November, ig44 



Bellrose: Duck Populations and Kill 



367 



pressure resulting from baited areas and 

 live decoys fell upon the mallard and 

 black duck than upon other species. 

 Table 15 shows that, in 1933, 83.80 

 per cent of the bag was made up of mal- 

 lards and black ducks. In the 1941 

 season, of comparable length and dates, 



28,000 mallards at the Chautauqua Na- 

 tional Wildlife Refuge, near Havana. 

 As indicated by band returns, the shot- 

 gun mortality, the first season, of 27,680 

 fall banded mallards was 2.9 per cent in 

 1939; 6.8 per cent in 1940; 2.6 per cent 

 cent in 1941; 7.0 per cent in 1942; and 



Photo by Bob Becker 



Mallard and pintail blocks, or wooden decoys, being picked up in a marsh smartweed area 

 that has yielded large kills of Illinois River valley ducks. 



only 63.72 per cent of the bag was com- 

 posed of these species. Even in 1935, 

 when feeding was done in areas not shot 

 over and live decoys were outlawed, the 

 mallards and black ducks comprised 

 88.79 per cent of the total bag; in 1938, 

 mallards and black ducks formed only 

 55.70 per cent of the bag. The large pro- 

 portion of those species in the 1936 and 

 1937 bags, when baiting and use of live 

 decoys were illegal, was due to the fact 

 that the open season extended from 

 November 1 through 30, a period in 

 which mallards formed over 90 per cent 

 of the waterfowl population. 



Banding returns show that baiting 

 and live decoys resulted in heavy shot- 

 gun mortality to the mallard. A study 

 of tables in Returns from Banded Birds, 

 1920 to 1923 (Lincoln 1924) indicates 

 that 218, or 16.4 per cent, of the mal- 

 lards banded by Lincoln during the 

 autumn of 1922 near Browning, Illi- 

 nois, were killed that hunting season in 

 Illinois; a mallard kill rate much higher 

 than in recent years in this state. 



From 1939 through 1943, the Illinois 

 Natural History Survey banded about 



5.7 per cent in 1943. Lincoln banded 

 his mallards at a gun club, and we 

 banded ours at a wildlife refuge. While 

 this difference contributed to the greater 

 survival of Chautauqua-banded mal- 

 lards, the kill rate of Illinois mallards 

 in 1922 must have been at least twice 

 as great as it has been since 1939. Re- 

 turns from 2,452 mallards banded in 

 Canada* show a shotgun mortality, the 

 first year, of only 8.9 per cent in 1940, 

 5.7 per cent in 1941 and 6.4 per cent in 

 1942. These mallards had to face shot- 

 guns in the northern zone as well as in 

 the central and southern zones and 

 therefore had more time in the season 

 of banding in which to be killed than did 

 those banded by Lincoln near Browning. 

 Data on duck mortality obtained from 

 Illinois State Department of Conserva- 

 tion kill records, from Uhler's 1933 re- 

 port and from a comparison of first 

 hunting season band returns indicate 

 that the kill rate under baiting and live 

 decoy conditions was two to three 

 times as great as after their prohibition. 



*Information furnished by B. W. Cartwright of 

 Ducks Unlimited (Canada). 



