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Waterfowl Density Trends 
The density of breeding ducks in South Dakota was the same as in 1952. The 
estimates of 13.65 ducks per square mile, or 1, 021,000 birds are a non-significant 
2 percent greater than the 1952 estimates of 13.37 ducks per Square mile or 
1,002,000 birds. This trend of no change in the size of the breeding population 
occurred at a high level of duck density. The 1953 breeding population was 47 per- 
cent above the 1950-1952, 3-year average of 9.31 ducks per square mile, or 
694,000 birds. 
The coot breeding population was also similar in size to that of 1952. A total 
of 3,295 coots were observed on the ground transects, indicating an average density 
of 5.9 coots per square mile. This density is a non-significant 7 percent above that 
of 5,5 coots per square mile in 1952, 
Waterfowl Distribution 
Geographic Distribution 
The geographic distribution of the 1953 breeding duck population is shown in 
Figure 1. This distribution is similar to that of 1952. 
Physiographic Distribution 
The physiographic distribution of the 1953 breeding duck population is indicated 
in Table I. The James River Valley contained 41 percent of the State-wide population; 
the Prairie Hills, 21 percent; the Missouri Plateau, 20 percent; the Missouri Hills, 
17 percent; and the Minnesota Valley, 1 percent. This distribution is also similar 
to that of 1952 with the exception of a shift of about 4 percent of the State-wide 
population from the James River Valley to the Prairie Hills. 
Species Densities and Percent Composition 
Data pertaining to the estimates of species densities and percent composition 
are tabulated in Table II. 
Species Densities 
Species densities were estimated as the product of the percent composition and 
the average, minimum State-wide duck density. Substantial increases occurred in the 
densities of the shoveler (37 percent) and the redhead (24 percent); and a lesser 
increase occurred in the density of blue-winged teal (14 percent). Substantial 
decreases occurred in the densities of the canvasback (44 percent) and pintail (38 
percent) with lesser decreases for the ruddy duck (21 percent) and mallard (12 percent). 
There was apparently no change in the density of the gadwall. Approximately 5 times 
as many scaup were observed as in 1952; but in this late-migrating species such an 
increase probably means that more migrating birds were present at the time of the 
survey. 
