Annual changes in regional relative recovery rates were examined 
for Agassiz and Rice Lake bandings (tables 6 and 7). Direct recoveries 
of immatures from Rice Lake and adults from Agassiz suggested that 
larger proportions of these two samples were killed in the central 
zone in 1960 than in 1959. 
APPLICATION OF PRE-SEASON BANDING DATA TO OTHER WATERFOWL DATA 
The pre~season banding data for 1959 and 1960 were used with data 
from the Wing Collection Survey and Mail Questionnaire Survey to 
“estimate the age composition, harvest rate and size of the pre-season 
mallard population. Because of the weaknesses in the banding data, 
these estimates cannot be considered reliable; they are given here 
as examples of methods and to illustrate the potential value of such 
banding data. 
Calculation of Pre-Season Age Ratios from Age Ratios in the Hunting Kill 
Wing collections in the Mississippi Flyway during the 1959 and 1960 
hunting seasons provided estimates of the mallard age ratios in the 
hunting kill. Pre-season banding provided estimates of relative 
recovery rates. Wing collections indicated 0.77 immature mallards per 
adult in the 1959 kill (Geis and Carney, 196la), and 1.84 immatures 
per adult in the 1960 kill (Geis and Carney, 196lb). Average relative 
recovery rates for the Mississippi Flyway were 1.45 in 1959 and 1.42 
in 1960 (table 11). Since this rate is an expression of the number 
of times immatures are more likely to be shot than adults, the pre- 
season “age ratio can be estimated by dividing the age ratio observed 
in the kill by the relative recovery rate. Thus, for 1959, the 
estimate is 0.53 immatures per adult in the pre-season population 
(0.77 divided by 1.45) and for 1960 the estimate is 1.30 immatures 
per adult (1.84 divided by 1.42). 
Estimate of Pre-Season Population Size 
Data from pre-season banding, the Wing Collection Survey and the 
Mail Questionnaire Survey can be handled in several ways to yield 
population estimates (Carney and Geis, 1961). The method outlined in 
table 12 is a reasonable one, however, and will serve as an illustra- 
tion. 
The source of each number presented in table 12 is explained in 
the table, except for an additional quantity of ducks added at the 
end to adjust for mallards killed in Canada. The kill in Canada was 
not well represented by pre-season bandings because all but one of 
