60 
From the foregoing data it is easy to see which species of ducks are the 
most difficult to observe from the air. Both species of teal fall in this category 
with the little green-wing being especially hard to see not only because of its 
small size but also due to its tendency to frequent the wooded ponds. Separate 
count of the ducks by open or wooded ponds was kept by the Hawkins -Perroux 
team and while they saw 29 percent of the ducks seen on the ground they only saw 
14 percent of those in wooded areas and 33 percent of those in open areas. The 
wooded nature of the aspen parklands area is the real reason for the low percentage 
of ducks counted from the air. Observer Hyska did not attempt to identify all ducks 
as to species which made it possible for him to see a greater percentage of the 
total population present. 
An aerial brood census made on July 17 yielded the following results: 
Table XIII - Aerial Brood Data 
Broods from the July 25-29 ground count 183 
Estimated total production on the study area 249 
Broods seen from the air 104 
Percent of ground count seen from the air 57 
Percent of the actual total production seen 42 
Summary 
To briefly summarize the data from the Redvers Study Area we can 
conclude that: 
1. Weather and water conditions were favorable for both nesting and brood 
production, especially for the ground-nesting species. Ample water remained on 
July 30 to allow all broods to reach flying age no matter what kind of weather 
occurred after that date. 
2. Breeding pair population was high (120 pairs per square mile) but not 
higher than the amount of breeding territory (number of water areas) would 
indicate. There were 61 water areas per square mile. 
3. Nest data indicated 45.8 percent success, 
4, Brood data indicated 42.4 percent success. 
5. In general, the season was assumed to be considerably better than average 
for the area although no directly comparable ground data were available for 
comparison, 
6, Comparisons between aerial and ground data indicated that the aerial 
crew was able to see between 29 and 35 percent of the pairs and lone drakes . 
present, depending on the observer. Some species such as the teal were more 
difficult to see than some of the others. Regarding broods, the aerial crew 
recorded 57 percent of those counted by intensive ground methods. 
