Vol. It, No. It 
Page 3 
* 
Ducks were over twice as abundant in the Mississippi River valley as in the 
Illinois River valley during this period. Surprising numbers of ducks were found 
concentrated on a few temporary ponds and a few permanent marshes in the lower 
Rock River valley. The density of ducks was greater there than in the Mississippi 
River valley. 
During April, peak numbers of green and blue-winged teals, widgeon, gadwall, 
shoveler, lesser scaup, and coot occurred. By the'last census on April 26, the 
population of all species but the blue-winged teal, lesser scaup, and coot had 
declined to a few thousand. Although 13,000 lesser scaups and 10,000 coots Were 
still present near the end of April, they had declined markedly from the 380,000 
scaups and the 30,000 coots present at the peak of the spring migration. 
W-56-R-5 R. Jo Ellis, T. U, Meyers 
Raccoons and opossums were removed from the Allerton Park study area during 
the periods of September 1 to October 31* I960 and February 20 to March 31* 196l. 
Raccoon hunters and mink trappers supplemented this effort by removing 6 raccoons 
from the area during the hunting and trapping seasons. A total of 2? raccoons 
and 67 opossbms were removed from the area by all means between September 1, I960 
and March 31* 1961. Between February 20 and March 31* 196l, 2,962 trap nights 
were employed. Yet only 7 raccoons and 11 opossums x-rere caught. These results 
and a paucity of fresh signs indicated that the raccoon and opossum populations 
on the area were quite low by the end of March. 
Following the period of population reduction, an attempt was begun to 
determine the resulting effects on raccoon and opossum movements and population 
recovery. Sixty live traps were set on the study area on April 6. By April 22 
only 1 raccoon and 3 opossums had been caught. The raccoon escaped and no 
information was obtained. The opossums were all females carrying 6 to 12, or 
an average of 10, young each. This is nearly 2 more per litter than the average 
for the preceding U years. If the sample were larger, the increased litter size 
could be interpreted appropriately to indicate an anticipated response to the low 
population level. 
W-61-R-U J. Ellis, J. Harper, W. Anderson 
Three-hxxndred "California" pheasants (ail juvenile hens) and 300 x^rild-trapped 
pheasants (50 cocks, 9.0 young per adult: 250 hens, 1.72 young per adult) were re¬ 
leased on the Neoga area during the past winter. As of April 27, 21.5 per cent of 
these released pheasants have been found dead. Wild-transplanted pheasants 
comprised 5l per cent of these mortalities. Age ratios among the wild-transplanted 
pheasants that have died Was 10 juveniles per adult for cocks and 1.08 juveniles 
per adxilt for hens. Thus, the wild-transplanted adult hens have died at a more 
