352 



Illinois Natural History Survey Bulletin 



Vol. 2j, Art. 2 



T 1 r 



15 18 25 1 8 15 

 OCTOBER NOVEMBER 



Fig. 16. — Seasonal trend in activity of hunters at Illinois River valley waterfowl hunting 

 clubs, 1940-1942. 



3 20 

 DECEMBER 



27 



S 21 



iij 

 Q. 15 



CO 



a: 12 



\- 



z 



3 

 X 



6 

 3 h 



L 



NUMBER OF HUNTERS 



NUMBER OF DUCKS KILLED 



'-' oj cvj 



^ Al 



O I^ 



SEPTEMBER OCTOBER NOVEMBER DECEMBER 



Fig. 17. — Weekly averages of number of hunters in action and ducks killed at Duck Islani 

 Preserve over a 23-year period. 1914-1936. 



