Vol. 2h, No. n 
Page 2 
Ecology and Management of Squirrcl s - W-66-R 
C. M. Mixon, 
L. P. Hansen 
. ^ ec °very rates for ear-tagged fox squirrels, especially for young squirrels 
varied considerably among seasons at the Vermilion River Observatory near “ ’ 
Danville (fil/RL 2*(10):2). Fox squirrels feed extensively on tree seeds 
especially those of oaks and hickories, and the production of these seeds may 
vary tremendous 1yfrom year to year. Several researchers have suggested that 
this variability in mast production may influence survival rates of squirrels 
particularly during the fall. Correlations between the recovery rates of the’ 
different age classes of squirrels and white oak, black oak, hickorj and total 
mast production revealed only 2 significant relationships (P < 0.05). Survival 
o yearlings was positively related to hickory production and negatively related 
in C nnIut° ak - Pr °- UCt , IOn '- lack ° f other si 9 nif 'cant re 1 ationshios and the 
^‘Stencies m the significant values (positive and negative) suggest that 
chance and not biological significance may have caused the significant results. 
In fact , , significant relationships at the 5% level might be expected by chance 
alone given the large number of correlations performed. 
ahll faM 1 ure *? demonstrate any consistent relationship between mast 
a undance and survival may have been due in part to a lack of sufficient sample 
sizes but was probably due to the absence of a complete mast failure during the 
_ year study. At least 1 species of oak or hickory always produced seed, ^ox 
quirrels are opportunistic feeders, when preferred foods fail, they eat the 
most available food, including agricultural crops. Apparently, there were no 
extreme food shortages during the period of the study, and therefore recovery 
"••I-" " 0t * ffe fed by mast production. In next month's newsletter we 
look at other factors which might affect survival in fox squirrels. 
fe?P. onses oj £r«>irie Chickens to Habitat Manipulation - V/-66-R 
R.l. l/estemeier, 
J.E. Buhnerkempe 
Hest success for prairie chickens on the Bogota Study Area was above 
h!trh 9 H ’ Seven y en <«) of the 25 prairie chicken nests of known fate 
J e f , y contrast, for at Bogota, nest success averaged for C6" 
nests of known fate, though these differences were oniy significant at the olo 
_ however, there are alarming trends, such as increases in (I) parasitism of 
Si ::: e , Ch,C en n0 j t ?M V P heasan «> (2) unsuccessful parasitized nests ( 3 ) 
deserted nests, and (a) embryonic mortality (IWRL 2<*(10) :Z-h ). All of these 
adverse trends appear related to abundance of pheasants at Bogota. 
a „, *'*?• th ^ e is ' nounti ?9 evidence that both breeding efforts (tliBL 7 h( 7 )-a.,\ 
and nest(ng efforts by prairie chickens at Bogota are becominn increasinnlv ' 
concenti-atcd Since 1970, the central sanctuaries (Yeatter-Field-McGraw 
onnelley) at Fogota have shown an increase in the percentage of total prairie 
chicken nests found during annual nest searches. The central units accounted 
