Call me by your birdsong

00:06 Daniella Teixiera: I just think sound is one of the best ways that we can connect with nature as well.

00:10 Courtney Melton: One of my favorite calls is definitely that of the Rufous Whistler. It's a lovely song and chortle and it is very, very cheery.

00:17 Paul Roe: I live in Brisbane in a fairly suburban area, but there's s Magpie family which are sort of next door to me, and every morning they kind of come and sing and it's wonderful, sort of, hearing them singing. And it's almost turned into a bit of a conversation with waking up in the morning, going on to the deck, and you see the Magpies there, the Magpies are calling and you end up talking to the birds, which sounds a bit crazy, but I think it's lovely.

00:41 Eliza Herbert: Bird calls punctuate the soundtrack of our lives. Whether we live in the city or out in the bush, these calls have the power to transport us to different environments. Imagine the crow of a rooster in the morning and you're transported to a farm. Imagine the coo of pigeons and you're in a bustling city centre, the squawk of seagulls might evoke the sounds, sights and smells of the beach. While the crescendo of a kookaburra's laugh will take you to the Australian bush. But did you know that sound could also help us assess the health of our environment?

This is Big Sky Country, a podcast by Bush Heritage Australia. Welcome back to Season 2. I'm Eliza Herbert and I'm delighted to take you deep into the bush this season. We're going to travel the vast continent from the flanks of the mighty Murrumbidgee River in NSW where over 40,000 trees have been planted by sheer people power and up north to what's being referred to as the Galapagos of the Kimberley, where some slimy snails have scientists extremely excited. And across to the ancestral lands of the Waanyi Garawa people, where they're keeping culture and biodiversity alive. We're going to meet experts in culture, conservation and country who are working on the ground to address pressing environmental threats.  

First up, we're exploring the power of sound. How it can connect us both emotionally and ecologically to our unique landscapes, and ultimately, how it can help us to protect them.

02:28 Daniella: It's something that people don't give a lot of thought to. When we think of connecting with nature, we think of greenery or being in the ocean or maybe animals, but we don't think about soundscapes all that much. But I really think that it's so powerful but overlooked. So, I find sound recordings as interesting as, say, photographs or videos. There's so much that you can get out of that, and it can really teach you a lot about an ecosystem. And really, yeah, connect you to a place.

02:59 Eliza: Meet Dr Daniella Teixiera, a senior ecologist for Bush Heritage and a researcher at Queensland University of Technology, who blends traditional conservation methods with acoustic technology to study threatened animals and ecosystems through sound.

03:13 Daniella: There are two ways we speak about acoustics, so there's this discipline called eco acoustics and then also bioacoustics, and people use them interchangeably, but they really are quite different. So, a lot of my work has been bio acoustics focused. So that's really a single species targeted really getting down to the details of what individual species are doing, you know, things like threatened species, monitoring that kind of thing. Eco Acoustics is much broader than that. It treats soundscapes holistically, so they're really quite different. One is really species focused, and the other is really soundscape focused. But the really exciting part that, you know, keeps me up at night and gets me excited about my work, is how we can combine those two approaches together.

03:57 Eliza: Dani began her career as a marine biologist. But now, instead of the sounds of the sea, it's the sounds of the Australian Bush that fill her days. She first became involved in acoustics in 2016, when she began her PhD, focusing on the conservation, behaviour and bioacoustics of endangered black cockatoos. These birds were some of the first to catch her eye or, in this case, ear.

04:22 Daniella: On quite a few occasions, both for Red-tailed Black Cockatoos and Glossy Black Cockatoos, I was present the moment the baby bird leaves the nest, which is extraordinary and something not many people get to witness. And that's the the moment that you just feel so wonderful because you know that they've contributed to the next generation of their species. And you know, when there's only 400 of them left in the whole world, it's really quite amazing.

04:44 Eliza: Dani’s PhD field sites were on Kangaroo Island in SA and in southwest Victoria, where tall Sugar Gums and River Red Gums provide crucial nesting sites for the black cockatoos. The birds were often difficult to spot, but Dani’s research trips provided her with magic moments that many of us would be lucky to encounter, like identifying the sound of fledging, which is the moment when the baby bird leaves the nest.

05:08 Dani: So, there's a really characteristic sound event that happens at the moment of fledging. It’s this cacophony of sound. So, as you all can picture, like cockatoos are noisy - they're screechy and you know, just that's how we characterise them. So right before fledging, the little baby cockatoo, the nestling, becomes noisier and noisier. So, in the few days leading up to fledging, they start calling louder. They call much more often. So their call rate increases significantly and they come up to the edge of the nest hollow, because they all nest inside hollows. Come up to the nest of the hollow, edge of the hollow, and they start crawling. The parent birds are perched at the top of the trees, calling back at them. They may not come down to feed them, or maybe they will. And there's this whole event of backwards and forwards calling, and the baby is getting all worked up and agitated, and the parents are kind of flying around and they may fly up to another tree and they come back. And it's just this whole thing. It’s quite an event.  

We actually call it a celebration because sometimes the other birds in the area get involved as well, and when the baby bird decides to fledge, they fly away and all the birds kind of fly away with it. And you can actually see this on your sound recordings or on your spectrograms, which is how we visualize sound. There’s this massive burst of acoustic energy right at that moment that it takes its first flight. You can often actually hear its wing beats as well. Its very first wing beats. And then it flies away from the nest. And you know, the sounds kind of fade off into the distance.

06:36 Eliza: The significance of this moment was compounded soon after, when, in 2020, the Black summer bushfires swept through Kangaroo Island and wiped out a number of Dani’s study sites. When she returned to the area, she found melted nesting boxes and scorched Sheoak trees. But it was the sound of silence. The still air, where once there had been birdsong but was the most foreboding.

06:56 Dani: So, there was a lot of emotion and sorrow and grief that kind of came with that, but then equally, this desire to be part of a bigger and bolder solution, I suppose. The black summer fires for me really, like sparked this desire to do things differently. That conservation can't be what it has always been. We can't think so short-sightedly and narrowly with saving species. We need to be doing things that might seem outrageous today. But in 50 years’ time, people are going to thank us for doing that.

07:30 Eliza: The best science we have tells us that increased and more frequent bushfire seasons will occur during the next century as a result of accelerated climate change. We risk losing more and more of our precious landscapes and the animals who call them home. The black summer fires were a startling precursor of what could come.

07:46 Dani: We're losing stuff before we even really know that they exist. And we don't really know the consequences of that loss. But, more importantly, what does it mean for us and to people who've been on this land for literally millennia? I think it's a much bigger loss than just degrading ecosystem services and those human-centric ideas. It's not about that for me. It's this whole, like, living, breathing world that we're deteriorating, so the loss of sound is just another consequence of that, I guess.

08:21 Newsreader: Fires and floods, turbocharged by climate change are now combining with mining, pollution and invasive species, leaving Australia's environment in a state of crisis.

08:32 Eliza: In 2022, the Australian government published the state of the Environment Report, which was a startling call to action to the Australian public to protect our natural places, and was accompanied by an Australian government commitment to protect 30% of land and sea country by 2030.

08:47 Newsreader: A major United Nations conference on preserving global biodiversity has opened in the Canadian city Of Montreal. More than 10,000 delegates, including scientists, government officials and activists, are taking part in COP 15. Over the next two weeks, they will try to agree on how to preserve sensitive ecosystems.

09:05 Eliza: That same year, the loss of biodiversity across the globe was on the agenda. At the 15th Conference of Parties to the UN Convention on Biological Diversity, or COP 15. At this conference, nations agreed to what became known as the Montreal targets. Global targets that include a commitment to take urgent action to halt human induced extinctions of threatened species.

09:25 Newsreader: It's being hailed as the most significant agreement ever reached to save the world's lands and oceans. Countries at the UN's Biodiversity Summit in Canada have signed a landmark deal to protect at least 30% of the planet’s vital ecosystems by 20-30, a goal that will be known as 30 by 30. Currently, only 17% of the Earth's land mass and 10% of marine areas are under protection.

09:53 Eliza: To protect our environment, we have to know our environment. So how can sound fit into that?

09:59 Professor Paul Roe: I think if we want to account for nature, you know, if we want to sort of meet these, you know, coming Montreal targets and things, we need some way to measure the environment and I think eco acoustics is a vital part of that. And I think we can in part use the acoustic observatory to do that.

10:17 Eliza: Professor Paul Roe is a chief investigator at the Australian Acoustic Observatory, the world's first observatory to acoustically monitor biodiversity across Australia. Like Dani, Paul tracks ecosystems using sound and believes that sound could hold part of the solution to protecting the natural world.

10:34 Paul Roe: So, sound can tell us a lot of things. So at the most basic level, we can determine whether species are there or not. We can understand a bit about species behaviour because the species are making sound in order to communicate, to defend territories, to find mates and things. So by understanding what the animals are saying, by understanding what kind of perhaps calls mean, or the interrelationships between calls, we can get a good understanding of the environment.

We can kind of understand, for example, how species are reacting to change. If there's a bushfire or if we do something like some sort of restorations or rehabilitations, we can understand, you know, when do the species move back into that area? Are they happy? Are they breeding? And things like that.

11:22 Eliza: The acoustic observatory arose from a conversation between Paul and his colleague, Professor Dave Watson, from Charles Stuart University, during a time when they were completing regular bird surveys in the Sturt desert. They started to get an understanding of what was going on in their ecosystems when the ecologists weren't there in the fields and they thought, wouldn't that be great to do it all over Australia?

11:42 Paul Roe: We have 400 recorders in total, which is a lot of recorders, but obviously Australia's a, you know, it's a large country, so we need to decide where to put them. So we put them in these sort of representative areas to sort of try to understand what was happening. Particularly to get longitudinal data to understand how things were changing overtime as a result of land use change, climate change and invasive species and bushfires and floods and things like that.

12:08 Eliza: Since the idea for the observatory was hatched, it's now grown into a continental scale acoustic sensor network recording continuously across 90 sites in different eco regions on mainland Australia. For ecologists like Dani, the observatory is an incredible asset.

12:24 Dani: If you go and read the latest State of the Environment Report, you'll see that there's a lot of people who are deeply concerned and distressed about the lack of long-term data and our ability to actually understand what's going on with species and ecosystems. So technologies like acoustics can really go a long way to help us collect those big data sets.  

And although I think we really need to be good scientists first and foremost and bring our ecological knowledge into everything that we do. I want to also say that initiatives like the Australian Acoustic Observatory that are out there right now today collecting data continuously 24/7 at hundreds of sites across the continent are absolutely critical.

13:03 Eliza: The recordings and the data are freely available to researchers, citizen scientists and the general public so that they can be utilised in a number of ways. Think of it like a library of sound recording and archiving the sounds that are representative of our world.

13:20 Paul Roe: I think it's this idea that it gives us this sort of truth and it's something where also if you don't know a call, you can take the data, so you can take the environment to people. I think that's very powerful. So I think it's a little bit like sort of spatial data in GIS. It gives you this sort of truth. You know, you can kind of see that yeah, there's deforestation occurring. You can see that you have, the glaciers are melting. So, it's not just about, you know, one consultant or one ecologist saying they have seen something when they were in the field. We're able to actually get this sort of record. And I think having that archival and you know, fairly direct and permanent record of the environment is a very powerful thing.

14:04 Eliza: So while the acoustic observatory is a big picture idea, looking at sounds across the continent, what can we actually do with these recordings? Bush Heritage is one of the partners of the acoustic observatory and has recorders set up at 16 of its nature reserves, one of which is Yourka reserve on Jirrbal and Warrungu country in Queensland. Just a casual 130 km southwest of Cairns.

14:26 Paul Roe: And a lot of these reserves like Yourka are pretty remote and hard to get to. And so the idea is by having things like camera traps and sort of recorders, we can kind of have our eyes and ears there when there aren't people.

14:37 Eliza: Yourka sits in the Einsleigh Uplands and comprises one of the most diverse landscapes in the country. Weeping paperbark trees lean towards the Herbert River, while tall, wet eucalypt forests thread their way through the land, slowly transitioning into open Woodlands of Ironbark and Lemon-scented gums. These woodlands are home to vulnerable birds such as the Red Goshawk and Square-tailed Kite, as well as flocks of Red-tailed Black Cockatoos. Because Yourka occurs within a range where this species is still abundant, while in most places they occur they’re threatened.

15:09 Dr Courtney Melton: So the woodland bike community is a really sophisticated community. It's got a whole bunch of different species that sort of work in unison to provide a bunch of ecosystem services.

15:19 Eliza: Dr Courtney Melton is an ecologist with Bush Heritage working on a research project to assess the health of woodland birds using eco acoustics.

15:27 Courtney Melton: A lot of the woodland birds play important roles in pollination, so by them being in the environment, they're able to transport resources across the habitat area and sustain it that way.

15:38 Dani: We know woodland birds are declining really rapidly across Australia and that's mostly because of things like land clearing and other associated threats.

We have a lot of concerns about the communities of woodland birds. But we're also starting to figure out how we can measure those communities.

15:55 Eliza: One of the associated threats that concern Courtney and Danni is catastrophic bushfires, but Yourka is a great case study when it comes to fire. It has a tropical climate that alternates between two extremes. The hot dry season and the humid wet season, and it's country that is designed to burn.

16:11 Courtney Melton: Yourka Reserve is really special in the fact that it has so many different regional ecosystems, supporting a whole bunch of different species. And so what we're trying to do is sample that with acoustic recorders. So we're setting up a bunch of recorders in sites of different vegetation types, possibly with different fire regime history and understanding of when they were last burnt. Things like that. We'd like to understand the composition of the community in the different vegetation groups and in the places that have had different fire history or different management of fire over the years.

16:44 Eliza: Bush Heritage purchased Yourka in 2007 with recognition that fire is integral to the management of the land. Since then, reserve managers have carried out controlled burns which helped to prevent destructive wildfires and also promote new growth. Fire is also crucial for ecosystem maintenance into the future because managing fire to benefit biodiversity requires understanding of post-fire responses of ecological communities.

17:09 Courtney Melton: Different birds respond differently to fire and I think there's been some amazing research in that space, but we still have a lot of questions that we don't quite know the answer to yet. I’d be really interested to see what birds are using the habitat that's been recently burnt, versus what birds are using habitat that hasn't been burnt for quite a long time. And then also just doing, of course, vegetation surveys to see how those areas have changed in their composition of plants and what that means for the birds, so we can just get an insight into what it means to have an area that's been recently burned versus long, unburnt, and how that might feed into our management of a property like Yourka Reserve, and also how it might help us understand what the impacts of fire are to bird communities.

17:54 Eliza: Australian woodland birds have lost around 80% of their habitat to land clearing. To make matters worse, the Australian mega fires of 2019 to 2020 burnt over 20% of Australia's forests and killed or displaced 3 billion animals, including 180 million birds. Compared to controlled burns, like those at Yourka, these mega fires can have devastating impacts on the richness of bird species.

18:20 Courtney: When they're extreme fires like we saw in the 2019-2020 fires, that's when it's a really big problem. It's not something that's easy to recover from.

18:29 Eliza: Eco Acoustics is an ever-evolving field and we are only just beginning to understand what it entails. But we do know what it is not. It is not just a library of sounds, of threatened species, an archive of animal sounds that we might lose. It is a tool, A tool that can be used to prevent them from being lost in the first place.

18:50 Dani: There's so much room for growth. It's still a really young discipline, so it's really exciting to just be at the forefront of it now. And working with other researchers who are really paving the way for this technology.

19:02 Paul Roe: We're in a very privileged position now, I think as a species and I think we're the natural custodians of the world and it's, I think, it's our sort of duty and responsibility to look after it and you know the world is kind of like our body. In the end. You know, if we don't look after it, then it's not going to look after us either.

19:19 Eliza: For Dani, Paul and Courtney, their work in eco acoustics has been an opportunity for them to open their ears and tune in to the call of the wild. Because if we listen to our planet, we can learn how to protect it.

19:32 Paul Roe: It's sort of an integral part of our lives and I think if it was silent, we would be well, not only we'll be missing out on the beautiful sounds, but I think it would be an indicator that, you know, essentially the Earth's heartbeat has stopped.

19:45 Dani: I would encourage everyone to pay attention to the sounds around them. Really think of soundscapes as part of their environment. Where they live. Where they hang out on the weekends, where they go bushwalking, where they go swimming, even underwater. Pay attention to the sounds that are around you. It can really enrich your life and can tell you so much and really ground you.

20:11 Eliza: Join us for the next episode of Big Sky Country to meet more of the people on the ground who are finding solutions to some of our environments, biggest issues. Bush Heritage Australia is a leading not-for-profit conservation organization, protecting ecosystems and wildlife across the continent.

We acknowledge the traditional owners of the lands on which these episodes were recorded and recognise and respect their enduring relationship with their lands and waters. We pay our respects to elders, past and present, and any traditional owners listening today. If you want to know more about our work at Yourka Reserve and across the country, subscribe to this podcast, follow us on social media or sign up to our newsletter.

A huge thanks to all the supporters who make our work happen. If you'd like to donate to support our work, head to the link in the show notes funded by Chris and Gina Grubb and the Paul Hackett Memorial Scholarship for Bird Research. The project at Yourka will act as a trial with the potential to be rolled out across other landscapes managed by Bush heritage and hopefully other animal communities.

The Australian Acoustic Observatory represents a major collaborative effort by Australian academics, universities and conservation organisations, with input from 5 universities, the Australian Wildlife Conservancy, the Tasmanian Land Conservancy, Bird Life Australia and Bush Heritage.

A special thanks to Daniella Teixiera, Courtney Melton, and Paul Roe for sharing their words and expertise with us. News reports are from ABC and BBC respectively. Thanks to Bronte Ryan for assisting with the recording, and to Paul Hales and Leanne Hales for consistently sharing their knowledge of Yourka with us. This episode was produced by Coco McGrath and myself, Eliza Herbert. Intro music is Invertebrate City by the Orb Weavers and the episode was mixed and mastered by Mitch Ansell.