on the American Ornithologists’ Union Check-list of 
North American Birds (1957), and more than a hundred 
regional faunistic works. 
Nomenclature for birds follows the A.O.U. Check- 
list unless otherwise stated. For plant names we have fol- 
lowed three references, Jones (1963), Fernald (1950), 
and Rehder (1947). For insect nomenclature, we have 
followed primarily Borror & DeLong 1962); 
Except for the classic studies of Forbes (1879, 1880, 
and 1883), there would be almost no information on the 
foods of most Illinois birds. Though old, the studies are 
valuable especially for comparative purposes. For the 
many students who do not have access to the Forbes 
papers, we have summarized some of his data, usually in 
graphic form. 
We have discussed subspecific populations and other 
specimen-related data only for those species for which we 
have sizable series of recent specimens, i.e., specimens 
collected within the past 5-10 years. Thus, in the Mimi- 
dae, we have presented no specimen data for either the 
brown thrasher or mockingbird, because the number of 
recent Illinois specimens in existence is too small. In the 
case of the catbird, the television tower kills have provided 
us with an excellent series of specimens in fresh fall plum- 
age, and we have discussed variation in this species. The 
state research collection at the Natural History Survey 
in Urbana continues to grow, and in time we hope to 
present specimen data for most of the Illinois species. 
In our studies in various parts of the state, we have come 
to realize how extremely variable are the problems which 
bird populations face from place to place. Not only do 
these problems vary from northern to southern Illinois, 
but they may differ greatly even in adjacent counties. 
This heterogeneity of populations and _ their problems 
may be the most important single fact we can tell other 
students about the birds of Illinois, and we will never 
understand how populations survive without massive de- 
tailed information on this variability. 
In this report it was not feasible to cite all, or even 
most, of the papers that presented data (e.g. arrival or 
departure dates) for a given species. By that procedure 
the text would have been an almost endless list of refer- 
ences, with the manuscript prohibitively long. Generally, 
we have not included data from newspapers. 
For quick references on the Ilinois avifauna the use- 
ful distributional checklist by Smith & Parmalee (1955), 
birds of the Chicago region by Ford (1956), Chicagoland 
birds by Smith & Beecher (1958), and the checklist for 
southern Illinois by George (1968) are available in many 
libraries. 
Unless otherwise stated, the photographs were made 
in Illinois by the authors, and represent wild birds. 
Many people helped us in one way or another with 
this project, and most of them will be referred to under 
the species accounts. Here we wish to acknowledge some 
who helped in special ways, as in the use of scientific 
collections and other research facilities. We are very 
grateful to Paul W. Parmalee, Milton D. ‘Thompson, and 
4 
John Paul of the Hlinois State Museum, Emmet R. Blak 
and Melvin A. Traylor of the Chicago Museum of Nat 
ural History, Philip S. Humphrey and Alexander Wet 
more of the U.S. National Museum, William George anc 
John D. Parsons of Southern Illinois University, Donal 
F. Hoffmeister of the University of Illinois, and Joh 
Wanamaker of Principia College. 
To the Directors and staff of the Illinois Departmen 
of Conservation we are grateful for the use of the Depart 
ment’s facilities in various parts of the state. We are als 
very indebted to John E. Warnock and Emory Carson 0 
Western Illinois University for the use of facilities at th 
Alice Kibbe Field Station. 
Robert W. Guth of Eureka, Illinois, Mr. and Mr: 
Harry Shaw of Sterling and John Schwegman of the Illi 
nois Nature Preserves Commission made especially im 
portant contributions of data to the work. ‘T. E. Mussel 
man of Quincy and Lee Bush of Cambria gave ver 
valuable advice on the project in its earliest plannin 
stages. Ralph M. Eiseman helped with the bibliography 
Richard A. Anderson of St. Louis, Missouri, Karl T 
Bartel of Blue Island, Illinois, Charles T. Clark of De 
Plaines, Marion Clow of Lake Forest, Harold Fetter « 
Chicago, Larry L. Hood of Carbondale, Lee G. Johnso 
of Rockford, Mr. and Mrs. C. Turner Nearing of Dx 
catur, Philip Norton of Urbana, Peter C. Peterson « 
Davenport, Iowa, Robert P. Russell of Wilmette, Robe: 
J. Trial of Aledo, and Sarah S. Vasse of Brussels all mad 
valuable contributions of data on many species. 
A number of our colleagues at the Natural Histor 
Survey have helped with the project immensely. W 
would especially like to acknowledge Glen C. Sanderso 
and Thomas G. Scott for their support, encouragemen 
and advice on all phases of the study; Frank C. Bellros 
William C. Starrett, Charles F. Thoits III, Jack A. Elli 
Steven L. Wunderle, Philip W. Smith, and Marvin | 
Braasch for valuable contributions of ideas and data; an 
Milton W. Sanderson and Robert A. Evers for identifyir 
insect and plant species. James W. Seets prepared mo 
of the scientific specimens. We are also much indebte 
to Ruth Warrick and Deris F. Dodds for their patie 
help with countless bibliographic and library problem 
and to Carolyn S. Evers, Eleanore Wilson, Norma 
Hubbard, Dorothy M. Diehl, Linda J. Raisler, Hilc 
Wiesenmeyer, Renata Coates, Darlene Cacioppo, Juc 
Wildman, and Maxine Phillips, all of whom helped wii 
many phases of the project including the acquisition | 
equipment, cataloging of scientific specimens, and typi! 
of field notes and manuscripts. 
O. F. Glissendorf provided valuable  suggestio 
throughout the planning of the publications, and editt 
the final manuscript. Richard Sheets prepared the fin 
line drawings, and Wilmer Zehr, the final photograph 
prints. 
To Edythe J. Kirk of the University of Illinois Libra 
we owe a special debt of gratitude for her kind encourag 
ment and support in publishing the work. 
