged, indexed and typewritten by Mr. 
Henderson, and which are now the property of the State 
University. 
Messrs. R. B. Rockwell, L. J. Hersey, F. M. Dille and 
H. G. Smith, all of Denver; Mr.C.S. Thompson, of Glen- 
wood Springs ; and Messrs. W. W. Cooke, H. C. Oberholser 
and C. W. Richmond, of Washington, have all helped 
me in various ways with information or advice, and to 
all these gentlemen my heartiest thanks are hereby 
tendered. 
For the photographs illustrating principally the nests 
and eggs of Colorado birds I have to thank again Messrs. 
E. R. Warren, R. B. Rockwell and L. J. Hersey, as well 
as Mr. H. W. Nash, of Pueblo. In each case an acknow- 
ledgment of the source of the photograph reproduced is 
given. 
