

44 
Summary 
1. Water conditions in all study areas were generally above normal 
at the beginning of this survey in May. A dry summer caused a rapid depletion of 
ponds throughout Alberta, but seriously affected only Stratum C and portions of the 
southern edges of Stratum A. 
2. The breeding populations on Areas [, II and III were 10 percent 
below those of 1954, on Area IV they were the same as last year. 
3. Nest histories indicate an appreciable increase in nest success 
this year and a corresponding lessening of nest predation, Populations, lower by 
10 percent than in 1954, produced young in numbers nearly double those of 1954, 
4, Clutch sizes increased, brood sizes increased and altogether, the 
production of the study areas (except on Area I) was the best since these studies 
began in 1952. 
5. Aerial observation of breeding populations varied from 77 percent 
on the prairies to 50 percent in the parklands. Aerial brood counts improved in 
accuracy in 1955. On prairie Area II, they extended from 82 percent to 84 percent, 
in parkland Areas III and 1V, from 37 percent to 70 percent. 
