
34 
Table 9. -- Aerial Waterfowl Production Figures For All Transects Plus 
Lake and Stream Surveys 
Total number of broods 923 
Total number of ducklings 5422 
Average brood size 5.87 
The basic data above presents all too clearly the seriousness of the water- 
fowl production picture in Alberta in 1950. By both aerial and ground survey methods 
we found that only a fraction of one duckling was produced per female in the observed 
population. With a 7 percent reduction in the original breeding population this year, 
a rapid disappearance of water on the breeding grounds (which occurred after the 
birds had established nests), plus the indicated poverty of broods produced by those 
birds that succeeded in renesting, it appears that except for selected areas of limited. 
extent waterfowl production in Alberta has been poor this year. By means of an 
aerial] survey of many of the lakes and streams of southern and central Alberta, 
several lakes were found to have sizeable concentrations of broods. However, there 
is little indication that this is other than a normal situation or that populations 
unsuccessful on the prairies and parklands concentrated on lakes with any success. 
Summary 
The 1950 waterfowl breeding season in southern and central Alberta 
received another set-back, possibly even worse than that of 1949. The presence of 
water early in the season, followed by drought conditions, caused a wave of nest 
desertions among both mallards and pintails. Due to the period when this happened 
it is probable that most of the males had already left the incubating females and had 
begun to congregate for moulting. Regardless of the cause, adult females of both 
mallards and pintails were much in evidence as flocked birds from mid-June through 
July, appearing as 30 percent of the total adult pintails banded in the month of July. 
Clutch sizes for 1950 dropped from the 1949 level of 8.9 eggs per clutch to 
7.9. Brood averages were reduced from 6.4 to 5.9 ducklings per brood. Brood 
densities were reduced about 50 percent, from 1.03 broods per square mile in 1949 
to .51 broods in 1950, In 1949 there were an indicated .47 ducklings per adult 
observed in the breeding population, while this year this figure had been reduced to 
.24 ducklings per adult. Even with the addition of the month of July in which to make 
brood observations this year, a marked decrease in total numbers of broods was 
observed, Only 65 percent as many broods were counted on transects this year in a 
three month period (May through July) as were counted on the same areas in two 
months (May and June) of 1949. 
