MONTHLY WILDLIFE RESEARCH LETTER 
-2- 
Vol. 3, No. 7 
G. Sanderson, U. Meyers 
W-56-R-4 
Live-trapping, marking, and releasing for study of raccoon and opossum 
populations was conducted on the Allerton Park Study Area from April 8 through 
August 20. Eighteen adult raccoons, and 50 adult and 32 young-of-the-year 
opossums were caught in 3,995 trap nights. It is notable that no young-of-the- 
year raccoons were caught although at least a few were present on the area as 
could be seen by their tracts. During a similar period in 1959, 52 adult and 
101 young-of-the-year raccoons, and 123 adult and 62 young-of-the-year cpcssums 
were caught. 
Although the number of trap nights required to catch one animal is 
only a crude indication of abundance, the differences in the results for the 
past two seasons indicate that populations of both raccoons and opossums are 
lower on the study area than they were one year ago. This area does not have 
much food available for raccoons and opossums in late winter, especially during 
deep snows such as the unusually deep ones of early I960, and this may have 
affected survival. 
The snow and weather also may have affected the reproductive ability of 
the raccoons as is shown by the reduced number of young on the area this year. 
This could have happened if the deep snows limited breeding activities. Female 
raccoons appear to have a rather long period of estrus, but once they pass this 
period they become pseudopregnant and do not have another estrous cycle until 
the following year. 
An attempt was made to live-trap and mark raccoons on the raccoon and 
wood duck study areas along the Illinois River near Havana. Trapping was 
discontinued after 1,330 trap nights produced only seven raccoons. This rate 
of 190 trap nights per raccoon is similar to the 222 trap nights per raccoon 
required for the Allerton Park Study area this year. General observations of 
raccoons, tracks of both young and adults along streams, litters of young 
obtained after complaints by property owners, raccoon depredations on wood duck 
nests, and the number of litters found in cavities while checking for wood duck 
nests do not indicate that the raccoon population in these study areas is as 
low as live-trapping results indicate. It is possible that factors such as 
food or weather conditions which are not apparent at this time are influencing 
the success of the live-trapping of raccoons and opossums here. 
W-61-R-4 J. A. Ellis, W. Anderson 
Seventy-seven individual pheasant broods have been located on the Neoga 
area during this I960 breeding season. A complete count of chicks for 57 broods 
showed an average brood size of 8.5 chicks at an average age of 5.0 weeks. 
In August, 54 adult pheasants (23 cocks and 31 hens) were observed. 
Eight (15 per cent) were from game farm stock; 45 (83 per cent) were trans¬ 
planted wild pheasants; and the origin of one pheasant was not determined. 
