THE AUDUBON BULLETIN 
Published Quarterly by the 
ILLINOIS AUDUBON SOCIETY 
Field Museum of Natural History, Chicago, Ill. 60605 
lumber 155 September 1970 
SOME OBSERVATIONS CONCERNING 
AVIAN HABITAT PREFERENCES 
by S. T. Dillon, Staff Biologist 
MAX McGRAW WILDLIFE FOUNDATION 
i a recently published paper (Dillon, 1968), bird species and numbers 
roken into monthly percentages—plus the first and last date seen—were 
immarized for “nearly 2,000 acres” comprising the Max McGraw Wildlife 
oundation in northeastern Illinois, near Dundee. Acreage measurements 
iggest that the actual unit censused approached 1,360 acres rather 
1an 2,000. 
Major vegetational types were generalized in the 1968 report, but 
abitat preferences of each species were not presented. The present paper 
rovides a numerical relationship between the majority of avian species 
sen, and the habitat or habitats used by each species (Table 1), as well as 
more detailed discussion concerning the environment of the three 
larkedly varied census units. 
RIVER BOTTOMLANDS—tThe Foundation owns about 80 acres abut- 
ng the east side of the Fox River (Fig. 1-A). A soils and capability map 
rovided by the U.S. Soil Conservation Service shows eight soil types 
presented here, ranging from a muck to a silt and clay loam with a high 
me substrate. In general these soils have a high water content, are usually 
und on level to depressed areas, and are adequately suited for cropland, 
asture, woodland and wildlife. 
The elevation of the Fox River bottomland property ranges from 710 
) 730 feet above mean sea level. 
The flora is typical of wetland sites in this latitude and longitude. The 
inopy is lacking or is quite open over most of the 80 acres, but it thickens 
nd matures appreciably on more moist soils abutting the river. The species 
-e dominantly eastern cottonwood, box elder and sandbar willow. There 
-e shrubby tangles of tartarian honeysuckle and red-osier dogwood, with 
ore open-grown hawthorne spp. and smooth sumac. 
Upland herbaceous plants consist of sod-forming bluegrass, and wheat- 
rass spp.; the marshy herbs comprise dense, but limited, stands of spike- 
ish spp., broad and narrow-leaved cattail, and various sedges. 
Eight to ten acres normally are cultivated and planted to upland game- 
ird food and cover strips. Seeds used to plant this, and other cultivated 
nits on the McGraw property, consist of two species of sorghum (combine 
