31 
in the size and location of each study area. Where observations had formerly been 
made in 1/8-mile strips on both sides of a highway, this year they were made only on 
one side. This modification in our methods aids in cutting down on the number of ducks 
that might be re-counted as they fly from one side of the road to the other and it also 
makes possible the lengthening of the study area, a decided advantage in sampling a 
larger district and in making aerial flights. 
Weather and Water Conditions 
The warm, dry fall and winter of 1952-1953, followed by a poor run-off this | 
spring caused water levels generally throughout the province to be low by May 1, 
Exceptionally wet weather in June and July restored these levels and in the prairies 
caused marked improvement by August 1 over May 1 conditions. The later arrival of 
the rains to the parklands as well as generally warmer weather there, made for a more 
normal evaporation as shown by the data from Area IV. Pothole survival on Areas II 
and III showed only slight variation from conditions at the beginning of the survey. On 
Area IV, however, about 39 percent of the areas had dried up by August l. This study 
area is in the northern parklands and compares favorably with the 1952 summer loss of 
30 percent. 
Table I. - Precipitation on Study Areas - 
Areas May June July Totals 
I 2.20 6. 80 1.80 10, 80 
LI 1.70 5.90 2.60 10.20 
III 1.49 5.12 5.46 12.07 
IV 0.70 3.60 3.40 7.70 
On Areas II, III and IV permanent bench marks were established and regular 
checks of water levels made. On ArealIlI, 5 gauges on B areas showed an average loss 
for the season of 4.8 inches, while one gauge located on an A area recorded a sufficient 
rainfall throughout the season to offset the effects of evaporation and end the season with 
the same water depth as at the bepinning of the study. On Area Ill, 5 gauges on A areas 
registered an average gain for the season of 1.9 inches, 9 gauges on B areas an average 
gain of 2.4 inches, and 6 gauges on C areas an average gain of 2.8 inches for the season. 
In Area IV where rainfall was not as great and where evaporation was greater than in 
other districts all types of areas showed losses through the season, 4 gauges on A areas 
showed an average loss of 4.4 inches, 10 gauges on B areas an average loss of 7.7 
inches, and 6 gauges on C areas an average loss-.of 7.1 inches. 
Table II. - Pothole Survival 
Areas May 1 June 1 July 1 August 1 
1 62 No data No data No data 
Il 58 55 67 52 
lil 196 196 193 192 
IV 204 189 123 124 
wae ee ee ee ee a eee 
Total 458 440 383 368 
In Area lV where water levels were relatively normal, many 'C" areas that had 
already dried up were temporarily filled again in late July but because of the lateness 
of the season no beneficial effects resulted. 
