manuscript was edited by Mr. Robert M. Zewadski, 
Survey Associate Editor. This study was partially sup- 
ported by Federal Aid Project W-66-R, the Illinois 
Department of Conservation, the U.S. Bureau of Sport 
Fisheries and Wildlife, and the Illinois Natural His- 
tory Survey, cooperating. 
STUDY AREAS 
The two areas from which soils, plant seeds, and 
pheasants were collected were the two areas—Neoga 
and Sibley—studied by Harper and Labisky (1964). 
The Sibley Area (23,200 acres), which supports thriv- 
ing populations of wild pheasants, is located on Wis- 
consinan drift (Fig. 1). In contrast, the Neoga Area 
(10,240 acres), which lies in the southern fringe of the 
contiguous range of the pheasant in Illinois, is found 
on the geologically older Illinoian drift. The low-level 
pheasant population on the Neoga Area originated 
from releases of various strains of propagated pheas- 
ants and of transplanted wild pheasants (Anderson 
1964). Both of these areas are intensively farmed; 
corn and soybeans are the major crops. 
These two areas differ markedly in geomorphology, 
age, and nature of soils. The Sibley Area lies within 
that region of rolling topography formed by the Nor- 
mal and Cropsey morainic system; about two-thirds 
of it lies on a gently undulating morainic ridge and 
the remainder on a broad, flat outwash apron. The till 
is calcareous; the Cropsey moraine, in La Salle County, 
has a mean calcium carbonate content of 23 percent 
(Jones et al. 1966:366). The soils, which reflect the 
fine-textured nature of the glacial till, are silt loams 
or silty clay loams. The major soil series found on the 
Sibley Area are Elliott and Saybrook, both classified 
as Brunizem or Prairie soils, and Drummer, classified 
as a Humic-Glei soil. Elliott and Drummer occur on 
the moraine and Saybrook on the outwash apron. All 
of these soils are near neutral in pH in their surface 
horizons and have high natural productivity; most of 
the soils are tile drained. The age of the soils of the 
Sibley Area is probably about 16,000 years. However, 
a small amount of younger loess is incorporated in the 
surface horizons (Jones & Beavers 1963:439-440). 
The Neoga Area lies immediately south of the out- 
wash apron bordering the Shelbyville moraine, the 
terminal moraine of Wisconsinan glaciation (Fig. 1). 
Topographic relief is slight at Neoga. The soils of the 
study area, being of pre-Wisconsinan origin, have had 
a longer and more complicated history of development 
than those of the Sibley Area. The till is calcareous 
only at depths greater than 3.4 meters. Two predom- 
inant soil series, Cisne and Ebert, are found at Neoga. 
Cisne, a Planosol, is characterized by a shallow clay 
layer that impedes drainage. Ebert, an intergrade soil 
having properties between a Planosol and Humic-Glei 
soil, is more poorly drained than Cisne. Both soils are 
moderately acid; the pH in the surface horizons ranges 
4 
c 
from 5.3 to 6.0 in Cisne soils and from 5.6 to 6.5 in 
Ebert soils. These soils developed in 1.2 meters of loess 
(Fehrenbacher et al. 1965:568) overlying Ilinoian til] 
that has an ancient soil or paleosol in it. This paleosol 
is quite impermeable and restricts internal drainage, 
Thus, these soils, which have low natural productivity, 
are mostly surface drained. The Neoga soils may be 
100,000 or more years old. 
TECHNIQUES 
Sample Collections 
Samples of seeds commonly consumed by pheasants 
—corn (Zea mays) and Chinese foxtail (Setaria fab- 
erii)—and soil were collected at 10 sites on both the 
Neoga and Sibley areas during October 1966. The 
sampling sites, all located in cornfields, were distrib- 
uted proportionately among the major soil series on 
each area. At each site, about 15 meters from the edge 
of the field, a sample of soil from the 0- to 18-cm layer 
was taken from within 30 cm of the base of what we 
judged to be a normal corn plant surrounded by 
clumps of foxtail. Kernels of corn were harvested 
from the corn plant and seeds were stripped from the 
associated foxtail plants to complete the sample collec- 
tion at each site. 
Samples of primary feathers were taken from 14 
pheasants collected on each area during the autumn 
of 1966. The feather samples were taken from birds 
killed by hunters, from birds killed by vehicles on 
highways, and from birds captured by nightlighting 
(Labisky 1968:6-8). The collection of pheasants from 
the Neoga Area included only birds that had been 
hatched and reared on the area. The depth of the 
bursa of Fabricius was used to separate juveniles, or 
young-of-the-year, from adults. The Neoga sample 
included 12 juvenile males and 2 adult males; the Sib- 
ley sample, 11 juvenile males, 1 adult male, and 2 
juvenile females. 
Analytical Procedures 
Soil, including grit, was air dried and ground to pass 
through a 2-mm mesh screen. A subsample was then 
taken from each sample and ground until it would 
pass through a 0.25-mm mesh screen. Calcium and 
potassium concentrations in the soils were determined 
by X-ray spectrography; the finely ground soils were 
compressed into flat discs for analysis. The concen- 
trations of calcium and of potassium were estimated 
from calibration curves that we derived for each ele- 
ment by analysis of National Bureau of Standards 
samples and by analysis of standards we prepared 
by the addition of a salt of the element to soil. Sodium 
and magnesium concentrations were determined by 
flame photometry and atomic absorption analysis, re- 
spectively, after the soil had been fused with lithium 
metaborate (Ingamells 1966:1228). A total elemental 
analysis, rather than plant-available analysis, was per- 
