6 THHCE =A UDSULBHOIN #78 Us ae aia 
Quail nest destroyed by burning of roadside in July. Champaign County. Photograph 
by R. E. Hesselschwerdt. 
intensive and cover at a premium, or where agricultural lands revert 
to nature.’ 
As the result of careful field studies certain factors affecting quail 
populations can be evaluated. Others are still obscure. Hunting may 
be an important check on increase locally, yet in favorable environ- 
ment quails show a surprising ability to recover from losses in the 
face of considerable hunting pressure. Where the environment is 
unfavorable they will not be found even on game sanctuaries. Like- 
wise in favorable habitats they are normally able to maintain their 
numbers in spite of the presence of hawks, owls and other natural 
enemies, as shown by Errington. When birds are too numerous for 
the supply of winter food and cover the population can be expected to 
decline because of starvation, enemies, or migration. 
As is true for many forms of wildlife, quails frequently vary in 
abundance from year to year. One important cause for this in the 
northern states is winter-killing. The accompanying table shows the 
September population of quails on a 2,560-acre study area maintained 
by the State Natural History Survey on prairie chicken and quail 
range in Jasper County. In explanation of the wide variation in 
numbers it may be pointed out that the killing winter of 1935 and 
1936 followed a favorable nesting season when a good quail crop was 
"The Bobwhite Quail, Its Habits, Preservation and Increase, by H. L. Stoddard. Chas. 
Scribner’s Sons. New York. 1932. 
