
is illustrated by the July pond index indicating that the number of water 
areas in Stratum "B," increased over last year, while those in Stratum "A" 
decreased. Throughout the area, there will be sufficient water for broods, 
some portions still experiencing above normal levels. 
Water Index - Southern Manitoba - July Aerial Survey 



Ponds in Ponds in 
Years Stratum "A" | Stratum "B" Total 
1954 4.72 ,,400 384,200 856,600 
1955 339, 300 270,900 610,200 
1956 425,900 411,600 837,500 
1957 241,700 259, [00 501,400 
1958 163, 300 341,000 50, 300 
Average 328, 500 333, 500 662,000 

Breeding Population Indices 
Some individuals of most species arrived early in 1958; all but the 
gadwall being present at the Delta Waterfowl Research Station by April 10. 
However, there was a considerable later mivement of birds into the Province, 
presumably from the drier prairies to the south and west. Some of these 
birds remained as groups of pairs throughout the survey period. Since they 
were not seen as pairs or singles, their potential productivity is unknown 
and probably low. However, there is no question but what they will make up 
a portion of the fall flight. Hence, they are included as a separate popula- 
tion index of "flocked ducks," neither migrants nor actually nesting at the 
time they were seen. While it is usual in Manitoba to find from 50,000 to 
75,000 scaup in this condition, such groups normally occur among other 
species in negligible numbers. However, such groups amounted to nearly 
300,000 birds in 1958. On the other hand, the bulk of the population, 
amounting to nearly a million birds, occurred as drakes and separate pairs, 
indicating they were nesting or about to nest. There was an increase in most 
species over 1957 populations. The mallard, pintail and shovler were the 
only species prominent in the records which did not increase in 1958. 
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