What can a database compiled over 22 years tell us about the use of different types of wetlands by waterfowl in south-eastern Australian summers?

Understanding the roles of different types of natural and artificial wetlands in providing habitat for waterbirds is crucial to active interventions to conserve wetland biodiversity. This study made use of a large database compiled over 22 years from the ‘Summer Waterfowl Count’ to determine the relative use of five wetland types by 18 species of waterfowl in Victoria, south-eastern Australia. The abundance of 14 species and density of 15 differed significantly (P<0.05) according to wetland type. Waste stabilisation ponds supported significantly higher abundances and densities of many species, a greater number of species and a community structure that was markedly different from the other wetland types. Based on the findings of this study, we believe that the unique characteristics of each wetland type warrant the conservation of each. Moreover, waste stabilisation ponds are significant refugia for waterfowl in Victoria and the trend to modernise sewage treatment plants, to the detriment of waterfowl, should be approached with caution. It is suggested that these findings are probably applicable in other parts of the world, although further research is needed to confirm their universal application.