Ep 7: w/ Jason Van Weenen | Talking grey-headed flying foxes in metro Adelaide

On this episode we'll be chatting with SA's local bat expert and the Team Leader of Urban Biodiversity at Green Adelaide Jason Van Weenen about Adelaide's new-ish population of grey-headed flying foxes. All your flying fox questions will be answered, including why they aren't just called bats.

If you are intrigued by Jason's love of iNaturalist. You can get involved today. You'll contribute to local environmental science knowledge by signing up to iNat and recording your nature observations. Explore their website: www.inaturalist.org
"iNat is where I'm at!"

Welcome to another episode of the Green Adelaide Podcast. We are metro SA’s first environmental industry podcast.

We’re your insider scoop on all things cool, green, and wild in metropolitan South Australia.

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I’m your host Melissa Martin and I’m the Communications Manager at Green Adelaide who loves red-tailed black cockatoos.

Learn more about Adelaide's environment: greenadelaide.sa.gov.au

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Transcript

Melissa Martin:

Netflix or YouTube?

Jason van Weenen:

I tend to-

Melissa Martin:

Spotlight?

Jason van Weenen:

Spotlight more. Yep. I'd say delete both of those and put iNaturalist. Yep. I am hooked on getting out there and finding critters and helping to map the distribution of things. And so yeah, iNat is where I'm at.

Melissa Martin:

Welcome to another episode of the Green Adelaide Podcast. I am your host, Melissa Martin, and I'm the communications manager at Green Adelaide who loves red-tailed black cockatoos. We are metro SA's first and only environmental industry podcast. We're your insider scoop on all things cool, green and wild in metropolitan South Australia. Before we jump in, remember, subscribe to our podcast for the episode alerts. This episode we'll be talking about grey-headed flying-foxes, why they are here, what's special about them, and demystifying myths about them. And to do this, we have local bat expert and ecologist, the team leader of urban biodiversity at Green Adelaide, Jason Van Weenen. Welcome, Jason.

Jason Van Weenen:

Thanks, Mel.

Melissa Martin:

First off, let's chat about your career journey. Can you tell us about your career and how you ended up in your role today?

Jason Van Weenen:

Okie doke. Yeah, so I grew up on the west coast of South Australia and country town's Streaky Bay. And one of my best friends was, his parents worked in the national parks and I was always stunned going around to their home and them having sea lion pups or albatross or things that have been rescued and brought to their house. And so I was fortunate because we're friends and I'd often go out and do sea lion pup counts and surveys for hooded plovers on beaches and things at night. And I just loved all that sort of stuff. And got to see lots of biodiversity and I just was very passionate about it. I inquired when I was quite young around paths to get into the field and so that's what led me down a uni career, Adelaide Uni, studying natural resource management and then followed on with some... I was fortunate to get some contract work after that, helping out with some biological surveys. And that sort of then led into further work with the Department for Environment on a range of species conservation projects.

Melissa Martin:

Have you always worked in an ecologist type role?

Jason van Weenen:

I have. Apart from the high school days working in supermarkets and things like that.

Melissa Martin:

Yep. And so you spoke about what drew you to the field around this interest, especially with what you saw your friend's family, what they did. Was it that particular, being able to physically look after animals and look after the land that drew you to the industry or was it something else, you like the physical part of?

Jason van Weenen:

I think it was just around the wonder that is all the biodiversity that's out there. So I have loved learning about species and their behaviors and so that in particular. So whether it be a bird or a reptile, understanding the way it uses its habitat and its preferences, those habitat preferences, I've loved that learning side and the learning opportunities in the field are obviously endless because there are so many species too, which do so many different things. And so yeah, I really like that side of it.

Melissa Martin:

Yeah. And what do you wish you knew before you started?

Jason van Weenen:

In the power of hindsight, there's always, it'd be great to know a lot of things back then. I feel that an important part of everyone's journey is that learning process and that sort of process does take time. I guess interestingly, the ecology field and particularly the conservation field that I've worked in, once you sort of get into that space, there are lots of aspects around understanding species and threats, threatening processes, which means when you go out into the environment, you're often acutely aware of some of those things. And so it can be a little bit hard to switch off. So you're seeing these, whether it be a weed invading a native habitat or you can see that in lots of places. You might be on holidays and you'll see, wow, that looks like this weed is invading this water course or something like that. So you sort of tend to remain focused around those sorts of things. But I love that. I love looking at various issues around the place and-

Melissa Martin:

You'll learn a lot about a certain species or a certain topic. And then do you ever have a feeling that you wish you knew that 10 years of knowledge 10 years ago?

Jason van Weenen:

Oh, every day.

Melissa Martin:

Or do you enjoy the journey?

Jason van Weenen:

No, every day. That sort of stuff is... I think this comes with working with some fantastic people. There are so many incredibly knowledgeable people out there who share that wonderful information that they've gained over the years. And I idolize those people who are so knowledgeable and I think that sort of stuff is always awesome. It's great to be learning. I think it's a really important part of the role is to be constantly learning and you just wish you got there sooner. You always wish that. I guess other things that I wish I knew before, so one of the things that I've been fortunate enough to gain an appreciation through work and that is a far better appreciation about Aboriginal culture and I feel that I didn't get much exposure to that prior to my career. And I just feel that having a greater awareness around Aboriginal culture would've been nice to be an advocate sooner than... For me, that would be a nice thing to have known earlier, for sure.

Melissa Martin:

Yeah. And we were mentioning before we started recording about that Aboriginal culture wasn't really part of when you studied your degree, that wasn't part of it, but now it's a standard part of the degree and it's interesting and should have happened sooner, but it happened, that including in, it's part of the degree.

Jason van Weenen:

Yeah. Yeah. Well, I think just everything from that at schools and things like that, I think it's a really useful thing. Working with a lot of traditional owners on species conservation projects and that, that has been a real privilege in terms of getting an appreciation for things that I had no idea about, things about culturally respectful approaches to a whole range of different issues. I'm a lot more nervous about doing anything which unintentionally offend someone, things like that, but I feel so privileged that that's even on my radar now. And so those things are, I'm super grateful for. And yeah, that sort of stuff, I kind of think it would've been nice to be aware of some of those things much sooner.

Melissa Martin:

Sooner in your career. Yep. How would you, sorry, define success in the environmental field?

Jason van Weenen:

It's an interesting one. Particularly in the conservation field, there's an endless range of challenges facing biodiversity. So there's obviously a biodiversity crisis that we're facing out there with climate change and a whole lot of biodiversity loss. So I think one of the things about obviously success to me is that ability to remain focused, I guess, with a lot of the change that's happening there to try and always look for those opportunities that are going to have the biggest impact and be most constructive with time and not necessarily drifting away too far from the things that really make a difference because there is a lot of various things that might pop up as opportunities and things like that.

But a lot of the basic conservation and recovery actions really do tend to come back to protecting habitat, managing threats, all those sorts of things. And so for a lot of species it's just making sure that the basics are covered. And so it is a tricky one. So when you do have successes, it's fair enough to be happy when you make a good recovery progress and it does happen and things can be much safer and it's a really awesome thing to do, but you tend to not be able to just sit back and go, "Wow, we got there with that species," because there's a whole heap of other species which need attention.

Melissa Martin:

So you talk about focus and I guess I think about, because a lot of environmental projects are quite long-term, it's not like you'll start one in 2024 and finish in 2024.

Jason van Weenen:

Exactly.

Melissa Martin:

It'll be years to decades.

Jason van Weenen:

That's right. Yep.

Melissa Martin:

So how do you keep that focus for these potentially years-long projects?

Jason van Weenen:

I think, well, I tend to use some standard process around risk assessments. So we've got a whole range of species which have a status assessment done that identifies the threat category for the species and some of those threatening processes, some of the particular issues that a species may face. And so those listing processes and status assessment processes help identify what are some urgent needs out there. And then there's a whole range of recovery actions that can be implemented to turn things around typically. And so it's trying to make sure there's enough traction. So it's really coming back to those tangible activities which can be implemented to turn things around. So whether it be increasing the number of individuals, it might be a plant and you might propagate more and try and get them out there. It might be around managing weeds so they can regenerate naturally in certain sites and maintain their range. And so a whole range of those sort of tangible things.

The awesome thing when you go through a list and you've got a whole heap of priorities, there's lots of people out there doing stuff as well. So lots of community and councils and other stakeholders who are delivering great stuff for these, a whole range of species. And so we tend to, I find we try and look for gaps and make sure that we sort of don't necessarily duplicate the work of others or we just try and fill gaps. And some of that may be for a species, it may be a research gap, trying to break a bit of a recovery challenge that we might face with some species or a lack of knowledge around how best to work with a species. And so it can be variable from on ground actions, which are clear, tried and tested things that work, to trying to develop new, get new information to develop recovery actions which are going to work for species. So yeah.

Melissa Martin:

And now we'll go into our next round, which is our rapid fire round. So that means I'm going to ask you 10 random questions outside of the environment sector just to take us out of our safe space and get to know you a bit differently. So I will fire 10 questions at you and just tell me the first thing that comes to your mind. And so it could be your favorite thing, this or that, and just say the first thing that comes to mind. First question, do you like spicy cuisine?

Jason van Weenen:

I do. I love it.

Melissa Martin:

Would you rather drink tea or coffee?

Jason van Weenen:

Coffee.

Melissa Martin:

A horror movie, something you'd like to watch?

Jason van Weenen:

Not really, no. No.

Melissa Martin:

What's the worst one you've seen?

Jason van Weenen:

I think I used to watch them when I was growing up. They're all the standard ones. But yeah, that's something which I'm definitely not up there of my priorities to go and watch a horror.

Melissa Martin:

Which pizza topping is your go-to?

Jason van Weenen:

Well, at the moment it's a pizza place I go to. It's got a really yum veggie sort of topping, or eggplants, all that sort of stuff. I love it.

Melissa Martin:

Nice. What's your favorite thing about your job?

Jason van Weenen:

I love being able to work with such a diverse range of species and I love being able to work with some amazing people.

Melissa Martin:

Morning or night?

Jason van Weenen:

Both. I wake up early and I-

Melissa Martin:

[inaudible 00:13:50].

Jason van Weenen:

At the moment I'm hooked on going spotlighting and things like that. So at the moment I feel like I'm burning the candle at both ends. So I have to say both.

Melissa Martin:

You're only getting four hours sleep on that. Netflix or YouTube?

Jason van Weenen:

I tend to-

Melissa Martin:

Spotlight.

Jason van Weenen:

Spotlight more. Yep. I'd say delete both of those and put iNaturalist. Yep. I am hooked on getting out there and finding critters and helping to map the distribution of things. And so yeah, iNat is where I'm at.

Melissa Martin:

Yep. Is that their slogan? It should be. If animals could talk, which one would be the funniest to have a conversation with?

Jason van Weenen:

Well, if animals could talk? Well, I feel like a lot of them do. I can hear the bats chatter. Flying-foxes chatter a lot and I'm sure they've got good communication. Yeah, I don't know. It would be an interesting thing to have conversations with some critters. Perhaps because the bats are so chatty that it might be I'll put them down as the one.

Melissa Martin:

Yep. What's the weirdest thing you've ever eaten?

Jason van Weenen:

Insects.

Melissa Martin:

Oh?

Jason van Weenen:

Yeah, I've eaten insects. I don't know, I guess it's not. It's weird for us. It's probably not weird for other people. But yeah, it's just us.

Melissa Martin:

Yeah, for other cultures. Yeah.

Jason van Weenen:

Yeah. Other cultures, it's just-

Melissa Martin:

Any particular insects?

Jason van Weenen:

So I have tried crickets, those sorts of, cooked crickets, but I guess I have tried witchetty grubs and things like that and haven't necessarily found them weird. Probably uncooked witchetty grub would probably be the weirdest thing. Yeah, I'll leave it. Yep. That one.

Melissa Martin:

And the last question, what is or do you have a hidden talent?

Jason van Weenen:

Hidden talent? I think I just persist with things whether I feel like I'm not too bad at getting my head around some species. What is it? That if you spend 10 minutes a day on something, you become an expert. And so I feel that's where I'm at more than anything. Not necessarily naturally talented, that's for sure.

Melissa Martin:

Persistence is a talent.

Jason van Weenen:

Yeah. That might be it then.

Melissa Martin:

Thank you. That's the end of our rapid fire round. So now we will dive in to grey-headed flying-foxes and their population in Adelaide. But before we kick off a bit further, so you've worked with the bat for quite a while now. Were you drawn to the bats?

Jason van Weenen:

Bats are a threatened species in the field that I've been working in it. It's sort of, threatened species are a focus of my work and have been a focus of my work. And so that meant that when the species sort of arrived in South Australia because of its threatened nature, it meant I had an opportunity to get involved with that, learn more about it better.

Melissa Martin:

Yeah. Have you been working on them with them since 2010 or?

Jason van Weenen:

Yeah, since their arrival of a camp in South Australia, which was back then, so. Yeah.

Melissa Martin:

Wow. All right. So grey-headed flying-foxes are unique to Australia and they're their largest Australian bat species. They can be found in Queensland, New South Wales, Victoria and right here in South Australia. They've been visiting South Australia for many decades, but only in 2010 did they set up a permanent camp at Botanic Park in the city. The population has hovered between 20,000 to 30,000 in recent years and they had a peak recently of about 47,000 thanks to the cooler weather. Jason, can you shed some light on why the flying-foxes call Adelaide home now?

Jason van Weenen:

Yeah, so back in 2010, there was a range of challenging conditions for flying-foxes across their natural range and it appeared that some of those climatic challenges, lack of food in other parts of their range may have resulted in bats looking for food elsewhere, having forced to roam more widely in the search of food. And some of them found, made their way into Adelaide and other parts of South Australia. And ever since then that's sort of been this food resource, local food resources been on their radar. So that, basically those tough conditions forcing bats to move has helped them locate what is a significant food resource here in Adelaide.

Melissa Martin:

Yeah. And what particular things do they love?

Jason van Weenen:

So they love eucalypt blossom, so that's one of the main sorts of sources of food. So they love eucalypt blossom. Nectar from eucalypts, but they also take a variety of other tropical type fruits and things like figs, a whole variety of figs and palm fruits and things like that. So there's quite a range of things that they utilize. They also take fruit from orchards and things as well. Yeah, quite a range. But predominantly, I guess, the main driver of the population locally is those flowering eucalypt resources.

Melissa Martin:

And their population is growing in South Australia and in other places across Australia they can be in high numbers. I guess people have this perception that there's lots, but they are listed as a vulnerable species. Is there lots, is it vulnerable? I feel like the message is a little confusing.

Jason van Weenen:

Yeah. So our numbers have increased over the years, but I guess what we anticipate, so we're a bit unsure early on whether the bats in South Australia would actually survive because it's so hot and dry in South Australia. So it's right on the edge of their... It's one of the driest locations within their range. And so hottest and driest locations, they're susceptible to the heat. So there was a bit of uncertainties whether they would persist. They seem to be persisting. And so what we're anticipate now is that the numbers in the region will fluctuate in relation to resource availability. And so when we have high numbers it would reflect a high amount of food in the area. But we also expect that when that food supply, when particular eucalyptus stop flowering, that numbers will adjust down. And we have seen that already. So we're seeing the numbers rise seasonally, but then food does run out and that has seen the colony reduce in size, they lose condition, they haven't got as much food and then they have to start leaving Adelaide.

The species is very well connected, so there's one population of which there's movements between the camp. So what we see nationally is that the bats within a camp will fluctuate quite considerably depending on food resources in that area. So this is the thing which is a bit tricky. When we look at Adelaide and we say our numbers are growing, our numbers have sort of grown to the point now where they're just following resource availability, they will go up and down. So it's not a all one way thing. It's definitely an up and down. And so we see some seasonal trends and we might... The thing is across their range if things are really good in one area and really bad in another, so it can be a real food shortage in some areas. Or for example, the big fires on the south of Eastern Australia can really push bats from those other areas into other parts of their range. So you may see seasonal changes and drivers like that really elevate numbers in some areas.

And it's a fantastic thing for the bats in that they've got an ability to try and deal with these climatic or these seasonal conditions in different areas and adjust and try and overcome those challenges rather than being lost from particular areas. So what we're seeing is this number fluctuating, so we're up around that 46,000 mark at the moment, which is quite high. It's up in the highest we've seen. But we also anticipate that as conditions change that will head down again. And so there is the potential that it might peak even higher. So some camps nationally can be up at 150,000 bats for a short period of time whilst the food resources are there. If the food resources are not there, they obviously can't. And so we're basically seeing that fluctuation, but we should also anticipate that there could be some really big spikes down the track and that's just the part of the species trying to adapt to the landscape conditions that they're facing.

Melissa Martin:

If they were to run out of food for a certain season and they leave. In my head, I think animals don't accept different ones into their colony. So if they're leaving South Australia and they're going to a different state, can they just join another colony there?

Jason van Weenen:

They can and they do. So there's some really fantastic work, some tracking work that's showing that there's basically along much of Eastern Australia, there's just constant interchange of bats between camps all the time. And so even with our colony. The thing with our camp here in Adelaide is that it is some distance from other known camps and so it's a bit of a big deal. It's not quite as easy just jumping from one camp to the other, but where you've got lots of camps in relatively close proximity, it's easy for bats just to jump from camp to camp. And so that moving between camps is really what they do and what they do well. And so whilst we look out the Botanic Park camp and see bats, a lot of those faces may be different from yesterday so that we just can't assume that they're all just the same ones there.

Melissa Martin:

Yep. Are there benefits of having flying-foxes around our city?

Jason van Weenen:

Yeah, flying-foxes, I guess they play a role in pollination, so that's where they're really long distance seed disperses. I guess from a... This species is of conservation concern. So it is listed based on concerns over population declines. So the numbers at the moment around that, there's been national surveys and they're sort of in that 600, 700,000 flying-foxes, which sounds like a lot, but across its range there is that underlying concern about declines. The benefit of having them here in Adelaide is that we're playing a significant role in their conservation. So whilst we wouldn't have had flying-foxes in the Adelaide region in the past because it was far less diverse in terms of eucalypts and fruits and so it was a grassy woodland, a few different species, but now we've got a magnitude of species that have been planted across the Adelaide.

We've got irrigated sites and it's a bit of an oasis for species like flying-foxes. And we've seen that with our rainbow lorikeets, which are daytime nectarivore, they fly around and you sort of have quite a lot of overlap and we've seen their numbers explode in the Adelaide region and surrounding Mount Lofty Ranges region. And so what we're seeing is that the flying-foxes are just following that same path, utilizing the resource that we've planted for them and capitalizing on that. And that having them here helps play a part in their national conservation now.

Melissa Martin:

And why are they called flying-foxes and not grey-haired bats?

Jason van Weenen:

So the flying-foxes are in that megabat group and if you have a chance to look at them up close, they do have a real fox-like appearance and they've got a foxy head on them. And so that flying-fox name has been assigned to that group, similar looking bats. And so that's where they get their common name and it helps just separate them out in a common name. Typically they're a bat and they're just in that megabat group as opposed to the microbat group.

Melissa Martin:

Other states talk about, we mentioned earlier about some of the problems around having a bigger population of flying-foxes around. So smell, noise, poo on your washing outside, power outages, diseases. Is Adelaide experiencing these problems and is it on a serious scale?

Jason van Weenen:

Right. So there's a lot of the problems that get mentioned around flying-foxes relate to camps in particular. And so that's where you've got, so for example, we've got basically all the flying-foxes in South Australia living in the heart of Adelaide. So there's some camps in the South East, but predominantly most of the bats are here in Adelaide, the ones within South Australia in the heart of the city. So the concentration of animals, like a concentration of pigeons or a concentration, you do get those smells and things that come with having lots of animals living in one side or spending time in one location. And so that's where you walk through the camp, you will notice the smell and you'll also notice that can be noisy at times. There's in the lead up to breeding season, we know when bats are mating they can be quite vocal. Yeah. So there's those sorts of things that come with camps.

There are also a whole range of other things when bats are out foraging for example, they can be foraging around houses and feeding in people's backyards. And one of the things that we, if you've got a really good food resource in your backyard, it might attract bats and it might, if it's really good, bats will actually defend it from other bats and that's where they become quite vocal and squabble over that resource. And so if you've got bats, if you're out in the burbs and you've got bats in your backyard at night making noise, well, it's probably you've got a really good food resource which the dominant bats are trying to protect from other bats. And so that's where people might hear them out and about at night. And otherwise if it's not a great resource, they might be still going there but you just don't hear much. So in lots of other areas there could be bats visiting and without much vocalizations and basically going unnoticed.

So when they're out foraging, obviously that's when they pick more chance of coming into, if they're feeding in a yard they might be defecating and that can impact on clothes and things like that. And so I guess one of the things with that feeding out and about is that it tends to be a very... Fruit trees or a eucalypt flowering, will be a flower over fairly short periods of time. And so you have that impact. It'll be a short-term thing generally that you need to avoid or manage around. But then as soon as that resource has gone, well, then the bats will too. And so yeah, it provides a bit of relief after that flowering or fruiting has changed.

Melissa Martin:

With your work, I guess dealing with volunteer groups and different areas in how, I guess management of that population in Adelaide and just helping mitigate the potential problems that could happen from humans interacting with animals. Have you found the kind of problems that I mentioned around power outages and maybe noise being a big impact on Adelaide?

Jason van Weenen:

Interestingly, we've got a power infrastructure which has been set up for a whole range of things, but not flying-foxes. So we've got an infrastructure, power infrastructure system that was set up without flying-foxes. It's very different to those that were set up with flying-foxes. And so now all SA Power Networks are looking at the infrastructure and trying to figure out ways to retrofit safety aspects on there which prevent or reduce the impacts of outages. So when young bats leave the camp in January, that sort of period, they venture off and they're basically on their elves and they land on things and unfortunately they can out cause outages. And so SA Power Networks have been working to try and look into those outages in a bit more detail. They've been installing things called frisbees which help prevent bats shorting out critical infrastructure components. And so as some of these programs are rolling out, we hopefully see that the improvements from that work. But yeah, it's one of those novel things of having an infrastructure system that just isn't set up for a species that understandably that wasn't even in the area.

Melissa Martin:

Now we'll go onto our next section, which is pretty much random questions about bats. And so this has come about because we at Green Adelaide get a lot of random questions about bats from media, social media and just direct inquiries. And so I've just scattered them and just see if you can answer them for us. The first one, which we've kind of tapped on, but why do we see these flying-foxes more in the warmer months? Based on flowering?

Jason van Weenen:

Yeah, so flying-foxes, I guess what we do is we see in spring we can have a slight increase in numbers in the Adelaide camp. So lots of southern camps across Southern Australia can see a decrease in winter and an increase in spring summer. So that may reflect flowering and those seasonal conditions. And so ours, our camp sort of does increase a bit over the warmer months. The other thing as well is that over summer you've got, depending on the seasonal conditions, you'd hopefully have some pups being recruited and that causing an increase in colony size over that period too.

Melissa Martin:

So pups getting older or pups being born?

Jason van Weenen:

So their pups are born in spring, so they're around that September time, October and then they're starting to venture out on their own in that January, February, March time. So then you sort of get that January, February you're starting to potentially see more as these young ones are starting to venture out. I guess the other thing with summer as well is that it's a much lovelier time to be out and about and spending time outside over summer. And so there's not likely to be sitting out looking up at the sky in winter when it's raining and freezing. And so the possibility of seeing them or the probability of seeing them might increase slightly as well over that summer period when it's much more lovely to be out and about.

Melissa Martin:

And as bats are not native to Adelaide, we have covered this a bit, but I guess people assume they're pests because they're not from here, from South Australia and obviously we've covered that's not true, they are a threatened native species. Was there anything you wanted to add to that I guess around this perception that people think they are pests?

Jason van Weenen:

Yeah, so I think, I guess that it does come up, or they weren't here naturally, they shouldn't be here now. I guess one of the things is it's a bit of an interesting situation. We've basically planted up Adelaide and provided a lot of this food and basically saying don't come and take this food. They're just doing it like our lorikeets are. And so we're basically provide a resource. The interesting thing with the flying-fox is that they are threatened, we should really be encouraging threatened species to be adaptive and do their best to survive into the future. And so we're mindful of that and we're mindful of the part that we can play in their national conservation. So we are, I guess, embracing that presence of the colony, trying to understand it and being really mindful of the role, the conservation role that having bats in South Australia can play.

Melissa Martin:

And do all bats, particularly grey-headed flying-foxes and so microbats and I guess megabats carry disease?

Jason van Weenen:

Can carry, it's not that they all do carry. So that's the thing where a lot of the viruses of concern can be detected in flying-foxes, but they tend to be at really low frequencies. The problem with that is that you have to treat every bat as if it's carrying a disease. So you don't touch bats even though there's a low probability. You treat it as everyone is a... So if you happen to be scratched or bitten by a bat, you'd have to treat as if that bat was carrying a serious disease and you'd have to follow the right course of action to make sure you're safe. And so it's one of those things where they don't carry lots of disease, they can carry a whole variety of diseases, but we just have to make sure that we're as safe as we can around the bats and try and not come into contact with them if we can.

Melissa Martin:

And are flying-foxes dirty animals?

Jason van Weenen:

No, I wouldn't consider them to be dirty animals. I think the perception that they may be dirty may be coming from the people visiting camps and they can be quite smelly places as a camp, but the animals themselves are actually quite clean. They spend a lot of time grooming and that sort of stuff. And you certainly, if you were to look at them, if you ever get a chance to look them up close, they always look impeccably clean. Yeah, so it's probably more an association of a camp being somewhat of a smelly place with the fecal material in those areas rather than the bats actually being dirty.

Melissa Martin:

And why do so many bats die in Adelaide's heat?

Jason van Weenen:

So as I mentioned earlier, South Australia is one of the hottest and driest parts of their range. And so what we've observed over the years has been in Adelaide's heat wave events, when you're getting the temperatures up in above the 40s, we see flying-foxes succumb to heat stress, particularly young flying-foxes. And that's a problem for them where you might have adults moving to the River Torrens for a drink and rehydration. Often youngsters can't make that move and so they are left behind in the camp and they suffer as a result and are lost. So what we see is that in quite a number of years you can lose most of the young bats that are out there. So a large proportion.

A whole variety of stakeholders work together to try and protect the bats as best we can. And also there's some work happening with trying to cool the camp and so people may see sprinklers and things on in the middle of a heat wave and wonder what's going on, it's not water-wise, but it does actually play a really important role in cooling the camp footprint. And if we can avoid lots of bats dying, we know that it's not necessarily going to change the number of bats in South Australia, that food resource is going to be the main driver. So what we're doing by trying to cool the camp is that we're just trying to prevent a big welfare issue and a lot of high risk issues of bats coming down all over the place in the heart of Adelaide.

Melissa Martin:

And micro bats. So microbats versus megabats, obviously one's small, one's big. Are there any other megabats in Adelaide? Because microbats, there's probably a few of those species in Adelaide. Is flying-fox the only megabat in metropolitan Adelaide?

Jason van Weenen:

So in South Australia in metropolitan Adelaide we only have the grey-headed flying-foxes, but there is in other parts of South Australia, I think we've had the odd little-red flying-fox record in some of the arid areas. Little-red flying-foxes are shifting their range, moving sort of into some southerly areas. So in years to come we may see that species also extend into South Australia more regularly.

Melissa Martin:

And last question, what should you do if you find an injured, sick or dead bat on the floor?

Jason van Weenen:

Yep. So the recommendation is that you call one of the care groups. So that's Bat Rescue SA or Fauna Rescue. Fauna Rescue have a bat rescue team. And so they are definitely the first ports of call. And just the reason for that is that it's much safer for the bat if it's injured, to have someone who knows about the appropriate handling of a bat to reduce the stress. They've got a lot of tricks up their sleeve to do that and do that really well and in a really good position to make some good decisions around the way to work with bats that are coming into care and minimize all that stress. And even with the dead bats, it's really important that people remember that you could accidentally get scratched or you're not supposed to be handling dead bats and that. So just to be on the safe side using the support of those organizations is recommended.

Melissa Martin:

Before we let you go, just if we could finish off with a couple of takeaways from your experience in the environmental sector. So for our listeners who are new to the industry or just need some inspiration to get into the industry, what's one learning from your career to date in the environment sector that you wish you knew when you started or advice that you'd give someone who's ready to start?

Jason van Weenen:

I often provide the same bit of advice because I see a lot of people who get out there and volunteer and the importance of that. And I'm amazed that when I come into this work site, there are people here I've volunteered as a school kid with in the building. It's unbelievable. So that volunteering is really important. One, you get to become a familiar face with lots of people. You get to learn from people who are working in the field and that exposure, that experience is really handy. You often have people who might go through training degrees and things like that, but to provide yourself with a bit of an edge, having that diversity of experiences is really valuable and it can be-

Melissa Martin:

Great. Cool. Thanks, Jason, for your time.

Jason van Weenen:

No worries.

Melissa Martin:

That brings us to an end of episode seven of the Green Adelaide Podcast. Thank you to our special guest, Jason van Weenen, who is a local bat expert and also the team lead of Urban Biodiversity at Green Adelaide. I hope you have learnt to at least kind of love all the grey-headed flying-foxes that we see all around metropolitan Adelaide, particularly in Botanic Park. And I hope that maybe you'll notice them a bit more and maybe point out some facts that you have learnt. Great spots to see them is of course Botanic Park, but I would also suggest the [inaudible 00:42:54], the good one to go to at dusk. This podcast is your insider scoop on all things cool, green and wild in metropolitan South Australia. I'm your host, Melissa Martin, and this is our last episode for 2023. I'll catch you for our next one at the end of January, 2024. So Merry Christmas and happy New Year. Bye.