Vo 1. 14, No. 2 
Page 3 
population on Forbes in 1971 was lower than the long-term mean estimate 
of the posthunt population (7-6 quail per 100 acres), and also repre¬ 
sented a decline of 74 percent from the prehunt population level in 1970. 
On Dale, the posthunt estimate for 1971 was slightly higher than the 
long-term mean estimate (11.4 quail per 100 acres) for this period. The 
posthunt estimate in 1971 represented a decline of 61 percent from the 
prehunt population of 1970. However, the posthunt population on Dale in 
1971 was 60 percent greater than the posthunt population on that area in 
1970. 
5. Responses of Prairie Chickens to Habitat Manipulation R. L. Westemeier 
Each year since 1963 , the acreages of potential nesting cover for 
prairie chickens have been recorded on the 16-square-mile Bogota Study 
Area. The total acreage declined from 837 acres in I 963 to a low of 376 
acres in I 966 . In 1 96 3^ sanctuary grassland amounted to only 5 percent 
of the total; undisturbed fields of legumes (leased by the Illinois 
Department of Conservation) comprised 221 acres or 26 percent of the 
total, and grassland on private farmland comprised the remaining 561 
acres or 69 percent. Since 1966 the total acreage of potential nesting 
cover has steadily increased to 770 acres in 1970, 71 percent of which 
was due to the establishment of nesting sanctuaries. 
When the numbers of prairie chicken cocks censused on booming 
grounds each spring were tested for correlation with the total acreages 
of grass and leguminous cover available for nesting each preceding 
spring, a nonsignificant correlation was revealed (r = 0 . 636 ). However, 
when only undisturbed fields of grass, grass seed meadows, grass hay 
meadows, or lightly grazed grass pastures were analyzed with respect to 
the numbers of prairie chicken cocks, a significant correlation did 
result (_r ~ 0.758, _P <C0.05)» It is probable that an even better 
correlation would result if only good nesting cover were measured. Use 
by prairie chickens of otherwise attractive cover is often precluded by 
such factors as poor drainage, close proximity to woodland, low fertility, 
or excessive grazing. 
In 1963 ^ the 837 acres of available nesting cover produced a 
population containing 65 cocks the following spring. By contrast, in 
1970 the 770 acres of available nesting cover appear to have supported 
a population that will contain at least 150 cocks (preliminary estimate 
based on winter counts) in the spring of 1971* It is becoming clear 
that the present sanctuary grasslands are capable of producing a much 
higher population level than those that occurred on a similar acreage 
of private farmland. 
6. Rabhit Management G. B. Rose 
Of 1,469 rabbits captured on the 100-acre 4-H Area at Robert 
Alle:-ton Park from i 960 through 1970, 122 were recaptured the first 
year after initial capture, 28 a second year after initial capture, 6 
