SPEAKER_00 0:00

I'd like to acknowledge the Wandrew Warong people as the traditional owners of the land where this recording was made. Over the past few months, I've been walking through reserves around Melbourne, Vietnam, and recording conversations along the way. I've met with traditional owners and First Nations peoples, conservationists, ecologists, and others who've chosen a place that matters to them. We walk and talk about nature, what lives there, what's changed, and what needs protect it. You'll hear our footsteps, the wind in the trees, the birds overhead, and the city not too far away. This is Finding Melbourne's Nature. Today we're at Mullam Mullum Park in Donvale, a beautiful patch of bushland in Melbourne's east. If you've ever travelled through the Eastlink tunnels, you've actually passed beneath the Mullum Mullum Valley. Perhaps without even knowing it. I'm walking with ecologist and herpetologist David DeAngelis. He's president of Frogs Victoria and someone with an incredible knowledge of Melbourne's reptiles and frogs. We explore the forests and creek lines, looking at some of the wildlife that still survives here, including the threatened southern today. We talk about the fight to protect this valley, the threats facing frogs around Melbourne, and the remarkable diversity of wildlife that can still be found in a suburban reserve. I'll pass over to David to introduce himself.

SPEAKER_03 1:43

David DeAngelis and I have worked professionally mainly as an environmental consultant and more on the fauna than flora side, but much broadly in ecology. Since I graduated from La Trobe Unib in 2009, after sort of finishing off with a passion project for my honours on reptiles, yeah, which along with frogs, so herpetology being I guess a key interest or obsession of mine, um but ever since I can remember, you know, being completely absorbed by wildlife and fauna conservation. And then I suppose it was when I was at high school at Whitefries, which is kind of relevant to the area that we're in because it's on the Mullamullum Creek in Donvale, close to where we are, that really gave me an appreciation of habitat for fauna in terms of the indigenous flora. And that led on to my first job, which for me, incredibly luckily, was on bush crew during school holidays.

SPEAKER_01 2:57

School holidays.

SPEAKER_03 2:58

With Indigenous Design, who were contracted to advise on bushland management at the school. And at that stage I was volunteering down at the creek with whichever other students I could twist their arms enough to come down with me during lunch times when the teachers would let us and you know, free periods among VCE, pulling out sweet ptosphums and planting tube stock. And I guess I was noticed, you know, doing that sort of stuff for free and was offered work during the holidays on Bush Crew, and I definitely well, yeah, it didn't take me long to say yes. Um well I mean never looked back, but I you know there's not a point in time that I can remember that I can point to and say that's when the interest really began. It was it always was for me. Right this is a perfect example, I guess, of an area where yeah I could spend hours, you know, walking walking through a patch of bush like what we're in right now. And for someone like me who started off on bush crew in um ecological land management and restoration, it's hard to get a better quality patch of bush than this. I mean it's just about completely free of weeds. Yeah, and it's it's one of the few pockets in the Mullamullum Valley that's still as as good quality as what we can see that yeah, hence sort of managed fairly intensively by Parks Victoria since the freeway tunnels went under the valley. I've always been attracted to the more cryptic or over you know, often overlooked or misunderstood things. So yeah, I mean nothing against birds and mammals, but I I think it's exciting as well because we know, if not frustrating in some ways, like there's a heck of a lot that we know about most native birds and mammals. Not you know, there's always questions and areas to learn more, but it's nothing compared to the lack of knowledge around even basic natural history information in relation to you know a lot of reptiles and frogs, even some of the more common ones.

SPEAKER_00 5:14

And to set the scene, I guess we're looking here at chocolate lilies and stackhouse.

SPEAKER_03 5:22

In flower at the moment, yeah, and then other other things. So there are a lot of orchids in here as well. And there's some some interesting uh shrubs as well that don't occur very commonly, at least this close to Melbourne. Yeah, right. So I think there are uh which one of the Persunias in here, uh things like acacia myfolia, yeah, which in the context of the Mullum Mullum isn't very common, but there were only a couple of remnant plants, and of course Cambirdzell has been involved in spreading it a bit, um, to to try and secure that local population. Yeah, something, an example of a plant I guess that's not necessarily uncommon elsewhere. But I suppose for this part of Melbourne or or where we are, there are a lot of examples. And there would be others, you know, wherever else you are, but we're I guess just fortunate that locally rare plants like that have been noticed and been able to be helped, I guess, to to persist in the valley. And that kind of crosses over to my fauna interest in terms of the southern today. Yeah, which we'll we'll get to, I guess. So at the top of the hill, um we're in Valley Heathy Forest, which is kind of a well it is a a threatened EVC and then at this point now that we've moved down towards kind of mid slope, we'd be in Valley Grassy Forest and grading down to riparian forest along the creek. Yeah, so it's interesting, at least these steeper parts of the valley, how that those um veg communities transition. But yeah, real really noticeable.

SPEAKER_00 7:21

Wow, the creek's beautiful here. I haven't been along this part. Yeah, it's really nice.

SPEAKER_03 7:26

Well, yeah, I suppose the quality of the veg, although there's you know Japanese honeysuckle and you know if you look closely, there'll still be plenty of weeds. But yeah, that that's mainly thanks to well actually the various bushcruz land management teams that Manningham contracts to manage these parts of the valley and uh well some parts that council still manages and Parks Victoria do their own work and and also obviously have contractors. Intensive management in some parts and in others not so much. Well, it's hard when you've got angled onion and as you'd know, um let alone blackberry, but you know, let alone the introduced grasses, but yeah, it's no different in that way from any other creek around Melbourne. The riparian zone is kind of you know a bit more degraded and weed invaded, but I'm just happy not to see concrete down the creek line here, it's nice. Oh yeah, oh um so we didn't get an open cut freeway, yeah, but we got you know this instead, so yeah, I do actually I'm I'm old enough maybe just to remember when you know what's now East L known as East Link but back then the Eastern Freeway Extension was proposed and then kind of happened and it was a major success story in terms of the community campaign. And really, and you know, according to the state environment minister at the time, Gavin Jennings, like I remember him saying very insistently that had it not been for the community campaign, chances are there would have been an open-cut freeway through the valley. Despite the presence of powerful owls and platypus and well, which back then wasn't recognised as a threatened species, or let alone Southern Todelet, because that sure as hell wasn't recognised as a threatened species at the time. And yeah, no, you know, it's probably not an exaggeration to say that not many people cared, apart from Craig Cleveland and you know, a few of the rest of us who were in the know, but yeah, so had it not been for that massive community advocacy, the situation would have been obviously far worse than what it is at the moment because there were still some impacts and there were people involved in that advocacy that weren't still weren't entirely happy with the outcome. It's fair enough there was a lot of high quality veg lost at the tunnel entrances and then little bits subsequently with the construction of the shared path and bridges and that sort of thing. But I I think even you know those people realise that it could have been a completely different story had the tunnels not gone underneath.

SPEAKER_00 10:48

How would you describe the Southern Todlet to someone who'd never seen one before?

SPEAKER_03 10:53

Oh, what a great question. So uh well, although I'm a a bit biased, well actually to be fair, they they don't sound too spectacular in terms of uh a frog call, they're kind of a squelch. Yes, as as you'd know then. And uh yeah, and it can be hard to hear, especially somewhere like in the Mullum where there's a very small population left. Oh, a tiger. Oh geez. Oh, and I just said we don't often get tired. Well they're they're they're both here, copperheads and tigers. Yeah, yeah. And actually while we're on snakes, yeah, my other interest, yeah, so the Mullum Mullum is recognised amongst, you know, the herpetologists who are in the know as a sort of hotspot in Melbourne or this close to Melbourne for the white-lipped snake. Yeah, so they are still common enough, I guess. You don't see them very often because they're so small and cryptic, but yeah, they they do turn up once in a while.

SPEAKER_00 12:08

So um I guess seeing a tiger snake and we're maybe a few metres away from it, perhaps, it kind of got a bit uh I won't say excited, but it seemed surprised to see us. Um and it flared up.

SPEAKER_03 12:20

It did flare up, yeah. Um which is typical of tiger snakes, but luckily it um didn't do what some of them do, and they kind of hold their ground and yeah, rear up and kind of mock strike at you and or or or for real for something.

SPEAKER_00 12:39

What would you say to people who might be scared of tiger snakes or against snakes and things like that? Let's say you come across a t uh a snake in a park like we just did. Why are they important for the habitat or what's special about them?

SPEAKER_03 12:51

Yeah, well again, I well in some ways being as biased as I am, I don't know. But but thinking about it maybe a bit more critically. So like I would say intrinsically, like I, you know, I have an appreciation for them because it's my interest. But thinking perhaps a bit more critically or um uh you know about other reasons why we might want to keep them around, despite fairly enough, people, you know, it's probably fair to say most people are at best wary and you know perhaps not uncommonly you know afraid or or or have even more extreme reactions to snakes. You know, in some ways fairly enough because all of the local species that are large that we get in this area, mainly being tigers, lowland copperhead, and occasionally brown snakes, usually higher up in the valley, are incredibly venomous, obviously. And that kind of applies wherever you are around Melbourne or southern Victoria. But I guess as part of the ecosystem, they're an integral part of the food chain and food web. So as much as I love frogs as well, we'd possibly be in trouble if there weren't well no, we would absolutely be in trouble if there weren't things to eat them, including snakes. But obviously a lot of other things do as well. And that's not to say that they're not food for other things as well, so.

SPEAKER_00 14:28

Do you know much about the life cycle of a tiger snake?

SPEAKER_03 14:31

Oh, only insofar as they so both tiger snakes and copheads give birth to live young, and that's it's a general, it's a very broad general kind of rule, but it it is kind of true that because both of those species are very well adapted to cooler or more temperate environments and living around damper environments, arguably, so although you might find both species higher up the hill, because frogs form a portion of both species' diet, apart from anything else, you do tend to find them often closer to water. And because they occur in these cooler, more southerly latitudes and in cooler microhabitats, giving birth to live young is an advantage. You don't have to incubate eggs.

SPEAKER_00 15:26

And would you have advice as a herp lover? I hope it's okay to declare you that. Oh, yeah, or obsessor. Obsessor. When when you're coming close to them and we're about to walk past it, what would you encourage a bushwalker who is walking past a snake that had just arced up a little like that one just did?

SPEAKER_03 15:44

Oh, exactly what we did, which was to stay still. I mean we've got the advantage of a bit of familiarity, so yeah, but for someone who didn't to stay still, usually they'll um do exactly what that one did and sliver off. Um at worst, tiger snakes are behaviourally, and although you know it's absolutely true, individual animals have their own personalities and there's a bit of flexibility there in terms of, you know, like with many species, you get ones that are a bit more agro and aggressive and ones that are much more placid and relaxed. But generally, tiger snakes are a bit more reactive to some you know a person's presence, let alone a dog or or any you know a cat. They will often react in that way. At first they'll respond, you know, either nervously or a bit aggressively, and in some cases they'll arc up and lunge forward. Copperheads and and even browns, you know, unless you're poking them or you're really, you know, cornered them or something, won't do that as much.

SPEAKER_02 17:04

Okay.

SPEAKER_03 17:05

But even if if you come across a tiger snake that did that and sort of came forwards a bit, it's possibly part of the reason why people tell stories about being chased by snakes. But they're not necessarily chasing you, they're trying to push you away and sort of hold their ground.

SPEAKER_00 17:25

It'd be remiss of me not to mention that just six days after this recording, I was bitten by a tiger snake in a remote location. It's quite a story, and I'll save it for another day. But David's advice really helped me. So we were saying, what would a toadlet look like to somebody who'd never seen one?

SPEAKER_03 17:41

That's right. Before we were distracted by the snow. Exactly. Um okay, so not only is the call not very exciting, but you know, some people have accused them of being not the most exciting to look at, a little brown or dark grey, or you know, occasionally they do have olive green or even yellow colours on them, but um I suppose the uh visually more exciting part of these todlets is the underfide. Yep. Yeah, so as many today species do, they have bold black and white or pale and dark marbling on the belly. And in the southern todilet uh it tends to be only on the upper belly and around the thighs and yeah, lower down on the abdomen and under the arms and legs and under the throat is usually orange or um or yellow, or in some populations, in some areas it can almost be red. Wow. Uh so uh having said that though, I mean unless you ask them nicely to roll over, which doesn't often work, you you'd never really see them because although they do occasionally go foraging and uh often in summer or warmer times of year when they're not breeding or otherwise needing to be around you know very close necessarily to where they breed, they are otherwise usually have a very high fidelity to their breeding spots. Okay. So and that from a micro site perspective means under the grass or moss or leaf litter, some sort of ground cover, or occasionally down yubby or crayfish burrows, depending on the site, and they remain concealed in a little shallow, a very shallow burrow where the females lay their eggs and then the male remains with them until they uh those areas flood and the eggs hatch. So I guess that's the other really unusual thing about them, or one of the most unusual things is that they lay their eggs on dry land.

SPEAKER_01 20:06

Yeah.

SPEAKER_03 20:07

Yeah, but in these very shallow depressions usually or seasonally inundated drainage lines, and in some cases they'll use artificial sites like uh wheel ruts off the side of a dirt track or something. And what they're relying on, given that those sites are dry when the eggs are laid, is for them to flood in early or or a little bit into winter usually, so the eggs are laid in autumn.

SPEAKER_00 20:39

What size are they?

SPEAKER_03 20:40

Oh the uh the the frogs themselves?

SPEAKER_00 20:43

Yeah.

SPEAKER_03 20:44

Um not very big. Uh approaching three centimetres at most.

SPEAKER_00 20:50

So hard to spot.

SPEAKER_03 20:52

Yeah, and so the most reliable way actually of recording them is by their call. And at least in this part of Melbourne we don't have to worry about confusing them with all the well two other species of pretty much identical sounding todlets in Victoria because they are the only one that occurs in this part of Melbourne.

SPEAKER_00 21:16

How widespread around Greater Melbourne were they?

SPEAKER_03 21:19

Uh yeah, that's a a bit of a sad story. Okay. And this is probably where we have to acknowledge Craig Cleland because he's done the 20 plus years of monitoring of them across most of Melbourne and beyond in Victoria. Uh for example in Manningham historically there would have been probably over a dozen sites, and at the moment uh it's this last remaining one in the Mullum that we know of, potentially with a couple of others that that we know still exist in Manningham, but it's a similar padding. Across other municipalities, so in Millenbeck, where they've done fairly intensive monitoring for the species over the past few years. Even in that time, so over the past uh five to ten years, the some subpopulations have died out, as best as anyone can tell. And uh yeah, others aren't doing as well as they used to.

SPEAKER_00 22:24

What are the big threats to it? How are they dying out? Is it loss of habitat or is it predators?

SPEAKER_03 22:30

Yeah, in some cases they're very obvious threats, like loss of habitat when someone ploughs through an area or uh where the frogs are breeding, or um you know, other disturbances dumps a whole lot of mulch on them, or and in other cases perhaps not so obvious, but it it seems to so kitchen fungus may place a little bit of a factor, although possibly more for metamorphs, because although it's not known entirely, the adults may be less susceptible to the disease for the fact that they are spending most of their lives not in the water. They're very terrestrial frog, and kitrid fungus needs to be well damp or moist to survive.

SPEAKER_00 23:21

If someone's listening to this and they've never heard about kitrid fungus, are you able to sum that up?

SPEAKER_03 23:27

It's a nasty disease for frogs that suffer from it, and not all do, but but enough do suffer from it that it's a major worry because it attacks the frog's skin. So it's a microscopic fungus, and there are several different species, but there's only really one that's known of that negatively impacts on frogs, the amphibian chytrid fungus. Again, chytrid needs to be moist or damp and it's present in the water. If it dries out completely, chytrid can't survive. So it's not like some other fungal diseases that affect other things in the natural world like cinnamon fungus or phytophora, which can survive drying out at least in a part of its life stage. Kitrid can't. Which makes frog skin a perfect substrate obviously because it's it's moist.

SPEAKER_00 24:24

And where does it come from originally and how long has it been the landscape, do you know?

SPEAKER_03 24:28

The thinking is now that it's most likely originated in parts of Asia and as far as anyone can tell would have arrived in Australia in around the 1970s because that's when the first specimens carrying the fungus were detected. Probably late a bit later than that in the wild, but subsequently through looking at researchers I think at James Cook University many years ago looking at museum specimens of frogs from the 70s detected the disease in the specimens.

SPEAKER_00 25:11

Right.

SPEAKER_03 25:12

And how it got here is still a good question. It used to be said so there was an out of Africa origin story initially for the fungus. It's possible that there could be more than one or a few strains and from different parts of the world, or that uh so African clawed frogs were very popular in hospitals at one stage. Really? And and unis, they were kind of the frog version of the lab rat.

SPEAKER_00 25:43

Yes, right.

SPEAKER_03 25:44

Although it wasn't known for sure, the thinking was that possibly these African clawed frogs came in to Australia with Kitrim on them. One of the main reasons they were used in hospitals, interestingly, was um as uh an old-fashioned pregnancy test. Oh. Because if you injected the urine of a lady who was suspected as being pregnant into a female African clawed frog, it stimulated a hormone response so the frog would start ovulating. I didn't read this, that's amazing. Yeah. But with the advent of modern pregnancy tests, no more need for the frog. No one ever carrying around a frog, yeah. So yeah, so perhaps, you know, there there are no fer uh feral or introduced populations of African clawed frogs in the wild in Australia, but the thinking was perhaps, you know, it wasn't uncommon at that point in time for people to throw things out into the bush. Yeah. And that's possibly how one way, or at least an example of how Kittridge could have possibly come into the country.

SPEAKER_00 26:56

And I've heard it could be even through selling fish and things like that too, is that right, potentially?

SPEAKER_03 27:02

Yeah, because although fish won't suffer from it, yeah, yeah, they can still potentially carry it, or at least the water that they're in. Yeah.

SPEAKER_00 27:11

And what effect does that have on frogs in general?

SPEAKER_03 27:14

So the ones that are susceptible to the disease uh that can die from it, uh, it eats away at their skin. And that so ultimately they'll die of a heart attack. It affects their water balance and you know whole physio physiology pretty much, but also leaves them vulnerable to secondary infection. So we're actually on Wallert Creek.

SPEAKER_00 27:45

It's a beautiful creek, it's glorious to look at.

SPEAKER_03 27:48

Yeah, there are probably a couple of threatened species that occur along the banks of the creek. Lovely. One of them is uh burrowing crayfish. So what we suspect to be Engaeus Victoriensis, the foothill, uh I think it's called the foothill burrowing cray. And that's also, along with the southern toadlet, the other, I guess, semi-aquatic species of fauna that we have in the Mullamalam Valley that's considered endangered in Victoria. Yeah, so occasionally you'll see the little burrows or holes in the banks.

SPEAKER_00 28:28

Um I get asked all the time, what are those little holes that I see? And it's it's usually a burrowing cray.

SPEAKER_03 28:34

And painfully difficult, often where you might have more than one species to identify what it is. Yes.

SPEAKER_00 28:44

Unless you consult the small number of experts that do you know how many different species of reptiles and frogs might be in this particular park?

SPEAKER_03 28:55

Yeah, we can probably go through a list and and count them as we go. So well we know we've got tiger snakes and copperheads and white-lipped snakes. So that probably oh an eastern brown, so that probably rounds us off for the snakes. The skinks, there's delicate skink and the closely related garden skink, and weasel skink, which is a shade skink, so it does things a bit differently and that it doesn't mind unlike those other skink species hanging around in more densely shaded situations because it's what we call figmothermic largely, so it maintains its body temperature by staying a bit more well insulated under litter and in logs and under rocks and that sort of thing. Eastern three-line skink, which is only notable because the males, when they're breeding, get a red flush colour under their throat. And then historically Jackie Dragons, but not so much anymore unfortunately, although they're still in parts of Warandite. Marbled gecko, but that isn't a species that's considered indigenous to the area. So yeah, they've traditionally naturally occurred more north of the divide. But Peter Rawlinson who's no longer with us but uh an academic at La Trobe used to say that they naturally came through the Kilmore Gap and perhaps you get them to the north and west of the city in river redgum sort of woodlands, but definitely not this far east in Melbourne. So that gets us to about 10, which is yeah, pretty good for a park in Melbourne. Yeah, I think so.

SPEAKER_00 30:48

What about how are we doing for frogs at this reserve?

SPEAKER_03 30:51

So we've mentioned the southern todlet, which is uh the only threatened species that we know still occurs in the area. Uh historically though, growling grass frog, and unfortunately, and that species does suffer heavily from chytrid fungus. Yeah, so unfortunately we as far as anyone knows, we we don't have any growling grass frogs anymore. But other species have variously been able to persist with the disease, and in one way or another, the populations have survived. So the the more usual suspects or common species like southern brown tree frog, uh spotted marsh frog, in some parts there would be striped marsh frog, uh obviously the poblonk or banjo frog, many people's favourite. Um, common froglet, which is actually well known as a transmitter of chytrid fungus. Oh. Even though it doesn't really suffer from it itself. Uh, we'll finish off the tree frogs. So whistling tree frog, uh which is a little bit less common than Southern Brown, but so closely related, they are now thought to hybridise with each other. Then Perrin's tree frog, which interestingly, despite how common they are over most of Melbourne, are another introduction. They're not indigenous to the Melbourne area. We can actually pinpoint exactly when they were first recorded because it was Murray Littlejohn and Peter Harrison, one of his colleagues, in 1985 at Yanyun Reservoir recorded the first Perrens tree frogs in Melbourne, but otherwise, so they're really a frog from north of the divide and Gippsland. So that covers us off on the tree frogs and then the marsh frog, spotted, striped, and the powerborn called banjo frog, which is in the same genus. Do we still have Victorian smooth froglet? Yeah, so there are multiple species that occur not far away. Yeah. Yeah, but but may not have necessarily been recorded in the Mullum Mullum specifically.

SPEAKER_00 33:02

Got you. Very interesting. It's a good, it's a smorgasbord of um.

SPEAKER_03 33:07

Yeah, well, I mean, well, we could uh probably argue it's probably a realistic comparison actually, there are probably as many frogs and reptiles in the Mullum Mullum Valley as there are in the UK or something like that. Really? And this this is one of the other things that's kind of fascinated me. Like I'm lucky that uh we're in Australia because Australia is now recognised as of several years ago, having the greatest diversity of at least reptiles of any country in the world. Really? Yeah, well well over a thousand species. Yeah, and and the numbers keep increasing literally every year.

SPEAKER_00 33:55

We beat Mexico, which uh well I think Frogs Victoria have a very worthy president. Oh, your knowledge is astounding and it's amazing to hear you talk about this stuff with such absolute passion and oh I can't help myself. A huge thank you to David for taking us on this walk through Mullam Mullum Park. If you'd like to hear more from David, I encourage you to get along to one of his public walk and talks that he often runs. They're absolutely wonderful. Or you might want to get involved in the field nats where he's a big part of the fauna survey group. If you want to learn more about frogs and frog conservation, check out the Frogs Victoria website online. It's a great group to join as well. If you're interested in doing some volunteer work, check out the Friends of the Mullum Mullum Valley. And if you want to hear more episodes, check us out on finding Melbourne's nature.com or on your favourite streaming services. Thanks so much for listening. I'm looking forward to the next walk, and please, if you feel like it, drop us a line and tell us what you think.