ANNUAL MORTALITY RATES 

<=. 
70 70 O 
_ 
+ 
60 
60 a 
Qo. 
50 a 
> UNREPORTED [50 0 
@ HUNTING KILL = 
40 40 - 
os Le 
30 ante 390 2 
REPORTED KILL = 
20 20 
Ww 
10 NONHUNTING MORTALITY 19 oO 
0 Ss 10 IS 20 
FIRST-SEASON RECOVERY RATES 
Figure 21.--Suggested Method for Determination of the 
Percentage of Waterfowl Killed by Hunters 
Precise data on this problem were not gathered in the present study. 
Solid dots represent adult Mississippi Valley mortality rates for 
T9Z5=26 (table 63) for mallards plotted against first~-season recovery 
rates for continental waterfowl obtained in this period and cited 
by Lincoln (1930); open circles represent estimated adult mallard 
mortality rates for T9Q0-46 (obtained by time-specific analyses in 
table 65) plotted against first-season recovery rates for unaged 
mallards banded in Canada before the start of each hunting season. 
The points A, B, C and D are explained in the text. | 
156 
