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WATERFOWL BREEDING GROUND SURVEY IN SOUTH DAKOTA - 1950 
Ray Murdy 
Introduction 
td 
Waterfowl breeding ground studies in South Dakota were greatly expanded 
during 1950. An aerial waterfowl and water area survey was initiated to measure the 
density and distribution of breeding ducks and water areas ona State-wide basis. The 
number and distribution of ground transects were increased to give State-wide coverage. 
A brood census was initiated on portions of certain ground transects in an effort to 
establish indices relating numbers of broods to numbers of pairs and to square miles 
of coverage. Other brood counts were made to estimate average brood sizes by species 
and age classes. And lastly, a joint duck-banding program was undertaken with the 
U. S. Fish and Wildlife Service. 
This report contains a brief resume of the studies mentioned above. Each 
will be dealt with in detail in future Quarterly Progress Reports of Pittman-Robertson 
Project 17-R-3. The results of the duck banding activities are discussed by J. H. 
Stoudt, Biologist, U. S. Fish and Wildlife Service, and are not described in this 
report. 
Field Methods 
Ground Transects 
The type of ground transect used was the standard 1/4-mile wide transect 
with ducks being recorded by species as pairs, lone drakes, unpaired drakes, and 
unpaired females. Water areas were classified according to size, permanency, and 
occupancy. These ground transects were run by 42 State game wardens in 49 counties 
spread over the entire State (Figure 1). The 2,312 miles flown resulted in a coverage 
of 578 square miles. Of this, 309 square miles represented transects in the East 
River country which had been run in 1949, and so can be used to measure trends. 
This survey was made during the 4th week of May (21-27) as the late spring appeared 
to have set back the breeding season about three weeks. 
Aerial Transects 
The aerial transects were laid out east-west across the State at 12-mile 
north-south intervals beginning 12 miles south of the North Dakota-South Dakota State 
Line continuing across the State to a point 12 miles north of the Nebraska State Line. 
This year every other transect was run, resulting in 8 east-west transects 24 miles 
apart. The approximate location of these transects is indicated by the rows of figures 
in Figure 2. These transects were 1/2 mile wide. Ducks were recorded as the 
number‘ observed, and water areas were listed as the number and acreage by perman- 
ency classes. All data were recorded by sections; i.e. the number of ducks and the 
number and acreage of water areas in each permanency class were recorded for each, 
mile along the transect. Six transects were flown by State game technicians and 2 
were flown by Lloyd Ayers, Biologist, U. S. Fish and Wildlife Service, River Basin 
Studies. These transects were flown at the same time as the transects were being 
run on the ground. 
Brood ''Census'"! 
The brood ''census"' was made in an attempt to establish indices to brood 
densities and the ratio of pairs of breeding ducks to numbers of broods. Portions of 
