79 
the adaptability of most species of ducks led to their seeking different types of 
cover for nesting, rather than causing them to move elsewhere. 
The spring migration in 1955 was the earliest on record. Reports 
from the Delta Station indicate that all species were represented by April 15. 
Early migrants, such as mallard and pintail, arrived in numbers by April 1. 
Nesting of mallard and pintail was reported by officers of the Manitoba 
Game Branch to be underway by mid-April. By May 5 many hens of these species 
were incubating, as was evidenced by gatherings of drakes. The first significant 
hatch occurred between May 25 and June 1. 
With the exception of possible effects of reduction of nesting cover, 
conditions were ideal throughout the southern portion of the Province. 
Breeding Population 
Breeding populations for 1954 and 1955 are shown in Tables III and IV. 
There was a considerable increase this year, particularly in Stratum "B", The 
increased use of Stratum 'B" was also accompanied by a much wider dispersal 
of birds in Stratum "A", particularly into the normally droughty southern portion 
of the Stratum. This may have been due to the abundant water and early break-up. 
The greatest increase was in ruddy ducks and coots, probably reflect- 
ing the preference of these species for regions with high water levels. Pintails 
‘also showed a marked increase, mainly in Stratum "B", The only important 
decrease was in the canvasback. Although the decrease was slight, the variation 
from the trend shown by other species is quite considerable. 
Included in Tables III and IV are "flocked scaup'"'. These are birds 
seen in proups of mixed sexes which are judged to be migrants or non-breeding 
summer residents. They are almost certainly not a part of the nesting population 
of the area and have thus not been corrected for unseen hens on nests in the 
analysis of the 1954 and 1955 data. 
Breeding populations for 1951-1955 are shown in Table V. Due to the 
exclusion of non-breeding scaup in 1954 and 1955, these two years have been 
slightly undervalued. The index for 1951 is also somewhat undervalued due to the 
fact that no correction was made for absent hens on nests in Stratum "B", 
This year's spring population was considerably above that of the 
previous three years and slightly higher than that of 1951. 
