Vo l. 18, No. 6 
Page 3 
The first pheasant nest on a prairie chicken sanctuary was found in 1969 , 
and since then from 4 to 10 pheasant nests have been found annually. In addition, 
nine cases of nest parasitism were discovered between 1970 and 1974. Although 
pheasant eggs have been found in only 1 to 5 percent, annually, of a total of 
380 prairie chicken nests during this 5 -year period, 3 of 16 prairie chicken 
nests (19 percent) found as of 18 June this summer contained pheasant eggs. In 
two of these three instances this summer, pheasants probably caused the failure 
of the prairie chicken nests. One nest containing six prairie chicken eggs and 
four pheasant eggs was abandoned. The other nest contained 12 intact prairie 
chicken eggs, most with dead 22 - or 23 -day embryos, and 7 pheasant eggs, 5 of 
which had hatched. According to work by Dr. H. H. Shoemaker of the University 
of Illinois, the incubation period of prairie chickens is 25 days whereas that 
of pheasants is 23 days. It remains a moot question whether a prairie chicken 
or pheasant hatched the pheasant chicks and abandoned the nearly full-term 
prairie chicken embryos. Both of the above nests were typical prairie chicken 
nests, as prairie chicken feathers were incorporated into the nest bowls. 
Pheasant broods are also commonly noted on the sanctuaries at Bogota. On 
the Yeatter and Mark sanctuaries, where pheasant broods were most commonly 
observed in 1974, the numbers of prairie chickens on booming grounds dropped 
about 50 percent between 1974 and 1975—the overall drop was 29 percent at 
Bogota. On the sanctuaries in Marion County, where pheasants are not present 
(fortunately), one flock (Kinmundy) held stable and another (Farina) increased 
40 percent between 1974 and 1975 (MWRL 18(5):2). We have no reason to believe 
that predator populations and adverse weather were dissimilar in Jasper and 
Marion counties in 1973-74. 
It is possible, but unsubstantiated, that stocking of pheasants by local 
sportsmen is supplementing natural reproduction on the Bogota area. Stocking 
of pen-reared birds would increase the potential for introducing disease to 
prairie chickens. Whether the pheasants at Bogota are the result of natural 
reproduction, stocking, or both, their presence also provides a temptation to 
hunters to trespass on sanctuaries and therefore increases the likelihood of 
shooting prairie chickens. 
The problem is thus twofold: (1) the desire of local farmers and sportsmen 
for pheasants presents a people problem, and ( 2 ) the presence of pheasants poses 
a threat, or at least an additional adverse factor, to prairie chickens and 
their ultimate preservation for the people of Illinois as a whole. 
