ree Ug De Oo Nioy Ob elt oN 15 
Nests of dead grass, stems and leaves are constructed starting in mid- 
April, and a hen will begin to incubate her clutch of 10 to 12 eggs in late 
April or early May. The incubating period, about 23 days, is about the 
same as for quail or pheasants, and prairie chickens are not as capable of 
compensating for destroyed nests by repeated re-nesting. 
A high mortality results when the meadows are plowed or moved 
before July. The lack of good, undisturbed nesting and brooding cover is 
the chief reason that prairie chicken populations disappeared at a rate that 
approached extinction a decade ago. 
Sometimes the main reason for a species decline is so obvious that it 
is not readily apparent, or is unappreciated by most people—and this was 
true regarding the prairie chicken. Historically, action generated by concern 
over decreasing populations has been directed toward control of hunting, 
while the plow and the mowing machine-—not the shotgun—were the pri- 
mary causes for the bird’s decline. 
OPPORTUNITIES FOR PREDATOR-PREY relationship studies have been 
excellent on the Jasper County sanctuaries, and they have proven biologic 
conclusions that predators will not tend to eliminate a species, or even take 
healthy birds. Westemeier says the prairie chickens undergo daily threats 
or attacks from hawks, cock pheasants and coyotes, but that he has never 
seen a successful predation by these animals. 
One recent observer reported three attacks by marsh hawks in one 
morning’s two-hour booming ground period—one of the attacks lasted 11 
minutes, during which time all chickens on the booming ground flushed 
except four or five of the central cocks, which stood their ground as the 
hawk swooped low and made diving attacks at first one, then another. The 
count on the booming ground at the time was 39 birds—27 cocks and 12 hens. 
The hawk attack is characteristic—a folded-wing dive and strike at the 
cock, which, in anticipation, is standing with head held high and ducks the 
strike, retaliating instantly with a counter-strike as the hawk flies off out 
of reach. One such attempt at each cock, and the hawk relents. 
This particular hawk folded its wings and sat down in the middle of 
the booming ground. The flushed cocks and hens returned instantly, and 
the booming activities resumed, with the hawk observing from a central 
location. The chickens paid him no heed—he represented no threat on the 
ground. The predator observed the booming ritual for six or seven 
minutes, then arose and swooped low once over the ground before flying 
away into the distance, creating hardly a stir among the prey flock. 
The biologic conclusion is that he had observed no ill, injured or weak 
of the prey species; hence, gave up and retired from the field. 
AS THE DEPARTMENT OF CONSERVATION assumes managerial super- 
vision of the prairie chicken sanctuaries in its Nature Preserve system, 
efforts will be made not only to perpetuate and increase the flocks now 
established but to re-introduce the species to other areas of the state where 
sufficient grassland may exist in a preserved status. 
Extermination of a species is a high price to pay for progress, and IIli- 
nois citizens do not have to pay it—thanks to the efforts of the Prairie 
Chicken Foundation, the Prairie Grouse Committee, the Natural History 
Survey and the Department of Conservation. It has been a volunteer effort, 
now backed by state recognition and a state preserve system. 
—John G. Warren 
