Vol. 25, No. 8 
Page 3 
densities of hatched quail nests were found in the unburned and post-burn II 
categories that were either undisturbed or high mowed the year prior to nesting. 
For pheasants, our data were far too limited to make even a judgment about prairie 
management and nest success. 
Nest success by the 3 Gall?formes was also considered in relation to the 
degree of nest concealment by prairie grasses. These data were mostly for nests 
in fields dominated by prairie grass, but the data also included nests in fields 
not dominated by prairie grass but which had prairie grass at the nest sites. 
For prairie chickens (sample of 90 nests), nest success decreased significantly 
(P_ < 0.05) as the quantity of prairie grasses concealing the nests increased; 
success ranged from 68.3% with vegetation other than prairie grass to only 14.3% 
when nests were fully concealed by prairie grasses. For pheasants (sample of 13 
nests), nest success ranged from 33.3% with vegetation other than prairie grass 
to 50.0% when nests were fully concealed by prairie grass. These data suggest 
that the amount of prairie grass at nest sites influenced the probability of 
hatching differently for pheasants than it had for prairie chickens. For 38 
bobwhite nests, hatch success was relatively high regardless of the quantity of 
prairie grass at the nest site but phenomenally high, 85.7%, for 14 nests that 
had no prairie grass at the nest sites. Here again, perhaps the association of 
nests with clumps of prairie grasses reduced the probability of hatching. The 
data for pheasants and quail, however, were not statistically significant (P_ > 0.05). 
Predators evidently key on vegetative clumps in April and May in their 
search for avian prey--often the eggs and young of redwings and dickcissels. 
These birds typically nest in such clumps, particularly in post burns II, III, 
and IV. Thus, nests of prairie chickens, and perhaps bobwhites, that are found 
in vegetative clumps have a higher risk of predation. Rotary mowing or combining 
imparts a more uniform structure to stands of prairie grass, which in some manner 
enhances nest densities and success for prairie chickens. Predators apparently 
have more difficulty finding chicken nests in relatively uniform mowed stands 
than in undisturbed or hayed stands, particularly by the 5th or later nest season 
after burning when redwing nesting is minimal. Redwings and dickcissels are 
probably the primary attractants of predators to post burns ll-IV. 
Ecology and Management of White-tailed Deer--W-87-R C.M. Nixon, L.P. Hansen, 
J.E. Chelsvig, P.A. Brewer 
The last 2 reports (MWRL 25(6):3; 25(7):4) have dealt with the dispersal of 
adult bucks and orphan and non-orphan fawns. This report focuses on adult and 
yearling females. 
The primary time of dispersal for female deer (as for male) is spring-- 
mostly during April and May. The does are subject to the same environmental 
conditions as other deer but they are also subject to the effects of pregnancy. 
Production of placental hormones changes as the fetus(es) develops. Researchers 
?n ilew York found that plasma estrogen levels remained constant from January 
through March but increased substantially during April and again during May. 
These increases coincide with dispersal times for deer in east-central Illinois. 
It Is believed that the increase in estrogen during the final 2 months of 
gestation may be partly responsible for triggering spring dispersals. 
