 A area of the floodplain, defined as the maximum area of contemporary flooding, has been identified by BirdLife International as an Important Bird Area (IBA) because it has supported up to 650,000 waterbirds during times of major flooding, and regularly supports over 1% of the world populations of black swans, freckled ducks, pink-eared ducks, grey teals, Australasian shovelers, straw-necked ibises, yellow-billed spoonbills and white-headed stilts.Other birds that have been recorded in large numbers include whiskered terns and Eurasian coots.Reduced inundation of the floodplain, through the construction of water management works, has resulted in waterbird numbers dropping by 90%, from an average of 140,000 in 1983-86 to 14,000 in 1998-2001.