Vol. 7, No. 11 
Page 4 
Table 3- Distribution of dates of quail hatching on the Forbes, Alma, and Dale 
areas in 1964. 
Dates of 
Hatching 
Percent of Broods 
Hatched by End of 
Period (Cumulative) 
According to 
Estimated Ages 
of 24 Broods 
According to Primary 
Wing Molt of 81 
Night1ighted Qua i 1 
25 
May 16 - 30 
June 15-29 
50 
May 31 - June 14 
June 30 - July 14 
75 
June 30 - July 14 
July 15 - 29 
100 
August 30 - September 14 
August 15 - 29 
5. Responses of Prairie Chickens to Habitat Manipulation R. J. Ellis 
The need which prairie chickens have for grassland, particularly undisturbed 
grassland, was demonstrated in I 963 when 850.7 acres of potential nesting cover 
on the Bogota Study Area were searched. Nine of the 11 prairie chicken nests 
found were in 134.5 acres of idle grassland (Ellis 1964: Table 5)- In May, 1964, 
it was pointed out that the federal conservation reserve contracts were expiring 
rapidly and that the fields concerned were being put back into agricultural 
production (Monthly Wildlife Research Letter, May, 1964). In recent years these 
fields provided the largest part of the undisturbed grassland available for 
prairie chicken nesting. 
To detect changes in land use in the prairie chicken range of Illinois, 
particularly the reduction of grasslands, cover on the areas where prairie chickens 
are censused annually (Monthly Wildlife Research Letter, April, 1964) was mapped 
in the spring of 1964 and again in late summer, 1964. The spring mapping revealed 
the cover present during the summer of 1963; the summer mapping revealed the cover 
present during the summer of 1964 (Table 4). 
The changes in land use from 1963 to 1964 were detrimental to prairie chicken 
welfare. All cover types which prairie chickens might utilize for nesting were 
reduced; grain crops were increased. 
