normal weather conditions during the hunting seasons. 

 The frequency with which soybean occurred in the crops 

 rose from 25.92 per cent during the period of little or 

 no snow to 35.59 per cent when there was 4 to slightly 

 over 7 inches of snow, while frequency of occurrence 

 of cowpea increased from 1.91 per cent to 4.66 per cent. 

 When soybean or cowpea was found in a crop collected 

 during the period of deep snow, it was often the only 

 food present. 



Field observations made during the period when 

 snow covered the ground offered a possible explanation 

 of the attending dietary changes. A nearly ideal com- 

 bination of food and cover was formed in unharvested 

 soybean and, to a lesser extent, in high soybean stubble. 

 Beneath the snow there were large quantities of soybean 

 pods and many connected pockets and openings. The 

 snowfall was deep enough to make most foods unavail- 

 able at ground level. Snow formed a fairly continuous 

 roof over the soybean fields, but it was not so heavy 





as to crush the soybean plants to the ground or to close 

 the openings necessary for ingress or egress. The same 

 situation seemed to exist in fields of cowpea. When 

 covey ranges included such fields, the birds apparently 

 utilized these fields almost exclusively. Inasmuch as 

 heavy snow is unusual in southern Illinois and soybean 

 is capable of maintaining bobwhites through winter 

 weather (Damon 1949:24), this plant might well justify 

 its use in food patches for areas devoted to bobwhite 

 management. 



The volume of corn in the diet remained fairly con- 

 stant during the period of deep snow. That of most 

 other foods declined sharply. The fact that the volume 

 decreased for acorns, white sassafras, desmodium, 

 smooth sumac, and other foods associated with heavy 

 woody cover may be significant. The birds represented 

 in this study apparently did not depend upon food as- 

 sociated with heavy woody cover during the period of 

 deep snow. 



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w 



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Fig. 7. —A sassafras fencerow adjacent to wheat stubble, an excellent combination of food and cover for bobwhites in 

 winter. Conmon ragweed, lespedeza, and wheat provide food; the stubble provides desirable roosting cover during the 

 relatively mild winters of southern Illinois. Photo from Southern Illinois University Photo Service. 



19 



