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Summary 
Breeding Population: - The number of breeding pairs, as measured by ground 
transect, indicated an increase in North Dakota of 25 percent over 1949. In South 
Dakota the raw data indicated a 5 percent decrease, but further analysis of all existing 
data, plus additional transects run in 1950, indicated a small increase of about 10 
percent. 
Species Composition: - Relative abundance of breeding pairs changed to some extent 
in 1950, probably due to the delayed migration. Blue-winged teal increased consider- 
ably in North Dakota, while mallards increased only slightly and dropped in relative 
abundance. In South Dakota, pintail and shoveler showed increases in 1950 while 
gadwall decreased, 
Nesting Success: - Nesting was delayed in most species for from ewe to three weeks. 
Loss to first nests was again extremely high, with the main causes of nest loss due 
to agricultural operations with predation also a very important factor. 
Brood Survival: - Production of broods was quite satisfactory as compared to 1949. 
In areas where there was a large increase in breeding pairs, brood production did not 
quite keep pace with this increase, However, the over-all production was unque stion- 
ably somewhat higher in 1950 than in 1949. 
Brood Averages: - Brood averages were very much the same as in 1949 with only a 
small decrease of about 2 percent in brood sizes between Class 111 broods of all 
species. This percentage is too small to be significant. 
Conclusions: - An increase in breeding stock was subjected to the usual heavy nest 
mortality and while more broods were produced than in 1949 the survival index is 
believed to be under that of 1949. Blue-winged teal made up most of the increase in 
breeding pairs and broods. : 
