101 
In Table II brood data for 1950 and 1953 are compared. From these it can 
be seen that although the mallard population reached its greatest density in 1953 
production was less than the previous year. Based on the breeding population 
estimates and subsequent brood counts the mallard population was 52 percent 
successful in 1952 but only 34 percent of the pairs produced broods in 1953. The 
pintails were somewhat more successful than in 1952. Success in 1952 was 
44 percent and in 1953, 52 percent. This may indicate that the pintails were more 
advanced in incubation at the time of the May snowstorms and "sat the storm out" 
while more mallards deserted. Since the study area is uncultivated, the normal 
success of the pintail here may also indicate that the failure of pintails to produce 
elsewhere was due as much to farming operations as weather. 
Of particular interest is the nesting success of the blue-winged teal. One 
hundred and eight broods were produced from the 154 pairs, a 70 percent success. 
The blue-winged teal hatch was late as indicated by the data. Only one brood was 
seen on the June brood count while in 1952, 29 broods were counted on a Similar 
date, and in 1951, 13. 
The total production of 73.4 broods per square mile was again a record for 
the area as far as our records are concerned, exceeding 1952 by i0 broods. In 
1952, 54 percent of the estimated breeding population produced broods; 
52 percent in 1953. However, the population in the previous year was almost 
uniformly successful, whereas this year the mallards were only 34 percent 
successful, the loss here being compensated for by the exceptional success of the 
blue -winged teal. 
In summation, the 1953 breeding population in the Caron Potholes was the 
largest of which we have record. Brood production was exceptional for tne blue- 
winged teal, about average for the other late nesters and for the pintails, but below 
average and disappointing for the mallards. 
SOUTHEY STUDY AREA - 1953 
R. T. Sterling 
The study area is located 41 miles north of Regina, Saskatchewan. It comprises 
a 2 square mile area which is characterized by moderately rolling terrain with 
numerous small potholes most of which are willow and aspen ringed. The area is 
90 percent cultivated. 
Only 6 of the 125 ponds in the study area contained water at freeze-up in 1952. 
All were filled by spring run-off in 1953 and snows and heavy rains during late spring 
and summer resulted in most being near spring level in August. In August, 96 ponds 
still contained water as compared to 6 the previous year, and more than half will 
have a carryover of 6 inches for next year. 
The breeding population was determined from a count of territorial pairs 
conducted on May 22 and 23, Earlier than this heavy snows and freezing temperatures 
forced most of the pairs to leave the area for larger marshes containing open water. 
Some pairs became established after the territorial count was made as canvasback, 
