84 
The phenology of the brood season may be indicated by the age 
distribution of broods as shown in Table IX. Although not as prominent as in 
1954, there were many Class I broods seen on the survey, indicating that hatch- 
ing was probably still underway, and that there were more broods to come. 
This was not true of Stratum "B"' where relatively few broods were in Class I, 
as shown in Table X. 
Table IX.- Age Class Distribution of Broods Stratum A, Manitoba Aerial Survey. 


Year No. of Brds. Aged %inClassl %inClassII % in Class III 
1951 710 40.7 40.7 18.6 
1952 494 36.0 24.5 39.5 
1953 150 22.0 43.3 34.7 
1954 200 61.5 33.5 5.9 
1955 172 41.9 30.2 ° 27.9 

Table X. - Age Class Distribution of Broods - Stratum B, Manitoba 
Aerial Survey. 
Year No. of Brds. Aged %inClassI %inClassII % in Class III 
1954 35 62.9 20.0 17.1 
1955 23 17.4 43.5 39.1 

Complete counts were made on very few broods, and there may be 
considerable selection of broods on which counts are made. However, data 
relating to the size Class II and III broods are presented in Table II. These data 
indicate that broods were smaller in 1955 than in the four previous years. 
Table XI. - Number of Ducklings Per Class II and III Brood, Stratum A, 
Manitoba. 
Year No. of Broods Counted Average Size 
1951 7 7,4 
1952 6 5.8 
1953 22 7.0 - 
1954 26 5.7 
1955 28 5.6 
