For the birds

ISOBEL DEANE (PODCAST HOST)

Welcome. This is the Sydney Ideas podcast, bringing your talks and conversations featuring the best and brightest minds at the University of Sydney and beyond.

FENELLA KERNEBONE

Well good afternoon and welcome to Sydney Ideas, this is the University of Sydney's public talks program. My name is Fenella Kernebone. I'm the Head of Programming for Sydney Ideas and thank you for for joining us. It's great to see you here. Before we begin, I would firstly like to acknowledge the Traditional Custodians of the lands on which we all meet, live and work and share ideas wherever you happen to be today. I also acknowledge the Gadigal People of the Eora Nation; it's on their ancestral lands that the University of Sydney is built. And as we share our knowledge, our teaching, learning and our research practices within the university, we also pay our respects to the knowledge embedded forever within the Aboriginal custodianship Country. Today is all about our birds. We've got a range of short talks for you and there's some time for your questions towards the end, and we can't wait to hear your questions as well. We're talking about birds. It's going to be a whole lot of fun. It's now my pleasure to welcome you to your moderator and your MC, Kurt Iveson, who is an Associate Professor of Urban Geography in the School of Geosciences. He's an active union and community organiser. His academic research and teaching focuses on the relationship between cities and citizenship and his latest book is Everyday Equalities: Making Multicultures in Settler Colonial Cities. He's also a regular media commentator on urban issues in Sydney, and that's why he's here, so thank you so much Kurt. Great to have you here and over to you.

KURT IVESON

Thanks very much Fenella and hi everybody. Thanks very much for joining us. So look, there's nothing like a disruption to our everyday habits to make us notice a few things that we usually take for granted and tune out. And while Sydneysider's experience of the recent pandemic has been really diverse, many of us have stayed at home for work in school and care. And those folks have spent a lot more time in their neighbourhoods than usual. And with the noise from traffic and planes and construction reduced, lots of people have been tuning in to the sounds of the birds in the neighbourhood, pay more attention to those birds and other wildlife that they share their neighbourhoods with. Now, it's fantastic I reckon that we're paying more attention to this. In my field of urban geography, we talk about city life as a being together of strangers. But we're paying a lot more attention to the different urban natures with whom humans share the city, and thinking about sees as a being together of species as well. And as we're about to hear, scientists like biologists and ecologists are likewise paying a lot more attention to cities, and the urban environment as habitat for flora and fauna. Now I'm sure if you think about some of the different places you've lived, some of those diverse urban habitats will come to mind. For me, growing up on the northern outskirts of Sydney near the edge of a national park, life was accompanied by the sound and movement of cockatoos and lorikeets, currawong and kookaburras. Now since I left, the brush turkeys have joined them in my old neighbourhood, and they're tormenting my dad and many other backyard gardens. But I've now moved to a neighbourhood near the Cooks River, and the habitat I can feel around me has changed dramatically. Ibis are a really big presence in a nearby parks. And if they happen to take a rest in my backyard on their journey from the river to the free food at a nearby high school, they're chased away pretty quickly by the resident miners who will also take on any currawong or lorikeet that's there to stop by. So tonight's talks are all about some exciting new research into the lives of birds in our urban environments, both the impacts of urban development on wildlife, and also the adaptations that birds are making to their urban habitats; and there's a couple of threads I reckon that you'll see connect all of these talks. First, you'll get insights from scientific research into the struggles that our bird neighbours are having in making their homes in the city. But I think you'll also get inspiration into the role that we can all play as part of the scientific index. Many of our talks tonight are reporting on really great citizen science projects that create platforms for pulling the observations that you and I and our fellow urban inhabitants can make to generate really fantastic datasets that are telling some surprising stories about our cities. So we've got five short talks for you and a chance for you to ask some questions towards the end. Our five speakers are going to be Professor David Phelan, whose research here at the university is aiming to identify the causes of Rainbow Lorikeet paralysis syndrome. Dr. Holly Parsons from Birdlife Australia on the powerful owl. Dr John Martin from the Taronga Institute of Science and Learning on the much maligned ibis and Dr Lucy Aplin, from Germany's Max Planck Institute, on the magnificent sulphur-crested cockatoos; and also Professor Dieter Hochuli on the brush turkey. Dieter leads the Integrative Ecology Group at the University of Sydney and his research group there uses a range of approaches to examine the mechanisms driving the ecology of a whole range of species, especially in novel ecosystems in cities; and it's been my pleasure to get to know data a bit better doing some work together with him recently. So Dieter, let's hear all about the brush turkey research that you've been doing.

DIETER HOCHULI

Right. Thanks Kurt. Look, I'm gonna share a story about one of Australia's more unique birds and how it manages to thrive in urban environments. It's kind of a feel good story about a classic Aussie battler, the brush turkey, or the aguila. It's a tough, resilient, hard working animal that went through some really hard times during the Great Depression, and virtually disappeared from the city landscape in the 1930s. Now it's slowly recolonised its former habitat to live amongst us as an urban dweller with us and Australia's biggest city. Seeing them in the urban environment, it's very common for a lot of us, and I want to tell their comeback story. I want to share some insights in understanding why they do what they do and probably start with one of the problems really. They're not universally adored and the main reason for this is the way that they hatch their eggs. The males build mounds, they move the plant material around and sort of create a giant compost heap. This brings them into conflict with a lot of gardeners who would prefer to have their gardens looking the way that they planted them rather than carefully arranged into a slowly rotting pile of dying plants. But I'm not a gardener so I actually prefer to look at them as animals who are incredibly industrious. They work relentlessly and they're blissfully ignorant of the changing fashions in garden design; if you're watching this one here on on your screen doing its work. Look, the females lay their eggs in the mounds; the males control the mound temperature by working them until the eggs hatch, and the chicks then head off into the world. And after that, it's pretty much hands-off or wings-off way of raising your kids. So one of the big parts of their comeback story is their ability to move through the suburbs and that's something we've been doing as part of the Big City Birds project, which includes, as you can see here, John Martin from Taronga Conservation International, Alicia Burns for there as well and Matt Hall is doing his PhD on these animals. And what we've been doing as the Brush Turkey Wing of the Big City Birds team is really trying to understand how these animals are moving through the suburbs. And I've got a real connection to the turkey that you can see on your screen at the moment, because this turkey was caught at the Sydney Uni campus in Camperdown in 2020. We gave him his tag number 97 and watched him move through the inner west for a few months, mainly within a few kilometres of where we caught him. He then found his way to Kings Grove a few months later, we think it may have been through navigating using green spaces and parks and stepping stones. This turkey is now a resident of Oatley in Sydney's south; it's about 15 kilometres as the turkey flies. We only know about its movement through the Big City Birds app, and the citizen science project we've got and through people sharing its movements through social media. One of the things you might want to think about is the behaviours these animals show and what they're thinking about when they're moving through the suburbs, and I probably tried to capture what I think these turkeys are thinking as they're interacting with us and moving through our suburbs. It's probably what's on the screen there. We measure flight initiation distance to try and work out how bold these animals are. This is essentially, involves in this video here, where you walk towards the bird at a constant speed until the animal exhibits a response to a potential threat. It's widely used to assess behavioural responses to threats within species and among species. Now, turkeys seem to be one of the boldest species around us in terms of native birds, they really don't seem to give a – give one. Right. But more interestingly, we looked at variation in boldness among individual brush turkeys and the city birds are much bolder than their country cousins. So one of the really fascinating questions for us is whether these traits mean that bolder individuals are more likely to be moving through the city, or whether it's just a case that they've got used to the disturbance of city so much that they're basically not worrying about us too much. And that's really why we're collaborating with citizen scientists throughout the city bird project to track the movements of these birds. So, they're not popular with some people. They're quite amazing city dwellers that are really working unbelievably hard to do well here. So you might as well you know, make your peace with the brush turkeys. They're back, and they're not showing any signs of leaving. Now their parenting is pretty old school. But there's a lot to lock in their determined attitudes, their commitment to getting the job done and their ability to focus in the moment in the here and now. So, you know, if I'm putting a bit of our human worldviews on them, I reckon they've got a pretty good handle on mindfulness or this hashtag that I was trying to promote which didn't take off – "moundfullness". In all honesty, though, we know that spending time in nature is critical to our wellbeing as people living in cities and the reality for people living in Sydney, particularly in the leafier suburbs, is it, you're going to be sharing your space with these animals so get to know them, get to know their biology, and let us know when they come to your neighbourhood. Thanks Kurt.

KURT IVESON

Thanks Dieter. What a fantastic way to end and hopefully my dad's tuning in this afternoon to hear about how we might be able to rethink the brush turkey I know he's sharing his data with and seeing that industriousness and all other capacities that they're demonstrating. So look, let's shift from the brush turkeys to the powerful owl, another creature that also survives in our cities, but is it thriving in the same way? So really pleased to welcome our next speaker Dr Holly Parsons, who's an ecologist and community educator who oversees citizen science, education, engagement and research projects in the urban space as the Urban Birds Program Manager for Birdlife Australia. But Holly, listen, before we get to hear about the owl – last Sunday was the final day of the Aussie Backyard Bird Count with Birdlife Australia I know you're running. I know it's too soon for results but how did it go?

HOLLY PARSONS

Look, it was amazing Kurt. So yeah, it's too early to know the state of play yet. But we had over 5 million birds recorded throughout Australia. We broke the record on our first day on the Monday for the most number of people out watching birds, which was twenty-six and a half thousand people. So lots of great people, I think, coming out of this pandemic hibernation that we've had, and connecting back with birds and hopefully feeling a lot better for it.

KURT IVESON

Oh, that's so great to hear. All right. Well, I want you to talk to us about your work on the powerful owl.

HOLLY PARSONS

Thank you. So look, for all intents and purposes, powerful owls shouldn't really be found in Sydney. They're this large forest owl with this impressive 1.4 metre wingspan, they're a top-order predator; you would usually find them in territories of continuous forest of thousands of hectares. They're naturally found along the east coast of Australia, so from sort of mid to southeast Queensland, hugging the coastline down through to Victoria and just eking into South Australia; and we classify them as threatened or vulnerable in each of the states that they're found in. And if you talk to any birders from the 90s or earlier, powerful owls were a rarity. If one turned up, it was a massive talking point. It's still a talking point – they're awesome birds, and they're really special to see but there's many more of them living in Sydney than we ever had anticipated. While that's exciting, especially because this is a threatened species, it doesn't mean they're safe and life in the suburbs is unsurprisingly really tough for powerful owls. So 10 years ago, the concept of the Powerful Owl Project at Birdlife Australia began. And it had its roots, really interestingly, coming together from some researchers in owls and in urban spaces, including myself, wanting to do some nocturnal bird work as well as an amazing woman in the northern suburbs of Sydney, who just found one of these birds in her backyard; wondered what on earth it was and started collecting sightings. And so the citizen scientists really drive this work and they take their role very seriously, we'd be lost without them. They're not necessarily birders. Most of our citizen scientists are people who just have this passion for nature in general, and particularly care about the local community; so they can see changes going on and they want to make a difference. At the core of the work that they do is monitoring. They watch the population, their own little patch year after year, and report back on what's happening with their individual birds. In the last 10 years we've monitored – well, we thought we would start with about 25 to 30 pairs. We have been monitoring 253 breeding territories in locations stretching from Newcastle in the Central Coast down through to the Illawarra. This season's results are still flowing in because we're just coming to the end of the breeding season. But we've been monitoring about 144 active locations this season, and breeding has been attempted in about 103 of those sites. There are clear areas where powerful owls favour. They like the northern suburbs of Sydney, the Northern Beaches. There's some emerging sites in southwest Sydney and also through Sutherland and Heathcoate and the like, no doubt that's linked to where there's really good canopy cover. And through this monitoring, we can see sort of how the birds are faring overall. But because we have these amazing volunteers on the ground locally, we can provide individual site specific recommendations to land managers for doing things like when is appropriate time to be doing weed removal, and importantly as we've just come through when hazard reduction burns are planned – doing our best to ensure that the risk to the birds is going to be minimised. If they breed, the birds are quite good at actually getting the chicks to fledge, so getting them out of the hollows. But if we focus just on those successful numbers of 253 territories, and 103 breeding attempts, I think we don't we don't get a complete story. Through the keen eyes of our citizen scientists, as well as reports that come in from the public and amazing wildlife rescue, we're also sadly getting an idea of where these birds are getting into trouble, and even worse, where they're dying. One of the trends we're seeing more frequently in these urban powerful owls, is birds ending up in odd spots. In workshops, on school grounds, in supermarket loading docks; we had one in a shopping centre, popping up in car yards; and part of the reason these owls might become stranded in these wrong spots could be the landscape elements that are allowing them to move across the landscape of being increasingly lost in the urban space as we lose tree cover. Strangely enough, powerful owls are really short distance fliers, they hopscotch through the vegetation and along and over built structures as well in the urban space. So green corridors are really essential for facilitating their movement, and that movement is essential in turn, not just for supporting them hunting and supporting their prey, their ability to find mates – but for preserving the genetic health of the population as well. So we've been doing some early investigations into the genetic makeup of this population, and have found that actually, there isn't a lot of movement. There's distinct subpopulations of powerful owls in Sydney, with similar genetic structures confined into different regions in the Sydney basin. We need to understand more here about how this is working so we can better encourage the movement of these birds safely across the landscape. Car strike is a really significant threat for these birds, we've had 55 recorded mortality events this year, about half of those were the result of collisions with cars, and mortality events are ongoing. I think only two days ago, we got reports of five different dead powerful owls. So the mortality work alongside us trying to understand through looking at pellets or our vomit is that the diet of these birds has shifted. And this is raising some questions around emerging threats for these birds. We once thought that they were exclusively our boreal hunters or tree top hunters. But this pellet analysis and photographic evidence of the birds showing this isn't the case anymore. Owls are taking prey like rats on the ground, you would think that that's a good thing, keeping some some rats down. But it's actually a bit of a worry, because rat poison doesn't just kill rats. And we've recently been collaborating with a wildlife vet and showing that rat poison is indeed impacting powerful owls, particularly the second generation rat poisons that you buy on the shelves. These results have got us really worried. And it's adding to the growing knowledge of how dangerous these rat poisons are, for wildlife across Australia, and why we're doing some work in Birdlife Australia on getting these products removed from public sale, in line with what's happening elsewhere in the world. I'll just finish up by saying keeping long term projects like this running is really difficult. Funding bodies are always looking for new projects all the time. But strength really comes from this long term monitoring of populations. And for the powerful owls, it's helping us understand this species in an urban context, which is very different to what is happening to them in their natural forest ranges. There's great power in this kind of work, and it's really driven by the passion of the people who are involved who want to protect this really powerful species. So if you do want to get involved, search for the Powerful Owl Project on Facebook, and you can contact us through there. We're just coming to the end of the breeding season. But we will be recruiting for new citizen scientists who want to keep an eye on some birds in their patch in the new year. Thanks very much for having me.

KURT IVESON

Thanks so much, Holly. And look, I'm sure you and Dieter and everybody else will be getting for some applause, if only we were all in a room together. That was fantastic. And just such a story too, about all that complex interaction between the birds, the tree cover, our cars, the management of other species like rats, and all those things that are interacting there. So thanks so much for that.

So our next speaker is Dr John Martin and he's a research scientist at the Taronga Institute of Science and Learning. His research program there is directed to understanding the ecology of wildlife in human dominated landscapes. And we started with brush turkeys tonight that may not be everybody's favourite bird, but I think the white ibis that John is going to talk about tonight, might even take the prize for the bird that's most maligned in Sydney by its human neighbours right now. So John, over to you to tell us about the ibis.

JOHN MARTIN

Thanks Kurt. We'll touch on the love and hate relationship, but we'll get to that. So first and foremost, you've probably never thought about it, but ibis are carnivores. So just think about that. Lions. Crocodiles. Ibis. Not your normal list of species. But despite that, you know, they're actually hunting animals. They're eating fish, they're eating frogs. So you've probably seen them eating some really odd things that aren't animals like bread, and noodles, and rice. So these things are completely just an urban anomaly. They certainly aren't something that's occurring in the natural diet out in the western wetlands. But we're going to come back to that later. So let's start at the beginning. An ibis egg is about the same size as a chicken egg and I'm going to assume that everyone here can visualise holding a chicken. The males and the females both incubate the eggs, takes about 23 days. They tend to have two to three eggs and a clutch, and the eggs hatch on successive days. Now, when they hatch, they are just these gorgeous tiny little fluff balls, and you can just hold up like four or five of them in the palm of your hand. And they got these little gonzo noses. So they're really, really adorable. And yes, they have a fully feathered head. So you know, you hopefully you're all aware that the adult ibis is bald. So the chicks grow fast. At about eight weeks of age, they're pretty independent, often because the parents want to go and have another clutch of chicks. But what we've seen from some historic studies way back in the 50s, and some recent stuff over the last 15 years, is that these chicks are dispersing really long distances. So, you know, we've had birds moved from Sydney up to Townsville, it's about 2,000 kilometres. We've also had birds move from a few years ago, back in the 50s, moved from Victoria, all the way to PNG, and that's about 4,000 kilometres. So these these young birds dispersing long distances, and so importantly, I mentioned Papua New Guinea and that means that the Australian white Ibis isn't just an Australian species, it also occurs in parts of Indonesia and Papua New Guinea. Alright, so these chicks, they start to lose their head feathers at about the age of two and they recede down and they're becoming the bald adult ibis that we're familiar with. But I want you next time you're looking at some Ibis is to pay closer attention to the feathers on their heads, and also for the begging and feeding behaviour of the chicks. Right now it's peak breeding season so go into your local park where you know you see ibis, and you'll expect to see some chicks being fed; and it's something to pay closer attention to. So we're talking about these young birds, they're two or three years old, and we really don't know how long they live in the wild. So we've actually colour banded some birds here in Sydney. So we did this a number of years ago in Centennial Park, Botanic Gardens, Hyde Park – and we know that some of these colour banded, marked individuals are at least 17-years-old right now. That's pretty old. If you think about it, you know, this is a 2kg bird, 17-years-old is quite a long time. But they might live a lot longer and those birds that we think are about 17-years-old, could even be 30 or 40 years-old but we just don't know, we don't have that long term data. So to Holly's point, there's real value in being able to collect data over the long term. So if you're out and about, as Dieter mentioned, we have the Big City Birds app and that allows you to report sightings of ibis as well. So you might see colour band logos, or you might see wingtags as Dieter mentioned with the wingtag turkey, or nesting sites; all sorts of information you can report to us there about the bird behaviours, and your reports are actually how we learn about how they move across the landscape. Without the involvement of citizen scientists. I can't learn that a bird that I tagged in the Botanic Gardens has gone to Bondi, Bankstown or Brisbane. I can't be in all those places, especially at once. So there's real value in the data that you can contribute to our scientific research. Alright, so, moving long distances isn't anything new for white ibis, their natural behaviour is to be following the floodlands that occur out in the western wetlands. So we have these big rain events and across the Murray Darling, there'll be floods at different parts that could be even 1,000 kilometres apart from year to year. And so those birds have to be able to move across that landscape to access those habitats which they create foraging habitat, and also nesting habitat. However, we humans have dramatically altered the inland wetlands and we've reduced the frequency and the size of the floods, by retaining water for towns, so for us to drink and shower, all these things, but also for agriculture. And so there's a really valuable long term data set, which we've touched on already. But these things that they really allow us to get a greater understanding of how species are responding to human changes. And so this 37 year data set from Professor Richard Kingsford monitoring these western wetlands, and there's about 70 odd bird species that they monitor each year, once a year, they do a flying survey; and pretty much all those species have been declining over the last 37 years, and that includes the Australian white ibis, aka the bin chicken. So that's pretty concerning. But let's think about that for a second. There's not just the birds out there, there's the fish and the frogs and the plants. There's the mammals, there's a reptiles, there's insects, spiders, and of course, there's a range of birds that don't move that far; and all of these species are likely to be declining. It's just we don't have good data about them. Okay, so let's think about what we can learn from the Australian white ibis. Now, I like to put this to you, is that the Australian white ibis, also known as the tip turkey in my world, but a lot of other people call them sausage snatcher – many stories about people losing a sausage to the white ibis I can tell you. So I think that they're probably one of the most well known birds that are occurring out in those Western wetlands and I'm really a big fan of those funny names like bin chicken, and the art and the songs and tattoos and the cartoons, because it allows people to be talking about these birds. In general, we humans, we don't really care about species, if we don't know about. So I'm much happier that we're talking about ibis have been chickens, rather than no-one even knowing what their name is. Okay, and what are they doing in the city? This is the big question. So they've declined out in the western wetlands and we've seen a big increase over the last 30 years in the urban environment. The way I interpret that is that the Ibis drew the short straw, although it might have turned out to be the lucky prize, and they have flown to the city to fly the flag to say: You guys have stuffed up the habitat out in the western wetlands, we're here to let you know that you need to fix it. You know, if they were protesting, they'd be chanting, 'More water, more often. More water, more often.' You know, they want these floods to be occurring to be bigger, they want these wetlands to be created. So the ibis is actually a conservation messenger. Believe it or not, you thought they were just a dirty bird that wanted to share your lunch, but they're actually here to teach us something. Alright, so the city is this dramatically different landscape and you got to think about it, the cities are built for people. They're not built for the birds. They're not built for the animals and plants. They've had to learn to adapt to learn with cars and cats, and people – that can be a problem, you know, people might actually harm these birds – and they've also had to learn to eat a variety of different delicious foods. And so you can report those through the Big City Birds app as well so if you see birds eating Thai food, Italian, Lebanese, or Aussie fusion, maybe a bit of a haloumi brekkie burger, we want to know about that. They've also adapted by nesting in palm trees and so I call these the ibis apartments in the city; and this is an absolutely alien landscape for ibis to be nesting in. They normally would be in a beautiful waterfront wetland where they've crushed the vegetation and build a raft nest, and that's a temporary thing that they move, fly away from. The water recedes, and they have to leave that space. And so one of the things that we've seen in the city is that there's abundant food and water, and lots of palm trees and other good habitat for them so they're actually breeding more often in the urban environment, supplemented by all the food that we're providing for them. The consistent food. It's not the boom-bust cycle anymore. It's just an open buffet, and the ultimate buffet is the landfill. All of our household waste that goes to the landfills every day, there's food in that and believe it or not, about half the ibis in the Sydney region are regularly foraging at landfills on a daily basis. So when people are complaining to me about white ibis, I can tell you this is a human issue. It's actually not an ibis issue. They're just adapting to the situation that we've created. Lastly, let's go back to the food situation here, which we've just touched on, and so people have also raised some concerns about the ibis diet, because they see them eating all this rubbish food, which is actually what we eat day-to-day: bread and noodles and things like this. And so I've seen through our research that ibis actually have quite a balanced diet. Yeah, they'll feed a little bit from the bins, they might try and share your lunch with you. They might go to the landfill. But we also see them foraging on natural food sources on a day-to-day basis and this varies between different birds. But we've all seen it on a wet rainy day, you go down to the cricket oval, and what's there? A bunch of ibis probing into the soil and eating all the worms, so it's good tucker. They're also going to the wetlands, the creeks; they're foraging on natural food sources, so fish frogs, all the different invertebrates that are in there, in the water column or in the mud. They're really getting a bit of a balanced diet, which is ultimately, what we're encouraged all of us to do, you know, all in moderation. And so just my concluding point is, if you're someone who feeds ibis, I can tell you, they don't need that food and I encourage you to feed in moderation if at all, because lots of other people actually feed them. And I'm sure you don't want to feed them something like meat, but that's actually what they naturally eat. And so feeding them bread or other foods like that – human foods – are not particularly good for them. So let the ibis be ibis. Let them fly around and forage in the wetlands. Thanks.

KURT IVESON

Ah, awesome John. Let the ibis be ibis, right on. Also, for me as an urban geographer, it's just such a fantastic story about how human activities in the regions are actually interacting with what's going on in our cities as well. What a great presentation as well. Everybody we've heard from John and Dieter and Holly, who are all working closely with citizen sciences and the public to assist with their research. And our next speaker, too, is involved in a really exciting new citizen science project. Earlier this month, he launched the Rainbow Lorikeet Paralysis Syndrome Project, calling for your help to identify the potential causes of a devastating disease that's affecting Rainbow Lorikeets. So welcome Professor David Phelan, who's the Director of the Wildlife Health and Conservation Centre and Avian Reptile and Exotic Pet Hospital at the University of Sydney, to tell us about this new study that's also supported by WIRES. So David, over to you.

DAVID PHALEN

Thanks so much for introducing me, and thanks for everybody who's come here today. I think we all know that Rainbow Lorikeets are amazingly colourful little birds that have beautiful plumage but they have an amazing and colourful little personality; and they have something to say about pretty much everything. And so it's been very hard for me actually to be part of this project to see what kind of devastation this disease causes. I've been fortunate though, to have some bright people helping me in multiple different institutions, but in particular I want to make a shout out to Lauren Bassett, my research associate and Maya Yaffe, my veterinary student that's volunteering her time just to support this. So on this next slide, what you can see is that lorikeet paralysis is a disease that affects Rainbow Lorikeets, and also affects scaly breasted lorikeets. But by and large the vast majority of the birds that come into care are Rainbow Lorikeets; and these signs include partial or complete paralysis, so the inability to control the muscles in any part of your body. And if you could imagine that, you're walking through the jungle and you eat something that within a few hours paralyses you and you're just laying there on the path. That's the kind of experience that these poor Rainbow Lorikeets have. We can recognise them very quickly when they're brought into care, because they have very characteristic change of voice, and they also are unable to blink and in severe cases, they're unable to swallow. How many birds are affected by this every year? We're thinking that probably it's many hundreds of birds but it could be possibly many thousands of birds, because we only see the ones of course that come into care. Lorikeet paralysis is a uniquely Australian disease and it's got a very relatively limited range. And you can see on this map that it's only present in southern – southeastern Queensland along the coast, and in northeastern New South Wales. Also on the slide, you can see a graph on the right hand side and you can see that it's a seasonal disease. If you look at the blue bars in the figure, you can see that lorikeet paralysis occurs almost exclusively during the warmer months of the year. We've had our first cases now, at the end of October, and it will start to peak and rise in number and all the way till the end of December, beginning of January, where we'll have many dozens of lorikeets presented every year with this disease. And then after February, it starts to taper off until by June, it's pretty much gone, and we don't see it again until October of the next year. Again, as I mentioned before, if you can imagine, lorikeet paralysis is a devastating disease, from the point of view of the affected bird. But it also provides a very big challenge for wildlife carers and wildlife veterinarians; and the reason for that is that it takes many, many days, up to many, many months sometimes for these birds in hospital first to get through the crisis stage, and then in care for them to recover from this disease, regain their fitness so that they can be released and survive back in the wild. Also, a significant portion of these birds with the advanced disease that we see come in with the most severe forms of this disease, even though they get really intensive care, and are treated by really competent veterinarians, will still die. So there is a lot of these birds that do die. And again, you can imagine how devastating that is to all the people that are that are caring for them.

KURT IVESON

Given its distribution and seasonal variation in nature, we really think that this disease is the result of lorikeets consuming toxic plants, whose flowers or fruits are only available during certain times of the year. And so what is the plant that we think it might be? Well, this is where you can help us out. What we desperately need is people in the areas where lorikeet paralysis is occurring, in northern New South Wales and southeastern Queensland along the coast, to join our project in iNaturalist, to sign up and iNaturalist, and start making observations about lorikeets that are feeding in your backyard and letting us know what they're feeding on. That way we can start to get an idea of what kinds of plants they're feeding on during the season when we don't see lorikeet paralysis, and then we can see what they're feeding on during the seasons when we do see lorikeet paralysis, and therefore start to narrow down the list of plants that they're feeding on that might be causing this disease. And when we can identify just a several or a few plants that are causing this disease – that we think might be causing this disease – then we can start testing those plants to see if they have a toxin or not. So again, I really want to thank everybody for attending and I look forward to your questions; and I particularly look forward to your support. I hope that I'll see all of you signed up or most of you signed up for our iNaturalist study this Saturday when we go through and look at all of the new people that have joined us so far. Thanks so much David, and all that information that David has been giving you about the work that he's hoping you might be able to collaborate with him on, the information is all now up there on the Sydney Ideas website for you to explore; and if you're joining us on the Zoom this afternoon, we're sharing lots of great links and information from all of our speakers in the chat. So do check it out and explore those links once the talks are over. So our final speaker tonight is based in Germany; has woken up early for us, and is a Max Planck Research Group Leader for the research group there on animal behaviour, heading up the cognitive and cultural ecology lab at the Max Planck Institute for Animal Behaviour. So Dr Lucy Aplin's research explores the interaction between cognition, sociality and ecology in birds, and Lucy is especially interested in emergent properties, social networks, animal culture and cultural evolution. Lucy, I know some of Lucy's work has been featured in the news actually quite recently here. So do tell us more about the sulphur-crested cockatoo and why they're so unique and some of the emergent sort of behaviours that your research is noticing.

LUCY APLIN

Thanks Kurt, hopefully a slightly happier story than our last talk. So I'm going to tell you about how citizen science and my favourite Australian bird the sulphur-crested cockatoo, has given us new insights into animal culture and the way the spread of innovation may play a role in urban adaptability. So what is a cultured animal? Isn't this an oxymoron? Well, the best place to start is with ourselves because cultural behaviours are ubiquitous in humans, shaping our diet, our songs to our social structures themselves. Culture has even shaped our evolutionary history. But while we're extreme, we're not alone. Seminal research first extended the concept of culture to the lives of other great apes, showing that behaviours like stone tool use in chimpanzees are acquired from observing others with knowledge shared across groups, and this knowledge is then passed down over potentially many generations. Since then, we've extended the scope of cultures diverse species and shown that it matters. For example, shaping hunting behaviours and killer whales, and migration routes in birds like geese and cranes. In whooping cranes, migratory knowledge even needs to be retrained into reintroduced birds as part of conservation efforts. The loss of migratory knowledge in cranes is a really good example of how, that unlike behaviours that are innate and genetically encoded, cultural knowledge is ephemeral and could potentially be lost. But on the other hand, it can be also potentially be a source of new adaptive behaviour through the spread of new innovations. And for humans, cultural knowledge has facilitated our colonisation of almost every terrestrial habitat on Earth. But what about another animals? Well, let's return to the sulphur-crested cockatoo. So cockies share a lot of similarities with these cultured animals actually. We're all familiar with this raucous larrikin, but we might not appreciate just how remarkable they are. So this is a one kilogram parrot with a brain size on par with primates, and a lifespan as long as humans. They have a long juvenile period of seven years, and they're very slow breeding with only one or two chicks a year. Yet, despite all of this, they're opportunistic and generalist, eating a wide range of food and expanding their range and inhabiting our cities. Many Sydneysiders can also attest to how comfortable with human city cockatoos can become, and it's with the help of citizen scientists that we've been able to use the many eyes and thumbs of the human population of Sydney to give new insights into the lives of Sydney's cockatoos. So in 2016, it was first reported to us that there'd been the recent emergence of a new foraging technique in cockatoos opening bins. So standard household bins are obviously widespread across Australia as are cockatoos, but this behaviour is not. So we conducted annual citizen science surveys to track where it occurred, and thank you to everybody who sent in information and participated. When we mapped these, it showed clearly that there had only been two likely independent sites of innovation in the Sydney region once down south and once up north around Turramurra; and there's been geographic spread outwards from these over time. The evidence is overwhelming that this geographic spread has been as a result of social learning, with the information hopping from roost to roost, being carried onwards by dispersing birds. So we're still tracking this over time. So do please help us update this map for 2021. Then, by closely observing birds in different hotspot areas as they open bins, we were able to identify that bin opening is actually a really complex behaviour; it involves five distinct steps that take months for the birds to learn, highlighting just how difficult it is for them. Birds in different areas actually show a little variations in how they do these steps. For example, in some areas, birds open the bins by holding the handle, while others hold the rim. This might seem minor but it suggests that actually local subcultures are already starting to emerge at intriguingly local scales. Lastly, to identify the behaviour at the individual level, we temporarily marked the entire cockatoo population of Stanwell Park, a coastal town between Sydney and Wollongong, about 120 birds. And we use these unique paint combinations that wash off in a few months and the birds don't seem to notice them. But this allows us to conduct close observation of individual birds while they forage and when they're opening bins. So this is the social network of the cockatoos of Stanwell Park. Every bird is a dot, and the lines between them are the proportion of time they're observed foraging together. So the birds that tried to open bins are in the colour here. And excitingly, we could actually see that the birds that were more socially connected to successful bin openers were further along themselves in the process of learning the behaviour, just as we would expect to see, given that these birds have more opportunity to observe it. We also see that the behaviour seems to take months to learn, as I reiterated before, so it really is hard for them. And finally, I'm sorry to say that it is actually a bro culture. 80% of nin openers are male, and they also tend to be further up in the social hierarchy. We're not exactly sure why this is, but we're still doing some work to understand why. Of course, bin opening isn't so funny for the people who have to clean up the mess afterwards and people have very understandably responded by starting to protect their bins in all sorts of creative ways, some of which work better than others. So we've also been tracking these techniques and the birds response to them, and we're hoping to have some results soon to help give people information on what is the most effective way to manage this behaviour over the long term. So, are cockatoos feathered flying primates with culture? Maybe. We can at least sure that the spread of innovation in this species can lead to one urban adapted culture, and I suspect there are many more to find. To help us answer some of these questions, we've recently expanded citizen science app to the Big City Birds to collect data on behaviours and context, as you've heard from some of the speakers before. Please continue to report any new innovations you observe, as well as roost sites and foraging behaviour, and will continue to use this information to reveal just how intelligent and creative these big city birds can be.

KURT IVESON

Thank you so much, Lucy, and what a fantastic set of talks, so thank you, not only Lucy, but to all of our wonderful speakers this afternoon; and as I said at the end of David's talk too, if you want to read about any of our speakers and the research that they're doing, do head on over to the Sydney Ideas website. So a question from Sarah here. Aside from more greenery and native plants, are there other ways that we can support birds in suburbia? And particularly she asked, Do bird baths or providing fruits and seed help? And importantly, are there things that people should not be doing in terms of, I guess feeding and encouraging birds in their backyards and their neighbourhoods?

HOLLY PARSONS

Oh okay. I'll go first. Okay. Very controversial question. The birds that we feed in urban landscapes tend to be the ones that don't need our help. They are already birds that are doing really, really well because they have some of those skills like Lucy was talking about, or they have, can eat a wide range of different things, and they're generally doing really well. So I guess if you – we would always rather people created great habitat for birds. That is going to help the vast majority of species and there are local actions that you can take so you can do things in your own space. The danger around feeding birds is increasing chances of spreading disease amongst the population, which I'm sure David can talk to, particularly beak and feather disease and also feeding incorrect foods that's going to result in malnutrition or other problems. So you need to do some research on the most appropriate foods if you are going to go down that route. I think on the other side of the bird feeding issue, aside from the bad things, we want people to be connected to nature, and bird feeding is one way that people establish that connection. We just want to make sure that people, if they are going to do it, you're going to do it much more responsibly, and really consider the potential impact. So if you do do it, think about what you are feeding, making sure you are keeping everything impeccably clean, and it is something that you view as a treat. So it is a treat for you. And it is a treat for the birds as well, they don't need it, despite the looks they may give you. And there is the chance for real harm. So it is something that you do need to have a good think about.

JOHN MARTIN

I'll just add to that. The other thing people can do is keep their cats indoors. So cats are killing thousands and thousand of birds and other animals; and that's something everyone can do.

LUCY APLIN

Yeah, and I think I would just say exactly what Holly said, if you're gonna feed the birds, do it well. Do your research and feed them food which is not so bad for them.

DAVID PHALEN

And the same thing about providing water through bird baths; and bird baths can get soiled and contaminated with some pretty bad bacteria, and they can also be a place where disease transfer can occur. So if you're going to have a bird bath, you really should be cleaning it out every single day, and maybe put a pie plate in with some water instead of filling the bird bath up. And you could just bring the pie plate in and run it through the dishwasher, and put another one out. Alternately, I mean, certainly with our climate change occurring, birds in the middle of the day can get very hot, and they're seeing temperatures they've never seen before. In those situations, rather than a bird bath, maybe just putting out a sprinkler on just a very, very low setting would be a really good way to allow the birds to come in, get a little bit wet, cool off, and you can help them a lot that way without having them congregate in one spot where they can pass around their viruses and their bacteria and get exposed to diseases that can have major impacts on populations.

KURT IVESON

Thanks David. And look, I'm going to use a little bit of moderator's licence here to jump to a question that's not necessarily next on the list but I know came in from a lot of folks before the event as well – which is that, I guess we have talked quite a bit about some quite big birds tonight, and there's some little bird lovers in our audience that would like to know, how we can think about their place in the city and what we can be also doing to think about their habitat and their movements and whether there's any projects that you're involved in with little birds that you'd like to share with our audience.

HOLLY PARSONS

I might jump in again, if that's okay. So a program that I run is Birds in Backyards. That's a program that's been running for over 20 years now and it started because there was this noticeable decline in small birds in urban Sydney, and is now Australia wide. So you can help by taking part in doing a 20 minute count like the Aussie Backyard Bird Count, but also giving us some information about what your gardens are like. Because we use that information to then be able to provide researched habitat preferences for what these particularly small birds need. There are a few key issues. So gardens are incredibly important and gardens need to be connected across a landscape. You know, particularly for these little birds that are not often very strong fliers and needing to rest along the way. So good quality, native vegetation, locally native you can get it and really putting everything back in from about two metres down. When we design gardens now, we tend to clear, and actually for these small birds, we need to put space back in and reiterating John's point as well. Keeping cats indoors is a massive one. If you've got dogs in the backyard to making sure that you have a safe space within your garden that will give the wildlife – and it's not only birds – but it's reptiles and things as well a safe place to to hang out. But getting those plants in is a really great way to help them.

KURT IVESON

Beautiful, thank you Holly. Dieter there's a question here for you too about the ecological impacts of the return of turkeys to the urban scene. I guess, how landscapes are changing, and what other species might be impacted by their return?

DIETER HOCHULI

Well, I guess the mechanism by which they're moving so much litter around is really fascinating. So there's a school of thought that the amount of work they're doing is changing the rates of nutrients, breaking down nutrients turning over in systems. So there's a reasonable expectation that you're going to see some shifts in the soil dynamics. They're likely to be changing what's growing in some of those areas below two metres, like Holly mentioned, especially when mounds are being created. We're looking at those ecological impacts, we've been trying to work out not only what their their role as ecosystem engineers might be, but also why they're turning up in such big numbers. We thought for a while it might be through the loss of foxes or through foxes being controlled in cities, but every mound we've had a camera on has fox visitors. I guess, in terms of the ecological impacts, we've learnt a little bit from how lyrebirds move so much litter around, they may actually be implicated in reducing leaf litter or what fire ecologists call fuel in some of these systems, sso there may be a net bonus to some of the bush land where these things are coming in. But in terms of the ecological impacts, they're going to be working these gardens and these soils around and moving around an awful lot.

KURT IVESON

Right, thanks Dieter. And so this is again, a question that I could probably, I'm sure all of you could talk to for a while, and we won't have time to hear from everybody in heaps of detail. But I guess most of you have mentioned in passing at some point tonight, that there are implications of the research that you're doing and the citizen science that you're doing for place management, as geographers like me would call it. And I guess I'm very curious to hear then, whether any of you have got some positive stories about partnering with place managers to think about, I guess, moving us beyond the kind of pest management approach to you know, urban planning and thinking about cohabitation productively, and thinking, you know, in a bit more of a multi-species lens where we might sort of coexist with a bit less, you know, conflict in our neighbourhoods, in our suburbs.

JOHN MARTIN

Well, look, I guess, it's a difficult one to be honest. With respect to ibis, I've certainly found that education has been really important and so that's been part of broad scale stuff so events like this, talking on the radio, newspaper stuff, TV stuff. But working with different land managers so different parks, for example and different councils, will implement different programs like bins that prevent the ibis being able to get to the food. So that reduces that conflict, because they're not seeing that rubbish being thrown on the ground and perhaps there's less ibis around. The other factor there is things like the education so I've certainly had tonnes of people when I'm chatting with them not know that the ibis is a native species. It's a completely different lens that we look at this bird, if it's an introduced thing, like a cane toad, or if it's a native bird, the Australian white ibis. So I think that's been really valuable to be able to talk with people about that as well. But yeah, neither of those really hit the nail on the on the head as to your question. It certainly happens. But it's, it's pretty – it's pretty challenging to convince people when they've got a big ibis nest in their backyards and things.

KURT IVESON

And I think it's it – I mean, this is where it feels where my discipline is, too, which is that the challenge is even if we just go back to Holly's talk about, you know, there's all sorts of management going on about rats, but that's going to impact the way that you know, owls occupy the environment and so forth. That yeah, a lot of intersecting issues for us to be thinking about and having to really, I think we're at that point, right of having those difficult conversations about how we bring those conversations into fruitful policies. But listen, we've probably got time for one more question and Lucy, I'm going to ask this one for you because it's rocketed up to the top of the questions there on Slido. Somebody's asked about, I guess again, patterns of movement within the city and migration of cockatoos and corellas. Six to 10 months ago at Bayview there were thousands of sulphur-crested cockatoos roosted at night in four to five gums around our house. Corellas as well. And a month ago, they just disappeared. All gone, with only a few remaining. So what causes this behaviour? I sense I can't tell whether or not our anonymous questioner is happy that they're gone or very sad. But it'd be good to know what might cause this behaviour, whether they'll return, etc.

LUCY APLIN

Well, in terms of the corellas I'm not terribly surprised to hear that because we do know that there are seasonal movements of corellas in and out of the city to the agricultural areas and then back into Sydney, although more and more they're also sticking around in Sydney. For the sulphur-crested cockatoos, I would be very surprised to hear that because actually our research and research from people before, has shown that these roost sites are actually traditional and extremely long lasting; decades, multiple decades, sometimes the bird stay in the same roost sites. We do see the move very occasionally. But it's usually just sort of down the street and caused by some perturbation like perhaps a visit by a powerful owl, can convince the cockataoo roost that another spot might be better. So perhaps there's been something like that recently happen in the area. But I would strongly suspect that they're not very far. Our research, especially in Northern Sydney has shown that these cockatoos are just not moving, you know, over a 10 year period, the maximum movements are sort of between five and 10 kilometres from where they were originally tagged. So they're pretty local and pretty resident.

KURT IVESON

Wow, and so again, just even those different patterns of behaviour. Some of these birds being very local and place-bound, and others really travelling quite huge distances across the landscape and across the city – such interesting presentations. Thank you so much and I guess I do want to leave everybody who has come to these talks tonight, and is now fired up about wanting to do something, to just remind you of all the amazing links to these citizen science projects that we've popped in the chat and that are up on the Sydney Ideas website, particularly David's events that are happening around this weekend that you can get involved in, as he finished his talk telling you about so do get amongst it folks. And it's my job now just to thank you very much for joining Sydney Ideas, the public talks program here at the University of Sydney. And of course, thank you to our speakers, Dieter, Holly, Lucy, John, and David. So thanks again for making time, all of you tonight and we'll see you at the next Sydney Ideas talk everybody. Thanks very much.

ISOBEL DEANE (PODCAST HOST)

Thanks for listening to the Sydney Ideas podcast. For more links, resources or the transcript, head to the Sydney Ideas website or subscribe to Sydney Ideas using your favourite podcast app.

Audio transcript

Lorikeet Paralysis Syndrome Project

Big City Birds – adapting to change

Powerful Owl Project

Dr Lucy Aplin, University of Konstanz

Professor Dieter Hochuli, University of Sydney

Dr John Martin, Taronga Conservation Society Australia

Dr Holly Parsons, Birds in Backyards

Professor David Phalen, University of Sydney

Moderator: Associate Professor Kurt Iveson, University of Sydney

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