If the results indicate nearly constant production, the necessity 
for an annual production survey will be questionable. If, on the 
other hand, black duck production varies a great deal from year to 
year, the size of the fall flight will vary also and it will be 
necessary to detect annual changes in production before the flight. 
Since present data do not rule out the possibility of variable 
annual production, plans must be made to continue and refine the 
duck production surveys in eastern Canada. 
It may be possible to estimate black duck production each year 
from phenological data gathered in May. If further study demonstrates 
a relation between the phenology of the nesting cycle and annual pro¬ 
duction among black ducks in eastern Canada, the value of phenological 
data gathered in May and June will be greatly increased. 
While the Canada goose and the black duck are unquestionably 
the species of major concern in eastern Canada, valuable data are 
recorded for many other species of waterfowl while the surveys are 
being conducted. Frequently, one-half to two-thirds of the ducks 
observed are species other than the black duck, most commonly 
mergansers, Mergus spp ., and goldeneyes, Bucephala clangula americana . 
In recent years, there has been a substantial increase in the number 
of mallards, Anas platyrhynchos platyrhynchos, observed. Evaluating 
the status of these species in eastern Canada should be included in 
the overall objectives of the surveys. 
12 
