Nature Bulletin No. 99   January 18, 1947
Forest Preserve District of Cook County
William N. Erickson, President
Roberts Mann, Superintendent of Conservation

****:THE PRAIRIE CHICKEN

In late January the prairie chicken cocks begin to "boom". Feeble and 
infrequent at first, booming increases as winter merges into spring and 
continues until June. The cocks gather in groups, regularly, before 
sunrise and again at sunset, on open ridges or slight rises in the prairie. 
Year after year they come to the same locations where each male 
establishes a "territory" which he defends fiercely. Fights are frequent.

As a prelude to booming, the cock runs forward a short distance, stops, 
stamps his feet rapidly and pivots in a half or full circle. As he dances, 
the two brilliant orange air sacs -- one on each side of his neck -- are 
inflated, his long horn-like neck feathers are erected, the fleshy orange 
eyebrows are also inflated and his tail spread fanwise, snaps with a loud 
click. Then comes the boom.

The sound is like that made by blowing across the mouth of a large 
bottle and consists of three notes, evenly spaced, rising at intervals of a 
quarter or a half tone and lasting about 3 seconds. They seem to say 
"oo-loo-woo" or " Old-Mul-doon". Amplified by the resonant inflated 
air sacs, they can be heard a mile away. When several cocks are 
booming at once the calls blend into a continuous humming sound.

In pioneer times there were vast numbers of prairie chickens in Illinois 
and the other prairie states. They were slaughtered by the thousands for 
city markets. The invention of the steel plow destroyed most of their 
favorite food and cover. In 1933 it became unlawful to kill them but 
today there are probably less than 30,000 left in Illinois, confined 
largely to 50 square miles of sand prairie along Green River in the 
northwestern part of the state and to 2600 square miles of gray-soil 
prairie in the southeastern portion where 85% of the world's crop of red 
top grass seed is produced. We saw only three in the Chicago region 
last summer.

The cardinal is the state bird of Illinois, as it is in three other states. The 
prairie chicken should be the official bird of this, the Prairie State. 
Maybe, then, we would save it from the fate of the passenger pigeon.