Vol. 22, No. 11 
Page 3 
Considering all study areas, the hickories, white oak, scarlet oak, and 
beech appear to be deliberately selected as leaf-nest sites by squirrels. 
From average leaf-nest densities found on our study areas, gray squirrels 
would need 1 to 2 and fox squirrels 2 to 3 grape vines per acre for leaf nest 
attachment. Leaving this number of grape vines growing does not appear to 
threaten crop tree growth even on good timber growing sites. Vines left in a 
few oaks, hickories, or beech will probably be favored by squirrels, but vines 
left in noncommercial species would also be suitable. 
The destruction of grape vines should not be a routine silvicultural 
practice, especially where wood fiber is just one of the forest Droduri-s Th^ 
emphasis should be on control, not eradication, wherever rampant growth of grape 
vines is a problem. The cost of removing vines may be justified on high quality 
hardwood sites where grape vines can severely damage young crop trees following 
clear-cutting. On lower quality sites, however, the destruction of grape vines 
is unjustifiable both economically and ecologically. 
Responses of Prairie Chickens to Habitat Manipulation R. l. Westemeier 
Prairie grasses, mostly switchgrass, indiangrass, and big bluestem, are now 
predominant species on about 186 of the 1,001 acres of prairie chicken sanctuaries 
in Jasper County. Prairie grasses are also started, though not dominant, on 29 
acres. An additional 143 acres are tentatively scheduled for establishment of 
prairie grasses because of erodable slopes, waterways, or fields that are not 
suited to periodic plowing because of size, shape, or aesthetics. Thus, the cover 
on at least 358 acres (oyer one-third of the sanctuaries) at Bogota should eventual 1 
involve prairie restoration. Redtop, timothy, brome, and legumes probably will 
continue to be the basic covers on the sanctuaries in the foreseeable future. 
. Although prairie grasses were shown to be among the poorest cover for nestinq 
prairie chickens regarding ( 1 ) density of hatched rests and ( 2 ) percentage of 
success (MWRL 21(11): 2 - 3 ), there are indications that this situation is changing. 
Despite the disappointingly low use of prairie chickens of apparently attractive 
_' t ° f r Pra 'or<S there has been d stead Y increase in nest success in these 
7 ^n 25 % ,! n u 197 ? t0 75% in 1579 ^ 1978 when success dropped to 
5i/o) \ In 1979, all hatched nests ( 3 ) among 8 nests found on the Yeatter Sanctuary 
were in fields dominated by prairie grass. On all the sanctuaries in l 979 , prairie 
grass predominated around the bowl of each of the 5 nests found in fields of 
prairie grass. From I 9 S 6 to 1 973, prairie grass predominated around the nest 
bowls of only 64% of the nests found in fields of prairie grass. 
The improving use of and increasing success in prairie grass by chickens may 
be due to gradual improvement in the quality of our prairie grass stands: type of 
management appears to be a key factor. Nest densities and nest success were corn- 
weed' cant &S °J, Pr V rle mana 3 emsnt: ( 1 ) no disturbance, ( 2 ) mowing for 
w d control (mw), seed (ms), or nesting enhancement (mn), ( 3 ) haying, and ( 4 ) 
fresh burn. Although data for all categories are still limited, Results foi the 
mowing category (mw, ms, and mn) compared favorably with redtop, timothy, and 
