November, 1944 



Bellrose: Duck Populations and Kill 



341 



1938-1942 period, table 2, and for each nois during the years of this study and 



year during the period, table 8. may therefore be considered as the 



Comparative Shooting Pressure. — species most favored by the open seasons 



Table 8 discloses that the blue-winged from 1938 through 1942. A glance at 



teal had the lowest shooting pressure fig. 8 and figs. 11-15 reveals that most 



quotient of all important ducks in Illi- blue-wings passed through the valley 



20-- 



15-- 



I 



o 



2 



UJ 



u 



cr 



Q. 



iO-- 



5-- 



BLUE-WINCED TEAL 



— c c WIDGEON 



— X X — SHOVELER 



— X X— GREErj-WINGED TEAL 



10-16 17-23 24-3l 31 6 7-13 1-1-20 21-27 28-4 5-11 12-18 19-25 25-1 2-8 9-15 16 22 2329 30- b 7-i3 142021-27 

 AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER 



Fig. 8. — Five-year average, 1938-1942, of the seasonal migration of the blue-winged and 

 green-winged teals, widgeon and shoveler in the Illinois River valley. 



OCTOBER 



2-e 9-15 16-22 23-29 30-6 7-13 14-20 21-27 28-3 

 NOVEMBER DECEMBER 



SEPTLMBEP 



Fig. 9. — Five-year average, 1938-1942, of the seasonal migration of the pintail, coot and 

 gadwall in the Illinois River valley. 



