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Soundtrack of the bush

Published 18 Jun 2021 
by Bron Willis

Australian scientists, in collaboration with Bush Heritage and other conservation groups, have built a world-first acoustic recording network that will change the nature of ecological monitoring forever.

It’s dawn on the flooded plains of Naree Station Reserve and Yantabulla Swamp, Budjiti country in far northern NSW. The Royal Spoonbills and Great Cormorants are calling across the wetlands. Recent rains in 2020 have attracted hundreds of migratory waterbirds to the swamp, a spectacle many researchers would love to witness in person.

But migration events such as this are hard to predict, the roads are now impassable, and the chorus of birdsong falls on deaf ears. Or so you’d think.

Yantabulla Swamp after flooding. Photo Kylie Fisher.
Yantabulla Swamp after flooding. Photo Kylie Fisher.

Not far away stands a small, solar-powered acoustic recorder atop a star picket, erected firmly in the earth. The unit is capturing every moment of the raucous dawn; the tell-tale grunts, growls and soft honks of the Royal Spoonbills laid down in crystal clarity on an SD card.

All that’s needed now is for someone to collect the SD card when the reserve dries out, and the identities of Naree’s avian visitors will be unveiled.

The unit is one of 360 currently laid out across the country, including on 16 Bush Heritage reserves, as part of A20: the Australian Acoustic Observatory, a world-first network of acoustic sensors.

From woodlands to wetlands and forests to deserts, these sensors are recording the sounds of Australia continuously for five years. At the helm of A20 is Professor Paul Roe from the Queensland University of Technology.

Bush Heritage staff set up an A20 acoustic recorder  on Naree Station Reserve, Budjiti country, NSW.  Photo by Amelia Caddy.
Bush Heritage staff set up an A20 acoustic recorder on Naree Station Reserve, Budjiti country, NSW. Photo by Amelia Caddy.

“Sometimes it’s a good idea to close your eyes and listen,” says Paul. “We’re very visual animals yet there is so much more to be gained if we just stop and listen. Birders know this – they listen as much as they watch."

The Acoustic Observatory is a ground-breaking project that will provide insight into the ecosystems in which the recorders are placed, with a level of detail that has never before been possible.

“This isn’t a project where you can just look in an ecological textbook and say, ‘Oh, we want to do biodiversity monitoring using eco-acoustics’ and find an answer,” says Paul. “This is very much at the bleeding edge of what’s been done.”

The units are checked every six months, and recordings downloaded once a year. Once the data has been collected and analysed, it will help scientists to map daily and seasonal changes in animal behaviours, record the presence of species that are hard to see or track, and provide early warnings about potential issues in an ecosystem.

Great Cormorants at Naree. Photo Roxane Francis.
Great Cormorants at Naree. Photo Roxane Francis.

The project represents a major collaborative effort by Australian academics, universities and conservation organisations, with input from five universities, the Australian Wildlife Conservancy, the Tasmanian Land Conservancy, Birdlife Australia, and Bush Heritage.

When Bush Heritage’s Executive Manager for Science and Conservation, Dr Rebecca Spindler, first heard about the project she was quick to jump on board. “It’s like having an expert volunteer out there on reserve constantly - rain, hail or shine,” she says.

Paul Roe says setting up the Observatory would have been impossible without the contribution of these organisations – the staff and their armies of volunteers.

Collaboration is vital, particularly for places like Australia that are suffering the effects of climate change – and where we have organisations like Bush Heritage that are really doing something to conserve land and species.”

The data-analysis phase of the project will be colossal and cutting-edge. “We can train computers to pick up specific sounds. We’ll be able to grow algorithms for particular species that we’re interested in,” says Paul.

Ecologist Graeme Finlayson setting up an acoustic monitor. Photo Amelia Caddy.
Ecologist Graeme Finlayson setting up an acoustic monitor. Photo Amelia Caddy.

And, because the data will be available to anyone due to the ‘Open Source’ software it uses, researchers will be able to refer to it for decades to come to help identify long-term trends, such as those associated with climate change, development or land clearing.

Another huge benefit of the Acoustic Observatory is its capacity to engage and inspire more people in the fight to protect Australia’s landscapes and native species.

“The data makes the health of our landscapes easily visible – and if we’re going to bring more people on board to care about our climate and our landscapes, we’re going to need a way to easily show them the health of our country,” says Rebecca.

“We’re also going to need a lot of volunteers to listen to the recordings periodically and analyse the data. That will mean there are more people with a vested interest in and knowledge about the health of our landscapes and species.”

Rebecca is thrilled to see Bush Heritage volunteers, staff and scientists at the forefront of such a groundbreaking project. “This is likely to be our most successful citizen science foray to date,” she says.

For more information about A20, visit: