Waterfowl Production on the Woodworth Station
in South-central North Dakota, 1965-1981

Table 42. Reduction of brood size of 12 duck species between
age classes for July and August counts,
Woodworth Study Area, 1965-81.


Table 42. Reduction of brood size of 12 duck species between age classes for July and August counts, Woodworth Study Area, 1965-81.
  Reduction of brood size from average age Class I to Class III ducklings
Species Number Percent
Dabbling ducks
Mallard 0.5 8
Gadwall 0.3a 4a
American wigeon 1.3 18
Green-winged teal 1.5 27
Blue-winged teal 1.0 14
Northern shoveler 0.8 14
Northern pintail 2.8 42
Total dabbling ducks 1.2 17
Diving ducks
Redhead 2.9 44
Canvasback 2.0 37
Lesser scaup 0.9b 13b
Ring-necked duck 2.0b 33b
Ruddy duck 0.6b 12b
Total diving ducks 1.5 25
All broods 1.1 16
aBased on Class II brood size because of no sample of Class III broods.
bAverage brood size increased between Classes I and II; no sample of Class III broods.


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