44 
Table 2. ~- A Comparison Between 1949 and 1950 Species Densities * Along 153 Miles 
of Transect in the Principal Farm Pothole Districts (1, 2, 3, 6 and 8) of 
Te ee EL ee Th ee 
Species 1949 1950 | 
pice SF Ae a OL, IT OM la. a Le ORL As ON, I RL SO EY A es 
Mallard Li. 3 °12.4 
Gadwall 2.3 2.0 
Baldpate 3.5 3, 8 
Pintail 5.8 5.1 
G-w. teal 1.4 1.8 
B-w. teal 16.1 16.6 
Shoveler 4,1 3, 3 
Redhead Z2.2 3.1 
Canvasback S,.1 3,4 
Scaup 4.2 5.8 
Ruddy 1.4 4,0 
Misc. 0.6 1.1 
Coot 9.2 8.5 

*xExpressed in terms of total numbers of each species per square mile. 
Waterfowl habitats in Manitoba having lower densities than the ''prime' areas 
are; the swamplands of southeastern Manitoba, the lowlands (interlakes country), the 
mountains, the rock country and the tundra. Only an airplane is suitable for sampling 
these areas due to their inaccessibility. In re-organizing this year's aerial transects, 
some exact comparisons with past years were lost. For example, in 1949, the density 
figure for the swamplands was 20.6 ducks per square mile. This year's figure was 
3.0. We now realized that past samples were biased by including too much of the 
better duck habitat of the district. The decline, therefore, probably was less great 
than the figures show. How much less is not known. 
In the four inventory districts included in the lowlands (11, 12, 15, and 17) 
population changes, from 1949 to 1950, were slight. In the four mountain areas 
sampled (Turtle, Riding, Duck and Porcupine) two showed gains and two losses. 
Conclusion: No change. 
The rock country gave these results: 
Table 3. -- A Comparison Between 1949 and 1950 Aerial Surveys on the Pre-Cambrian 
Shield of Manitoba. 




Sq. Miles Sampled Ducks per Square Mile Change 
Region 1949 1950 1949 1950 
E, Lake Winnipeg 67.0 142.8 3.4 1.8 
N. of 54° Latitude oe 98.5 5.0 3.8 
Total 80.0 241.3 . eR 2.6 — 29.7% 
For northeastern Manitoba, in the muskeg transition and tundra areas, interior 
to Hudson Bay, a population density of 4.2 ducks per mile was found in a sample of 231 
Square miles. This is higher than the 2.2 ducks per square mile reached in [949 ina 
sample of 42 square miles. The two surveys were made at identical calender dates, 
-but since phenological dates for the two years differed the results obtained are not 
exactly comparable. Along the Hudson Bay coast the 1949 count showed 42 ducks per 
Square mile, as against this year's 29. Comparing the coastal and interior figures we 
would conclude that in 1950 the exodus of ducks, which had completed their breeding 
