72 
Although the increase this year may be somewhat exaggerated due to the 
lateness of the breakup and the relatively early date on which the survey was 
conducted, the increase shown is quite considerable and the wet portions of the 
Province more than compensated for the dry areas. 
Table I. - Water Area Index, Southern Manitoba May Aerial Survey. 
Ponds in Ponds in Ponds in Strata 
Year . Stratum A Stratum B A and B 
1951 240, 500 185, 900 426, 400 
1952 174, 200 155, 400 329, 600 
1953 186, 600 311.700 498, 300 
1954 258,200 1,075,400 1,333, 600 
The spring breakup was slow and snows with freezing temperatures in late 
April and early May retarded the start of nesting, although many birds had already 
arrived in April. Alex Dzubin reports that by April 20, about 80 percent of the 
normal May 15 population of mallards and pintails were settled down on the 
Roseneath area. May and early June were generally cool and wet. Rains during the 
period from June 4 through June 8 were considerable, concentrating along the 
southern border of the Province and tapering off northward. There were scattered 
violent showers in some areas. Virden reported 3.11 inches of rain fell in one 24 
hour period. However, no stations north of Rivers and Brandon, which mark the 
southern limit of the best breeding range this year, reported over 2.3 inches for 
the four-day period, or over 1.6 inches in one day. The remainder of June also 
experienced above normal precipitation, July was more nearly normal and precipi- 
tation occurred mainly in the form of local showers. However, water levels were 
still extremely high, potholes generally being flooded into the shoreline vegetation 
or into grain fields. 
Table II shows the July aerial pond count for Stratum A. 
Table II. - Ponds in Stratum A, Manitoba Counted During Production Surveys. 

Date Index Ponds per Square Mile 
July, 1952 125,971 12.2 
July, 1953 150, 854 14.6 
July 14-18, 1954 472,362 45.6 
July 28 - August 2, 1954 254,629 24.6 
