Bird species boom at Bool Lagoon

Known as Pulan in Bunganditj, the Australasian bittern has been detected at Bool Lagoon for the first time in 18 months, signalling improved conditions across the iconic Limestone Coast wetland system.

National Parks and Wildlife Service (NPWS) Conservation Ecologist Bradley Clarke-Wood said the return of the bird species is an encouraging sign for the health of the lagoon.

“The Limestone Coast's wetlands and groundwater-dependent ecosystems face ongoing pressures, including changing water availability. After two years of unfavourable conditions at Bool Lagoon, freshwater inflows arrived in June, creating a haven for birdlife,” Mr Clarke-Wood said.

“In July and September 2026, NPWS deployed acoustic recorders to the Bool, which captured the distinctive booming calls of male bitterns during their breeding season.

 “Australasian bitterns are exceptionally difficult to observe because their plumage provides excellent camouflage in dense reeds and sedgelands, so the recorders have proven invaluable for detecting the elusive bird species, which can easily go unnoticed during conventional surveys.”

Acoustic recorders enable NPWS to continuously monitor wetlands, even when observers are not present, and better understand where bitterns are occurring and how they are using habitats. Recordings can be analysed using automated sound-recognition tools, with any potential detections reviewed by experts to confirm the species.

Mr Clarke-Wood said, with the remaining Australasian bittern population estimated to be between 247 and 796 individuals in Australia, the timing of the species’ return is particularly exciting.

"Bitterns are highly responsive to water availability and can move quickly into wetlands when conditions are right. With water expected to persist across a large area of the wetland over summer, conditions may also support breeding opportunities if suitable habitat and food resources remain,” Mr Clarke-Wood said.

 Since June 2026, volunteer surveys have recorded 72 bird species at Bool Lagoon, including the Australasian bittern, glossy ibis, hardhead and magpie goose.

Bool Lagoon and Hacks Lagoon form one of South Australia’s largest freshwater wetland systems and are recognised as a Ramsar wetland of international importance.

They are among the largest remaining examples of intermittent, shallow wetlands dominated by grasses and sedges in a region where many comparable wetlands have been lost over time through drainage, declining groundwater level and climate change.

Seasonal flooding creates a mix of open water, reedbeds, sedgelands and other aquatic vegetation that support a diverse range of wildlife, including nationally and internationally listed threatened species such as the Australian painted snipe and southern bell frog.

The wetlands also provide important drought refuge for waterbirds, including around one-third of the southern Australian brolga population, and have supported more than 20,000 ducks.

Visitors can experience the recovery firsthand from a range of viewing locations, including the bird hide overlooking Hacks Lagoon, the elevated viewing platform along the Gunnawar Walk, and the lookout at Big Hill.

To learn more about Bool Lagoon Game Reserve and Hacks Lagoon Conservation Park, visit the National Parks and Wildlife website.

For information on volunteering and helping care for the region's natural environments, visit the Limestone Coast Landscape Board website.