BOARD OF NATURAL RESOURCES 
AND CONSERVATION 
DEPARTMENT OF 
REGISTRATION AND EDUCATION                                            JOHN
J. HALLIHAN. CHAIRMAN 
BIOLOGY    WILLIAM TRELEASE 
JOHN J. HALLIHAN. DIRECTOR 
FORESTRY  0 HENRY C. COWLES 
SPRINGFIELD                                                  GEOLOGY    
EDSON S. BASTIN 
ENGINEERING  .  L, R. HOWSON 
CHEMISTRY  WILLIAM A. NOYES 
UNIVERSITY OF ILLINOIS- 
PRESIDENT ARTHUR C. WILLARD 
STATE OF ILLINOIS 
HENRY HORNER. GOVERNOR 
STATE NATURAL HISTORY SURVEY DIVISION 
THEODORE H. FRISON. CHIEF 
URBANA 
November 1, 1938 
Dr, Rudolf Bennitt, Chairman 
Administrative Committees 
Missouri Cooperative Wildlife Research Unit 
Columbus, Missouri 
Dear Bennitt: 
Dr. Frison handed me your letter regarding the status of prairie 
chickens in Illinois same time ago. I have hesitated to answer, hoping I

could get together more information on some of the points you bring up. What

I have obtained is rather meager, but I will try to give some kind of answer

to your questions. 
1. The two enclosed maps give the best information we have on 
the distribution in 1929 and at present. The earlier map is based largely

on Leopold's manuscript on "A Game Census of Illinois" (1929) which
he loaned 
me some time ago.  The 1938 map brings together our present records. 
2. The closed season first became effective in 1933. My belief 
is that population densities in 1932 were about the same as now, although

somewhat lower than in 1935 (populations have declined somewhat sine6 1935

because of renewed agricultural activities in the best range). The average

of the best areas is probably about 40 per square mile in the fall. This

refers only to the occupied range and not to whole counties, as the distri-

bution is spotty even in the best counties. 
3. I believe the total population was slightly higher six or 
seven years ago than it is now, because some of the range in the central

highly cultivated counties has since been lost and the northeastern counties

have lost some colonies and others apparently are now reduced to small remants.

4. Dr. Thompson estimates the annual kill at that time at less 
than 50 per year. My guess is that it was somewhat higher, probably 300 to

500 per year. 
5. Reduction in range and in numbers was undoubtedly chiefly 
because of continuous intensive cultivation and grazing. Disappearance of

birds in some of the highly cultivated counties apparently has been gradual,