25 Oxley Creek Common
About this episode
A local patch can hold a lifetime of birdwatching stories. Hugh Possingham shares the joys of birdwatching at Oxley Creek Common in Brisbane, including the tiny Mistletoebird.
Episode illustration: Mistletoe Bird
Hugh Possingham has devoted his life to stopping habitat loss around the world. He completed a PhD in Mathematics and Ecology at Oxford University in the UK and this led to a career in universities in the USA and Australia. He has mainly worked as a university professor and is currently at the University of Queensland. He also served two years at Chief Scientist of Queensland and four years as Chief Scientist of the Nature Conservancy. Hugh has over 1000 peer-reviewed scientific publications and his list of achievements goes on and on. Amongst all of this, he still likes to go birding at Oxley Creek Common in Brisbane.
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Kirsty: Today we are travelling to Brisbane to visit Oxley Creek. This creek is known as ‘Benarrawa’ in the Yugara language. I would like to pay my respect to Elders past and present, and acknowledge all Traditional Owners of the Country that Brisbane (known as "meanjin") is on.
Kirsty: Welcome to Weekend Birder. I'm your host, Kirsty Costa. Friends, I'm so chuffed to have Hugh Possingham join us for this episode. This remarkable leader, scientist and mathematician is also a passionate birdwatcher. Here is how it all began for Hugh.
Hugh: My father was a birdwatcher, although he was an engineer. He went to England for a while and of course, there's so many birdwatchers in the United Kingdom. And I started birdwatching there. When we came back (to Australia), he would take my brother and I birdwatching. To be honest, for a long time we didn't really like it that much. Wandering through the South Australian deserts looking for small brown birds and it was 35 degrees Celsius. In factf often he would leave me with my toy soldiers to fight the ants for four to five hours under a shady bush as he wandered off. I don't think we do that as parents anymore, but it was fine to leave your eight year-old under a bush for five hours in the day. In the end, I sort of thought, "Well, this isn't going to work". So we started birdwatching. Both my brother and I (Jimmy) have been birdwatching ever since. I suppose like everything. I think Spike Milligan once said the only incurable disease is bird watching. He's never heard of anybody reforming. So be careful. You'll never get rid of it, because once you do it, it just grows and grows.
Kirsty: Hugh's family's favourite birdwatching spot was bulldozed in 1978. He was only sixteen years-old at the time. Since then, Hugh has devoted his life to stopping habitat loss around the world. He completed a PhD in Mathematics and Ecology at Oxford University in the UK, and this led to a career in universities in the USA and then back in Australia. Hugh has mainly worked as a university professor and is currently at the University of Queensland. He also served two years as Chief Scientist of Queensland and four years as Chief Scientist of the Nature Conservancy. Hugh has had over one thousand peer reviewed scientific publications and his list of achievements goes on and on. Amongst all of this, he still likes to get out two to three times a week to go birding, and one of his favourite places to go birding in Brisbane is Oxley Creek Common. And that's what Hugh is going to tell us about today.
Hugh: It's in the suburbs of Brisbane, just maybe eight kilometres south of the centre of the city, and it's only a five minute bicycle ride from my house. It's about one hundred hectares and in fact it was a Department of Primary Industries Research Farm when we first arrived in Brisbane in 2000. It was full of cattle, in fact it was pretty well grazed within an inch of its life. It was often just dirt. There's one hundred hectares in the middle of the suburbs on the edge of Oxley Creek, which is creek in very poor condition. It's mangrove lined, it's called an F-Rated creek in the Healthy Land and Water Rating Scheme, which F is not for "fabulous" (it is for "stuffed"). So in some senses it looks really bad. And around 2002, the Department of Primary Industries decided they didn't need these research farms anymore like this. So they, without really telling anybody, made it into a public park. And a few of us sort of found it and they found a little trail system and we started going there. And lo and behold, almost twenty five years later, we have a bird list on eBird. Over five and a half thousand visits of two hundred and twenty four different species now, for a piece of land that is almost completely unnatural. There have been some plantings, vegetation has recovered a bit, but basically it's full of weeds. It's messy, it's not at all natural habit in any way. That's a quarter of all the bird species in the continent, and you can see them in a five minute bicycle ride from my house. I used to go there a bit and we started finding odd and interesting birds. It's a fairly open space. So for example, we've had nineteen species of birds of prey there. If you keep looking up, you never know what's going to fly over regularly. There's nice birds like Black-shouldered Kites and Brown Falcons, even occasionally Wedgetailed Eagles, White-bellied Sea Eagles. These are things that you don't often see in the suburbs, and it's because it's a big area of open grassland. The nearby state school has an egg program and they continue to graze some cattle there, which is actually good in this case. They have not grazing it down to the dirt. There's a lot of grass and there's a lot of casuarina and Forest Red Gums coming up. But that grazing I think is actually very important because again, if you look at a Google Map of Brisbane and you look for big open spaces, this is one of only one or two places and the other ones are airports. So it's that openness. There's some wetlands in there so we can have things like Black Stork and Magpie Geese. There are Freckled Ducks who turned up, Chicanas or often people call them Lily Trotters.cOdd things keep turning up. Then in 2004 I decided, "Well, it will be interesting to see how this site changes through time". There's a Friends group and I'm the president of the Friends group, and we do a lot of weeding. We do a lot of planting along the track. We put in seats and signs and stuff. So in 2004 I thought, "I should practise what I preach as a scientist (although I'm more of a mathematician and a modeler), let's get some data on this place". And so I started doing a hundred minute bicycle ride through the site, and I've been doing it for twenty years. Once a month, every month for twenty years. It was a bit of a gap when I was overseas for four or five years or so. What I find is fascinating is just to see first the seasonal changes I didn't expect. So there's common birds like the Brown Honeyeater. You think, "Well, there's always Brown Honeyeaters, isn't there?". But in fact, if you start counting them properly, the actual numbers and you do it regularly, you realise in the middle of winter there's one hundred and in the middle of the summer there's fifteen. Those seasonal patterns slowly reveal themselves through time. We have a lot of winter visitors. All those birds that find Victoria way too cold and sensibly move to Queensland in winter. We get your Grey Fantail come up and your Silver Eyes, Golden Whistlers. The Grey Fantails turn up and then there's ten of them, twelve of them on my census. And then in the summer there's basically none. I think in Australia we tend to think, "Oh well, there isn't a lot of change from the month. That's what happens in Europe". In fact, so many things are happening from month to month and you only learn that by going out month after month. And the other odd thing was also not just the seasonal patterns (which are somewhat expected), but the year-to-year variation. There's a lot of variation in the water birds at the moment. The water birds numbers are very poor because all the water birds are sitting in the middle of New South Wales and Queensland making merry as there's so much flooding out there. But when we had the Millennium Drought, we had so many interesting waterbirds turn up. Yet inland waterbirds like Yellow-billed Spoonbills and Red-kneed Dotterels rarely turn up because basically they're desperate and they're pushed out of the centre of the continent and they all flock to the coast. Seeing those long-term changes and some climatic changes, cyclical patterns of droughts and rains. But then there's also long term increases and decreases and changes because of the habitat being changed.
Kirsty: As Hugh watched the changes in the bird population in Oxley Creek over time, he also became fascinated with the changes in birdwatchers themselves.
Hugh: I started recording the number of birdwatchers and counting them, not just a number of birds. Early on they were hardly any birdwatchers. Nobody knew about the site. So we started posting things in birds and putting things up on Facebook and we formed the Friends group. More and more people came so early on. On average it was literally one birdwatcher every two visits. Now, on average I'm getting twelve to thirteen birdwatchers. So it's gone twenty five fold up. And I started recording them, you know, are they alone or are they in couples? They've got binoculars or camera? And so that was also changed a lot. So in the early days, twenty years ago, 70-80% had binoculars. There were very few cameras and now it's about 70% cameras. So there's more and more people birdwatching I think, because they're using their cameras. So it's just interesting to see the changes in the way birdwatching is happening and the increase in the number of birdwatchers. Pre-covid, we were getting people from all over the world. You can go out in a good morning on seventy five bird species in the morning in three hours, just wandering around this degraded site in the middle of suburbia.
Kirsty: In his spare time, Hugh leads a lot of community walks at Oxley Creek Common and a bird that a lot of people come to see is the Mistletoe Bird. This species is also one of his favourites.
Hugh: Firstly, their chest is bright red. They're tiny and they hang around often in the mistletoe, in the canopy. So mistletoe are those parasitic plants that feed off eucalypts and casuarina and other bushes and they basically extract all their nutrients and water from the tree. Mistletoe Birds tend to be in the mistletoe. The males are the ones with the bright red on their chest. The females are pale on the chest and a grey on the back. And the only red they have is a tiny bit of a wash of orange red on the event or the lower belly. They're just as cute and just as important. Officially, you might think they look a bit like a Scarlet Robin or maybe a Rose Robin. They are much smaller. They hang around in the canopy and they quickly dart from place to place and they have a very distinctive call. And that's that deep call, "juu-jip", which actually tells me where they are first. If there's thirty people, they all want to see a Mistletoe Bird because I tell them about how the Mistletoe Birds disperse the mistletoe fruits. They eat the fruit and they're the only bird that wipes its bottom on a branch. Those birds, they eat some fruit, they digest the fruit, they poop out the seed and it just drops where they defecate. I think they like to poop just before they fly out. Mistletoe Birds, in fact, wipe their bottom on branches. So effectively they're planting this sticky seed on the branch in their gut passage. The time it takes between eating and pooping is only literally fifteen minutes. So often they dispersing these seeds reasonably close within 100-200 metres of their parent plant. Imagine having dinner parties if gut passage time with fifteen minutes. You'd need to have lots of toilets and you'd have to space the courses very carefully with mistletoe berries. And I don't want to encourage too many people to eat them because the mistletoe berries are there for the bird. You can eat most of them and they are incredibly powerful laxative. So if you do suddenly find some juicy red mistletoe and start feasting on them, make sure you know where the nearest toilet block is.
Hugh: I would have thought that this complicated mutualism between Mistletoe Birds, mistletoe, the trees, the fruits and the flowers would have disintegrated in a suburban environment. It's actually reconstructing. We even have two mistletoe species that only live on other mistletoess. So they can't live on a plant, a tree or a bush. They have to live on an another mistletoe. There's specialized butterflies that live on the mistletoe. The mistletoe produces fruit and flower when lots of other things are not in fruit and flower. So the Mistletoe Bird really is an ecosystem engineer. It's helping reconstruct this entire ecosystem. Dave Watson, who's at Charles Sturt University, has written many papers about the importance of mistletoe and Mistletoe Birds for restoring habitat in these sorts of disturbed ecosystems. Anyway, it's a beautiful bird. Best heard rather than saying because it is so tiny, the fact that I can tell it's call means that I pick it up. There's usually half a dozen at the site really quickly, and then if we really lucky, they'll sit on a dead branch and we will get a good look at them.
Kirsty: Hugh's description of a Mistletoe Bird wiping its bottom on a branch will stay with me for a long time to come. I love that phrase 'ecosystem engineer'. It reminds me of what Alex Maizey was telling us about the Superb Lyrebird in Episode 16. They are also ecosystem engineers as they turn over tonnes of soil and in the process they move around the plants and the other living things that can be found on the forest floor. Hugh says there are many benefits to returning to the same place time and time again to birdwatch and record data, including getting to know where individuals and groups of birds are living.
Hugh: At Oxley Creek Common, there used to be two pairs of Mangrove Gerygones. These Gerygones are small grey birds. I love Hugh: Mangrove Gerygones because they've got a habitat in their name and they always stick to mangroves. There was a pier by the canoe pontoon and there was a pair down by the gauging station. They have a very iconic call, a lilting sort of trilling, wafty call and they're very hard to see. They're just small and grey. You hear them and you know they're there. People coming along. You can say, "I want to find a Mangrove Gerygone". Now, if they don't know their call, they're going to struggle because it's a tiny small grey bird in the dense mangroves. Play them the call and I say, "You can go to hear the canoe pontoon. You can go here to the gauging station. If you wait and listen, you'll eventually hear a Mangrove Gerygone and then if you're lucky, you'll be able to track it down". These individual family groups stay in the same places. The sad thing about that, of course, is when they disappear. So we're down to only one Mangrove Gerygone. We don't I don't think there's even a pair left. So one of the pairs is completely disappeared and the other pair is down to a single individual. The downside with getting to know these birds really, really well, of course, is the sadness of disappearing as a pair. Even though these numbers I'm talking about going from four to two to one, they're not huge numbers of birds, but it's somewhat indicative of what's happening to some of our woodland birds and some of our flycatchers and things like Willie Wagtails. And if you don't actually keep going back to the same place, you'll never notice the difference.
Kirsty: Hugh's love of scientific observation and the recording of numbers and data came from his father, who was an engineer.
Hugh: My father always taught me to record everything, and even in the day when we first birdwatching, it was common for people to make lists. He got us counting every bird. So I've always counted everything. Of course, the rise of both eBird and Birdata means now you can enter all those lists onto your iPhone. So I've always been very focused on counting everything, making the best possible estimate of the birds I can get. Because if you don't do those counts, you never actually see those subtle changes. If I just put down X for Willy Wagtail, the X's wouldn't have changed because there's still a Willy Wagtail there. I wasn't going four for four and then two for two and one for one. You would never pick up changes. So I do encourage people to use Birdata and eBird but it doesn't really matter which one you use. The other thing I suppose I like doing - I like running public bird walks. I probably run one a month for different catchment groups. Often those bird walks are thirty or forty people. Some come with no binoculars. Most of them have never been walked before, which is great, and they think they're going to see a lot of birds. And I sort of say, "Well, there's thirty of us. We're stomping around the grasslands and woodlands and forests will scare most of things away. But what we'll do is we'll keep close together. We'll go quickly to a spot where we can sit and wait and hope something turns up and we're going to listen". And often, you know, things don't turn up but there's always noise. Australia is so good because birds call all year, all the time, even in these suburbs. So I go to my first spot at Oxley Common and say, "Well, we can hear some birds. What do you think they are?". Well, there's a Figbird, there's a Magpie Lark, there's an Oriole, it's a Lewin's Honeyeater - the machine gun, "Choo choo choo choo choo choo choo". We talk about the bird calls and people start realising that they actually do know a few bird calls. They know kookaburras, they know magpies, some of them know the Koel, which up here is very common. I think it's started to invade Victoria and even wandered a little bit through into Adelaide. I remind them that five hundred years ago, Indigenous people were all birdwatchers. Not that I'm an expert on this. If you look at some of the local Indigenous groups and you look at the names of things they've recorded, it's often a bird and almost all the birds are named onomatopoeically, that is, they're named after the call of the bird. We call Koels because they go "cooee cooee" at night and drive people crazy. The Indigenous people here, the Yerongpan and Chepora people, call the Koel "toowong" and now there's a suburb here called Toowong. So the suburb of Toowong was named after the Indigenous name for the Koel. If everybody called every bird onomatopoeically, we'd actually have no language problems at all, would we? We'd just call them all and you'd immediately know what the sound was. Listening to birds and naming them after their call was really quite deep in our psyche. I think often on these walks, as I say at Oxley Common, is a big group of people. I'll get seventy five or eighty species in the three hour walk, twenty five of them we never saw - we just heard somewhere in the distance.
Kirsty: Listening to birds is one of Hugh's favourite things to do. And he enjoys watching the people he's birdwatching with learn all about the birds around them without ever seeing them.
Hugh: Human beings are pretty visual animals. I mean, we're incredibly good at recognising thousands of visual images. People look through their bird book, they see the birds, they can memorise them and if they see it, they quickly find a pattern that matches them. We're pretty good patternigs. I mean, the fact that they do it on those magazines where they just show the eyes of a movie star and just from the eyes, you can tell that it's Clint Eastwood. Given there are billions of eyes on the planet, that seems to me incredible. People then think they don't know anything about bird calls and say, "Oh, do you have to be good at music?". I mean, in the end, it's just practice. It's just practice and it's just listening and thinking. We are so visual. Well, we ignore our nose in almost entirely, but we are very visual so we're so focused on the listening and the talking and the visual. Just getting people to stop and just stand still for five minutes and just listen and hear all the sounds they're hearing. Most people have never stopped to listen. They just don't stop and listen to anything. And the fact there are all these calls and all of them are identifiable.
Kirsty: I don't know about you, but I've learnt so much by listening to Hugh and other birdwatchers too. All those little tidbits of information really come in handy when we're out doing our thing. Thank you for taking the time to talk to us today, Hugh. Your tireless conservation work and the way that you involve people in birdwatching is really inspirational. Connect with Hugh on social media by visiting the episode notes or visiting weekendbirder.com. The bird recordings were shared by Marc Anderson on the xeno-canto website. Thanks, Mark! This website is such a great place for you to visit and learn about the songs of the birds that are all around you.
