354 



Illinois Natural History Survey Bulletin 



Vol. 2j, Art. 2 



CANVASBACK--.,.^^^ 

 RING-NECKED DUCK- 

 LESSER SCAUP -^^ 



MALLARD- 



SHOVELER- 



WIDGEON AND. 

 GADWALL 



PINTAIL 



GREEN-WINGED- 

 TEAL 



BLUE-WINGED TEAL- 



.50 



^-4.0 



3.0 



2.0 



>• 

 < 

 o 



a. 



0. 

 IT 



u 



I- 

 z 



X 



q: 



UJ 



a. 



15-17 18-24 25-31 



OCTOBER 



1-7 



8-14 15-21 



NOVEMBER 



29-5 



LO 



6-12 13-19 20-23 



DECEMBER 



Fig. 20. — Seasonal composition of the duck bag made by Illinois River valley club hunters 

 in 1942. 



Fig. 17 shows the seasonal trend in the 

 number of hunters shooting and the 

 number of ducks killed per week over a 

 23-year period at the Duck Island Pre- 

 serve. Ihis duck club is not typical of 

 many Illinois River valley clubs in that 

 most of its members reside within 30 

 miles of the club and are able to respond 

 readily to hunting conditions, as shown 

 by the close correlation between num- 

 ber of hunters in action and number of 

 ducks killed. Eut even at this club, 

 over a 23-year period, the number of 

 hunters in action early in the season was 

 larger than the number late in the sea- 

 son. 



From previous discussion, we know 

 that mallards and black ducks as a 

 group are the most difficult species to 

 bag in Illinois. Figs. 11-15 show that 

 as the season progressed, 1938-1942, 

 these species comprised relatively more 

 of the population. Figs. 18-20 show 

 that as the season progressed, 1940- 

 1942, there was a steady decline in the 

 kill per hunter-day of blue-winged and 

 green-winged teals, pintails, widgeons 

 and shovelers, while there was at least 

 a comparative increase in the number 

 of mallards and black ducks taken per 

 hunter-day. It is evident that the 



composition of the flight makes for a 

 comparatively high bag early in the 

 season. 



Studies made by the Illinois Natural 

 History Survey demonstrate that juve- 

 nile ducks are about twice as easy to kill 

 as adults and that, generally, juveniles 

 of a species predominate among the' 

 early arrivals of that species. These find- 

 ings account in part for a greater kill 

 being made in proportion to the popu- 

 lation of some species in the early part 

 of the hunting season than later. 



Optimum Shooting Dates 



A waterfowl hunting season com- 

 mencing, as it did in the past 6 years, 

 no earlier than October 15 and running 

 into late November or December was 

 probably optimum for these years in 

 Illinois in that it afforded good duck 

 hunting and placed most of the shooting 

 pressure on species best able to take it. 

 From evidence previously presented, 

 it is obvious that, with a season set atij 

 such a late date, shooting pressure falls 

 to a greater extent on mallards, black 

 ducks and diving ducks than on the 

 more vulnerable teals, shovelers, pin- 

 tails and widgeons. 



