Maned Ducks and Farm Dams: a Success Story

Abstract

Maned Ducks Chenonetta jubata were first seen in the study area, near Taralga, in the 1930s, when the first farm dams were built. This study tested the importance of farm dams by comparing numbers of Maned Ducks and their broods, in the periods September-December of 1981-83, on three pastoral properties with differing numbers of dams (40, 10, 14). There were significant differences among properties in numbers of Maned Ducks and their broods but, when compdred on a per dam basis, there were relatively few differences in these two measures. Where differences occurred these were attributable to dams being close to where wheat was being fed to livestock, a strong predictor of relative abundance. The species used farm dams almost exclusively and not the creeks within the study area (1981-83). Most dams were used by Maned Ducks at least once; only small dams covered by emergent surface vegetation were not used. During breeding, Maned Ducks were usually found on dams within 400 m of tree hollows. Broods tended to stay on those dams close to where t!ley were hatched although the size of the dam was also important through the fledging period. After breeding, the area of the dam was an important predictor of relative abundance of Maned Ducks. Most dams satisfied the ecological requirements of this species and this study provided evidence that the number of dams is the main determinant for the number of Maned Ducks and the number of broods hatched.