^j|^v"-^| 





Fig. 6. — Harvested cornfield adjacent to brushy area and fencerow, an ideal combination of food and cover. However, a 

 mechanically harvested field gives the bobwhite little concealing cover. Photo from Southern Illinois University Photo 

 Service. 



well as seasonal weather conditions. Along with the 

 broad effects of weather, a specific condition — such 

 as an ice or a snow storm — may cause the most striking 

 variations in the bobwhite diet. Even a thin covering 

 of ice can make most foods inaccessible to the bobwhite; 

 snow can have the same effect. 



For the study area, mean annual temperatures for 

 both years were nearly normal — 56.15 degrees F. in 

 1950 and 56.18 degrees F. in 1951- Precipitation was 

 heavy in both years; it totaled 67.99 inches in 1950 

 and 54.05 inches in 1951 in contrast to the established 

 annual average of 43.53 inches. The established aver- 

 age precipitation during the growing season (March 

 through October) is 30.06 inches. Precipitation during 

 the growing season in 1950 amounted to 38.94 inches. 

 It was more nearly normal (31.25 inches) in 1951- The 

 above figures were interpreted from climatological data 

 reported by weather stations within the 34 counties 

 represented in this study (U.S. Department of Commerce 

 1951, 1952). 



Measurable quantities of snow covered the ground 

 for two periods during the 1950 hunting season. During 

 the first snow, which lasted from November 22 to 29) 

 the depth did not exceed 1.3 inches. However, from 

 December 6 to 11, 4 to slightly more than 7 inches of 

 snow covered the ground throughout most of southern 

 Illinois. No snow fell during the 1951 hunting season, 

 but near-record snowfalls were recorded immediately 

 before and after the hunting season. 



Definite changes in food habits were apparent during 

 the time when deep snow covered the ground, table 4. 

 There was a substantial increase in the amount of soy- 

 bean in the diet. Cowpea and purple meadow rue, the 

 latter normally occurring in the crops in insignificant 

 quantities, were the only other foods which increased 

 considerably. Soybean and co^^-pea formed 57.45 per cent 

 and 2.77 per cent respectively of the total crop con- 

 tents during the period of deep snow. In contrast, these 

 foods accounted for 18.79 per cent and 1.21 per cent 

 respectively of the volume taken by the bobwhites under 



18 



