44 
The waterfowl nesting and rearing season is seldom finished by these deadlines, 
In a year such as 1953, when the entire nesting season is late, the season's total 
hatch may not have materialized fully until the latter part of September. 
We therefore do not attempt, in these air surveys, to measure the actual total 
number of waterfowl produced each season. Instead, we measure the breeding 
population and the various factors that will influence the nesting success of that 
population as the season progresses. On the basis of this "Measure of Production 
Prospects", we issue, on June 1 and again on August 1, a Forecast which reflects 
the degree of success or failure of the eventual season's hatch. Ina sense, this 
procedure is somewhat analagous to agricultural crop forecasting, in that we 
consider our nesting population to represent ''seed"', and the various other measure- 
ments to represent ''growing conditions",''maturity", "yield", and others. Each 
item considered in these forecasts is presented graphically on the attached charts. 
Early-Season Prospects 
Saskatchewan enjoyed periods of warm, open weather during late April and 
early May. We anticipated that a substantial carry-over of breeding ducks from 
last year's exceptional hatch would be available at the start of this 1953 nesting 
season. However, surface water conditions were somewhat precarious at this time. 
There was enough water in the potholes this spring, even in the drought-susceptible 
Grasslands, to attract nesting ducks. But soil-moisture reserves also were 
encouraging to farmers, and we feared that early-season plowing of stubble-fields 
might disrupt the first-nesting attempt of pintails and mallards. These birds nest 
in great numbers in wheat stubble, because of early-season scarcity of natural 
nesting cover in the intensively-farmed wheat country. 
The May, 1953 Breeding Population ("Seed -Stock"') 
Our hopes for a substantial breeding population were quickly realized. Our 
May, 1953 air surveys showed a breeding population of 40.2 ducks per square mile 
(20.1 pairs per square mile) for southern Saskatchewan. This represented a 
breeding population index of almost 5 million ducks on our Survey area. This 
"Population Index''is a minimal figure, since air survey teams miss some ducks. 
This May, 1953 population exceeded the large 1952 population of 38.9 ducks per 
Square mile, and the latter, by the way, had been the highest May population we had 
recorded for Saskatchewan since 1947. 
The mallard showed a strong increase this year (up 27 percent from last year), 
while the pintail, which spearheaded last year's big increase over former years, was 
down only 3 percent from 1952, All of the later-nesting surface ducks, particularly 
blue-winged teal, were down from last year, but present populations still compared 
favorably with long-term averages. It may be that unseasonably cold weather during - 
the first half of May delayed arrival of these species, and resulted in a low count on 
air-transects flown prior to May 15. Some divers, notably the canvasback and 
redhead, were up from last year. 
Surface Water ("Growing Conditions") 
In addition to recording ducks on our air-transects, we record the number of 
ponds and other water areas within the transect strips. This figure reflects the 
