
151 
Table 3. -- Duck Brood Census Data 
a a a a a a a 
Number Square Number Pairs Per Broods Per 
County Broods Miles Pairs Brood Sq. Mi. 
Beadle 7 13.2 104 15 0.53 
Brookings 3 12.7 46 15 0.24 
Brown 5 13.6 253 51 0,37 
Day 11 10,2 149 14 1,08 
Edmunds 3 4.2 165 55 0.72 
Faulk 18 7,0 320 18 2.57 
Grant 9 10.8 233 26 0.83 
Hamlin 1 14,2 110 110 0.07 
Kingsbury 13 13,4 73 6 0.97 
Lake 16 19,5 166 10 0,82 
Marshall 3 3.0 92 31 1,00 
Miner 0 10.2 36 - 0 
Moody 0 6.5 30 - 0 
Roberts 33 9.0 538 16 3.70 
CED ESR SO SRE, FADE IR SE SSE? A WE TS AE ATIC 2” ARSE HR SRG TOE GA ETIES 
Totals 122 147, 5 2,315 19 0.83 
Brood Sizes 
Complete counts were made of the number of ducklings in 527 broods of 9 
species. The average brood size for all species and age classes was 7.02. Class 1 
broods averaged 7.37 ducklings per brood; Class 11, 6.84; and Class 111, 6.70. The 
data pertaining to average brood size and sample size by species and age classes appear 
in Table 4. Brood counts were not made in 1949 so no comparison can be made with 
brood sizes that year. . 
Table 4. -- Average Brood Sizes 


Class 1 Class 11 Class 111 Total 
Species No. Av, No. Av. No. Av. No, Av. 
Broods Size Broods Size Broods Size Broods Size 
Blue-winged teal 107 8.11 80 7.15 62 7.42 249 7.67 
Mallard — 35 7.06 18 7.39 16 6,94 69 7.12 
Pintail 22 5,00 15 3.73 46 5.30 83 4.95 
Shoveler 6 7.67 3 6,67 14 5.82 26 7.00 
Gadwall __. 27 7.19 25 7.32. 12 7.92 64 7,38 
Ruddy 8 5.50 8 6,63 1 5,00 17 5.00 
Redhead 9 7.56 2 9.00 - - ll 7.82 
Baldpate 2 9.00 3 6.33 1 7.00 6 7.33 
Canvasback 1 9.00 1 7,00 - - 2 5.50 
6.85 155 6.70 627 7,02 
~J] 
Ww 
~] 
—_— 
6 3] 
LS 3) 
Totals 217 
Summary 
1. Waterfowl breeding ground investigations by the South Dakota Department 
of Game, Fish and Parks in 1950 included a continuation and expansion of the survey by 
ground transect and the initiation of an aerial waterfowl and water area survey, a brood 
"census", brood size counts, and a cooperative banding program. 
2. Weather conditions during the spring were very unfavorable for waterfowl 
nesting. Low temperatures and frequent storms resulted in a delay in breeding activ- 
ity that was estimated to be about three weeks. 
