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Swift Parrots: Beating the Odds
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The swift parrot is one of Australia's most critically endangered birds, with around 750 mature individuals breeding only in Lutruwita/Tasmania.
In the first episode of Swift Parrots: Beating the Odds, we share our findings from monitoring nest outcomes on mainland Tasmania, backed by close to two decades of long-term population monitoring.
Field observations, passive acoustic monitoring across nearly 150 sites, field cameras trained on active nests, glider surveys, health and diet analysis, and swift parrot mortality investigations show the species successfully nest and raise chicks wherever remaining habitat supports them, even in the presence of sugar gliders.
While competition and predation from a range of species impact nest survival, ongoing habitat loss remains the decisive threat to the species’ future.
To have any hope of reversing the swift parrot population trajectory, our efforts must focus on protecting remaining breeding habitat.
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Read the report and find out more over at the Landscape Recovery Foundation website: https://landscaperecovery.com.au/projects/swift-parrot-conservation
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This work was supported by the DCCEEW Saving Native Species grant and was funded by Saving Native Species and envirodynamics.
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CREDITS
Podcast produced by envirodynamics.
Show theme music: Easy Lemon by Kevin MacLeod.
Welcome to Swift Parrots Beating the Odds. The story of Swift Parrot conservation has previously focused on glider predation over habitat loss as the main threat to the species. Over two years of intensively monitoring swift parrots during the breeding season in Tasmania, the team from Landscape Recovery Foundation has found that swift parrots do successfully nest on mainland Tasmania and that nest success was occurring at a rate much higher than previous modelled estimates suggested. Their findings pointed to habitat loss being the main threat to swift parrot conservation. We can protect the species, but we need to focus on protecting remaining habitat. Here's our conversation with Leanne and Matt about the findings of their report. Hello there, welcome to Swift Parrots Beating the Odds or why habitat must be protected to save the species. I'm Dr. Ollie Dove and I'm joined by Dr. Leanne Wicker and Dr. Matt Webb from the Landscape Recovery Foundation and Envirodynamics. Now we're going to be talking about a very important animal, the Swift Parrot, and lots to do and lots of information that Leanne and Matt have been working on over the past few years and longer than past few years in the case of one particular impressive study. In this episode, we're going to be covering a big scale of the topic and lots of the information and all the important things to know. And then across the rest of the season, we'll be looking deeper into certain topics and diving into nuggets of information and all any questions that you might have and going even further. But we are currently in the beautiful land of Palawa country. We're in Luch Rida, Tasmania. So I'd like to acknowledge the traditional owners of Palawa as well as the traditional owners from the land on which you're tuning in from. So welcome, Leanne and Matt.
SPEAKER_00Thank you. Thanks.
SPEAKER_03Now, to start us off with, I think myself and our listeners slash viewers, if you're tuning in on our YouTube version, would like to know you two a little bit more and get to know who the experts are. So can you tell us a bit about yourself and what you do at LRF?
SPEAKER_00Yeah, hi, thanks. I've got a strong interest in threatened species conservation, and a lot of that's been within Tasmania for a couple of decades. Um and a a large part of that has been uh working on uh the swift parrot in Tasmania in its breeding range.
SPEAKER_04And hi, um thanks Ollie. I'm Leanne and I'm a veterinary ecologist, so I'm really interested in trying to understand how the health and welfare of wildlife living in the wild, how we can understand that better to conserve species. So I've been working with Matt for the past couple of years trying to understand just what are the different factors that um contribute to swift parrots being successful in their breeding when they're here in Tasmania?
SPEAKER_03For those of you that are watching us on YouTube, you're going to be seeing lots of beautiful footage of swift parrots throughout this episode. But some of you will be listening through audio channels. You're also very much welcome here. And Matt, you've worked with Swift parrots for a very long time. Can you, for our listeners, especially the audio ones, describe what a swift parrot looks like and tell us a little bit about them?
SPEAKER_00Yeah, so they're um they're quite a beautiful small um little parrot, uh, very bright green with some red and blue um on them. They're one of the one of one of the world's few migratory parrots, and so uh it their entire range spreads across um a large part of south east southeastern Australia, um, but then they migrate here in uh in spring summer to breed, and so Tasmania is the only place that that they breed.
SPEAKER_03Across the last 20 years, what have you been studying about their behaviour?
SPEAKER_00For almost 20 years now, we've uh been running a population monitoring program uh in the breeding range in Tasmania to just to better understand the spatial and temporal movements of um of where the birds are each breeding season, which is uh uh influenced really heavily by f the flowering patterns of uh certain food tree species, although they eat an awful lot of other um yeah, there's a lot of other food sources for the birds, but but where they settle each year to breed is largely determined by yeah, the flowering patterns of um eucalyptus globulus, blue gum, uh black gum, which is eucalyptus ovata, and also eucalyptus brookeriana. But then on top of that, wherever the flowering is, which can be very concentrated or widespread, that also uh well the birds also need hollows, tree hollows for nesting. So you need those they need those things um key resources to be to either co-occur, ideally, or be nearby to each other. And I guess w w one of the issues for one of the big issues for swift parrots is the availability of habitat and habitat loss. But because of this spatial structuring uh of the population each year, um yeah, it means sometimes there's very little habitat remaining or available for the birds, whilst we're losing habitat overall, but not even all of that is available in any given year.
SPEAKER_03In recent years you've added acoustics data into the mix of things. What does acoustics tell us about the Swift parrots?
SPEAKER_00Yeah, so uh uh using acoustic acoustic monitoring uh has really sort of been a it's uh been a bit of a game changer in terms of understanding breeding success, which is really important, obviously, for uh for conservation, but but even also just uh understanding the temporal use of of an area in in a given season. It allows us to get uh this really long time span of information from many sites that it's it's not possible to you know to do just through field observations. And and also really importantly, uh it allows us to get really good really solid information on breeding or nesting and nesting outcomes uh by interpreting the audio. Uh and critical to that is is having a uh we've we've got custom-built recognizers for acoustic data for swift parrots. Um two of the primary adult calls and and all but also chick begging calls that they make when um you know, when they're a week to two weeks uh away from fledging and they come up to the entrance of the hollow uh when the adults come back to feed them, and and it's quite a loud begging call and it's quite distinctive. And by having built uh built uh recognizers for them, it allows us to process uh huge amounts of data without needing to manually uh go back through them. It it took a long time to to develop the recognizers, but it's really paid off in the end in terms of understanding you know w where birds are are successful, just even where birds are, and what they're doing after breeding as well.
SPEAKER_03And with all the years that you've spent out in the forests working with the swift parrots, being amongst their natural habitat, uh what changes have you seen as the years have progressed?
SPEAKER_00Well, we've we've definitely learnt a lot more about the species and just its its spatial ecology, breeding biology, um but uh yeah. Uh that I've seen over yeah a couple of decades is just continuing habitat loss. And and the yeah, swift parrot habitat is not easily replaceable, and in particular nesting habitat, but um most of it is hundreds of years old. Um and then feeding habitat as well, it's the best f uh feeding habitat is you know, it's usually over a hundred years old. It's still they're not they're not quickly replaceable resources. And each year when we're doing the monitoring, you know, it's well you we've we find swift parrots in certain locations, and then the following year we'll turn up to places that we know are critically important uh for them. And they're gone. They've been cleared, logged, burnt in wildfires. Um and really what what what the species has been relying on for a long time, it's really just you could call it the remnants of what used to be here, like a lot of species are dealing with, but but because they're they're so specialized in their needs, um you know, there's even less um available for them. And yeah, this is it's really the primary reason why they're so endangered. They're listed as critically endangered. But it yeah, it's a hard thing to to watch over many years because it yeah, it's it theoretically should not be happening uh in many of these places because we know that that it's critical breeding habitat for the species, but it it's it's still being lost.
SPEAKER_03And I can imagine that can be a very difficult thing to face when you're seeing there and you're out there year after year. And that brings us into the Saving Native Species Project and what that was for. And as you were talking about there, habitat loss has been hugely impactful on the swift parrot population. And another story is that predation is also having an impact on swift parrots. When you were out in the field for all of those years, what were you seeing that didn't quite match that story?
SPEAKER_00What you're referring to there is uh predation by sugar gliders, which is is definitely a threat and was identified as a threat some time ago. But field observations over you know, over many years, um, like what we're seeing out in the field uh hasn't quite been matching uh some of the modelled predictions. And it was it just seemed quite clear that there was a lot more going on here and just the the whole uh yeah, the system is just a lot more dynamic and and we've sort of regi had reduced it down to something very simple and almost binary, where um most swift parrot nests uh uh on mainland Tasmania were sort of considered to be predated by sugar gliders and almost all nests on the offshore islands uh were successful. I mean, I after seeing uh seeing this for so long, yeah, it w it really needed to be addressed in in a more comprehensive way, uh just to really understand what is going on here. And there's a lot more to to find out. Uh, but uh yeah, in this project we really have seemed to have just really started to better understand uh what's actually going on for swift parrots.
SPEAKER_03And that brings us to you, Leanne, and how you fit into the picture because before I started working at envirodynamics, I had never heard the phrase veterinary ecologist. And I'm pretty sure a lot of our listeners or viewers might have not heard it either. So, what is it and what brought you into the Swift parrot world?
SPEAKER_04Thanks, Wally. Yeah, so well, I'm not sure that veterinary ecology really um has been established, um, but it's but it's obviously a real thing, as in, let me see, how do you describe it? So I'm a veterinarian and I have spent most of my career working with wildlife. And we're all really used to this concept that vets work with wildlife when they're in captivity or when they're being rehabilitated or we're responding to an emergency. But we also know that to have um, you know, really beautiful, biodiverse ecosystems with healthy, thriving populations of wildlife, they need to be healthy and there's a health component there. So veterinary ecology is really about it's a term that we made up. Yeah. I love it, it's great because it's about trying to understand what are the health and welfare uh aspects of wildlife, living in the wild, not in captivity, but in the wild, and how do we better manage our ecosystems and habitats into the future to support healthy, thriving wildlife into, you know, well into the future. So that's the aim. And I got involved in this work um many, it is quite a few years ago now, um, because of this whole drive towards sugar glider predation being the main threat, it really started driving funding priorities, research priorities, management priorities. And so there was this real interest in whether we could manage sugar gliders in in Tasmania to save a species. And Matt was involved in a project in the north of Tasmania, near Devonport, in a little area called Kelsey Tier, and it's a little isolated forest patch, and so we thought that it might be possible to manage gliders if they're an introduced, it's a marsupial, it's a native Australian marsupial, but introduced into Tasmania. And we thought maybe there'd be an opportunity to manage them in an isolated area, a bit like an island.
SPEAKER_00And to better understand what's going on, like as an ecologist, it's sort of there there's a there's a lot, you know, there's a lot of in there's a lot of knowledge that ecologists don't necessarily have. And it really, you know, there's sort of bleedingly obvious sort of important uh aspects to the survival of individuals and populations.
SPEAKER_04So I became involved because we started to be really interested in, I mean, sugar gliders are protected in the rest of Australia, you know. And we thought if we're going to manage certain euphemism, it means to euthanase, you know, sugar gliders, if you're going to do that to a species that is, you know, protected in the rest of Australia, and we don't really know a lot about sugar gliders and their wild diet other than what we've seen, and they're not necessarily an easy species to study, they're cryptic and they're nocturnal. It sort of also oppos pr presented just an amazing opportunity, you know. Like, could we look at their their gut contents and see what are they eating? Like, are they, since they got, you know, introduced into Tasmania, is it real? Like, are there is it something about living in Tasmania? Is it cold or is it something that drives sugar gliders to being carnivorous? Because that was part of the story for a long time, that perhaps they were desperate for protein. We also didn't really understand, you know, what density of gliders in Tasmania. There was sort of this sort of idea that they were across the state and that they were like there was just gliders everywhere and raiding nests. And what we found just didn't answer didn't really fit that story. So even in this area where we know there's a sort of potentially a higher density of sugar gliders in other areas, and there's about maybe a hundred nest boxes there, which gliders really love to live in, there was just many months where we wouldn't find any. There wouldn't be any in there. Um, and when we did find them, and we would look at their gastrointestinal contents, or like basically what they've eaten, what is their diet, and it just looked like gliders everywhere else, like that they look like plant-eating, nectivorous, insect-eating little mammals. And they, you know, there was no real evidence that was that that there were was any really carnivorous behaviour. And so it just fed into what we were seeing, like in the broader picture for swift parrots, that maybe there's more to this, and maybe, you know, sure, absolutely no doubt that sometimes a sugar glider might predate a swift parrot, but we just weren't seeing any evidence that it was this main part of their diet or that there's that that it was a major threat. And so, yeah, we so we really realised there's a need to intensively monitor nest outcomes and really see what the ev what the evidence said, like what's actually happening out there for swift parrots when they come down here to breed in Tasmania and how successful are they?
SPEAKER_03Across the years and the longer term and the shorter term, you've collected multiple forms of data. You've got acoustic, you've got spatial, you've got the population in the breeding range, and those watching on YouTube will see that there's also camera trap footage, and there's just lots of different data sources coming in. So, in terms of, as you mentioned, the broader picture, what are you seeing?
SPEAKER_00Well, uh a part of the project was to just try and get a much better understanding on how uh it's not just predation, it's uh nesting outcomes uh might vary, or do they vary in space, time, particular regions, particular habitats? Um is habitat availability um an issue? Probably the single most important thing t to have come out of this project is just a a whole br like it's a whole whole lot of information from different sources that uh that's increasing our understanding. But yeah, the single biggest thing is swift parrots nest successfully on mainland Tasmania. And unfortunately there's been uh let's call it uh narrative that's developed over over many years that all all swift parrot nests are eaten by sugar gliders um on mainland Tasmania. And the only other places that uh sort of really um support uh you know a decent sort of number of swift parrots during the breeding season is primarily Mirah Island and Bruni Island. And they are really important, critically important, but so is everywhere else on the mainland. And it it's you know, unfortunately just the the narrative sort of became so so strong uh that it sort of inf it's influenced decision makers, industry. Um it's sort of got a life of its own almost. But it's it's uh you can imagine it's sort of a bit of an easy out, uh, a lot of the time um when there's competing interest for um you know industries. And swift parrots. So it's it it's it's so important to be better understanding what's going on uh with uh swift parrots during the breeding season. Um a lot of the well most of uh of the data that the predation is based around, i it is it's you know fairly dated. Um and uh you know it's a small sample size. We've only got a small sample size as well. But it it's over just two years. Two breeding seasons. And it tells such a different picture to to what a lot of people have have really uh and a lot of people and governments and industry industries have uh sort of just used as a bit of an out um in terms of threatened species conservation. And it's for a species that really can't afford to be losing any more habitat.
SPEAKER_04Like so many issues in ecology uh or you know, issues or threats facing threatened species, it's quite complicated. Like the world's not simple, and we've managed to to simplify it into you know predation, not predation, habitat loss, not habitat loss. So one of the reasons that I was so excited to get involved in this work is that, you know, complex questions um probably need multiple different perspectives, and so like working alongside Matt, who has just such a long-term understanding of the ecology of the species at this landscape level, you know, this was a really wonderful opportunity to bring different perspectives, different disciplines together. And we worked with quite a multidisciplinary team. And so, you know, this project really only went for two seasons, but it's really embedded in this really long-term knowledge of the population and their movements over the broad broader landscape in Tasmania, but also we just went at it with so many different ways. We we kept thinking, how else could we answer this question? How else could we answer this question? And so I think that's actually one of the real um really amazing and quite wonderful outcomes of this project that we use so many different ways. We used our field observations and acoustics, and we looked at we used camera traps to monitor nests, and then we introduced necropsy of the swift parrot chicks that we found and understanding glider diet and genetics and all of these different ways, and all of them pointed to the same finding. And so while it goes over two years, it's quite spatially broad. We we were really intentional in making sure that the work we did was spatially representative across the mainland of us, Tasmania, and every way we looked at it, it just still kept coming up with the same answer, and that is Swift parrot nests can be quite successful on mainland Tasmania, even in the presence of gliders. Um, and there's so many different factors that influence their outcomes, and we need to be better at addressing multiple different factors or even just acknowledging different factors and managing the species better, because the continued focus on just one threat, sugar glider predation, is never going to save the species. It's certainly not going to reverse the population trajectory.
SPEAKER_03They say a picture paints a thousand words, so those of you watching us on YouTube will have been able to see some of that data to help paint that picture and see what the spatial data looks like. But for those of you listening, don't worry, you can also see it. If you look through the show notes, you can find a link to the publicly available report to have a look at it because it might help you get a bit better of an idea of what Leanne and Matt are talking about today. But in terms of those different data sources, which sound incredible because to have been able to do a two-year project, which you say isn't that long, but actually for some research projects is a really long time to be able to have funding for that long for a focused thing and to be able to have teams like genetics involved, as well as that the habitat things, the habitat, the camera traps, the acoustic traps, like it actually sounds like an ecologist stream to have all of those sources. And I would love to be involved in a project like that. It sounds brilliant. Now, with the camera traps, it is not easy to find uh where the swift parrots live. And even if you actually find them and find their hollows, they might be above you and they're up quite a big tree. And so the tree has to be climbable to be able to put the camera trap up in the first place. So just one thing to emphasize to listeners and viewers is how impressive it is, even if you don't think, or the numbers might look small compared to the 20-year-long data set, it is still very impressive work to have achieved that amount. And with the camera traps, as you were talking about that sugar gliders might not be the only thing predating on swift parrots, what else did the camera traps tell us?
SPEAKER_04Like, I I I can't help but say this. So, like sometimes between the two of us, uh, Matt and I are accused of boiling the ocean, like it, yeah, it it really was it actually has been a dream. Like, what an exciting opportunity, hey, to like put all these different ways of answering the same question. Okay, so in terms of um yeah, the cameras, I like, you know, I've worked with, I've been friends with Matt for a long time and have been, you know, out in the field with him for different reasons for many years. But actually finding a swift parrot nest, oh my god, I don't think I ever realized as well, like just how time-consuming that is. And these little birds, I mean, they're so beautiful and they are quite loud as they announce, they go, you know, they fly in and you can hear them flying in, and you go, there they are, and they've got this behavior that looks like I'm about to hop into my nest. And so you can sit there and watch these birds for like an hour more, and then they go, Yeah, sorry about that, and off they go somewhere else. So it can be hours to find a single nest. And yeah, like you said, and and they they they like nesting in old trees, you know, big old trees. And so sometimes they're dead and they're not safe to climb. So in the end, um, we ended up getting camera traps onto as many nests as we could over those two seasons, and yeah, so the tree climb had to climb up and you know get them. And we ended up with over half a million camera trap images, and you know, there's AI programs, but we really wanted to understand the behaviour as well, and we didn't know what to expect. So it, you know, we actually just had to sit and look through uh all of this this footage and images, and what we found was actually there's a lot going on at those nest hollows. Uh Swift parrots nest in quite a wide variety of hollows, um, and some of them with quite large entrances, sort of surprisingly large entrances. Um, and we said, see a whole range of species. Absolutely, we saw sugar gliders, but we didn't see sugar gliders at all hollows. Um, we saw sugar gliders near hollows, uh, but not really interested, just sort of moving past through the landscape. They might land and then just keep going. So we detected sugar gliders at about maybe just um a bit over half of the nests. They weren't the most common visitor to hollows, uh, with lots of different species introduced and also native. So we saw predatory uh species including black carawong and uh yellow waterbird, shrike thrush, honey eater, a whole range of native species, boobuk owls, uh, but also introduced, so starlings. And for for the first time, we actually have really clear footage of a carawong uh raiding a nest. And there's been a another part of the dogma has been that swift parrot nest hollows are too small for other species to access. Well, the carawang doesn't care, just stuck its long neck and its beak in and plucked out a little grey chick. Um, we we have such clear footage of that, really hard to see, but that nest did go on to fledge two swift parrot chicks, which was quite interesting. And we also um watched have footage of starlings and green rosellas entering and exiting um swift parrot hollows. Um, some of those nests did go on to successfully fledge one chick, but you it's hard not to imagine that maybe during those starling or green rosella or other species entrances into the hollow that they maybe, you know, killed uh a younger chick or uh or an egg. And so a whole range of species, not just predators and not just gliders, also competitors, you know. Birds don't like other birds nesting in their area, and sometimes they just go in and kill the birds. We know that it's reported for a wide range of species, particularly sarlings, but also rosellas and waddle birds and strike thrushes. We just know they do that, you know. And so the camera trap footage showed that very clearly. And in the end, uh using the camera trap footage, there's no real relationship uh whether a nest succeeded or failed, and whether a sugar glider visited or didn't visit. And we even have footage of a sugar glider going right into the hollow. And you can hear um one nest the sugar glider entered when an adult female was sitting on the eggs, and again later the night before, the three chicks fledged. And you can hear the swift parrots just saying, Get out of here, and the sugar glider going back out. But absolutely, our camera trap footage showed us that sugar gliders can be in the same area and enter right down into an active swift parrot nest and come back out again, and the nest still succeeds. So, have no doubt that sometimes a sugar glider will eat, you know, a chick. Yeah. But not just sugar gliders, and often, you know, maybe rarely, certainly carawongs and some other species were more common visitors. So none of this will be surprising to anyone who's studied forest ecology or forest dwelling birds or or even has an idea, you know, swift parrots are a forest species and they're dependent on nest hollows. In a landscape that's been quite heavily altered. You know, we've we've logged and cleared for agriculture and urban development. There's lots of reasons why we have lost hollow-bearing trees over time. And so, yeah, none of this will be surprising. Hollows are a limited resource in forests and increasingly limited as we continue to, you know, lose habitat. And so things that we found weren't uh it shouldn't really be earth-shattering. Starlings are known to do this. There's been previous reports with swift parrots. You know, some of the earlier papers were quite clear. Cookaburas have been documented predating on swift pat chicks in the past. So it's sort of like we got a little bit lost along the way.
SPEAKER_03Now, before we go into the tail end of today's episode, with a couple more questions to go, the three of us are gonna quickly we're gonna stop talking and we're gonna show you two clips. Now it's gonna be related to what Leanne was talking about before, in that the first clip shows a sugar glider visiting a swift parrot hollow. Now, that hollow was known to have three chicks in it. When Leanne was going through the footage, you can imagine how her heart might have stopped seeing that glider visit it. And you can hear, if you listen closely, the little chicks screeching away. But the second clip is going to show you that morning when you see three Swift Parrot chicks' heads pop out for their last feed, and those three chicks went on to fledge later that day. So enjoy the clips. Earlier you touched on the diet analysis work and you were looking at the diets of the sugar gliders. What sort of results were you seeing?
SPEAKER_04Yeah, so when you look at the gut contents, it it just basically is you know what that animal ate. Um and actually with sugar gliders, because of their digestion, you it's not just immediate either, like you know, what an animal ate that day, because they have this quite long intestines, they have a quite a long cecum, it's the same as our appendix. And so the contents in there, so it can show actually quite a number of days. So it gives you a really good understanding of what is this animal's diet, you know. But when you're just looking with your eyes, um, I don't have microscopes in my eyes, so I can see you can see insect exoskeleton and you can see bits of sort of plant matter. If you get a light microscope out, you can have a little bit more of an understanding. But actually, you're kind of kidding yourself if you think that you can really understand their diet just by looking at it. And so we're really lucky that technology has advanced to the stage that it has, and we work with a great genetics lab in Melbourne, Enviro DNA, uh, where the conservation geneticists really understand what we're trying to get out of this information, and that's I think really important as well. And so it's a thing, it's called DNA metabarcoding, like a barcode, you know, of groceries in a shop, really. And so you collect the gut contents all from all different parts of the uh gastrointestinal tract, in their stomach and their intestines and even their feces as well, their scat. And we submit that to the lab and they extract all of the genetics. It's amazing, actually. And then they sequence all of it, and then they can say, is it plant, is it insect, is it vertebrate, like what is in there? And what we found really isn't surprising. Um, it shows that sugar gliders in Tasmania have a really similar diet to what we know to be their diet on mainland Australia, which is where they're naturally distributed. They're mostly plant eaters. They like eating, you know, eucalyptus acacias just like they do everywhere else. They probably probably actually eat a lot of the same food that the swift parrots and all of the other uh nectivorous species are after. Uh so about 80% of their gut contents were different plants. Uh, some of them were introduced. I think there's some some plants, some of the sugar gliders have been raiding people's gardens. Uh about just under 20% were invertebrates or insects, so they like to eat insects that would be a great protein source to them. And a very, very, very small percentage, so just over 1% of the all of the thousands and thousands of reeds that we we got were different vertebrates. Uh, so that was different birds. So we do know that a small number of the sugar gliders had had had potentially um predated on different bird species, and that was included um uh blue wing parrot and green rosella, there's a whole range of different species there, but but such a small number, and it's I think it's 0.0002% or something, like a such a small percentage of uh the reeds or the results we got included swift parrot genetics. So we know that they're potentially there. It's really hard to know whether that meant that the sugar glider did really predate or whether they were perhaps, you know, living in a hollow where a swift parrot had been. We also know that uh sugar gliders, when the swift parrot adults are feeding their chicks, and we're going to take their nectar for feeding their chicks, it's a bit messy. And you can see on the camera trap footage, you can see some spillage, so nectar around the hollow, the entrance to the swift parrot nest. And the camera trap footage in the evenings or late at night often showed um ringtail possums, brush tail possums, and sugar gliders licking and chewing the bark all around. Uh, so consuming the nectar that the swift parrot chick uh adult had regurgitated. So we could also just be seeing that swift parrot genetics. So, yeah, really, really interesting, um, quite exciting to be involved in this. It's the first time we've ever done anything like this. Um, it it's it's really unique data. And and and what it shows is that probably sometimes some sugar gliders will, you know, and we already, you know, we know that, they sometimes will eat um, you know, chicks and eggs in nests. But most of the time, and the vast majority of their diet is composed mostly of plants and and then insects. So they're really just little omnivorous, gen opportunistic little little creatures who yeah, eat plants and insects. So that's what we found.
SPEAKER_00And live in hollows.
SPEAKER_04And live in hollows, yes, who live in hollows, and they're there all year round, you know, they would use the hollows. I think I think that's really important to know as well. Like when we look at the camera trap footage and the diet analysis and everything, all of the different ways that we looked at this, it just shows swift parrots nest in forests where there's a whole range of other species, including sugar gliders, and they coexist. And most of the time their interactions are just benign, they just hang out in the same space, and then sometimes it's not.
SPEAKER_00Like that's exactly right. And you know, it's when you consider that gliders uh they're resident all year round. Um well, presumably, they probably shift around as well, but in general, you know, th they'll have multiple den sites, tree hollows, yeah, that swift parrots use, but they could be there for years, um, with no swift parrots turning up. And then because of flowering conditions uh in a given season, all of a sudden in one year, a whole bunch of swift parrots descend on a particular area where there's a family of gliders living, or there could be several. Um depends what sort of scale you're talking about. And the less habitat there is, the fewer the hollows, the more likely there is to be interactions, competition. Um but it yeah, it really highlights uh just the importance of habitat uh in this whole equation.
SPEAKER_04Yeah, one of the things that we were really interested in understanding is, you know, maybe we're just looking in the wrong spot. Maybe there are areas where there's so many sugar gliders and they really are like locally and temporally uh like a big issue. You know, maybe we still haven't seen that. Um but we gosh, we spent so much time in the field looking for sugar gliders. So we did so many nights of spotlight surveys, double count spotlight surveys. We had a really intensive trapping effort, so uh, you know, thousands of nights of trap nights trying to trap gliders uh across the swift parrot breeding range. Um, all of these different ways that we tried to understand where where are all of these gliders and and and are there are there like tons of them, you know. And we know that they're there. I mean, there's definitely sugar gliders, probably across the the entire breeding range on the mainland of Tasmania. Um, we we know they're there because we did see a few, but in all of the many nights of spotlighting, uh, we saw four gliders during our formal spotlight surveys. And of all of the trapping nights, less than 1% of trap nights resulted in actually trapping any gliders. Like it is a very intense effort that goes into find and trap uh sugar gliders in Tasmania. And so I think, and and that's been found before as well, that perhaps the density is actually quite low. Uh and so, you know, some of the the sort of former approaches which talked about things like managing sugar gliders, you know, they're just not realistic. Well, A, they're quite less than 1% trap success is actually a very low trap success, and masses of resources go into trying to do that. But also, you know, they're definitely there, and perhaps, you know, sometimes they predate on swift parrots, but there's just not that many. You know, there's so I think it's worth, you know, putting that threat into perspective and and trying to be real about the you know, what that really looks like. So we know there are sugar gliders throughout, you know, the breeding range in mainland Tasmania. You know, how many they are or what density they're in, yeah, we don't really know, but there's no evidence that suggests they're at high density. The methods that we use to trap, they're they're the same methods uh that are used on like throughout their range, quite successfully on mainland Australia, and have previously been used in Tasmania as well.
SPEAKER_03And there's many more questions that I could ask each of you, and many questions that I'm sure our listeners or viewers can think of as well. So make sure you come back for our deep dives across episodes for the rest of the season, because we will go further into some of these topics that we've talked about today, but we don't want to keep you for the whole of your day today. The last question that I'll ask the two of you is what do you think about the trajectory of the Swift Parrot from here?
SPEAKER_00Overall. you know, over the past twenty years, all of the evidence is pointing towards their declining, uh and also we're seeing their habitat being lost, like critical breeding habitat being lost. And so that's pretty grim. Um however, uh they're not a lost cause. There's a viable population uh of swift parrots still. We just need to allow them to keep going and hopefully allow new habitat uh to come online uh before we t clear it, cut it down. There's a lot of hope to be able to not only protect the species but in the longer term uh hopefully even recover. This is going to take um you know real political commitment over long periods of time uh you know to increase the area of available habitat and protect what's currently left which as I said earlier it's really remnants of uh habitat that that the species is relying on. But yeah the the swift parrot's still in with a chance.
SPEAKER_04You know we've had some people ask us all right so if maybe sugar glider predation isn't such a big issue well they're fine are they fine? And I think that we our findings are very clear. There's it's very busy. There's a lot of competition for those limited resources. And so while we our findings don't support sugar glider predation being the main threat to swift parrot survival there's an awful lot of predators and competitors in the same forests looking for those same hollows. And so and that's only going to become worse with increasing habitat loss. So yeah we maybe we remove the focus on just one species but we we ha we can't think that oh well fine they're fine you know uh because competition for those you know hollows and predation by by all of the other forest dependent species is is only going to increase if we continue to lose habitat.
SPEAKER_00Ultimately it comes down to to having all of their re requirements met as as well. So there's increasing competition uh with decreasing uh availability of nesting habitat but the same exactly the same applies with feeding habitat and then on top of that we they need feeding and nesting habitat to co-occur. And really that that's probably the take home message uh for decision makers and if we're gonna conserve the species hopefully recover it um they're the primary sort of things we need to be aiming at.
SPEAKER_03Thank you both so much for your time today and thank you listeners and viewers for tuning in today. I think if you're like me you can very much see that there's two massive messages from today. One, ecology is complicated it's not a simple thing at all and two there is hope for Swift Parrots. A lot of work ahead but it's not game over and I think that's a really wonderful message. So we will see you next time for some deep dives into some more Swift Parrot topics