Vo 1 - 20, No. 3 
Page 3 
Mean Estimates , 
of Population 
S ize 
Reg ression 
MLE 
Regression 
MLE 
Before boxes 
121.8 
124.8 
75-8 
107.0 
Boxes present 
132.6 
131.6 
38.2 
96.3 
After boxes 
126.0 
116.6 
__ ll 
in f j h ^rv^f mp ! icated by the P artial failure of the tree seed crop 
in the fall of Iy73- It appeared that the squirrel population on Danville A 
le!els rea The me !' 1 P rSSent . in was increasing from pre-nest box ' 
levels. The mean population estimate was 1 38 squirrels in the fall of 1973 
but declined to 98 squirrels in the spring of 1 974 . On Danville r j,.„ „ , 
boxes were not present, the squirrel population declined even more! from 
about ,00 squirrels in the fall of , 973 to an estimated 53 in of , 974 . 
Adequate shelter is important to the well-being of the squirrel Dooulation 
henJ n i- a f eqUate f °u d Supp,y must be available each fall for squirrels^ ' 
benef.t from nest boxes. The higher recovery rate for Juvenile squirrels on 
the boxed area for the 1973-74 fa 11 - to-spr i ng period, compared wi?h Jhat on the 
that boxes can partially offset !he det^n^f £f£. 
rite of iuvlnnl! I Ure * • S6emS reasonab]e to attribute this higher survival 
rate of juveniles to an improved heat-energy budget for fox sauirrels in n P ct 
boxes compared with juveniles forced to speld the Winter in s Adi t 
!^! h dSaa ly ‘ ake P° ssessi °" of the better tree cavities elch ?.‘h a!d 
pr vent the subordinate juveniles from using them. 
— ?p0nses — f - rairl ? ^ h i cke P 5 - 12- Habitat Manipulation R. L . westemeier, 
D. R, Vance 
nralrif 6 !!- r nth ' Y " ewSletters have dealt with the problems of predation on 
,h h k and P arasitism of prairie chicken nests by P pheasants 
Within the past 4 years, these two factors have become most serious from the 
*n r° f , d r l ! n !? 9 prairie chicken numbers on the Bogota Study Aroa 
o" | C : n £; * S ! m " ar Pr° blem i Involving free-ranging 2nd feral dogT 
on several of the sanctuaries in Jasper and Marion counties, has also hean an 
period . 6 l ° SUCCe5Sful management of prairie chickens, but for a much longer 
l40-a!ro e M^™-V? 95 have l0ns P resente 8 a problem in the management of the 
of tS S Bogota. Five active farmsteads (mainly two 
“ S •****' "^Pb^farmstead^thus^the^number p? 95 ' 
rris' 
ch icken cocks oe/ 3t B ° 9 ° ta have maintained an average of 20 
- °s7*VZ \°ooZZ ZZTXlr, 
