MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
NATURAL HISTORY SURVEY 
Glen C. Sanderson and Helen C. Schultz, Editors 
NOV 4 1969 
Urbana, Illinois 
October, 1969 
Vo I. 12 
, mo 
1. Pheasant Populations and Land Use S. L. Etter, 
R. E. Greenberg 
Incidental to the standardized counts of pheasant broods, made on the 
Sibley Study Area in July and August each year, the numbers of rabbits observed 
were also recorded. The numbers of rabbits observed along 640 miles of roadside 
transect (two 40-mile routes were driven weekly) were high in 1962 and 1963 
(193 and 179, respectively), decreased drastically in 1964 and 1965 (103 and 33, 
respectively), and remained low during 1966, 1967, 1968, and 1969 (52, 45, 51, 
and 53, respectively). Thus, the trend in rabbit numbers on the Sibley Study 
Area has closely paralleled that of pheasant numbers. 
These data indicate that the reduction in acreages of forage crops (hay and 
small grains) and the removal of fencerows and other brushy areas during the 
past 8 years have resulted in a reduced carrying capacity for rabbits as well as 
pheasants. Although data on the abundance of other resident birds and mammals 
have not been collected, it appears probable that the changes in agricultural 
practices, 1962-69, have drastically reduced the ability of the Sibley Study Area 
to support resident wildlife. 
2. Manipulation of Pheasant Habitat G. B. Joselyn 
It is desirable to compare pheasant nest establishment and success on 
seeded roadside plots with that occurring on "typical" unseeded roadsides on the 
study area. Because most farm operators usually mow roadsides several times 
each summer, managed control roadside plots (which remain unmowed until late 
summer) are not representative of other roadsides on the study area. Therefore, 
additional roadside segments on the study area were picked at random and 
searched for pheasant nests each summer from 1963 through 1969* 
For the 7 years, pheasant nest density on seeded plots (2.6 nests per acre) 
was somewhat more than double the density of nests on all (mowed and unmowed) 
unmanaged control plots (1.2 nests per acre); seeded plots had between 1.0 and 
2.1 more nests per acre during each of the 7 years. Nest density on seeded 
plots was more than triple that on unmanaged plots which were mowed (0.8 nest 
per acre), but only about one-fourth higher than the density on unmanaged control 
roadsides which were unmowed (2.0 nests per acre). 
3 • Factors Influencinq Distribution and Abundance of Pheasants W. L. Anderson, 
D. R. Vance 
It is well known that hen pheasants selectively consume limestone (calcium 
carbonate) grit during the laying period. Thus, determining the mineral makeup 
