Hello everyone, and welcome to Talk Nerdy. Today is Monday, March twentieth,
twenty twenty three, and I'm the host of the show Kara Santa Maria
and I am just getting over COVID. I actually had COVID last week when
I recorded the previous exercise episode, Slime with Susanne Wedlick, and you could
probably hear it in my voice pretty badly. I also had it when I
recorded this episode and the next one that comes out. Even though it's a
short time, I happen to do a lot of podcast recordings. I'm on
the tail end. I'm I'm now testing negative. I just still have a
little bit of the sniffles, and so I apologize if my voice is maybe
a little bit deeper and a little bit different than usual, But that would
be why I've got a great episode for you this week. But before I
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talk Nerdy. All right, so let's talk about this week's episode. I
had the opportunity to chat with a fascinating woman. She is science and kind
of natural history writer, tons of books and articles with specifically a focus on
Australian nonfiction, and she's won a lot of awards as well. Her books
have won the Victorian Premier's Literary Award for Nonfiction, the Federation of Australian Writers
Award for Excellence in Nonfiction, a Whitley Award for Popular Zoology, and she's
been shortlisted for the Children's Book Counsel of Australia and National Biography Awards and longlisted
for the NIB Literary Award. She's got a new book called Kowala, A
Natural History and an Uncertain Future. So yeah, we talk all about Kowala's
today without any further ado. Here. She is doctor Danielle Clothes. Well,
Danielle, thank you so much for joining me today. It's a pleasure.
Thanks for having me, and thanks for writing a new book. I'm
excited to talk about it. You've actually written several books, though, or
you've written several books on your own, and you've also had your writings featured
in several books. And it looks like the age range is really kind of
all over the place, from little littles all the way up to books for
adults. Yeah, that's right. I mostly you think of myself as writing
for adults. I guess that's my core audience. But I've also written several
books that turned out to be very popular with children, so I wrote a
few more that was specifically for kids. And that's particularly in paleontology and fossils
love it. And so you yourself are a biologist, you are trained as
a conservation biologist. How have you chosen across the board, like all of
the different areas that you like to write about. I guess I've I've always
been a little bit into disciplinary So even though my doctorate is in biology and
zoology and animal behavior and conservation, I did start out doing an arts degree,
so I started out in psychology and doing animal behavior, so I've always
had a really broad range of interests and I think writing has really promoted that
and enabled me to just to follow whatever interests I have. So my books
are all revolve around environmental themes, I guess, either either scientists or natural
history stories or particular animals or ecologies. But yeah, they are pretty broad
ranging, for sure. And this I mean, I may venture to say,
I could be wrong. It feels like it may be kind of your
most specific of your writings because you chose to focus in on one Maybe I
shouldn't say species, maybe not maybe one genus. I don't know. You
tell me, Yeah, it is one species indeed. Okay, at least
in the modern era. There's been a lot of other species of koalas in
the past, but the only one we have left is one particular species.
And yeah, you're right, this is probably my most specific book in that
sense a lot. You know, I've written a lot on bushfires and different
scientific stories, museum collections, those sorts of things, so they've been a
bit more wide range. And this one, I guess is really coming back
to, you know, the core of my training in a way. And
that it is very much a behavioral and evolutionary study of an animal, and
also looking at their conservation and what we need to do to keep them keep
them with us. There's so much to dive into, from the sort of
you know, paleo evidence or at least the historical evidence, all the way
up to what's going on now and with the future holds. But I'm curious,
and of course anybody listening who hears your accent, it's like, okay,
yeah, Koala's Australian, Okay, But is there a deeper connection there
other than the fact that obviously these animals and you share the same land.
Is there anything particular that you know drew you to wanting to write a full
length book about them? Yeah? I guess. Koalas is such an iconic
species, you know, they are, you know, a post child for
conservation, not just in Australia but internationally, and particularly in the face of
the recent bush fires that we've had over the last ten or twenty years in
particular, Koalas have really been at the forefront of that and the impact on
koalas. And there's a huge level of human concern about Kuala's that extends way
beyond what people normally care about in terms of the animal kingdom. So I
think the black Summer bushfires that we had along the East coast of Australia a
couple of years ago, a few years ago now we're particularly telling in the
way people responded to those fires. And they are the first bush fires I
know of in my study of our history of fires in fact, where wildlife
was front and center of people's concern, both in Australia and overseas. I've
never known that to happen before. Usually people are purely concerned about the impact
on people and the human peril. But in that one, koalas were really
the forefront of that campaign and that concern, and there was there was just
a massive um anxiety and affection I guess for animals and the fate of fate
of koala's in the face of those fires. And I think that's one of
the reasons I particularly wanted wanted to look at them, because I guess as
an Australian, I'd always taken them a little bit for granted. Um,
you know, there's they're so well known and yet you hardly ever see them.
Um, it's easy to forget that they're They're real animals with complex lives
and play an important part in the ecosystem, and they're not just a fluffy
toy that you pop on the end of your bed or children's story. One
hundred percent. And I think that knowing that you know, the core audience
of this show of tark Nerdy is mostly I would say in the English speaking
world, just you know, by virtue of the fact that I'm an American
and podcaster, I'd say that probably the small majority is American lists, but
then we have listeners from the UK, from Australia, from South Africa,
and then that follows with places where English is not the dominant language, yet
English is a common language, because I do have listeners all over the world,
and I'll say that as somebody who travels quite often, I probably have
about the same, if not maybe slightly more information about koalas than like the
typical American, only because I've seen some, I've been around some, I've
gone to some conservation centers in Australia that said, my knowledge is limited.
So I'm gonna I'm gonna give you like my top three or four koala factoids,
and you can just like skewer me for a what I don't know or
what I'm getting wrong here. So I know that they are not bears,
even though everybody calls them koala bears. I know. I think that they
eat eucalyptus. Yes, okay, good. They can carry chlamydia, which
is fascinating to me. And I know that in Los Angeles at the La
Zoo several years ago, our famed mountain lion, which recently passed away p.
Twenty, who did snack on a koala that they forgot to bring back
into the enclosure because this this specific koala doesn't like to sleep in trees.
It likes to sleep on the ground, and so that was a nice news
story for a while. That's pretty much about that one. So yeah,
somewhere in the world, at some point in time two species nary should they
have mixed m a you know, American mountain lion and an Australian koala did
engage in some tasty I don't know, meat swapping. So yeah, that
was interesting. But beyond that, I know nothing. Please please enlighten us.
Yeah, well that's pretty accurate. You're you're absolutely right, then they're
not bears. Um, although they've been called that for quite a long time.
You know, when Europeans first came to Australia, they called them monkeys,
sloths, bears. I think the bear monica really um hooked in in
the in the nineteen thirties, that kind of era when the children's toy industry
really picked up. You know, the whole teddy bear craze kind of kicked
in, and Koalas make perfect teddy bears. You know, they've they've really
got the natural posture for it. I think they're they're probably quite a bit
more cuddly than most bears, I don't think so, at least don't try
to eat you. Um so, So, yeah, I guess, I
guess that's where that comes from. Really, it's it's a it's a children's
toy monica. But yeah, they're marsupials, so they have a pouch.
So they're related to the great family of marsupials that dominates Australian mammal fauna and
is so distinctive and so very different from the rest of the world. So,
you know, the kangaroos, the wombats, the possums, all of
those sorts of animals all have pouches and are part of a great lineage that's
quite distinct from from the rest of the mammals. So so that really sets
them apart, and along with the whole wape of other things. You're pretty
spot on with with everything you've said. Actually, they do indeed e eucalyptus
leaves um. Yeah, and they get chlamydia, and they get chlamydia.
That's correct too. Yes, they suffer terribly from chlamydia. So they've they've
got a rather unfortunate host of actually transmitted diseases actually, which which is causing
them a great deal of difficulty at the moment. So this is this is
something that I've long been curious about, and I think there's a lot of
things about the Australian sort of ecosystem that are quite unique. Australia, like
America, really in this way, is like a huge island, yet it's
not, you know, it's it's very much surrounded on all sides by quite
a bit of water. So there's all of the weird kind of evolutionary things
that happened or that happened continue to happen in islands that have contributed to the
unique kind of flora and fauna. But I'm super curious about marsupials in general.
Are there things that you can point to that sort of confer evolutionary advantage
to marsupials and or are there things that make them way more I guess sensitive,
or way more potentially negatively impacted by things like deforestation and climate change and
disease. Yeah, I think we probably just need to see marsupials as an
alternative stream of evolution for mammals. They're not. I wouldn't say they're more
or less adapted. Every everything's adapted to the monitor to the world they live
in, to a greater or lestic extent, you know, depending on the
change that happens in the particular characteristics they have. So, you know,
we have hugely successful animals like kangaroos. You know, there's a great many
kangaroo species that are that are absolutely booming in numbers and are very successful if
you take them overseas um so, you know, and we have possums that
also get established overseas. So there's there's nothing intrinsically vulnerable. I think.
I guess the the issue of the Australia being You're right, it is a
big island and because of its continental land mass. That means it can support
a very high level of diversity, as large land masses can. However,
it's also a big island and very much an island. It's it's the most
isolated of the big land masses apart from Antarctica um. Whereas America, for
example, has had land bridges both between North and South America of course,
and also with Europe. So the species there have been impacted by more invasions
of different species. So I guess when you have a lot of contact with
new species coming in the type close, little evolutionary relationships that evolved between species
that are isolated together for a long time don't evolve. So you've just got
a much more disrupted evolutionary system. And I think that's why Australia is characterized
by quite a lot of strange, strange, almost symbiotic relationships between species that
perhaps gets sort of mashed together a little bit in other places. So you
know, we've got a really high level of mimicry. You know a massive
amount of cuckoos for example, you know, with the heartland of different species
of cuckoos and relationships with different species, mimicry between orchards, and wasp spider
mimic cry. You know those sorts of evolutionary partnerships, you know, symbiotic
relationships between ants and trees and butterflies. They're very complex and very highly evolved,
and they can only really occur, I think in a place that has
has not had many new species coming into it a lot. And I think
I'm curious, is that in and of itself there's very intricate, very protected
evolutionary dance. Is it in and of itself vulnerable against the modern impacts of
you know, the anthropathy and of human intervention. Yeah, I guess so
in that just because it's I mean, it's not that those those impacts have
just happened in the past in other countries where other continents, where invasive species
have effectively come and gone and moved between continents and had their impact, whereas
islands tend to be isolated from those factors. So that's why I think Australia
is particularly vulnerable to extinction of mammals and other groups is because they're both.
It's both a large land mask with a high biodiversity and an island continent with
a high vulnerability as a result, because those species have been isolated, So
it's not that they're more vulnerable, it's just that the the you know,
they're facing impacts that other countries have already dealt with, and their species have
already gone extinct, So that makes sense. Yeah, and I'm especially curious
about kowala's as as their own species, because I do think that there is
a and and correct me if this is a complete sort of misunderstanding, But
there's almost a stereotype, we could say, almost a bias that Koalas are
kind of slow and kind of stupid and not very adaptable and sort of just
like out there just waiting to go extinct, which is a really sad stereotype,
but I think it's one that a lot of people might hold. M
I think we really like to blame species for their own name, right,
you know, that's much more comfortable to us than to actually blame it ourselves.
Yeah, and it's also it is ultimately also stems from a very Eurocentric
view of the world, you know, very Western view of the world.
You know, when Europeans first went to America, they had very much the
same reaction. They basically, you know, famously European scientists said that American
fauna was degenerate, um, lesser than you know, European, and that's
what would happen to humans if they went there. So you know, there
is that very eurocentric bias, and Australian fauna has suffered from that as well.
That massupials are commonly commonly pitched as being lesser than Placental or Eutherian mammals
because they're less familiar. That's just just just because people don't know as much
about them. They look different, um, so they can't be as good
and and so there's a there's a broad mythology that marsupials are stupid, UM,
less avanced, more primitive. All of these sorts of things UM and
koalas are you know, sort of set at the apex of that they really
don't ye sadly, which which I do I do go through in my can
debunk a lot of a lot of that mythology around koalas, and a lot
of it you know that it's tied to the trees they eat. So people
will argue that koalas are slow and stupid because they eat eucalyptus leaves, which
are toxic, and therefore they don't have enough energy to do anything else,
and therefore their brains have shrunk, none of which is true or even makes
sense if you think about it. So right, right, and like,
there are plenty of species on this planet that have a very specific diet that
evolved, as you said, almost like symbiotically with a particular source of fuel.
So I'm curious about I don't know why, but it does capture the
imagination this like cuddly little mammal on these trees that specifically eat this one leaf.
I think we see something similar with pandas. Right, yeah, it's
the same story. Yeah, Yeah, you've chosen badly in evolutionary terms,
and therefore you're going to go extinct. You know, we always say koalas
only eat one thing. They're they're up to nine hundred species of eucalypse in
Australia. They're the dominant tree in our forests. They're the major tree and
they are difficult to eat, so a lot of mammals struggle with eating them
because the toxins in them make them feel sick. Kualas have managed to exploit
those trees that really vast forest to state, so they're really that's an actually
really good move and not only that, but they've managed to adapt to a
wide range of species, so they Koalas, as a species eat are known
to eat at least seventy species of eucalypse, although individual koalas only eat between
three and ten different species of eucalypse, but that's still a pretty wide range.
So we have this interesting thing whereas as a species they're actually generalists,
but as individuals they're specialists, so they specialize on particular trees that are found
in the area that they grow up in. Obviously, there's no point in
adapting to eating a tree that's found on the other side of the country,
right. I was wondering if there's that a function simply of what's available.
Is it a function of culture, of what's been learned within the family,
like this is good. Do this because this is what mom and dad taught
you. Yeah, it's a really interesting question that it seems to be quite
closely associated with what they physically can eat, because, like most herbivores,
kualas can't actually digest the cellulose and lignant in their plant diet themselves. They
have to have a microbiome to do that. But their microbiome is very specialized
so it appears to be adapted to the particular species of eucalypt that they eat,
and they receive that microbiome from their mother. So they have to actually
be inoculated with the bacteria. They need to eat leaves, so little Joey
Kualas when they're feeding on milk, they can't eat leaves at all. They
will mess around with them, but they don't eat them. So it's not
until they received that inoculation from their mother in a very messy and slightly unpleasant
method. Where to hear about this? Yeah, So the koalas have a
they keep their gut that the majority of the bacteria I suppose is contained in
a secum, which in humans is the appendix. But we only have a
residual scum which is about the size of our thumb, whereas koalas have one
that's a meter and a half long or so, so it's quite a lot
larger. And that's like a pocket that holds a microbial soup. And the
Koalas chew up their leaves, wash the fine particulates into the secum. Then
the bigger bits just get passed through um and they sit in that soup for
days, for quite a long time while they get digested, and then the
nutrients are absorbed in that way, so that pro is really specific. And
when um mothers need to wean their their joeys, they actually evacuate the contents
of the secum. So it's not a normal fecal you know, dropping um.
It's a bright green soup. Interesting now, and the joeys absolutely love
it. And it's very messy and um looks pretty disgusting, but there's something
in it that attracts them. There must be some sort of factor or some
sort of scent or something. They try to know that is what they need,
right, They just they consume as much of that as they possibly can,
and from then on they eat leaves. Oh that's fascinating. And so
are they getting some of it, some of this microbiome in their breast milk,
But then the vast majority has to come through this like scum dump.
Yeah. I don't. I don't know if anybody's looked at what biome comes
through through the breast milk, I should say, estill, is it breast
milk? There are different kinds of mammals, all right, I'm so confused.
Yes, yeah, but definitely the pat feeding is really really crucial to
koalism, and they could certainly not survive. They wouldn't be able to consume
or digest that food properly. So there's there's arguments. You know, we
do this with captive animals. Zookeepers will be familiar with this process that if
herbivores are struggling in a zoo, young herbivals, they get diarrhea or whatever.
It's very common for zookeepers to crush up fecal samples from a healthy adult,
put it in their milk and feed it to them, and that's a
way of inoculating them. And we do this with humans as well, so
humans can also be inoculated with fecal samples. That's a standard medical practice.
And interestingly, there are some people who seem to be extremely good sources or
donors for this, so they the super poopers and the examples are really prized
by the hospitals for reinoculating a human gut biomes with the right bacteria to enable
people to be healthy. So I think increasingly we're learning how important that is,
and it's it's really particularly important in Koala's you know, I'm curious,
there's something and I think again, we think about pandas in this same way,
which is funny because it's like, yeah, koala bears and panda bears,
and like you said, they're at they're at the foot of little kids
beds all over the world. But there's something about them, going back to
this stereotype, which absolutely is a very colonial, very kind of your eurocentric
stereotype, that there's something almost tame about them. Like they're clearly wild animals,
they're not domestic hits, but there's something that has long felt and I
think I worry a little bit actually about the imagery and the coverage of some
of the wildfires playing into that where you would see these struggling koalas and you'd
see like a koala hand reaching out to a human hand or like you know,
grasping a human being as they're like taking it to safety, and it's
like, oh, no, we should not be hugging koala. Mm.
Yeah, that hugging is a really interesting thing, and I think that part
of it is, you know, koala's have got some characteristics that really tap
into some human emotions, and you know, some of our instinctive behaviors correlate
just purely through coincidence with with koalas. So koalas have faces that we intrinsically
react to as faces. You know, we have special neurological receptors that makes
us very susceptible to those particular shapes of faces. So so they koala's sort
of generate that kind of very um maternal or paternal response um to them with
with a childlike feet, you know, they're they're quite childlike in size.
They the way they sit, the way they hold their arms up to their
to their parents, and also young koalas if they're approaching people, will very
commonly put their arms up to either climb up you or to to or to
be picked up, so they solicit um responses from humans. Not all the
time, a lot of koalas will just try and move away from you and
would prefer to keep their distance. But occasionally young koalas will come into contact
with humans or injured koalas or kohala's looking for assistance, and they don't have
an intrinsic They're not particularly flighty animals, I guess in their they don't run
away the way a lot of other animals do, and it's quite unusual for
a wild animal I think um in you know, if if if you imagine
you're trying to rescue a cat or a dog from a place that it's it's
stark um. They're rarely allow human assistance. You know, they normally cause
problems for you if you're trying to get them out of a tree or something.
Right, and they're domestic and domestic animals that are accustomed to humans and
used to seeking assistance from humans, whereas koalas seem to react quite differently.
They seem to be willing to accept assistance or even seek assistance from humans on
occasion. That's not to say that we should necessarily go and inflict our company
on them in every opportunity. Most of the time they prefer to be on
their own, but they do have a strange response to humans, and they're
quite curious animals. They like to look at humans and keep an eye on
them, so you always notice they're watching you from the top of the trees
if you happen to be nearby. So they do present a difficulty for humans
in knowing how to respond to them, because because they do have a way
of interacting with us that's unusual. Yeah, And of course I think people
in our way, we feel compassion, we feel empathy. We also have
that like cute factor, and sadly, I think that, you know,
even under normal circumstances, not dire circumstances like during the wildfires, people are
like, oh, cute thing, I want to pat it, which is
not okay. No. I mean we're primates and we like fiddling with things,
you know, and humans are quite unusual in being particularly interested in other
species. We're very, very attracted to other species and wanting to touch them
and pat them and interact with them far more than other species necessarily do.
But you know, koalas do approach other animals. You know, they'll approach
horses and kangaroos and all sorts of other species, so they do have interspecific
interactions. So so it's it's it's an unusual I think. I think they
just happened to tap into a few key things that really hit our buttons and
create that very emotional response to them, right, which which I guess did
work in their favor. I mean, sadly, in the grand scheme of
things, not really, because when we talk about these horrific wildfires, I
mean we know, in the heart of hearts right, that our human activities
are what's what's causing these problems. But at the same time, there was
a really big rescue effort, was there, not absolutely that there was.
Koala's attract more funding than any other species, I'm told in terms of conservation
efforts. But the conservation efforts are largely directed at rescuing injured animals, which
obviously is it worth, very worthwhile thing to do. But we seem to
be very keen on rescuing animals and not so keen on protecting them in the
first place. And really we need to be devoting more effort to making sure
those almost have the habitat they need to be safe and healthy, rather than
having to rescue them when they run out of habitat and come into contact with
cars or diseases or other factors that are impacting there. There will being right,
and so let's let's sort of take a step back. Obviously I want
to talk about the future and you know, the future of this species and
kind of what we can be doing to help protect them, but also let's
look at their past, because I think a lot of people, you know,
we're sort of aware of, like certain ancient animal species were aware of
dinosaurs, were aware of some of the great kind of larger mammal species that
have gone extinct. But I don't know how common knowledge it is that a
there were kind of great koalas that in the fossil record, and be this
sort of interesting thing that again happens because of island ecology. We're you either
get really big things are really really small things. Yeah, yeah, I
mean koalas are really interesting because as I mentioned earlier, I've written quite a
few books for kids about Australia's fossil history and megafauna, and I guess one
of the things that always interested me is when we look for pictures of fossil
koalas, they always just look like modern koala's just like a little bit bigger,
which is not a very exciting picture, you know. We ever to
present, oh it's a koala, and I thought, well, how do
we how do we even know what those kalas look like? Because the only
things we have to go buy are their largely their teeth. Because Australia has
quite a poor fossil record because it's such an old continent and we've had a
lot of erosion, so we don't have a good fossil record in the way
of having whole skeletons and things like that, so we tend to just have
the teeth, which are the hardest bit. You know, teeth last longer
than anything else, which fortunately are very very distinctive, so they're easy to
identify if it's if it's a koala or not. But it doesn't tell you
much more about it other than a rough indication of size, So you know
you've got a big one or a small one, but you don't know if
it had the same types of climbing adaptations, if if it had if it
had the big fluffy ears, if it had the big black nose, did
it have a tail? You know, we're ancient koalas like possums or were
they more like wombats? You know, we don't We really don't know because
we haven't got the full skeletons of the prehistoric animals. So until those skeletons
come to light, we're not really going to know the details about prehistoric koalas.
All we do know is the type of type of food they ate,
so we know that they ate leaves rather than grass, and we know that
they changed in the toughness of the leaves they ate, so modern cares seem
to be adapted to the particularly tough leaves of the eucalypse, whereas some of
the prehistoric koalas were probably eating softer rainforest leaves. And it may will be
some particular adaptation to eucalypse that didn't have enabled the modern koala to survive where
some of their prehistoric cousins did not. I'm curious, you know, we
are using the word prehistoric and really talking about the fossil record. How old
were there, like, do we know when they first came on the scene.
Yeah, interestingly they're they're about twenty five million years old as the oldest
record of koalas, and that's around the same time that eucalypts first started to
appear on the Australian continent as well in the fossil record, so that's quite
interesting. Possibly they are earlier, earlier koalas, but we haven't found them
yet. So they have been around for quite a long time. And I
guess, you know, we did have a range of different ones and in
the megafaunal period there was also a giant koala which wasn't It wasn't a giant
in terms of you know, as big as a bear or a big bear,
but it was still about three times the size of modern kuala, so
a pretty hefty beast. Um for sure. What was the particulos? What
was sort of the milieu at the time, Like what were koalas hanging out
with? Do we know what other animals existed alongside them? Yeah? No,
that's that's really interesting. I mean the megafauna of Australia is quite interesting
because you know, we when we think about megafaunal species, we tend to
think about, you know, wooly mammoths and sabertooth tigers and giant sloths and
stuff like that, but of course they're mostly plus anal mammals are Eutherian mammals,
so we had giant marsupials instead, So we we had animals that are
quite different from anything that currently exists um and the close cousins of the of
the Kuala are quite interesting because they include Diprotodon, which was the biggest massi
pure megafauna, So that was a two to three ton animal um so,
so like a big grazing wombat or a bear if you like, that sort
of size animal, about the size of a small four wheel drive car if
you like. So, but it had a pouch and it carried its young
inner pouch, so we know we have fossil diprotodons. Actually that still have
the joey being carried in the mother's pouch and the we know it didn't the
joey wasn't walking because the feetbone footbones are not mature. So it was carrying
those those young animals in the pouch. So you know, there all sorts
of strange animals. There's thigh like a leo, which was a was a
giant predatory I guess we could call it a predatory possum, so it was
like a possum like animal, but um, it was probably more like a
leopard. So ambush predator in trees had an astonishing killing biteum just incredibly strong
jaws and big slicing blades for teeth in the in the back of its mouth
that sliced through through meat, and a retractable thumb claw for grabbing hold of
its prey. So that that koala that met with the mountain lion might have
sort of residual genetic memory of silacaleo leaping on it. It's amazing, Yeah,
always think about this when we when we look at the way that we
sort of describe a lot of these ancient species, and I'm like, man,
it was a rough time. There's a jungle out there, like literally,
Yeah. There was also Megalania, which was the other big predator,
which was which was like a relative of komodo dragon, only about five meters
long, so pretty enormousine and lizard that was really Yeah, you wouldn't want
to meet with that one either. It's so curious to me. I wonder
if if Koala is back in the day, you know, ancient koala still
had a very similar temperament, if they're like, oh, what are you
and it's like yeah, yeah, I mean, I think there was a
reason they stayed up in the trees, you know, safe, forced to
be relatively and I think being in the trip, being tree dwellers is actually
explains a lot about their personality or their temperamentum in their you know, their
lack of flight response, because their defense mechanism against predators is to sit tight
in a tree, and they are actually very hard to see in trees.
I had one just in my in my yard. I knew it was in
the tree, but it took me forever to find it. Because they're so
that they just curl up in the cook of a branch and don't unless they
move. They're very hard to spot, so that's their best defense mechanism and
that keeps them pretty safe from most predators. Um so you know, there's
the occasional there's a powerful owl which occasionally takes kualas, but pythons might occasionally
up in the tropics, but really until they come down on the ground,
they're pretty safe from most predators. And what are their typical predators on the
ground, Well, it's historically it's been m dingos of what you know,
which are the native Australian dog and now dogs generally form a really big threat
to koala's, so so dogs are a big problem for them. There's there's
a lot of dog attacks and cars are obviously a huge impact as well because
they do they do cross roads and they're not they don't run away from cars
either. It's a real characteristic with Koala's that it's not uncommon for them to
sit in the middle of the road when a car comes across them and just
wait, so which is not a great reaction in the middle of a busy
road. So clearly we've got you know, human impact. Dogs are domestic
hits, people letting them outside, letting them off leash, or or fairal
dogs that are running around. We're talking cars, roads, you know,
criss crossing their habitat. We're talking anthropogenic climate change as we saw, you
know. I mean there's so many aspects of that, from the wildfires to
you know, habitat loss. Are we really we are their biggest threats,
aren't we? Yeah? I mean the habitat loss is a really big factor.
I think for koalas. We have lost an awful lot of our forest
estate in Australia, and even the forest estate we have, we're continuing to
change it through native logging in the Eastern States, so Queensland and New South
Wales still have logging of native forests and that actually reduces the number of edible
gum trees and increases the level of toxic gum trees. So there's quite a
lot of gum trees that koalas can't eat at all. So so so even
though it looks like a forest, it's it's not an edible forest anymore.
So those those factors play a big role in it has even bigger impacts on
of course the others bess in the forest as well. We also tend to
like living in the same habitats koalas, so so we like you know,
the lush Um river bank areas of the forests, and those are also the
key forest areas that are best for koalas because the more water the trees get,
they're less toxic they are and the more nutritious they are. So breeding
Koala's in particular are they're walking a fairly fine line with their with their food
to be able to have enough nutrition to raise a joey to adulthood. It
takes a long time to raise a joey because of the low nutrient leaves they
eat um. And so you know, if you if you reduce that nutrition
further with the trees and remove the ones along the rivers and the and the
creek lines, then then you make it even harder. So again it's not
just it's not just the the existence of forests. It's got to be the
right forest. You know, Koala needs a very big area of forest to
water it. Most koalas have an average home range of about the size of
a sports field of forest and in poorer forest areas, more arid areas that
can be as big as Central Park. So that's one Koala per Central Park.
So they're very dispersed animals and they need a lot of different trees because
they can't just keep eating the same tree. It's it's not like that.
It's very characteristic of koala's When you offer them leaves. They maybe have been
eating the same leaf for quite a few weeks, perfectly, happily off the
one tree, and then suddenly they will decide they won't eat it anymore.
And we don't know why that is, but it's quite likely that the toxicity
levels have changed, the balance has changed in the leaf and it's no longer
palatable to them, so they need something else, and you have to in
zoos, you have to provide them with a really wide range of different leaves
from different trees, individual trees and different species to keep them healthy. And
that's what makes them one of the most expensive animals to keep in a zoo
outside of Australia. Wow. And you know this other thing that I don't
know is is it because of human intervention or is it a zoanartic thing that
went the other direction or is it not zoanartic at all? But these these
STIs sexually transmitted infections, and they're ones that are familiar to us, like
chlamydia. Is it the same chlamidia? Yeah, that's a really interesting question.
We've historically we've always assumed that the Chlamidia koala's have is the same way
that sheep have, and that sheep are transmitters of and that koalas may have
got that from sheep that when she arrived in Australia. There's some debate about
that at the moment, you know, genetic studies going on saying that there's
also there's many different varieties of chlamydia, so it's possibly that there is a
native variety as well, so that's sort of ongoing research. The other disease
that they suffer from is a koala AIDS, so a retrovirus that causes and
aids like disease, which of course exacerbates chlamydia as well, so it makes
that worse for them. And retroviruses have certainly always been present in Koala populations
for a long time, but they seems to be a particularly virulent form spreading
from the north down through the Koala population, which is having a really major
impact. And I guess the thing we have to recognize is that those sorts
of diseases typically affect populations that are under stress already. So if we have
a population that's suffering stress through habitat change, then those diseases will highly become
worse. So we've got to be careful about whether we attribute that as a
symptom or a cause of the problem. It's notable that the southern Koala populations
are doing much better. They're quite strong, and then they're not having the
problem the northern populations are, but they typically have had been. Chommittee is
absent in some of those populations, and I know the ones in the Adelaide
Hills where I live with they're very very abundant, are starting to show signs
of chlamydia, but they don't seem to manifest the same symptoms, so they
seem to be able to carry the chlamydia without it causing them particular problems,
whereas it's a massively debilitating and painful disease in other populations. So it's a
complicated issue. Yeah, as it treatable, Like obviously retroviruses are difficult,
you know, we now have in the human population. We have prep,
we have drugs, but they have to be taken on a very specific schedule.
They're very expensive, Like I can imagine that a kohala retrovirus would be
much harder to take care of. But is there a way to treat the
wild population of chlamydia? Yeah, the retrovirus are difficult, and worst thing
with them is that they're not only transmitted through birth from mother to offspring,
they're actually they genetically infect the baby before it's even born, so so that
the offspring is born with the retrovirus in their DNA. So that's that's a
particularly terrible component. Um Chlamydia is treatable, but koala is because they are
adapted to eating eucalypt leaves, they're extremely good at removing toxins from their system,
and they do this using their supercharged liver, so they have got double
doses of genes for removing toxins, and they remove medication from their system.
So in a human you might take a three day dose of drugs to remove
chlamydia. A koala, the same drugs would be thirty days. And how
hard is it to treat a wild koala for thirty days? Straight. Yeah.
Yeah, fortunately they're not they're not too bad. You know, they
are generally okay in captivity, but in terms of temperament, but yeah,
it is really difficult. So there are vaccines currently being trialed for chlamydia,
because of course, the other thing is that they simply get reinfected when they're
released back into the wild. But there are vaccine trials going on now which
seem to be successful, and that might help take some of the pressure off.
But again, unless we remove the address the root cause of the problem,
which is habitat loss, increasing drought, climate change, those factors,
you're just putting a band aid on the problem really, right, And that
of course brings me to probably sort of the most important and almost closing question
of the hour, which is, you know, what can we do?
Ultimately we're talking about systemic problems, large scale problems that have to do with
industry, that have to do with capitalism, that have to do you know,
they're so baked into what it means to be a human being on this
planet, which is to say, Adelai, you know, have these terrible
impacts on our wild ecology. I'm curious from a I mean, I hate
to even do this but from an individual perspective, other than vote, you
know, other than than work to try and make sure that we are making,
you know, meaningful systemic changes. What can people do m It's it's
a really big question, and it's it's I don't really know what the answer
is. I mean, we really need to make sure that we're providing more
habitat for species, you know, protecting our trees. I just think he's
such an important thing. And you know, the city, Adelaide, the
city I live closest to, is actually one of the few cities. It's
the only city I'm aware of where koalas are actually moving into the suburbs.
And that's because I say that I love Adelaide. Like I've traveled Australia and
I you know, everybody goes to Sydney and to Melbourne, and I love
them both. And you know, I've been to Perth and I've been to
Brisbane. But when I when I was in Adelaide, I was like,
what a charming city that everybody I talked to you from the US is like,
oh, I've never been there. Yeah. Yeah. And in Adelaide
you can see koala's in the streets. That is so cool. I love
that so much. So this really is a function. You know, I
often talk to people about like here in the US, it's like put a
freaking bat box up in your backyard, a hummingbird feeder on your balcony,
Like, why not make sure that your trees are healthy and happy and provide
habitat on your own problem? Yeah, yeah, just providing a minimum level
of tree cover. You know. I really it's so easy for developers just
to cut down trees and go, oh, I'll just plant some new ones.
But those trees are not going to be fulfilling their ecological function for another
twenty thirty, fifty, eighty hundred years. You know, We've we've got
trees in our cities that are, you know, two or three hundred years
old. You can't cut them down and think that you can replace them.
You have to protect them, and we have to be improved having our tree
cover. We've already removed so much treecover. We're losing species of birds um
that you know, they're just they're just hanging on as residual species. Really,
they're going to start disappearing in the next few years unless we increase their
habitat and increase tree cover. So we need to be doing everything we can
to increase the forests and the native plants that go with the forest, you
know, and and the other habitats as well. It's really got to become
a big priority wherever we live. You know, even if you live in
an apartment, at least have something growing on your balcony, provide some habitat
for something not just yourself. Yeah, I have. I have milkweed on
my balcony. Like literally, I'm on the fourth floor in like a concrete
jungle right now, and I've got milkweed on my balcony. And you know,
seasonally, I've got monarchs butterflies that are like hatching on my balcony.
It's very cool, Like it's not that hard to do, Yeah, and
we just have to kind of make the effort. So, you know,
this course leads me. I always close my show with the same two big
questions, and this, of course leads me, I think, pretty seamlessly
into those big picture questions. And you as somebody who obviously your most recent
book is about koalas, but you've written, you know, all about natural
history, all about conservation, all about science and kind of wildlife from the
extinct to the extent. So I'm curious, you know, how you might
approach these final two questions and just get ready because the kind of a big
picture. Okay, okay, So when you think about the future in whatever
context feels relevant to you, whether it be personal, whether it be communal,
familial, or you know, community level, country level, global,
cosmic, whatever. Number one, what is the thing that's keeping you up
the most at night that you're most concerned about. Maybe you're you know,
feeling worried or even a bit pessimistic or cynical. And then on the flip
side, so that we do end on a slightly more positive note, where
are you finding your optimism? What are you like genuinely authentically looking forward to.
I think the thing that keeps me awake most at night is the corrupting
influence of extreme wealth on our democracies and our governments. I think that worries
me the influence of a very few, a very small number of people with
a lot of money who are influencing the way our democracies run and the decisions
that are being made and the consequent terrible impacts that are being reached upon our
environment. That don't need to be there. We've got the solutions, we
know how to fix these problems. We can make life better for everyone if
we adopt more sustainable economic models, and we're not doing it because there are
wealthy vested interests blocking that. So that's the thing that keeps me awake at
night. The thing I drive most comfort from, I suppose, is the
grassroots community action and the work that local communities can do to improve their local
environment and the big changes they can make. So you know, we're seeing
a revolution in finally in solar energy uptake in Australia, and most of that's
been driven by individual households rather than governments, so that those sort of movements
you can you can you know, we only have a very small individual power,
but if we all do a little bit, it makes a big difference.
So we don't need everybody to do one hundred percent of the right thing.
We just need and we don't need a few people to do one hundred
percent of the right thing. We need everybody to do a little bit of
the right thing. So if we all do our bit as much as we
can, it might not be perfect, but I think that in the end,
sheer force of numbers will will you know, go a long way to
helping this situation. Yeah, yeah, I mean it's it's we often think
about this need for collective action and collective impact, but I think what you
just said really points to the fact that, like, we don't even have
to do it together like we should. We should, we should be working
together, for sure, but also just doing things on our own can make
a huge difference when when it's happening in the aggregate. Yeah. Yeah,
so you can't afford to give up hope, You've got to keep trying because
that's the only option we have. I agree wholeheartedly. Well, gosh,
okay, everybody. The book is Koala, A Natural History and an Uncertain
Future by doctor Danielle Clode. Danielle, thank you so much for enlightening us
today. Thank you for having me. It's been a real pleasure absolutely,
and everyone listening. Thank you for coming back week after week. I'm really
looking forward to the next time we all get together to talk. Already