Echoes in the Dark

Capes Conversations heads into the darkness to explore the nightlife of our region's forests and caves. 

As the sun drops, researchers armed with acoustic monitors and bat traps take to the bush around Mammoth and Jewel caves on a delicate mission. 

With great care, they’re learning which microbat species are living, feeding, roosting and moving through this landscape.  

The research is led by the Conservation Council of WA in partnership with Capes Foundation to better understand why these often-misunderstood animals matter - to the health of our forests, caves and the broader South West. 

The guests are Conservation Council of WA's Kelly Sheldrick and Capes Foundation Conservation Manager, Alysha Johnson.  

Show Notes

https://www.ausbats.org.au/bats-in-buildings-faq.html 

Mammoth Cave After Dark: Bat research in the Margaret River Region - Capes Foundation

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This show was recorded at RMR 101.9FM, Margaret River Region.

Transcript

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Kellie Tannock 0:01

Welcome to Cape's Conversations, sharing the stories that make the Margaret River region a truly special place to live and visit. Hello, I'm Kelly Tannock. Thanks for joining me. Today we're heading into the darkness and the nightlife of our region's forests and caves. As the sun drops, researchers armed with acoustic monitors and bat traps take to the bush around mammoth and jewel caves on a delicate mission. With great care, they're learning which microbat species are living, feeding, roosting, and moving through this landscape. The research is led by the Conservation Council of WA in partnership with Capes Foundation to better understand why these often misunderstood animals matter to the health of our forests, our caves, and to the broader South West. Joining me from the Conservation Council of WA are Kelly Sheldrick and Capes Foundation conservation manager Alicia Johnson. Welcome to you both. Alicia, let's start with you. We all know Mammoth Cave for its spectacular features and its fossils and the carry forest setting, but not much about its bats. How did they land on your radar as a research subject?

SPEAKER_01 1:05

For a long time now, the guides have quite often seen the odd bat hanging out in Mammoth Cave during the day while we're open. Most often they're sort of chilling on a stalicty, having a little snooze. And it wasn't until I saw that CCWA were doing a bat program in the Southwest, and I love bats and I love citizen science. So I jumped onto it. I think I sent Kelly a very long, very enthusiastic email saying that I'd love to take part. And I also said that I coordinate conservation works at some show caves and wanted to see if she'd want to come down and have a look and see if we can participate. And I guess the rest is history. So you got in touch with the Conservation Council. What happened from there? I think a few months later Kelly came down to the southwest. We visited a few caves and started to put out acoustic detectors. While we were walking through Mammoth Cave one afternoon, we were with one of my team members Di, and Dye pointed out to Kelly and asked if what we were looking at was bat poo, which it was. And I think Kelly will be alright with me saying that her eyes kind of lit up at how much bat guano there was, which is quite unusual. Each to their own. These detectors are meant to be in the field for a really long time. They've got a really good memory on the SD card, but we filled up that SD card with bat calls in three days or three nights, I should say.

Kellie Tannock 2:40

Amazing. Kelly Sheldrick from the Conservation Council. Give us the basics on microbats. What makes them different to the bigger fruit bats that we might be more familiar with?

SPEAKER_00 2:49

Yeah, so our fruit bats are uh well, as the name suggests, they tend to eat fruit and nectar. Uh what whereas our smaller bats that a lot of people refer to as microbats, uh, are obviously a lot smaller, but they also tend to eat insects, so they're insectivorous. So that's probably the main difference between the two.

Kellie Tannock 3:09

And and why is the Southwest such a key place to study bats?

SPEAKER_00 3:13

The Southwest has a few endemic species. So we have four species down here that are found nowhere else, and they haven't really been studied at all, which means that we can make lots of really cool discoveries just by taking a look in a few caves that haven't been explored before, or maybe attaching some radio tags to some bats and going out into the bush and trying to find them. Uh, there's just so much out there that we can really discover about them.

Kellie Tannock 3:40

Why are we so late to the party on studying these particular bats? Is it just that there are so many uh species out there?

SPEAKER_00 3:47

Yeah, I mean we have 42 species in Western Australia according to the WA Museum Fauna list, and that makes up around about 22% of all mammals in Western Australia. So there's a lot of species there. And with advances in technology, especially around genetics, we're also describing new species to Western science as well. So there's actually a species in the southwest, the Hulk Long Eared Vat, that was only described to Western science in 2021. So there's when we're still um describing these new species, then there's obviously still a lot to learn about them as well.

Kellie Tannock 4:23

That's actually really exciting, isn't it? It's a lovely story about science and local observation coming together. You've got guides noticing things and conservation staff asking questions, and then you've got your researchers coming in to investigate. How important is that teamwork on a project like this?

SPEAKER_00 4:39

Oh, I mean, it's really important, especially in a state like Western Australia that's so so large, and I mean most of the population is in the southwest as well, like 90% of the population. And even then, our population's so small in comparison to the size of the country. And we have a lot of bats that we need to learn about, and they're really elusive. Many people don't even realize we have them down here because we don't have fruit bats down here. So I feel like having more people on the ground and just being aware that they're out there really helped to even just narrow down where to focus, which I guess is what happened here with the guide pointing out the the guano. It helped us realize well, there's something really important going on here. Maybe we should focus a bit more energy.

Kellie Tannock 5:23

I'm Kelly Tannock. This is Cape's Conversations, and I'm chatting with Kelly Sheldrick and Alicia Johnson, who've both been involved in microbat research. And let's go to some music now. And when we come back, we'll find out how researchers actually study these tiny, fast moving animals in the dark and what the team has discovered around Mammoth Cave. This is Bunbury's Great Gable and Drift.

SPEAKER_06 6:26

I find it hard, I find it hard to stay when I'm on my own Soul just can to the stone. I'm losing all my fight Never No the door. I've read that I've lost another.

Kellie Tannock 9:43

This is Capes Conversations, a half-hour spotlight on this wonderful region, proudly sponsored by the Margaret River Bastleton Tourism Association. I'm Kelly Tannock, and we're talking about bat research around Mammoth Cave with Kelly Sheldrick from the Conservation Council of WA and Alicia Johnson from Capes Foundation. Kelly, a bat flying past in the dark sounds pretty hard to identify. How do you actually work out which species are present?

SPEAKER_00 10:09

Yeah, that's a great question. And yeah, you're right, they're pretty hard to identify when they're flying past so quickly. Uh, luckily for us, uh our insectivorous bats down here, they do something called echolocation. And what that is, it's the ultrasonic sounds, so the sounds that we can't hear with the human ear. And they produce these sounds either at their mouth or their nose, and they knit them into the environment and they bounce off the objects around them. It returns to the bat, and then from that the bat can actually build up a picture of their surroundings, which is really awesome. It's basically like a bat torch to help them see at night in the dark. Now, what's really great about echolocation is different species will produce these different echolocation pulses with what we call different parameters, so things like different frequencies. So we're able to record these ultrasonic sounds with special bat detectors that Alicia mentioned earlier, and then when we have a look at them, we can get an idea of what species are in an area, which is really, really cool.

Kellie Tannock 11:10

Sounds pretty high-tech to me. The project uses something called harp trapping as well. What's a harp trap and and how are you handling the bats safely?

SPEAKER_00 11:19

Yeah, so another way of surveying bats is by physically catching the bats. And we need to do this with some species because their echolocation calls will overlap. So the only way we can reliably identify them is to catch them and then identify them in the hand by looking at different uh features of the bat. So that might be taking measurements of forearms, looking at the nose ridge, and looking at other features as well. Uh, when we do this, we can also gather other information that we can't get from our acoustic survey. So this might be things like looking at the sex, uh, looking at the reproduction of the species, seeing whether it's breeding or pregnant as well. And one way of doing this is putting out what we call a heart trap. The only way I can kind of describe it is it's a really large heart-looking trap. Makes sense, yeah. Yeah, we've got a big rectangle that we erect up like a rectangle frame, and then there's some fishing wire going down the middle, just like the strings of a heart. And then at the bottom of that we have a bag. So essentially what we do is we put these heart traps out in flyways where we think we might get bat, and then the bat will be flying along, it'll hit the strings, it will fly down the strings and end up in the bag at the bottom of the trap. The bat then can't climb out because it's the plastic on the inside, and then we go to check the trap usually every 30 minutes, and we uh collect any bats that are in there. Now, this is really great because it's quite a low impact for the bat, so the bats aren't likely to get injured as they fall into the trap or anything like that. Um, so yeah, they're a really, really great uh invention to put up.

Kellie Tannock 13:06

It sounds very clever to me, and I assume when you're handling them that you're doing that with great care as well.

SPEAKER_00 13:12

Oh, yeah, yeah. They're very delicate. You need to have an understanding of how the wings move and just a bit about bat biology, I suppose, as well.

Kellie Tannock 13:23

Now you've got another interesting trick in your bag. Acoustic lures, how do they work and what are you testing there?

SPEAKER_00 13:30

Yeah, so acoustic lures is something that we use to increase our capture rate for our bat. And we were testing this a couple of years ago and uh including at Mammoth Caves as well, where we were testing European bat social calls because they were the calls that we actually had to test out. And we knew that these calls had used uh been successful in other places around the world. So we thought we would test them out on our West Australian bats and see whether the bats are interested in them. And we did this as a pair design. So we had some traps set up with acoustic rules and some without, and we actually found that the traps that had these acoustic rules they were a lot more successful in their category, in fact, like by 10 times more successful than our underwood traps, which is really amazing. So the benefit there is it means that we have to spend less time out in the field, which is very um time consuming, also quite costly, and but it also means that we can use the heart traps really effectively as well.

Kellie Tannock 14:35

Okay, so you've got the bat in hand. What information are you trying to gather then?

SPEAKER_00 14:40

So we're looking at a range of different things. We're looking at um confirming the identity of the bat of the species. Uh, we're also looking at the sex of the bat as well, we're looking at whether they're breeding, we're also collecting a few additional things as well. So we're taking guano samples from the bat, and that's the bat poop. Uh, we're also looking at whether the bat uh have any exoparasites, looking whether they've got any pick, or there's something called bat flies that we're also looking at as well.

Kellie Tannock 15:11

Okay, well, let's talk now about what the research is actually showing. And Kelly Sheldrick from the Conservation Council. What species have been recorded or confirmed in and around Mammoth Cave so far?

SPEAKER_00 15:22

So Mammoth Cave, our areas has a really good diversity of bats, and this is not so much using the cave itself, but around the surrounding vegetation around the cave. Uh, we've had gold bottle bats, chocolate bottle bats, uh, leather long-eared bats. Uh, we've also had two of our endemic species, and that includes the western long-eared bat and the hope-long-eared bat, uh, and also southern forest bats and white, and we've also recorded white-striped retail bats as well. Uh so it's the diversity has been really good.

Kellie Tannock 15:55

Alicia, these sound like really fascinating looking bats. I'm really keen to have a look at what they they look like. Where could we see them?

SPEAKER_01 16:02

That's really good timing, actually, because an article's just been published on capesfoundation.org.au, and there's some really incredible images there.

Kellie Tannock 16:09

Kelly, there's also been some interesting seasonal activity around Mammoth Cave. What have you seen happening around autumn?

SPEAKER_00 16:16

This is really exciting because what we think it is, is a behaviour that hasn't really ever been documented in Australian bats before, and this is this autumn forming behavior. So this is a seasonal social behavior that has been well documented in some bat species within the northern hemisphere. And what it is, it's where bats will aggregate at either cave entrances, maybe just used mines or tunnels, and it's usually two to three hours after sunset. So this is a nocturnal um aggregation of bat. And although there's some question around the function, and that it might even vary between species, is usually associated with mating or information exchange, or even winter roof assessment as well. And what we know with studies done in Europe or uh also in North America is that this warming behavior is really important for the life cycle of the bats that actually uh carry out this behavior.

Kellie Tannock 17:22

What do you mean by the life cycle? What's the how is it important to the life cycle?

SPEAKER_00 17:26

So because the autumn forming behavior is considered to be associated with mating, lots of different bats are coming from different colonies and they're coming to this one site and they do that during an autumn period. And during that autumn period, they're exchanging information about various things, but they're also carrying out this mating activity, and this is to help with the genetic diversity of the species. And so this mating behaviour is obviously really important to ensure that the species survives in the long term and to also ensure that genetic diversity as well.

Kellie Tannock 18:02

It's wonderful that we're still discovering these incredible things. Alicia Johnson from Capes Foundation, what's it like from a conservation perspective to realise that Mammoth Cave isn't is important not just as a visitor site but as part of the life cycle of these bats?

SPEAKER_01 18:16

It is so special. I think ecotourism has such a such an important role to play in conservation. And so getting to welcome people to a site like Mammoth Cave and educate them about the species that use at the site. It's that old adage of you can't protect what you don't know. And if we can change people's perception on a creature like the bat, having even just a small role in that is is so special to me.

Kellie Tannock 18:45

It seems like we're just learning so much more about the layers of this incredible place where we live. We'll take another short break now, but when we come back, we'll talk about why bats matter, not just to scientists, but to anyone who cares about the Margaret River region's forest, cave, and wildlife health. This now is Indigenous Perth hip hop artist fluent with summertime flow.

SPEAKER_04 19:08

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SPEAKER_03 19:36

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Kellie Tannock 22:07

This is Cape's Conversations. I'm Kelly Tannock, and today we're talking with Kelly Sheldrick from the Conservation Council of WA and Alita Johnson from Capes Foundation about bat research around Mammoth Cave. Kelly, bats can suffer from a bit of an image problem, can't they? They're often depicted as creepy or scary. What would you like to share about them with our listeners?

SPEAKER_00 22:29

I understand why some people might find them scary. They're an elusive animal. A lot of people don't know about them, they can't see them, they come out at night. So I kind of understand where that image came from. But what is true about the animals is that they provide us with a lot of really amazing benefits. They have really important roles in the ecosystem. And these roles can have benefits for us too. A lot of people refer to these as ecosystem. They eat so many insects in one night, including lots of mosquitoes, lots of moth, including a lot of crop pet as well. But they also eat things like cockroaches. I don't think a lot of people realize. But they're playing that really important role in keeping our insect populations in check. They play a really important role in pollination. Pollination of lots of our native plants, but also some of the foods that we really love to enjoy. So some of the foods that produce things like chocolate, coffee, tequila. And that's all thanks to bats about pollinating them. Apart from that, they also provide many reasons, so I might be here all day might be off. They also provide the benefit of seeds disturbed, particularly in our tropical rainforest where they're spreading seeds and ensuring that all the trees are going to be able to regenerate. And another thing to consider as well is the food that they produce is really high in nutrients, and that's a really, really amazing fertilizer. So there's lots of reasons why they're really important and they provide a lot of benefits to us as well.

Kellie Tannock 24:13

Right, they certainly sound like great helpers in the ecosystem. What are some of the pressures that are facing our bats in the Southwest?

SPEAKER_00 24:20

There's quite a lot, unfortunately. So there is a huge issue with cats. There have been some situations where researchers have been looking at the stomach contents of feral cats and actually found 10 or more bats in the stomach of one cat. So when you think about how much of an impact that could be having, it could be huge on the population. Other things that can be having an impact on that is the habitat loss. So not only the loss of roosting habitat, so things like old trees and uh caves, even that are no longer, they no longer have the right conditions to suit the bat's need. So for example, they might be drying out, but they might also be losing the connectivity between habitats as well, which is a really big issue, especially around some of our more urban developed areas. Access to water is a huge one. A lot of people don't realise that our bats do need to drink, and obviously the impact of climate change can have a huge impact. And I think we mentioned earlier as well that the negative impact that humans have towards bats can also have a really big impact because we tend to put all of the research effort and the money into our more charismatic species and we forget about all the other ones.

Kellie Tannock 25:39

Yeah, sure. Uh it's pretty alarming, and especially since we've just learned about all these lovely things that the bats contribute to our environment. What can local people to do to help their situation?

SPEAKER_00 25:50

The number one thing that anyone can do is educate themselves and others on bats, and it can help dispel some of the misinformation around bats out there. And a resource that I recently helped put together as part of my role in the Australia Bat Food Vietnam Committee with some resources that are available on the website, and this is to help people know what to do if they encounter that in building, for example, what to do if you find an injured bat, what to do if you've got a bat roof in your house. All these things that a lot of people are unsure about what to do. All these resources are available on the odds website, and that is probably the number one thing we can all do is just spread the corrected information.

Kellie Tannock 26:41

Well, look, it's great to know that this research is ongoing. What mysteries are you still trying to solve?

SPEAKER_00 26:48

I feel like the more research we do, the more questions we have. So with the autumn forming, the question we're trying to ask there is what is the function of that? We think it could be mating, uh, but it might be something else. We're also seeing this really unusual clustering at the cave during this um forming behaviour, and that hasn't been seen as far as I know anywhere else in the world. So, what is the function of these clusters is really interesting. So hopefully one day we'll have an answer to that, and we'll probably have more questions following it.

Kellie Tannock 27:25

Well, it's great to know someone's out there trying to solve them, and another reason to love the Margaret River region is though we needed another one. Thanks so much to Kelly Sheldrick from the Conservation Council of WA and Alicia Johnson from Capes Foundation. Today's conversation reminds us that even in places we think we know well, there's still a lot going on quietly around and above us after dark. At Mammoth Cave, research that started with guide observations has grown into a partnership, helping scientists understand which bats are there, how they move through the landscape, and why caves and the surrounding forest may be seasonally important. And also importantly, it shows that conservation isn't always about remote places and iconic species. Sometimes it's about listening beyond the range of human hearing, paying attention to small signs, and recognizing the deep connection between the health of our caves, forests and our wildlife. Sharing the stories that make the Margaret River region such a special place to live in and to visit. And a big thanks to our show sponsor, Margaret River Bustleton Tourism Association. We're going out today with a new release from Perth Outfit Dice and Call Me for a good time.