MISSISSIPPI FLYWAY 
SOUTHERN MANITOBA 
Weather and Water Conditions - 
Due to light snow conditions in this area last winter, 
the water situation was by no means as plentiful as last year. 
April rains assisted soil moisture and benefited farm operations 
but had little effect on increasing potholes and water areas. 
Practically no rain fell from the last week in April until May 20. 
Numbers of ponds during May decreased 33.7 percent from 1956 and 
28.9 percent from the four year average, 1954-57. Pond index 
in 1957 was 666,200 compared to 1,005,000 last year. 
By July the pond index had dropped to 501,400, which is 
67 percent less than the 837,500 estimated in 1956. 
Although water conditions were not considered to be good, 
by all appearances they had little effect on broods in most areas. 
There were some spots where ganging up of broods was noted in 
larger potholes or where shallower areas dried up. By and large, 
broods were still well scattered at the time the inventory was 
conducted. It appeared that sufficient water would be present 
to carry the broods through to the flying stage. 
Table 1 = May Water Area Indices - Southern Manitoba - Aerial Survey 
Ponds in Ponds in Total Ponds in 

Year Stratum "A" Stratum "B" Strata "A" & "B" 
1951 240 ,500 185 ,900 426 , OO 
1952 174,200 155,400 329,600 
1953 186 ,600 311 ,'700 4.98 , 300 
1954 258 ,200 1,075,400 1,333,600 
1955 314,700 407 ,700 742,400 
1956 390 , 700 614,800 1,005,500 
1957 262 ,200 404,000 666 ,200 
Average . 
1951-57 261 ,000 453,600 T1L4 ,600 

Breeding Population Indices = 
The breeding population index for this May showed 
practically no change for the over-all picture. The index for 
total birds this year was 6.2 percent under 1956, for all practical 
purposes no change. It showed a slight increase, plus 11.3 percent, 
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