14. 
Recovery rates of mallards varied, because of the sex, 
the area of banding, the migration route,, and the winter¬ 
ing area. The average direct recovery rate was 11 percent 
for males and 9.2 percent for females. Recovery rates 
from important production areas in the United States 
tended to be higher than recovery rates in Canada, and 
those in southern Canada higher than those of northern 
Canada and Alaska. Recovery rates for birds entering the 
Central and Atlantic Flyways were somewhat lower than for 
those entering the Pacific and Mississippi Flyways. 
15. A marked decrease in recovery rates was indicated for 
bandings from 1959 through 1961. The decrease in recovery 
rates for this period was concurrent with generally low 
waterfowl populations and restrictive regulations. 
16. Breeding population aerial census strata (fig. 2), discussed 
in part 1, were established on the basis of habitat types 
and relative population density. It was thought that by 
reason of their geographic configuration they might not be 
useful in analysing recovery patterns because of differences 
in distribution from portions of the same stratum. However, 
after analysing the distribution of recoveries from areas 
of reference with similar recovery patterns throughout, and 
after reviewing weather and habitat conditions over the 
period of study within each of the aerial census strata, it 
was determined that insufficient changes had occurred in 
the distribution of birds within census strata to invalidate 
predictions of kill distribution from these strata based on 
average band recoveries. Since breeding population and 
production data are readily available for each of the 
.census strata, it is concluded that the data on distribution 
of harvest from aerial census strata are useful information 
for management purposes. 
25 
