Science Extra: March of the cane toads
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The natural world sure kept us on our toes last year. There was an audacious plan to keep cane toads out of the Pilbara. They just reproduce with so many, you know, new toadlets. It's just mind-boggling how fast they reproduce, how fast they've started to move. More penguin news than you could poke a flipper at. You've never seen sand before, probably never seen plants, terrestrial plants before. Like, it just must have been the most discombobulating experience ever.

Plus, the social media sensation of a pygmy hippo and how it picked the winner of the US election. Welcome to Science Extra on Radio National. I'm Belinda Smith and today we're getting down and dirty with nature and the environment. Coming up, why some animals are up and about during the day while others prefer the cover of darkness.

And why the echidna seems to break all the rules. Echidnas are pretty cryptic. It's hard to see in the daylight, let alone at night time. Let's hope that I'm in the same spot as an echidna every now and again. But first, I'm joined by ABC environment reporter Peter DeCryfe. Welcome, Pete. G'day. And Dr Anne Jones, the ABC's resident nature nerd and presenter of What The Duck. Lovely to be here. Now, last year, the Bureau of Meteorology and CSIRO released their Climate Report Card for Australia. It

It's called The State of the Climate, and it found Australia overall has already warmed by 1.5 degrees compared to pre-industrial levels. It also showed the nation is living with more extreme and more frequent heat waves on land and oceans, plus longer fire seasons and more intense rainfall.

Pete, what did the report say the future has in store? I mean, the present sounds pretty grim as it is, right? Yeah, I mean, these are all the things we've been talking about for a while now, whether it's more rain happening way up in the north, a drying southwest, less rain in the east overall. Don't let all those, you know, wet seasons we've had fool you and these overlapping fire seasons.

And it's just going to be more of the same a lot of the time. I mean, the southwest of WA is beginning noticeably drier and drier for decades. And we've had massive tree and shrub die-offs in the early half of the year across some 1,000 kilometres of land. And then similar occurrences happening at the same time over in Tasmania at the exact same time, not having a lot of rain, having all these

you know, trees dying off. And some of the people who've been studying the die off in WA this time around, it's a lot worse than the last one we had in 2011, which was around the same sort of period. We're having big marine heat waves as well, which were wiping out seagrass and in WA and shark Bay infamously.

It's these large-scale die-offs. They might not happen every year, but it's something that we're expected to become more likely in the future. And the way it was sort of being described is almost like this kind of land or tree bleaching, like coral bleaching, I guess, as a way to kind of relate it to people. I think one of the ones that people might not be as aware of as well is just how much our oceans are changing. Not these big, you know, everyday heat waves, but...

just the whole structure of it, it's really amazing because you get these warmer ocean temperatures and the oceans are getting a lot warmer and they retain a lot of heat because it's such a big mass. Even if we reduce carbon emissions, it's going to take a lot longer for our oceans to cool down over the years to come. Since it's already quite hot as well, the surface temperatures affect our wind patterns, the wind changes, that big eastern current has now moved further south and

And it's more warming happening in the Tasman Sea, you know, around Tasmania. So we're getting all these warnings all the time for big amounts of warming around Tasmania, which is why we saw at the start of this year scientists go in to go and collect about half of this little marine fish called the red handfish. It's got these little hands and it kind of walks around. It's in fairly deepish water, but they were worried about

They weren't quite sure how hot it was going to get. So they went and collected a bunch just in case they all got wiped out. Yeah, I mean, this all seems very bleak. Was there any good news from this state of the climate report? You know, I think the thing that, and it's a bit bigger picture because all this stuff kind of can get a bit,

doom and gloomy and people are sort of saying experience these things and we get all sorts of different research papers over the course of the year saying we've already warmed too much like more than we think we have and these kind of things like there was a paper about sponges saying we've already warmed 1.7 degrees potentially but the takeaway message from all of

from most of the climatologists you speak to is just that there's still, you know, now is always a good time to start decarbonising. Right. It's always a good time to start decarbonising and technically it's still possible that the planet could stay within an average warming of 1.5 degrees

you know, degrees if you start getting these rapid declines. In Australia, it seems like we've sort of hit a peak already, although we're still emitting a lot and we sort of have about seven years of carbon budget left to sort of stay within some of the targets. You know, countries are going to be submitting their new targets soon.

in early 2025 for the next conference of parties, the big, you know, get together where people are trying to deal with this, you know, global problem. And so we need to have 42% of cuts of, you know, carbon by 2030, 57% by 2035. And if that doesn't happen, we're kind of on projections at the

at the moment for, you know, really big amounts, 2.6 to 3.1 degrees of warming by the end of the century. But, you know, there's still time. There's always a good time. Even if we go 1.5, you know, they are arbitrary kind of targets to a degree and it's really about just limiting it as much as we can. It's like that old saying, the best time to plant a tree was 20 years ago, but the second best time is right now.

Time is also running out for an ambitious project that aims to do what no one else has managed to do, and that's stop the relentless march of cane toads across the Australian mainland. Now, in the 90 years or so since they were introduced to Queensland, the toads have spread more than 2,000 kilometres west, and they're due to reach the Pilbara in a couple of years.

Now, Pete, people have tried loads of things to stop the toads. What does this particular plan involve? Mostly what we've started to try and do is just learn to live with the toads to a degree. I mean, people try to collect them and stop them, but they just...

reproduced with so many, you know, new toadlets just compared to even native frogs. It's just mind boggling how fast they reproduce, how fast they've started to move. So, I mean, you get all these toad busting groups all around the North, just trying to collect them, but it really doesn't make much of a dent. At the end of the day, they're nearly in broom on the West coast of Australia. And what the opportunity is, is there's this,

stretch of coastline between Broome and the iron port of Port Hedland where all the iron ore comes out of Australia and overseas. And there's this thin strip between the Indian Ocean and the Great Sandy Desert, massive desert, which they haven't been able to penetrate by going south through the Kimberley. And so along there is a bunch of cattle stations and they have artificial watering points. And so the idea is to create, you

you know, it's not a real barrier. It's a waterless barrier, which just means upgrading all of those water tanks so there's no leaks, getting rid of some old artesian wells that were dug up, just things that could allow the toads to continue to come south because they need water. If they don't have water, they can't keep moving. So the theory is if they proof that all up, they won't be able to breed, they won't be able to make it through if they can do that to about 150 kilometres away.

because it's only about 40km wide. Yeah, right. Okay, so the toads need water points as kind of like imagine a frog jumping on a lily pad across a pond. They need them within a certain distance in order to keep progressing that invasion, I guess. Yeah, it's a connection point. The state government of WA is on board with it. They're trying to get the groups behind it.

There's a couple of scientists from Curtin University and Deakin. They've gotten a bunch of traditional owner groups on board as well, the Karadjari people, Neonamata people as well. And so they're just having a lot of discussions about how to work this together. Really, they're probably going to need some funding from some mining companies to get it going. Potentially, it's the only chance to really ever stop them

And it would prevent them getting into the Pilbara area, which is actually one of Australia's 15 national biodiversity hotspots. There's lots that could happen if these toads do manage to get into the Pilbara. Like, how likely is it that this waterless barrier's going to happen?

going to work? Yeah, that's a great question. I mean, we don't really know until they try, but Richard Schein, who's studied toads for decades in their ecology, I mean, he, and he's not involved in this particular project, he's sort of studied waterless barriers before, but he reckons the feasibility, it's not necessarily super clear, but

From what he's seen and what's been suggested for this project, he reckons it's kind of encouraging and the potential benefits are just so big as we were talking about before that

they should, you know, at least have a crack at it, you know. And the state government does appear to be supportive. I think there's a bit of momentum actually happening for this project now that the toads are nearly here. It's been spoken about for a decade, but I guess now that they're nearly upon broom, it's finally kind of getting a bit of momentum.

You're listening to Science Extra on Radio National. I'm ABC science reporter Belinda Smith, and today I'm talking all things nature with self-confessed nature nerd and presenter of What the Duck, Dr Anne Jones, and ABC environment reporter Peter DeCryfe.

Now, another alien visitor to Western Australian shores last year was an emperor penguin who in November rocked up on a beach on the south coast of the state near Denmark. It was more than 3,000 kilometres from where it should have been in Antarctica. Now, the penguin was nicknamed Gus after the Roman emperor Augustus, and he was the most northern sighting of his species. Now, Dr. Anne Jones is

How does a penguin swim so far off course? That is a big question, but we've got some theories about it. Like he hasn't opened up yet. Like they've tried the good cop, bad cop on him. They've tried all sorts of things, but he's staying mute. Oh.

At the moment. No, look. Gus, come on, man. Come on, Gus. Give us something. Look, what could have happened, right, is that Gus is a young penguin still, most likely, and that he is a little bit inexperienced. Inexperienced birds are often the ones that do get waylaid and become what we call vagrants. And this is where you're like a

outside your normal range. And that's exactly what has happened to Gus. So what the working theory is, is that Gus has been following a current that's had lots of yummy things in it. You know, like there's this current that's travelling north and it's got like heaps of squid and lots of yummy fish. And Gus is like, this is awesome. And then all of a sudden he looks up and realises that

Oh, no, I don't know where I am, right? And so what he's done is come to the closest landmass and that just happened to be sort of in South WA. And like apparently, right, this is a big penguin. We're not talking about like one of our little baby fairy penguins, little penguins that we have. This is like a 1.4 metre penguin, like an absolute monster. He's a big boy. Yeah, apparently he like sort of like swung

swum up and waddled up out of the surf and the people that saw him come up onto the beach were like probably swearing to themselves what in the dark is that right and he had that little sort of like the little you know penguiny tail and the beautiful waddle and he looks like a painting like he's got the black and the white and the beautiful little yellow dashes he looks good but he

When the wildlife rescuers got there, the people who have all the permits and they're able to handle these birds, once they actually got Gus into a sort of like a container so that they could transport him, they found that he was just all feather and bones. There was really not much on him. So Gus...

could weigh something up to about 40 kilograms if he's in perfect condition as an adult emperor penguin, but he actually was only weighing 23. So he's probably half the body weight of what he really needs to be. So it's likely that he had a big swim to get to land and that when he got here, he was really exhausted. And one of the eyewitness accounts was really interesting. They said that what he did, you know, down there in the south of WA, they're gorgeous white sand beaches.

you've got to wear your sunnies to be there, you know, it's like so bright. And what Gus did was actually flop down onto his belly to perhaps try and do one of the belly skates that they do when they're trying to like move fast across ice because he thought that maybe that sand was snow. Like he's never seen sand before, probably never seen plants, terrestrial plants before. Like it just must have been the most discombobulating experience ever. Yeah.

In the end, Gus spent about three weeks recovering and fattening up. And after being checked out by a vet, he was released back into the ocean in November. The hope was he'd retrace his steps and get home to Antarctica. Well, Godspeed and good luck, Gus. Of course, we can't talk about birds and penguins specifically in 2024 without mentioning the social media sensation that was Pesto.

So he was a king penguin living at the Melbourne Aquarium, where he still holds the title of the aquarium's biggest ever penguin. At nine months old, just a chick back in September, he weighed 23 kilograms. That's how much Gus weighed when he showed up in Western Australia. Now, Pesto's since slimmed down. He's lost his brown fluff and is looking much more like an adult with those sleek, shiny black and white and gold feathers. But, like...

What a guy, pesto. He just took the world by storm. Why was he such a chonker at such a young age? Well, apparently it's partially genetics, right? Because his dad...

He's called Blake. He's a member of the population that they have at the aquarium there. And he is the biggest one in the aquarium. And so, you know, it's like where you think that like there's a whole family of basketballers and they're just all tall. Like there's some sort of genetic thing going on. But on top of that, like, you know, they're in the aquarium. They're being fed really well. And his foster parents, the two penguins that sort of like fostered him and brought him up as their own, were really good at feeding him.

really good parents. So he just like blossomed, you know, he's blossomed into a beautiful blubbery baby, which is exactly what you want from a baby penguin for them to be nice and warm. Because, you know, that blubber and that fluffiness is all about keeping the baby warm while it's, you know, growing into its full adult state. So, yeah.

Yeah, but it was a funny year though because there was a fair few babies that came through to become internet stars. There was Hua Hua, the panda, who was a twin and she was a chubby twin, has really interesting eye markings as far as pandas go, but she also had a little bit of genetic issues so she's actually got two rows of teeth and really short little legs. And on Weibo, which is like a social media platform in China,

The wah-wah sort of like equivalent of a hashtag got 1.6 billion views. What? So she is like the definition of viral. And then, of course, there's Mu Deng. Mu Deng was probably one of the heroes slash heroes

anti-heroes of the year. Mu Deng is this tiny little pygmy hippo. He's in a zoo in Thailand, became an absolute internet storm until they actually got Mu Deng to predict who would win the presidential election. And he predicted Trump and the internet turned, the internet turned.

But apparently mudeng actually means, you know, rough translation would be bouncy pork. Bouncy pork. Bouncy pork.

Mudeng, he bites everyone. He's a very energetic little pygmy hippopotamus. And yeah, so babies, baby animals were certainly one of the lights on the internet for this year. That's amazing that he got sort of cancelled by the internet for predicting Trump would win and then was right all along. So, you know. He was right. Can't discount the political genius that is Mudeng.

Thank you so much, Anne Jones and Pete de Cruyff. What an absolute delight it was to talk to both of you about this. Thanks, Belle. Thank you. And you're listening to Science Extra on Radio National. Of Australia's array of animals, I think echidnas have to be my favourite. When Europeans first encountered these shy, spiky enigmas, which they thought had mammalian and reptilian qualities, they named them after a creature in Greek mythology who was half woman, half snake.

Now, I've been lucky enough to spot a few on bushwalks around the country, one swimming in a creek using its little snout as a snorkel, but always during the day. And this led me to think that maybe they're diurnal like us, you know, active when the sun's up and all tucked up at night. But is it really that simple? Turns out echidnas don't neatly fit into categories when it comes to waking hours either.

Here's David Hamilton. He's a conservation ecologist with the Tasmanian Land Conservancy and was one of the ABC's Science Top 5ers last year. Have you ever found yourself reaching for that fifth cup of coffee, wishing that you were just a natural morning person, ungoverned by the shackles of caffeine? Or maybe you're a night owl, reserving your periods of peak productivity for after the sun's gone down. But why do we live our lives mostly during the day?

And how does our activity compare to the rest of the animal kingdom? Is our love of light the norm, or are humans just a bit weird? I'm Dr David Hamilton, a conservation ecologist with the Tasmanian Land Conservancy, and I'm also an adjunct researcher with the University of Tasmania.

I'm fascinated by our wonderful wildlife like potoroos, devils and quolls. Unfortunately for me, a lot of our mammalian wildlife down here in Tasmania is nocturnal, meaning I've spent quite a bit of time camped out after dark waiting for devils or quolls to arrive, wishing I was a bit more of a night owl myself. A lot of that time sitting waiting for devils that never turn up. My mind wanders to wonder why they actively seek the night.

That right there is the sound I've spent so much time waiting for. That is a Tasmanian devil. Devils got their name from terrified Europeans who, on hearing their guttural screeches echoing through the dark forests of Tasmania, immediately conflated them with some kind of otherworldly demon.

As it turns out, this is a rather unjustified reputation for these rather shy marsupials. I've been working on devils for 35 years. This is Professor Mena Jones from the University of Tasmania, who has a wealth of experience studying the species and their night-time ventures. Many different aspects of devils, lots and lots and lots of fieldwork involving radio tracking and trapping. Quite a bit of that fieldwork of the devils' own activity times would have been at night. Night animals are referred to as nocturnal,

The counterpoint to this is diurnal, which is active during the day. In general, devils are strictly nocturnal and they get out of bed at what we would call civic twilight. That's when it's too dark for people to see and we turn the lights on.

And that's when devils emerge from their burrows and come out into the open. And when they're out at that time of day, is there some specific thing that they're seeking in the environment that causes them to start being active at that time? Do we have any idea what it's driven by? Well, their preferred activity period is to get out of bed right on dark and be very active in the first part of the night, particularly the first two or three hours, because most Australian mammals are nocturnal, except for the numbat.

Some of our prey species, some of our mammals, the macropods, wallabies or paddy melons, will come out and graze in the late afternoon, specifically to avoid being preyed on by a devil. And you're saying there are lots of Australian species that are nocturnal as well.

suggestion is that a lot of that is driven by environmental factors in Australia. So they're avoiding extremes of temperature during the day. But I guess that's not so much the case in Tasmania. Do we know if there's anything mammals are avoiding by being active at night here specifically? Nocturnality may be hardwired.

even though the nights down here are often colder. But if these prey species are out and active in the middle of the day, then they're trading off the risk of being attacked and killed by something like an eagle with a devil. And we see this change in paddy melon behaviour, that paddy melons, which are probably the most common prey item for devils,

They will stay within... They sleep in cover during the day in the vegetation and they will stay within the edge of the vegetation...

until right on that civic twilight as well. And then they move very rapidly out into the open. If they come out earlier, they're really highly vulnerable to being preyed on by raptors, particularly eagles. And if they stay in the vegetation beyond dark, they're really vulnerable to predation by a devil. Mena has quite neatly described a third type of activity pattern, which is displayed by potentially vulnerable pre-animals like wallabies and paddy melons.

You see, night and day aren't the only two periods of activity that animals follow. There's also a much narrower activity period: twilight. This usually describes a period between the sun rising or setting and the land descending into darkness. It can also cover things like moonlit nights and cloudy days. Animals which preference being active in these periods of not quite full darkness are referred to as crepuscular. And lastly we have a fourth term, probably the least known but my favourite by far.

This covers those animals that can be active at times that don't seem to be governed by light conditions at all, but are likely driven by some external resource. Wombats often display this form of activity pattern, which I like to think of as basically being active whenever you're hungry. And on the subject of hunger, when devils are up and awake, their sense of smell is phenomenal. They've got a large wet nose and they're able to pick up

the smell of a barbecue from a kilometre away, and probably roadkill and other food in the environment. So avoiding a nocturnal scent-driven predator like a devil explains why animals might seek to be crepuscular, active in that very narrow band around twilight. In this case, prey species are threading their activity needle between two types of predator, large raptors that can hunt them by sight during the day, and devils that can hunt them at night via other means.

It's a brutal world out there in nature, but not all Australian animals take this crepuscular strategy. Last weekend, my partner and I drove down to the Tasman Peninsula and we counted eight echidnas along the way. This is Associate Professor Stuart Nicol. He's Tasmania's premier tachyglossologist. That's a fancy name for an echidna scientist.

Taki translates to fast, and glossus is tongued, so fast-tongued. Exactly how an echidna eats ants. They are one of the few animals that you'll see out in the daytime. You'll see some wallabies around, possibly some paddy melons, but mostly they're crepuscular. They're coming out at dusk or dawn, but they're out earlier. If it's a really overcast day, they'll be active. So clearly they're reacting to the light levels, but the echidna's a bit weird. Because when we started putting activity loggers on them,

And then GPS loggers, we found that something like 80 to 90% of the activity is during the night. This was a surprising finding for Stuart and his team. Because we see echidnas so often, it's easy to assume that they, like us, are a daytime animal, or diurnal to use the scientific word.

But it turns out echidnas don't really fit neatly into any category. They were overwhelmingly night time, which was a surprise when we started getting that data in because this is what people expect, that they were going to be driven by the temperature and so they're the animal you see around. They must be day active, but if you could see them at night, presumably if we'd taken that drive during the night time and if we could actually see them in the night time, there would have been probably a lot more echidnas around it.

Echidnas are pretty cryptic. It's hard to see in the daylight, let alone at night time. And also they do tend to follow cover. So when you're out looking for echidnas, it's very much, let's hope that I'm in the same spot as an echidna every now and again. So that perception is probably coming from a bit of a sample bias, that we are more likely to see them during the day, therefore we assume that the majority of their activity is during the day. That's true. I mean, I've found that's

In lots of areas of this sort of observational science, you're so biased in what the sample you can take, you assume that that's really representative of the whole, of everything that's going on, and clearly not. Now, Stuart isn't just a tachyglossologist. He's also done a bit of research on the echidna's fellow egg-laying mammal, the platypus. Platypus are often described as being nocturnal or crepuscular. They're certainly normally associated with being active at times when there's less light around.

But again, when it came to actually investigating platypus behaviour, Stuart found that they weren't conforming to expectation either. They're definitely a nocturnal animal, mostly. So what we found was that, interestingly, the dominant males were nocturnal and some of the less dominant males became nocturnal.

They came out in the daytime. So the timing of the activity could very much depend on how their relative seniority was. And there was another interesting one, is that some of the animals were clearly following the lunar cycle. They were adjusting their time, activity time, so that they're out...

In full moon, full moon must be a good time for platypuses. You've got the night, you've got all the things that you do, but you can actually locate things a bit better and work out where you are and see the other animals. So their behaviour pattern just shifting day by day as the timing of the moon changed. And I think I said, well, that was pretty cool. So it seems that species like echidna and platypus aren't necessarily constrained into one activity box.

and can display quite a high degree of flexibility when it benefits them. But what allows them this flexibility? Are platypus' bodies able to alter their internal workings on a whim to respond to something like a full moon, or does it require a bit of a transition period? We're all familiar with the feeling of jet lag when we've physically moved into a different time zone, but our body is still catching up.

This is due to our body having to alter our time of peak activity for key things like sleep and meal times. How does the body control when brain activity or digestive cycling are at their peak? To figure that out, we have to understand the concept of circadian rhythms. And for that, we're going to have to consult with Professor Frédéric Gachon.

an expert on the physiology of circadian rhythms from Aarhus University in Denmark. Almost all living species on Earth have a circadian clock. I've developed some kind of system to sense the time and to count the time. This clock is self-sustaining. I mean, even if you stay in a constant condition, for example, you stay in constant darkness for weeks like people in caves,

your clock is still ticking and because of this particularity you need to resynchronize your clock every day and it's why it's important to have light in the morning to resynchronize your clock to the new day. In arctic countries, during the season when you have constant light or no light at all, the animals completely lose their circadian activity, means they are randomly active during the day and night.

because it cannot synchronize the clock in this constant environment.

Yeah, that's interesting. So then animals up there where the light conditions are changing seasonally, they kind of lose that ability to be able to regulate their internal clock. Yeah, in extreme conditions like in Arctic conditions when you don't have photoperiod, I mean when you don't have this alteration between day and night, some animals indeed lose their capacity to adapt. They cannot keep this circadian behavior and they have a tendency to be constantly active.

There we have it. Our activity patterns are driven by our own internal circadian clock, with that clock requiring at least occasional bouts of light to keep itself in time with the seasons. This is something we have in common with the animal kingdom, even if our activity times don't exactly match up. I know from my own experience that even nocturnal animals like Tasmanian devils can come out to bask in the sun during the day. Turns out this not only provides them with a bit of much-needed warmth, but also helps regulate their circadian clock.

These internal clocks mean our body constantly knows the time, even if we don't feel like it does. It also means we're pretty good at adapting to things like shifting seasons and even time zones. However, if we want to be truly flexible in our activity, it might be time to think about becoming an echidna. That was Dr David Hamilton. He's a conservation ecologist with the Tasmanian Land Conservancy and was one of the ABC's Science Top Fivers last year.

Up now, the weather that changed us. We head back to 2009 when a blanket of heat smothered southeastern Australia, killing hundreds and melting cities and towns. Today, the story of how this event served as a wake-up call for Australia to manage extreme heat. Once a deceased person came in, their clothing and personal effects were documented and removed and then a full-body CT scan was undertaken on each and every person.

Rebecca Owen is standing inside the morgue in Melbourne. It looks a lot like a hospital corridor. Same colours, same sterile environment, but it's quieter. Then a guy comes past, pushing a metal trolley, wearing full blue scrubs and white gumboots. Come through, Tim. In terms of managing numbers, it's about, you know, knowing how many are in process, how many are on the way out, how many are on the way in. She's pointing out a giant cool room.

They call it the fridge, with metal racks down the walls. Their job is to find out the cause of death when it's not obvious or expected. Sometimes they also have to work out the identity. It's one of those jobs that people will say, it's not for everyone. And they say it because it's completely true.

It's a really privileged position to be in, to think that you can help somebody at potentially the worst time of their life, both the deceased person to look after them respectfully, but also to feed that back to the family that their loved one is in your hands and is in good care. In January 2009, Rebecca was in charge here at the Victorian Institute of Forensic Medicine while her boss was away. The work is usually routine and clinical.

Bodies come in, autopsies and examinations are done, then they go out again. But while Rebecca was in charge, more and more bodies started arriving. It was very busy. I would come and stand at a doorway like this and look down to see if any of these spaces were unoccupied. So I would just basically look and count. There's a space there, a space there. So I've got room for three in this room, maybe room for one in that room. I know there's 10 going out. I know there's 20 coming in.

It's a gradual increase, right? Like, when you're in a car and you're putting the accelerator down and then all of a sudden you realise you're going really fast. It was a little bit like that. Working here, you tend to take things in your stride when you're in that role, and it's not until at that time, it wasn't really until we literally were at capacity that you think, "Oh, goodness, this isn't going to go away any time soon." The morgue was full, something they'd never experienced before.

Rebecca and her team were considering bringing in emergency cool rooms to plug into the car park to store the bodies. So what had led to it? Why had the morgue suddenly filled up? It was because a natural disaster had hit. But it's probably not what you're thinking. It was a heatwave. It killed hundreds, and it became the wake-up call for Australia about the dangers of extreme heat. I'm Tyne Logan, the ABC's weather reporter.

And this is the weather that changed us. I'm looking into the biggest disasters in our history and how they've become the catalyst for change. You might not know it, but they've changed the houses we live in, the jobs we do, our politics and the way we understand our world. This is the story of the 2009 heatwave, Australia's deadliest natural disaster that you've probably never heard of.

You actually really don't feel the heat that badly for the first three days, but by the end of the third day, you're beginning to really feel it. As Dr John Nann rode to work in Adelaide in late January 2009, the roads were quiet. He was the manager of the forecast centre at the Bureau of Meteorology in South Australia. People were self-protecting. They were actually starting to stay at home, seeking shelter, seeking cooler spots. I was a bike commuter to work.

And the heat coming off the roads was phenomenal. You really, really didn't spend much time on those paved areas if you could possibly help it. So even as I rode through the park lands, it was still searingly hot. What had happened was a high pressure system had just parked itself over southeastern Australia and it was not moving. There was also a cyclone spinning off the coast of Western Australia.

And together, they were just pumping hot, dry air from the central desert and the tropics right into the southeast. So that's probably our worst possible scenario for a heatwave.

We could see that South Australia, Tasmania, Victoria and New South Wales would be simultaneously inflicted by this heat. I'd never seen anything like that in my living history, a heatwave of that size. The daytime temperatures were extreme. In the first few days, temperatures in Tasmania soared to record highs over 40 degrees, while Melbourne and Adelaide reached over 45. It just was this thing of...

Oh, my God, this is going to be one of those ones that just goes on and on and on. But it wasn't just the scorching daytime temperatures that were hurting. It was also the nights. They just weren't cooling off.

I often tell people that the minimum temperature is much more important during a heatwave than the maximum. If you've got a high minimum, not only do you get a little relief overnight, but it does mean that the temperature kicks in earlier in the day and rises to the higher temperature much sooner. And that high temperature will last forever.

well after sunset and continue to build. On one particular night, three or four days in, a site in the northern suburbs of Adelaide got to 41.7 degrees at 3am. That's a hell of a long time in which you're trying to manage heat. And I live in an old thick walled house

And we were moving the beds away from the walls into the centre of the house because the walls were too hot. You could feel the heat. As the heat beat down day after day, things started to crumble. Air cons were cranked to the max. That put a huge amount of demand on the electricity grid. Pretty soon, people were losing power. Got home for 10 minutes yesterday and the air conditioning was out. So did you get any sleep at all?

No. No, not yet. Not yet. No, we don't have air conditioning. We close the old blinds and don't use kitchen, so we don't cook during the heat weather. Struggling? Well, I haven't been to bed for the last 24 hours plus. The night before last, when it was, I got about 30 minutes proper sleep, I suppose, in the heat.

It wasn't just all the air-cons blasting that caused the blackouts. Some of the electrical infrastructure couldn't cope. The power connector between Tasmania and Victoria couldn't handle temperatures over 35 degrees at the Tassie end. What are typically called black swan events, things that you would never anticipate would occur, were happening day after day after day. Transport was also failing in Melbourne, with the heat buckling steel rail lines.

Ambulances were having to put on more staff. The Australian Open was still on, though, and the tennis players were not impressed. It's going to be 41 today, 43 tomorrow, the hardest week in a month, so why not to close the roof? And the Victorian fire authorities were starting to struggle as bushfires got the upper hand. Normally the fire activity...

drops down in the cool of the evening. However, last night didn't cool down very much and because the area is so dry, the fire activity continued as though it was a normal day. Even inside the Bureau of Meteorology, things were falling apart. Our data centre had a new air conditioning system

and we thought it was pretty robust. But by about halfway through the event, our data centre temperatures were going up and we were dead scared we were going to have our systems melt. And so in the end, what was happening was our techs came up with a brilliant solution and they stuck a sprinkler on top of our air conditioning system so that we could pull in evaporatively cooled air into it before it started to cool it. It was a hot mess. Amidst all of it, people were dying.

It might seem obvious now, but Rebecca says they weren't prepared for it at the mortuary. I think perhaps looking at the nature of the deaths that were getting reported, so it's a slow burn realisation that the numbers are bigger than they would normally be. And there's an awful lot of reports coming from hospitals or vulnerable people, elderly people, things like that, and thinking maybe this is linked to the heatwave.

All up, the heatwave lasted nearly two weeks. It came in two major episodes, with a brief reprieve in the middle. If you could call temperatures in the 30s a reprieve. It was hard on everybody. It was a bit relentless for a few days. And then it was relentless at home because it was hot. The heat contributed to over 400 deaths in Victoria and South Australia, according to state government reports.

Victoria's Institute of Forensic Medicine considered it the most deadly natural disaster in Australia's history. But it's hard to know the true numbers because heat isn't something that appears on a death certificate often. The figures are based on what's known as excess deaths, the difference between the expected number of deaths at that time of year and how many people actually died. Heat waves are that hidden killer and the information comes out slowly. And the evidence that you see...

tends to be written up in journals rather than the public media. It's not the hot weather that kills you in the end. It's the heart attack that happens because the heat was placing extra strain on the body, or the fatal accident at work because you were struggling to focus. People who are elderly or isolated or who work outdoors or have underlying illnesses are some of the most vulnerable. But heat can kill anybody.

People do not recognise that they are vulnerable to hate. And that is the big problem. And if you're thinking, this is nuts, how come I don't know about it? It's likely because of what happened next, Black Saturday.

A giant cold front pushed across the country, bringing an end to the heatwave. But it whipped up a deadly combination of ferocious hot winds and storms ahead of it. Almost the entire state of Victoria rocketed to record high temperatures.

several places hitting the high 40s. The land was dry from the heatwave and a decade of drought before it, and it just went up. 173 people died and more than 2,000 homes were destroyed in just one afternoon. Whole towns were caught unprepared and were trapped. And the loss of life and the surrounding landscape...

It was all horrific. Black Saturday lives in people's minds and it changed so much about how Australia responds to bushfires, including the addition of the catastrophic fire danger rating. And naturally, it's what everyone remembers from that time. But the heatwave also changed things.

Because people like Rebecca Owen now knew what heat could do. In many ways, the bushfires kind of overtook the natural disaster that had happened the week beforehand. So, you know, the heat wave in and of itself was a real tragedy. Not taking away from the bushfires, that was a horrible situation and a tragedy in and of itself. But to think that we were already at capacity going into that

made it even harder. The general story around the globe is until you're really smacked in the face by one of these events, you're probably not motivated sufficiently to actually change your systems and get ready for it. Since 2009, Dr John Nann has gone on to dedicate most of his working days to extreme heat.

with the Bureau of Meteorology and later the World Meteorological Organisation. John says the 2009 heatwave was Australia's wake-up call. I think everyone got a shock when 2009 occurred. Everything was close to failure and everyone knew it in government. And they all were a bit shocked by the reports on the excess mortality at the end of it. And they're all counting the costs in different ways at the end of it as well. So what did we learn?

For starters, we actually have a national heatwave warning service now. It tells you when and where there's going to be a heatwave, how severe it's going to be, and who's most vulnerable. And by the way, it's not about reaching a certain temperature, like 40 degrees. It's a very nuanced system, which takes into account what's normal for your area,

and how long the heat will last. So it's still quite new for the community to hear heatwave warnings. And then, of course, hearing the Weather Bureau and the health agency go off together with their messaging, coordinated messaging. So the health community is messaging and publicly warning about...

the dangers of heat and the need to seek cooling and the different strategies around managing heat. There's also some more logistical things too, like the heat action plans that are put in place by government and community groups. These include things like freeing up ambulances, staffing, all that kind of stuff. And when we get to an extreme event, you're actually seeing actions being taken to protect utilities such as power, water, traffic systems, transport.

Melbourne even has a chief heat officer. Their job is all about designing and preparing the city for extreme heat.

John says the changes have been gradual, slow even, and we're not there yet. But bit by bit, it has made a difference. These extraordinarily simple little things can make a huge difference the way that people recognise the threat. And at the Victorian Institute of Forensic Medicine, Dr Jodie Leditsky, who was Rebecca's boss...

says they're more prepared these days. The heatwave changed everything. We did think about pandemics, we thought of different disasters, but we really didn't think about a heatwave. Since the 2009 heatwave, since we look at that and maybe in future heatwaves, any prediction that we're going to have, say, three days above 40...

For us, from a planning point of view, we start to think that this is going to be a time where we're going to get a surge. We hope that it won't happen, but from a planning point of view, we need to be ready. Many of these changes were put to the test a few years later. In 2014, there was another heatwave in southeastern Australia, just as long and intense.

People died in that one too, but not nearly as many. And at least we had some idea that this was possibly going to happen and that we were prepared, that we had the plan, that we knew we were going to do. You can see why heat is often called the silent killer. It's by far Australia's deadliest natural hazard. Since 1900, extreme heat has killed more people than floods, fires...

All the rest combined. Heat waves are that hidden killer and the information comes out slowly. And the evidence that you see tends to be written up in journals rather than...

And this problem is not going away. It's getting worse. Unfortunately, with climate change, they're increasing in frequency and intensity. And we are going to see some pretty horrific stories globally over time. And I think the curiosity around heatwaves will only grow as we realise just how heavily impacted our communities are.

We certainly recognise in Australia as being one of the leading players in terms of coming to terms with heatwaves, but we've got plenty more to do. This podcast is reported and hosted by me, Tyne Logan. Joe Lauder is our reporter and producer. Research and editing by Stephen Stockwell. Sound engineering is Grant Walter. Script production from Will Ockenden. And our executive producer is Edwina Farley.

The Weather That Changed Us is a collaboration between the ABC News Climate team and ABC Science. Check out the full season of The Weather That Changed Us on the ABC Listen app. And that's all from Science Extra today. I'm Belinda Smith. We'll be back next week with The Year in Tech, where we'll pick apart a sophisticated scam. Have a great one. Bye. Bye.

Have you ever seen a movie and then wondered, "What can I believe?" Groundhog Day - it's a classic. But do groundhogs really know how to predict the weather? And what about Jaws? Are great white sharks really gonna hold a grudge and come for the town sheriff? And would moray eels make good henchmen, like in The Little Mermaid? Nope.

And it turns out, Hollywood lied to us. And that's also the name of the new series from What The Duck with me, Anne Jones. Out now on Radio National and the ABC Listen app. Find more great ABC RN stories that take you beyond the headlines on the ABC Listen app.