342 



Illinois Natural History Survey Bulletin 



Vol. 2j, Art. 2 



prior to the opening of the hunting 

 season. A greater proportion of the 

 flight was present during the open 

 seasons of 1938 and 1941 than during 

 the other three seasons. Table 8 shows 

 for 1938 and 1941 the highest shooting 

 pressure quotients for this species. 



Second among the species most fa- 

 vored in Illinois by the established open 

 seasons, 1938-1942, was the shoveler. 

 As shown by fig. 8 and figs. 11-15, much 

 of the shoveler migration in this state 

 occurred before the season opened. A 

 larger proportion of the population of 

 this species than of any other species, 

 except the blue-winged teal, passed 

 south before opening day. Data in table 

 8 disclose that extending the season to 

 60 days in 1940 and 70 days in 1942 did 

 not increase the shooting pressure quo- 

 tient for this species in those years. 



Figs. 11-15 reveal that much of the 

 green-winged teal flight, like that of the 

 blue-winged teal and shoveler, had 

 passed through Illinois by opening day, 

 1938-1942. Table 8 shows that the 

 green-wing was the third most favored 

 species. High water in 1941 caused a 

 large part of the green-winged teal 

 flight to leave the Illinois River valley 



earlier than usual. In that year, green- 

 wings were under less shooting pressure 

 than in other years and were next to 

 the blue-winged teal in being little af- 

 fected by the open season, table 8. 



Next to the blue-winged teal, the 

 pintail was, in the years of this study, 

 the earliest migrant to arrive in Illinois, 

 fig. 9. However, because greater pro- 

 portions of its flight occurred during the 

 hunting season, figs. 11-15, the pintail 

 was subject to more shooting pressure 

 than either of the teals or the shoveler, 

 table 8. High water in 1941 resulted 

 in a mass exodus of pintails from the 

 Illinois River valley early in October, 

 accounting at least in part for a low 

 shooting pressure in that year, table 8 

 and fig. 14. While the 1942 flight was 

 small, the majority of birds arrived 

 during the hunting season. A late 

 flight in 1938 helped to place pintails 

 under greater shooting pressure in that 

 season than in others. 



The widgeon, in the years of this 

 study, was subject to more shooting 

 pressure in Illinois than was the pintail, 

 table 8. The figure for 1938 indicates 

 that the later-than-usual widgeon flight 

 in that year contributed to a heavier- 



20 -- 



I 

 o 



< 



I- 



o 



I- 



2 



UJ 



a 



UJ 



a 



> RUDDY DUCK 



— X X — RING-NECKED DUC t' 



- — ' 1 CAfJVASBACK 



^ ' LESSER SCAUP 



MALLARD 



OCTOBER 



NOVEMBER 



DECEMBER 



JANUARY 



Fig. 10. — Five-year average, 1938-1942, of the seasonal migration of the ruddy duck, ring- 

 necked duck, canvasback, lesser scaup and mallard in the Illinois River valley. 



