Repeat waterbird ground surveys were conducted at 12 Macquarie Marshes sites in 2024-2025 in collaboration with NSW DCCEEW, who completed their annual spring surveys in October.

A managed environmental flow pulse was delivered to the Macquarie Marshes in September 2024 onwards following flows over winter.

This inundated all three parts of the Marshes (the northern, eastern and southern areas), creating feeding and nesting habitat for many waterbird species.

Despite some sites in the south drying out by the time of the December surveys, five wetland survey sites remained inundated into summer months and supported many species of waterbirds.

The Flow-MER waterbird monitoring coverage focused on the northern and southern Marshes wetland areas. The number of waterbird species recorded in these areas was: 

• August – 29 species
• October – 38 species 
• December – 37 species 
• February – 33 species. 

Macquarie Marshes, Northern Reserve Reedbeds (Image: NSW DCCEEW).

This included five NSW threatened waterbird species recorded during the targeted surveys: brolga (Antigone rubicunda), blue-billed duck (Oxyura australis), freckled duck (Stictonetta naevosa), magpie goose (Anseranas semipalmata), and Australasian bittern (Botaurus poiciloptilus).

Australasian bitterns are also listed nationally and are cryptic species, typically hard to detect during standard daytime ground surveys, so this observation was extra special.

The team are now undertaking the monumental task of analysing thousands of hours of acoustic recordings collected at eight wetland sites. This is not done just digitally. It requires manual listening of calls to confirm the accuracy of the species detections, including the presence of male Australasian bitterns who call at dusk and dawn when habitat is suitable for breeding.

This acoustic data, together with this year’s Flow MER ground survey monitoring and existing NSW DCCEEW ground survey data, will be used to compile the results of the first year of waterbird monitoring to be delivered later in the year. The results will document the outcomes of the 2024-25 environmental water delivery and inform water management decision-making.

The surveys were jointly run and funded by Flow-MER and the NSW DCCEEW with support from the NSW National Parks and Wildlife Service (NPWS). The team are working with the Macquarie Marshes Flow-MER Cultural Outcomes Lead to provide the opportunity for Aboriginal People to participate in surveys.