Bioacoustics and AI help scientists listen in on elusive Australian cockatoos

Barely a year after the Australian government classified the eastern pink cockatoo as an endangered subspecies, scientists have deployed technology to help study and protect the birds.

With the help of passive acoustic monitoring and artificial intelligence, researchers at the Queensland University of Technology found their way to a previously unknown breeding hollow of eastern pink cockatoos (Lophochroa leadbeateri leadbeateri) at the Bowra Wildlife Sanctuary in Queensland state, northeastern Australia.

“We had known that they were foraging there, but we didn’t know that they were breeding in that area,” Lola Lange, who was involved in the research and is pursuing her master’s degree in biology and environmental science at QUT, told Mongabay in a video interview. “We now know that it is even more important to protect the sanctuary.”

Pink cockatoos, with eastern and western subspecies, are endemic to Australia. However, the birds are hard to monitor and study because they live in remote arid and semiarid ecosystems. Despite their declining population, the difficulty and high costs associated with monitoring the birds have meant that there’s been very little research and academic literature that maps their habitats and studies their behavior. “In Queensland, we really don’t know why their populations are declining, what trees they like, what food they like and where they nest,” Lange said.

While figuring out how to track eastern pink cockatoos, passive acoustic monitoring was the most obvious choice to Lange and her teammates. The method of leaving audio recorders that can gather vast amounts of data over long periods of time has been increasingly used for noninvasive monitoring of animals that live in remote regions.

For her research, Lange and her teammates placed acoustic recorders at sites across eastern Australia. The study had two parts to it: while one looked at the spatial distribution of the birds, the other monitored how the birds reacted to changes in rainfall and increase in temperature over time.

For the spatial part of the study, the team deployed 22 recorders in the Bowra Sanctuary in Queensland. They also used four recorders already placed at the site by the Australian Acoustic Observatory, an observatory with a nationwide network of acoustic sensors. In a bid to get a sense of what types of vegetation the birds preferred, they left the recorders there for seven months last year. “Studying the vegetation is very important to understand their ecology and create appropriate conservation strategies. Do they rely on certain trees or on a certain type of vegetation?” Lange said.

The temporal part of the study involved using data from eight recorders placed across three sites in Queensland and New South Wales between September 2019 and April 2021. “We had some periods of drought and some really wet periods. We are trying to see, with those changes, if there are any differences in the bird’s activities,” Lange said. “Is rainfall and temperature having a big effect on the activities of pink cockatoos? Will the population of pink cockatoos further decline with more extreme weather events?”

Once the recorders were retrieved from the sites, Lange and her teammates ended up with almost 20,000 hours of recordings for the spatial study, and approximately 78,000 hours of audio for the temporal study. They then ran the data through an artificial intelligence recognizer to identify the calls of the birds and map out their distribution. It was this map that pointed Lange and her teammates in the direction of the breeding hollow they found in the sanctuary.

 

“There are two large water sources where we were expecting to find more activity, and they seemed to be more active in one of these sites. This led us to explore this area closely, and a hollow was found,” Lange said. “This site seems to have an overlap of resources: there is cypress, in which they were observed foraging, and many larger trees that could potentially be used for hollows.”

While not confirmed yet, preliminary statistical analysis also threw up another surprising finding: vegetation type wasn’t the biggest variable in the activity of the birds. Lange said she’ll continue to gather more data and analyze further in the months ahead to corroborate the initial findings.

“After that, our research will hopefully guide the road to the conservation of these birds,” she said.

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Banner image: Scientists are hoping to understand more about where the birds live and how they react to changes in rainfall and temperature. Image courtesy of Ceclie Espigole.

Abhishyant Kidangoor is a staff writer at Mongabay. Find him on 𝕏 @AbhishyantPK.