crop, as was frequently the case with acorns, the total 

 volume of complete and fragmentary units was measured 

 by displacement. 



For each food, one or more whole or partial units of 

 that food in a crop constituted an "occurrence." Fre- 

 quency of occurrence for any food was expressed as 

 percentage and was derived by dividing the number of 

 crops in which the food was found by the total number 

 of crops examined (including those that contained no 



in 1951; 60.4 per cent of the hunters contacted contrib- 

 uted crops in 1950 and 59.6 per cent in 1951- The aver- 

 age number of crops per contributor was 26.4 in 1950 

 and 23.8 in 1951- Contributions by individual hunters 

 for a single season ranged from 2 to 179 crops. Crops 

 were collected in each of the 34 counties involved in 

 this study. 



The date of kill was available for 3,925 of the 4,606 

 bobwhites collected, fig. 2. Each year a greater kill 



450 



400H 

 o 



lU 



d 350H 



lij 



300 



X 



§ 250H 



CO 



o 200H 

 S I50H 



100- 



50- 



13 15 17 19 21 



NOVEMBER 



23 25 27 



29 



5 7 9 



DECE MBE R 



Fig. 2. —The number of bobwhites killed on each day of the hunting seasons of 1950 and 1951 combined. The date of kill 

 was known for 3,925 of the 4,606 bobwhites represented in this study. 



food). The percentage of the total crop contents con- 

 stituted by any food was determined by dividing the 

 total volume of the food by the total volume of the con- 

 tents of all crops. In order to facilitate analysis of the 

 data, they were placed on approximately 20,000 Inter- 

 national Business Machine cards. 



RESULTS OF INVESTIGATION 



Contents of the crops of 4,606 bobwhites were ana- 

 lyzed; of these, 2,534 were collected in 1950 and 2,072 

 in 1951 during the Illinois hunting season, which ex- 

 tended from noon of November 11 through December 11, 

 table 1. Food was found in 4,171 of the crops, 2,326 in 

 1950 and 1,845 in 1951. 



Ninety-six hunters contributed crops in 1950 and 8" 



was made on the opening day of the hunting season than 

 on any other day, despite the fact that the season did 

 not open until noon. In the 2 years combined, over 11 

 per cent of the bobwhites for which the kill dates were 

 known were killed on the opening days. Fifty-four per 

 cent of the total kill was accomplished during the first 

 10 days of the seasons and 19 per cent during the last 

 10 days. Approximately 25 per cent of the birds were 

 taken during the first 3 days of the hunting seasons. 

 The number of bobwhites killed per day was only a 

 little greater on the week ends than it was on the 

 weekdays. 



Major Food Groups 



Foods identified as plant made up 93-94 per cent of 

 the total volume of the crop contents of the bobwhites 



I 



