Factors Affecting Waterfowl Brood Use of Stock Ponds in South Dakota

A July waterfowl brood survey was conducted from 1973 to 1976 on stock ponds located within four physiographic strata in South Dakota. Information was collected on weather, stock pond characteristics, land use and the condition of other wetlands located within the quarter section (64.8 ha) study plots. Multiple regression and multiple discriminant analyses were sued to determine the importance of these variables in influencing brood use of stock ponds. Vegetation type, distribution of emergent vegetation and pond size were important in determining if broods of any particular species utilized a pond or not. Shoreline distance was particularly important in explaining variation in brood densities. Highest brood densities occurred on stock ponds of 0.40 to 1.00 ha surface-water area. Blue-winged teal (Anas discors) broods were positively associated with alfalfa and negatively associated with total stream area on the study plot. Mallard (Anas platyrhynchos) broods were negatively associated with pasture and hayland. Pintail (Anas acuta) and gadwall (Anas strepera) broods exhibited a positive association with stock ponds that had a dispersed pattern of vegetation and were located in areas of high surrounding wetland densities. Older broods of all four species combined (subclass IIc and class III) were positively associated with stock ponds having a stable water level and emergent vegetation