Vol. 22, No. 2 
Page 2 
More leaf nests were found during fall (X = 319) than during spring (X = 176). 
However, a greater proportion of the spring leaf nests (61 percent) than fall 
leaf nests (46 percent) were considered usable. Apparently individual fox squirrels 
maintain fewer nests throughout the winter than they build during summer and fall. 
It is possible that fox squirrels may not build leaf r ists if abundant 
shelter is available. Because additional shelter in the form of nest boxes was 
present on part of the study area, we could compare the density of leaf nests on 
sites with and without nest boxes. T-tests revealed no significant differences 
between the density of leaf nests on the sites with and without nest boxes. 
Either nest boxes are less suitable than leaf nests as shelter for fox squirrels, 
sheUer SqU iL r ^ S V" lnnate u te " denCy t0 bu '' 1 d "ests regardless of other 
shelter. Based on other research work, we believe the latter to be true. 
kes) 
^ ons ? 5 - el £ rairie . Chians to Habitat Manipulation R. L . Westemeier, 
D. R. Vance 
Hnn.i^ reV f° US r e e orta .°' 1 the relationship between vegetative structure and nest 
dens t y t f ra ! J* ,e chtckens (MWRL 21 (2) :3 and MWRL 2I(9):3) indicated that nest 
However 9 ?h T"*?*" a s height and density of the vegetation increase. 
However, this direct relationship apparently does not apply to nest success. 
The technique used to describe vegetation structure (height and density) 
involves taking point samples at random locations with a small diameter rod 
graduated ,n centimeters. The rod is placed vertically in the normally spreading 
H ®'f tS are rec °rded for each point where vegetation touches (strike 
the rod at each location sampled. Sampled fields were divided into three 
categories: fields without nests, fields with 50 percent or more of nests 
successful, and fields with less than 50 percent of nests successful. Mean 
maximum height (MMH), mean height at all strikes (MH), and mean height at which 
strikes occur within each consecutive centimeter of height (MHCS) showed a 
consistent relationship to nest success (Table 1). | n nearly every case, fields 
success ha e d the^ n* with less than 5 0 percent nest 
success haH ^ J i* fetation, and fields with greater than 50 percent nest 
Jl d ve 9f t3t ' on of 1 ntermediate height. The only exceptions occurred in 
IQ 77 " 7 p^ m Sp ® cu,3 ^ d ,n MWRL 2 , (9):3 that the heavy snow cover in the winter of 
1977-78 may have flattened the preferred grass cover (the higher cover) thus 
reducing its height and increasing its density at lower heights. Fields with 
ZnJV nest . su ^ cess had the ^west MMH and MH values in 1978 and the highest 
dens.ty in the lowest height class (77-8 percent versus 67-7 percent for fields 
with no nests and 71.2 percent for fields with less than 50 percent nest success) 
confirming our speculations. H success;. 
These findings indicate that "predator-resistant" nest cover (MWRL 19(10)*3) 
shnri- m 6X1 St and that lt ' S a " ha PPy me d'um" between cover that is too 
it ^trart^J 0 3 t y act nestln 9 hens and cover that is so tall and thick that 
e tS P redat °rs or makes prairie chicken nests more susceptible to 
° Fut " re re P° rts ^11 elaborate on the relationship between vegetation 
the "best" nest SUCC6SS methods We m3y USe tD estab,lsh and maintain 
