Releasing water in the Murray-Darling Basin for environmental purposes is often aimed at supporting the breeding activities of waterbirds in order to sustain their populations. We know broadly where waterbirds gather to breed in the Basin, and the kinds of water flows that are needed to support nesting and chick-rearing until young birds can leave the nest and survive independently (known as ‘recruitment’). Managers have identified two areas where improved knowledge would support better management of environmental flows. First, an improved understanding of the habitats that provide food for growing chicks. Second, recent losses of colonies show there is limited knowledge about species site choices, nest success and eventual recruitment, and managing nesting habitats and predators.
The research will concentrate on understanding which flow regimes best support waterbird recruitment, and which environmental threats and pressures affect waterbird recruitment. Maximising the recruitment of young waterbirds into the adult population necessarily depends on the number of healthy chicks that fledge from each nesting colony, meaning that we need to protect and maintain nesting habitats both between and during floods.
The study will focus on colonially-breeding waterbirds such as ibis, egrets and spoonbills because they are important species for water management, are easily surveyed, and have known breeding locations. Between them, they represent a range of feeding and nesting habitats and are considered to be a reasonable model for other waterbirds in the Basin.
To uncover the gaps in current knowledge, the Waterbirds team consulted environmental water managers and scientists, and reviewed existing published knowledge. We found two main avenues for research:
What will the research be used for?
The Waterbirds research program is aimed at helping managers to identify, maintain or restore key habitats, and better understand the scale of habitats and environmental flows that are required for successful breeding. It will produce practical information for better managing water, vegetation and feral animals to ensure ‘event readiness’ at nesting sites during and between floods to maximise recruitment. The research will also identify key nesting habitats and foraging sites, and equip managers with the information they need to maintain or restore them.
Our field researchers will be working in known waterbird nesting sites in four sites spread across the Basin. We will use a number of techniques to collect data, including: