Mrs. Doris Dodds 
Librarian 
MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
Glen C. Sanderson, Editor 
NATURAL HISTORY SURVEY 
APR 3 1970 
Urbana, Illinois 
March, 1970 
? IL'*-' '* \ V 
Vol. 13, No. 3 
1. Pheasant Populations and Land Use 
S. L. Etter, 
R. E. Greenberg 
Anderson and Vance (MWRL 12(8):1-2) presented criteria for identifying 
Illinois pheasants as juveniles or adults by measuring the shaft diameter and - 
total length of the proximal (innermost) primary feather. Because their 
sample sizes were small (68 hens and 34 cocks) we felt it would be worthwhile 
to investigate more fully the use of proximal primaries as age criteria for 
east-central Illinois pheasants. 
We found that Illinois pheasants can be separated into adult and juvenile 
age-classes from the shaft diameter alone of the proximal primaries. Adults 
have larger proximal primaries than juveniles. A sample of 162 cocks 
collected during October and November, 1969> separated at 3-24 mm (0.1275 inch) 
with 96.3 percent accuracy, while a sample of 16 cocks collected during 
February, 1970, separated with 100 percent accuracy. Adult cocks have large 
proximal primaries with shaft diameters greater than those of all but the 
largest primaries of juvenile cocks. 
A sample of 107 hens captured during January and February, 1970, separated 
at 2.86 mm (0.1125 inch) with 95*3 percent accuracy. Accuracy for hens was 
much lower (84.1 percent) when the same criterion was applied to a sample of 
201 hens captured during October and November, 1969» due to the presence of 
late-hatched (July-August) juvenile hens which have larger proximal primaries 
than early-hatched juvenile hens. Since late-hatched juveniles survive from 
October to January less well than do older juveniles, separation improves 
greatly in January. Accuracy for aging hens can be improved in October- 
November by taking into account total length as well as shaft diameter. 
With shaft diameter plotted against shaft length, 92.5 percent accuracy was 
obtained when a separation line was drawn between point A (length 165 mm, 
diameter 2.79 mm or 0.110 inch) and point B (length 140 mm, diameter 3«05 mm 
or 0.120 inch). 
2. Manipulation of Pheasant Habitat 6. B. Joselyn 
During a recent meeting with personnel from the Division of Highways it 
was decided that the 2.25 miles of unseeded ("typical roadsides") (MWRL 12(12): 
l) along Highway 47 north of Strawn would be dropped from the study currently 
underway. 
It is the feeling of the Division of Highways that there is little to be 
gained by continuing this portion of the investigation because herbicides have 
