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This reduction in water areas was general over the State but was most 
severe in Missouri Hills (56 percent) and James River Valley (50 percent). The 
Missouri Plateau suffered moderately (32 percent) and the Minnesota Valley and 
Prairie Hills were affected the least (10 percent and 22 percent respectively). 
The decreases in water levels was accompanied by a 21 percent decrease 
in the breeding waterfowl population. The minimum state-wide duck density was 
estimated to be 10.85 ducks per square mile, compared with 13.72 per square mile 
in 1953. The current duck density is about the same (4 percent greater) as the 
1950-1953, four-year average density of 10.40 birds per square mile and represents 
a minimum population of 811,000 ducks. Coots decreased in abundance about 40 
percent below their 1953 level. 
The gadwall was the only species that showed an increase in density (21 
percent). The most drastic decrease occurred in the canvasback population which 
was 40 percent lower than in 1953. Substantial decreases occurred in the abundance 
of pintails (28 percent) and ruddy ducks (26 percent). Lesser, and similar, reductions 
occurred in the densities of mallards (19 percent), blue-winged teal (17 percent), 
baldpate (17 percent), redhead (15 percent), and shoveler (14 percent), 
The above changes in species densities resulted in a breeding duck population 
consisting of 42 percent blue-winged teal, 14 percent pintails, 13 percent mallards, 
11 percent scaup (probably 90 percent migrants), 10 percent shovelers, 5 percent 
gadwalls, 3 percent redheads, 1 percent ruddy ducks, and less than 1 percent each of 
canvasbacks, baldpates, and green-winged teal. 
Rainfall between the time of the breeding population survey in mid-May and 
the brood survey in mid-July was not sufficient to check the rapidly dropping water 
levels. At the time of the mid-July brood survey there were 40 percent fewer water 
areas (other than streams) east of the Missouri River than there was at the same time 
in 1953. This reduction in mid-July water area density was general over the eastern 
part of the State, averaging 47 percent in the Minnesota Valley, 34 percent in the 
Prairie Hills, 46 percent in the James River Valley, and 33 percent in the Missouri 
Hills. 
Despite the reductions in breeding populations and water levels, the east- 
river brood survey in mid-July indicated a duck brood density comparable to that of 
mid-July in 1953. An average of 0.65 brood per square mile was observed in the east- 
river country which is 8 percent below the 0.71 brood per square mile density in 1953, 
The distribution of broods, however, was considerably different than in 1953. The 
extreme eastern part of the State had a considerably higher brood density, especially 
in the north. In the Prairie Hills the density was 39 percent above that of 1953, The 
western portion of the east-river country contained substantially fewer broods than 
1953, averaging 60 percent less in the Missouri Hills and 36 percent less in the James 
River Valley. 
In short, the 1954 breeding population in South Dakota is 21 percent below that 
of 1953 but is approximately average for the four-year period 1950-1953. Water con- 
ditions are poorer than they have been at any time during the 1950-1953 period. But 
brood density through mid-July is comparable to that during the same period in 1953, 
