45 
activities, from the interior to the coast was less far advanced this year at the time 
of our survey, than in 1949, and that the total population of the area was about the 
same, 
Considering all these regions of low duck density together, the conclusion is 
that the 1950 population was somewhat less than that of 1949. This coupled with the 
status of little change for the prime areas adds up to a downward trend in Manitoba's 
1950 breeding numbers, 
Production 
For the second consecutive year, the duck crop in Manitoba (at least in-areas 
where measurements were possible) failed to measure-up to advance billing (breeding 
duck count). This lack of correlation, in some years, between the potential (spring 
counts) and actual production (brood counts) makes it highly desirable, from the water- 
fowl management standpoint, to delay setting hunting regulations until nesting success 
can be measured in terms of growing ducklings. 
It is worthy of special note that while the number of ducklings produced this 
year in Manitoba's finest pothole country was considerably below last year's production, 
neither nesting success data or brood size counts furnished a clue that a partial crop 
failure was in the making. This year 53 percent of all the nests under observation in 
pothole areas hatched, compared with 48 percent in 1949. Nests are found incidental 
to other field activities, hence the sample (181 nests) is too small to attach significance 
to the slight difference between the two years. The data seem to indicate that the degree 
of success was about the same both years. (See Table 4 in this report and Table 2 in 
the 1949 report.) The average brood size for all duck broods tallied was 6.7 in 1949 
and 6,4 in 1950. For all practical purposes this average for the two years appears about 
the same. (Table 3 in the 1949 report and Table 5 in this report present the brood data 
by age classes.) 
Appended reports of Kiel and Cole give details concerning the production drop 
of about 35 percent in Manitoba's best waterfowl area, District 8. In other districts 
containing numerous potholes we found a decline of 68 percent on 104 study areas spaced 
at random throughout these districts. Phenologically, the 1950 counts were made 
slightly earlier than the 1949 counts, hence late broods probably reduced the apparent 
degree of decline slightly. 
Despite the general downward trend in breeding success, there were local 
areas where gains were recorded. The marshes at the south end of Lake Manitoba 
were one such locality. There, canvasback and redheads apparently had an unusually 
good season. 
Aerial brood counts were made along most of the spring transects south of 
4° but comparable data for 1949 are not available due mechanical difficulties with 
the plane in 1949. 
Reports reaching the Manitoba Game Branch office at The Pas, from their 
field officers, trappers, and transient biologists, were that production on the 
Saskatchewan Delta was not up to par and definitely below par in the north country. 
It was pointed out that the predator cycle is near its peak while the prey cycle is now 
low. Food is in great demand.and, according to these reports, predation on duck nests 
has been unusually heavy. 
Our conclusion is that Manitoba produced considerably fewer ducks in 1950 
than in 1949. The production level now seems to be somewhere near that of 1948. 
