August 26, 2022 • 22 mins
What is a carnivorous and endangered marsupial? In this episode, Amazing Wildlife explores what makes the Tasmanian Devil so fascinating. Hosts Ebone Monet and Rick Schwartz discuss the history behind the creature’s unique name, the role they play in their habitat, and the breeding program to introduce the population outside of Tasmania. Later, Cora Singleton joins the show to give insight about the outbreak behind a dramatic decline in the Tasmanian Devil population.
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Episode Transcript
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Speaker 1 (00:00):
Hi, I'm Rich Schwartz. Hi, I'm Abony Mone. Welcome to
Amazing Wildlife, where we explore unique stories of wildlife from
around the world and uncovered fascinating animal facts. This podcast
is a production of I Heart Radio and San Diego
Zoo Wildlife Alliance, in international nonprofit conservation organization behind the
(00:23):
San Diego Zoo and Safari Park. This next species is
a carnivorous marsupio. At one point in time, this animal
was only found in one place in the world. Have
you guessed it, Well, here's an even better clue. This
animal was the main character in his own popular cartoon.
(00:47):
But despite this spotlight, there's a lot you might not
know about the Tasmanian Devil. Rick. Let's unpack a few
of those facts. The Tasmanian devil was once only found
in one place in the world. Rick, Where can you
find the Tasmanian devil living in nature today? Well, it's true,
(01:07):
ebany Tasmanian devils were once found throughout Australia, but keep
in mind that was a long long time ago and
throughout the last several centuries they have only been on
the island state of Tasmania. And although their range encompasses
the entire island of Tasmania. They tend to be pretty
partial to the coastal scrub land and forest areas. But
get this. Recently a small breeding population of Tasmanian devils
(01:31):
were reintroduced in New South Wales, Australia on the mainland.
So this reintroduction is the first of three planned reintroductions
of small breeding populations of Tasmanian devils. This of course
was done with a lot of preparation and planning to
ensure the best possible outcome for these new mainland populations.
The Tasmanian devil, as I mentioned, is a carnivorous marsupial.
(01:56):
So we've been talking enough and we've done enough of
these episodes. I have learned that that means it eats me,
and it carries it's young it's offspring in a pouch.
Correct correct, yes, So let's start with its diet. What
does the Tasmanian devil eat? Let's prey to the Tasmanian devil. Well,
first of all, hats off to you have any I
appreciate that you have been learning along with our audience
(02:17):
as well, because that means we're doing a good job here.
But but you're correct, tasmine and devils are carnivores, and
that means, like you said, they only eat meat. Now,
their usual prey consists of birds, reptiles, amphibians, and you know,
sometimes other small mammals. Sometimes maybe they can catch a
small kangaroo or small wallaby. Now that said, they are
also part of nature's cleanup crew. This is probably the
(02:38):
most important part of what they do. This means, like vultures,
they will happily consume carry on or an animal that
has already passed away. No hunting required for them this way.
And get this that tasmine and devil's jaws are so
powerful they can easily crush and ingest the bones of
any animal that they are consuming. Thus you will rarely
find anything left mind after the Tasmanian devils are done
(03:02):
with a meal. Wow, now I thought this is pretty cool. Rick.
Can you describe how one can tell if a Tasmanian
devil is well fed? Yeah? Well, Tasmanian devils are well
known for having a voracious appetite. They seem to be
born with the idea that every meal is a competition
that must be one at all costs. In fact, They
(03:23):
can even consume get this of their body weight in
one meal, I mean almost half their body weight and
one meal. But how can you tell if one's been
eating well over the last few meals. Well, you might
be thinking you're looking for a big belly, but like
other mammals, they store extra calories as fat. But unique
to marsupials, they store this fat in their tail, So
(03:45):
a plump tail means they've been eating. Well, wow, that's
so interesting. So the Tasmanian devil has a fierce reputation
um possibly because of its name. What's the story behind
its name? I know what you mean, but I mean
the named devil is right there. It's like that doesn't
really give you a very warm, fuzzy feeling, does it
(04:05):
at all? When European settlers first came across these carnivorous marsupials,
it was, how can I put this? Not a pleasant encounter.
In general, Tasmanian devils don't attack people, but they put
on quite an aggressive looking and loud show if they
feel threatened, making all sorts of growls and screams that
are really quite impressive for a smaller animal like they are.
(04:29):
With this, they will also gave their mouth open incredibly wide,
showing all these very sharp teeth. Oh and their ears
become flush with blood, making them turn bright red in
these situations, adding to the whole dramatic look and behavior
of everything. And of course settlers brought with them that
you know, their livestock is specifically chickens and other small
animals that ended up being very easy prey for the
(04:49):
Tasmanian devils. So the Tasmanian devils took advantage of these
easy meals, making nightly raids into the chicken yards. And
here's the thing. When Tasmanian devils end up feeding to together,
they make a horrendously large amount of noise is they
fight over the food. All of this has earned them
the initial nickname of the devil, and eventually the name
(05:09):
then became Tasmanian Devil. I can see why they got
that name exactly. It all really kind of makes sense
when you see the history of it. And I want
our listeners to keep in mind. They really aren't an
animal you would consider big. I mean, they only weigh
around eighteen to twenty five pounds and at the most
two feet in length. So what a Tasmanian devil lacks
in size, they make up in complete and total attitude. Well,
(05:31):
that explains it. So other popular marsupials, like the kangaroo
are often pictured carrying their offspring and a pouch, and
those cute pictures that circulate. But I was surprised to
learn that the Tasmanian devil also tote they're young. Can
you tell us about the reproductive cycle of the Tasmanian Devil? Oh? Absolutely,
(05:52):
But first, Ebony, I want to catch any new listeners
up to speed on what it means to be a marsupial,
And basically that means you were born very small and underdeveloped,
with eyes and ears not formed yet no hair. Usually
only the forelimbs are developed with functional digits. Then that
little underdeveloped baby called a joey must climb from the
birth canal to mom's pouch to find the milk duck
(06:14):
to latch onto for the next several months. And you
might have heard that term joey with kangaroos or kowala's,
but the term joey sticks for all marsupials, including the
Tasmanian Devil. Now, in the case of the Tasmanian Devil,
they are about the size of a grain of rice
when they are born weighing less than the half of
one gram. And remember earlier when I mentioned that they
(06:35):
seem to have this very competitive behavior around feeding, Well,
it does in fact start on day one, and it's
a matter of true survival. You see, the mom can
give birth to up to fifty babies at one time,
but she only has for milk ducks. And when a
marsupial Joey latches on, due to the physiology and body mechanics,
(06:56):
they will stay connected to that milk duck for several months,
meaning the first four to reach and stay attached to
one of the four milk ducks lives and the arrest
will perish. Wow, it's like survival of the fittest, no fastest,
most aggressive. I don't know. Wow, So what is the
relation between mom and Joey? Like, how long does the
(07:18):
offspring stay with mom? Yeah? With the Tasmanian devils, the
joys will usually stay in mom's pouch for about three
to four months, and then they stay in the den
for about another three months as Mom comes and goes
with food to feed them. At about six months of age,
they start to venture out of the den. Following mom
or writing on her back learning how to be an
adult Tasmanian devil. Then when they get around nine to
(07:39):
ten months of age, the young will start to head
off on their own. That brings us to social dynamics.
Do the Tasmanian Devils like? Do they interact with each
other in ways not related to reproduction? Well, I guess
you could say for the most part meany, the Tasmanian
devils are considered solitary, but with a network built in
(07:59):
at What that means is they don't live in family
groups or travel and packs. There's no real hierarchy dynamics
to everything they do, but they do come together often
when feeding and of course for mating and when mom
is raising her joeys. This means that they do have
interactions with a network of other Tasmanian devils that live
within the same regions. And it is worth sharing that
(08:21):
during group feedings we do see the larger, usually older
and stronger individuals dominating the smaller, younger ones, but this
is truly based on a physical contest of pushing and
biting each other. No real social dynamic as far as
that kind of structure. So what role does the Tasmanian
devil play in its habitat oh i, meaning they are
(08:41):
very important to their ecosystem. As we mentioned that, they
do prey upon a variety of smaller animals and this
of course helps keep those populations in check and balanced.
But equally important, if not even more so, it is
the consumption of carry on are already deceased animals that
we talked about earlier. Any animal that is part of
nature cleanup crew, consuming dead and decaying things helps prevent
(09:03):
the spread of disease and helps move along the process
of the life cycle. And it's worth noting ebony. With
the recent reintroduction of the species back on mainland Australia,
biologists and ecologists are both expecting to see a rebalancing
of the forest ecology, much of which has been out
of balance in the past due to introduce cats, foxes
and other invasive species. Rick, you mentioned reintroduction. The Tasmanian
(09:26):
devil population is endangered unfortunately, and some scientists predict extinction
could be inevitable. What's the Tasmanian devils like major threat
to survival? Well, unfortunately, for decades, this sort of really
kind of horrible facial cancer has been decimating the Tasmanian
devil population, spreading from animal to animal. When these stocky
(09:49):
raccoon sized marsupials bite each other, and it's worth noting
they don't just randomly bite each other. Part of these
sort of group feedings we were talking about, where the
dominant ones pushed back the less dominant ones. You know,
this is done through biting, just sort of a normal
way that they communicate with each other. And it is
said when this face cancer didn't exist yet, that sure
it would leave scars, but it wouldn't really damage them
(10:09):
too much. Unfortunately, now this transmits this cancer and it
kills up to the devils in Tasmania. They're only a home.
For quite a long time, some researchers saw extinction as
inevitable as you said, eany until recently. In fact, the
cancer was spreading exponentially like a pandemic across the population
of Tasmanian devils. But geneticists have calculated that each infected
(10:31):
devil now transmits the tumor self to just one or
fewer other devils, and that could mean the disease may
disappear over time. There's also an interesting fact that they
have found some populations that were free of this disease,
and they were able to isolate them and send them
away from the island to help prevent them from catching
this disease. So they have created some safe populations and
(10:52):
they're also monitoring this very closely. In coming up, we'll
talk more about how teams at the San Diego Zoo
Wildlife Alliance are working with partners to address other Tasmanian
devil conservation efforts. The first this now it's time for
the San Diego Zoo Minute, an opportunity for you to
(11:13):
learn what's new at the zoo and Safari Park. The
San Diego Zoo has one of the largest colonies of
Gallas tortoises in the world. We have had these giants
in our care since, making them the oldest residents at
the Zoo. That's the year when Charles Townsend of the
New York Zoological Society began his efforts to save the
(11:35):
tortoise from extinction by collecting juvenile tortoises and setting up
colonies for them in North American zoos. Did you know
Tasmanian devils sneeze to help avoid a fight. It's true.
These are known as bluff behaviors or behaviors that are
an attempt to scare an opponent before a real scuffle starts. Oh,
(11:57):
and get this, Tasmanian devil's travel a long distance each
and every night in their pursuit of food, sometimes covering
as much as ten miles. We're continuing our conversation about
the Tasmanian devil and the cancer that threatens to wipe
(12:17):
it out. Joining the conversation now is Corrus Singleton, a
senior veterinarian with San Diego Zoo Wildlife Alliance High Cora
hi Aberty. In scientific terms, what is the devil facial
tumor disease? Devil facial tumor disease is a transmissible or
contagious cancer, and that's very different than the cancers that
(12:39):
we typically think of, which develop within an individual and
stay within that one individual. Devil facial tumor can be
transmitted from one devil to another, just like an infection.
And you've probably never heard of a contagious cancer because
they're very rare, and there are only three that are
known to infect mammals in the entire world. Of those
three Tasmanian devils, of two of them, So how are
(13:02):
Tasmanian devils transmitting this cancer and what's happening to them
once that happens. Facial tumors are spread mostly by biting,
which is a common behavior among Tasmanian devils. As their
meeting and as they're feeding, devils bite each other on
the head in the neck, so the tumors are observed
to grow mostly around the mouth. And these tumors can
(13:24):
grow very large and make it very difficult for the
devils to feed, so many of them die from starvation.
So what a researchers know about the history of this disease.
Is it known how or or where it originated. Yes,
researchers do know how and where the devil facial tumor
disease originated. This disease was first documented in in northeastern
(13:48):
Tasmania actually by a wildlife photographer, and this disease is
spread rapidly south and west across the island and over
the past twenty five years, population numbers have declined by
almost across the island of Tasmanian. The second Tasmanian devil
facial tumor disease was diagnosed in so there are two
(14:09):
different transmissible tumors that devils have, and can this transmissible tumor?
Can it be transferred to other animals? Can another animal
be infected by this disease? No, devil facial tumor can
only affect Tasmanian devils. Other animals, including people, have an
immune system that's able to recognize tumor cells as invaders
(14:33):
and kill those tumor cells. So if we were to
contact a tumor from a Tasmanian devil, our body would
recognize that that was abnormal and would not allow it
to grow. But the reason that this tumor can infect
so many devils is that the devil immune system is
unable to recognize those tumor cells as foreign invaders, so
the devil's body allows the tumors to grow. Is this
(14:55):
tumor a threat to the population at the st Ago Zoo.
That's a great question, Ebony, because it's a really scary
disease and we're lucky that the answer to that is no.
Because facial tumor disease is a cancer of wild devils only,
and as this disease in the wild caused populations to
get smaller, conservationists agree that it would be really important
(15:16):
to protect populations of devils that are free from the disease.
So some wild devils were brought into human care, and
part of that process involved really long observation periods where
they were able to monitor devils for several years to
make sure that they didn't have the facial tumor disease
before they entered these protected populations. So the three Tasmanian
(15:37):
devils who live at San Diego Zoo were born within
these protected populations and are free from this horrible disease.
So what is the case of the Tasmanian devil and
the Tasmanian devil facial tumor disease? What does that say
about the importance of genetic diversity when it comes to conservation.
(15:58):
By studying genetics of Tasmanian devil, researchers hope to better
understand how this disease and the devil are evolving together
so that we can focus our conservation work to help
the devil survive this threat. In speaking of conservation work,
what has the San Diego Zoo Wildlife Alliance done to
address this problem? At the San Diego Zoo Wildlife Alliance,
(16:22):
we focus our conservation efforts in eight hubs around the world,
one of which is the Australian forests, where we work
to conserve the Tasmanian devil as well as koalas and platypus,
and we're partnering with governmental conservation and research groups to
learn more about why the devil has this cancer as
well as how we can help conserve the devil populations
in the wild. And specifically we've partnered with the Save
(16:45):
the Tasmanian Devil Foundation and the Australasian Wildlife Genomics Group
at the University of Sydney to learn more about the
genetics of the devil. During these conversations, we've talked about
human behavior being the driver of extinction for some animals,
but in this case, the Tasmanian devil populations have been
devastated by cancer. Someone my question, if human intervention is
(17:09):
therefore the appropriate response, given that this is a non
human cause problem, what would you say to that, Yes, definitely,
of any that can be a difficult question to tackle,
but really there aren't really any ecosystems around the world
that are untouched by human behaviors via either climate change
or pressures of development, or introduced species such as foxes
(17:31):
and feral cats in Tasmania. So while the facial tumor
disease is not a problem caused by humans, we have
altered the ecosystem and the climate in ways that make
it more difficult for the devil to adapt to this disease,
and human behavior directly contributed to the extinction of another
apex predator on Tasmania, the Tasmanian tiger, leaving the devil
to fill this important ecosystem role. So humans depend on
(17:54):
healthy ecosystems and our behaviors threatened this delicate balance. So
I see it as our responsibility as environmental stewards to
help the devil fight this disease. From a veterinarian's perspective,
does anything about that has Menian devil in particular stand out?
Does it require any sort of special care? Tasmanian devils
(18:14):
are really interesting. First off, they're very charismatic animals and
it's really enjoyable to work with them. But interestingly, from
a biology standpoint, they have a really short lifespan for
a mammal, and in the wild they only live up
to about five years, and in human care that can
live to be seven or eight years of age. And
while devils and zoos do not have devil facial tumor disease,
(18:37):
they do develop cancers, many different types of cancers, at
a higher rate than many other animals. So since we
know this about devils, we've designed a healthcare program specifically
for the Tasmanian devil that helps us to detect and
to treat cancers early. And it's really rewarding to see
the work that we do help an animal live a
longer and healthier life. What would you say is the
(19:00):
best part of your role as a senior veterinarian with
a San Diego Zoo Wildife Alliance, I feel fortunate to
be part of a conservation organization with a one health
approach where I can channel my passion for animals and
my skills in support of conservation. And one health refers
to the interdependence of wildlife health, ecosystem health, and human health,
(19:23):
And for me, each day at work is interesting and
full of variety. In the morning, I might be called
upon to help an injured insect or an ill elephant,
and then in the afternoon I'll work with a global
team of conservation allies to help devils or koalas or
platypus in Australia, and I know that what I do
here at San Diego's a Wildlife Alliance helps the animals
(19:43):
living in our care as well as helps the animals
in their habitats worldwide. What would you say to a
kid who wanted to one day be a veterinarian? Any advice?
M Yeah, lots of advice. So why do most kids
say that they want to be a veterinarian Because they
love animals. They love animals and they want to help animals.
(20:04):
That's right, and veterinarians do help animals in many different ways,
sometimes by doing exams and giving treatments and performing surgery,
but also sometimes by studying animals in their habitats or
by doing health research in a lab. And at its core,
being a veterinarian is about science and service service to
both animals and people. So hard skills like science and
(20:25):
math are just as important as soft skills like communication
and teamwork. And while I think that being a clinical
veterinarian is fantastic, kids should know that there are many
different ways that they can help animals and many different
ways that they can help and work with animals. My
best advice is to be curious and explore all the
different ways that they could work with animals, find out
(20:46):
where their passion for animals overlaps with the things they're
really good at and the things that they really like
to do. So maybe you're passionate about wildlife and you
like to work with computers, Or maybe you're passionate about
wildlife and you like to take pictures and make video
those or write stories, or maybe you like to design things.
Are you like to organize and lead teams? All of
(21:06):
these people work at San Diego's a Wildlife Alliance helping animals,
And for me, my passion is wildlife and conservation. I'm
good at biology, learning how systems work and solving problems,
and I like to work directly with individual animals and
populations of animals. So being a wildlife veterinarian is perfect
for me. And I think if kids can explore and
(21:28):
be curious, they can find those places where their passions,
their skills, and their interests overlap in support of animals.
Great advice. We've been talking to Cora Singleton, a senior
veterinarian with the San Diego Zoo Wildlife Alliance. Thanks Cora,
thank you. Thanks for listening. We hope you enjoyed learning
(21:49):
about the largest marsupio carnivore in the world, the Tasmanian Devil,
and being sure to subscribe and tune into next week's episode,
in which will be jumping into the story of one
of the more recognizable marsupials from Australia. I'm Ebony Money
and I'm Rick Schwartz. Thanks for listening. If you would
(22:12):
like to find out more about San Diego Zoo Wild
Lack Alliance, please visit sdz w a dot org. Amazing
Wildlife is a production of I Heart Radio. Our producer
is Nikkia Swinton and our executive producer is Marcia to Peanut.
Our audio engineer and editor is Sierra Spreen. For more
shows from My Heart Radio, check out the I Heart
Radio app, Apple podcast, or wherever you listen to your
(22:34):
favorite shows.
Hi, I'm Rich Schwartz. Hi, I'm Abony Mone. Welcome to
Amazing Wildlife, where we explore unique stories of wildlife from
around the world and uncovered fascinating animal facts. This podcast
is a production of I Heart Radio and San Diego
Zoo Wildlife Alliance, in international nonprofit conservation organization behind the
(00:23):
San Diego Zoo and Safari Park. This next species is
a carnivorous marsupio. At one point in time, this animal
was only found in one place in the world. Have
you guessed it, Well, here's an even better clue. This
animal was the main character in his own popular cartoon.
(00:47):
But despite this spotlight, there's a lot you might not
know about the Tasmanian Devil. Rick. Let's unpack a few
of those facts. The Tasmanian devil was once only found
in one place in the world. Rick, Where can you
find the Tasmanian devil living in nature today? Well, it's true,
(01:07):
ebany Tasmanian devils were once found throughout Australia, but keep
in mind that was a long long time ago and
throughout the last several centuries they have only been on
the island state of Tasmania. And although their range encompasses
the entire island of Tasmania. They tend to be pretty
partial to the coastal scrub land and forest areas. But
get this. Recently a small breeding population of Tasmanian devils
(01:31):
were reintroduced in New South Wales, Australia on the mainland.
So this reintroduction is the first of three planned reintroductions
of small breeding populations of Tasmanian devils. This of course
was done with a lot of preparation and planning to
ensure the best possible outcome for these new mainland populations.
The Tasmanian devil, as I mentioned, is a carnivorous marsupial.
(01:56):
So we've been talking enough and we've done enough of
these episodes. I have learned that that means it eats me,
and it carries it's young it's offspring in a pouch.
Correct correct, yes, So let's start with its diet. What
does the Tasmanian devil eat? Let's prey to the Tasmanian devil. Well,
first of all, hats off to you have any I
appreciate that you have been learning along with our audience
(02:17):
as well, because that means we're doing a good job here.
But but you're correct, tasmine and devils are carnivores, and
that means, like you said, they only eat meat. Now,
their usual prey consists of birds, reptiles, amphibians, and you know,
sometimes other small mammals. Sometimes maybe they can catch a
small kangaroo or small wallaby. Now that said, they are
also part of nature's cleanup crew. This is probably the
(02:38):
most important part of what they do. This means, like vultures,
they will happily consume carry on or an animal that
has already passed away. No hunting required for them this way.
And get this that tasmine and devil's jaws are so
powerful they can easily crush and ingest the bones of
any animal that they are consuming. Thus you will rarely
find anything left mind after the Tasmanian devils are done
(03:02):
with a meal. Wow, now I thought this is pretty cool. Rick.
Can you describe how one can tell if a Tasmanian
devil is well fed? Yeah? Well, Tasmanian devils are well
known for having a voracious appetite. They seem to be
born with the idea that every meal is a competition
that must be one at all costs. In fact, They
(03:23):
can even consume get this of their body weight in
one meal, I mean almost half their body weight and
one meal. But how can you tell if one's been
eating well over the last few meals. Well, you might
be thinking you're looking for a big belly, but like
other mammals, they store extra calories as fat. But unique
to marsupials, they store this fat in their tail, So
(03:45):
a plump tail means they've been eating. Well, wow, that's
so interesting. So the Tasmanian devil has a fierce reputation
um possibly because of its name. What's the story behind
its name? I know what you mean, but I mean
the named devil is right there. It's like that doesn't
really give you a very warm, fuzzy feeling, does it
(04:05):
at all? When European settlers first came across these carnivorous marsupials,
it was, how can I put this? Not a pleasant encounter.
In general, Tasmanian devils don't attack people, but they put
on quite an aggressive looking and loud show if they
feel threatened, making all sorts of growls and screams that
are really quite impressive for a smaller animal like they are.
(04:29):
With this, they will also gave their mouth open incredibly wide,
showing all these very sharp teeth. Oh and their ears
become flush with blood, making them turn bright red in
these situations, adding to the whole dramatic look and behavior
of everything. And of course settlers brought with them that
you know, their livestock is specifically chickens and other small
animals that ended up being very easy prey for the
(04:49):
Tasmanian devils. So the Tasmanian devils took advantage of these
easy meals, making nightly raids into the chicken yards. And
here's the thing. When Tasmanian devils end up feeding to together,
they make a horrendously large amount of noise is they
fight over the food. All of this has earned them
the initial nickname of the devil, and eventually the name
(05:09):
then became Tasmanian Devil. I can see why they got
that name exactly. It all really kind of makes sense
when you see the history of it. And I want
our listeners to keep in mind. They really aren't an
animal you would consider big. I mean, they only weigh
around eighteen to twenty five pounds and at the most
two feet in length. So what a Tasmanian devil lacks
in size, they make up in complete and total attitude. Well,
(05:31):
that explains it. So other popular marsupials, like the kangaroo
are often pictured carrying their offspring and a pouch, and
those cute pictures that circulate. But I was surprised to
learn that the Tasmanian devil also tote they're young. Can
you tell us about the reproductive cycle of the Tasmanian Devil? Oh? Absolutely,
(05:52):
But first, Ebony, I want to catch any new listeners
up to speed on what it means to be a marsupial,
And basically that means you were born very small and underdeveloped,
with eyes and ears not formed yet no hair. Usually
only the forelimbs are developed with functional digits. Then that
little underdeveloped baby called a joey must climb from the
birth canal to mom's pouch to find the milk duck
(06:14):
to latch onto for the next several months. And you
might have heard that term joey with kangaroos or kowala's,
but the term joey sticks for all marsupials, including the
Tasmanian Devil. Now, in the case of the Tasmanian Devil,
they are about the size of a grain of rice
when they are born weighing less than the half of
one gram. And remember earlier when I mentioned that they
(06:35):
seem to have this very competitive behavior around feeding, Well,
it does in fact start on day one, and it's
a matter of true survival. You see, the mom can
give birth to up to fifty babies at one time,
but she only has for milk ducks. And when a
marsupial Joey latches on, due to the physiology and body mechanics,
(06:56):
they will stay connected to that milk duck for several months,
meaning the first four to reach and stay attached to
one of the four milk ducks lives and the arrest
will perish. Wow, it's like survival of the fittest, no fastest,
most aggressive. I don't know. Wow, So what is the
relation between mom and Joey? Like, how long does the
(07:18):
offspring stay with mom? Yeah? With the Tasmanian devils, the
joys will usually stay in mom's pouch for about three
to four months, and then they stay in the den
for about another three months as Mom comes and goes
with food to feed them. At about six months of age,
they start to venture out of the den. Following mom
or writing on her back learning how to be an
adult Tasmanian devil. Then when they get around nine to
(07:39):
ten months of age, the young will start to head
off on their own. That brings us to social dynamics.
Do the Tasmanian Devils like? Do they interact with each
other in ways not related to reproduction? Well, I guess
you could say for the most part meany, the Tasmanian
devils are considered solitary, but with a network built in
(07:59):
at What that means is they don't live in family
groups or travel and packs. There's no real hierarchy dynamics
to everything they do, but they do come together often
when feeding and of course for mating and when mom
is raising her joeys. This means that they do have
interactions with a network of other Tasmanian devils that live
within the same regions. And it is worth sharing that
(08:21):
during group feedings we do see the larger, usually older
and stronger individuals dominating the smaller, younger ones, but this
is truly based on a physical contest of pushing and
biting each other. No real social dynamic as far as
that kind of structure. So what role does the Tasmanian
devil play in its habitat oh i, meaning they are
(08:41):
very important to their ecosystem. As we mentioned that, they
do prey upon a variety of smaller animals and this
of course helps keep those populations in check and balanced.
But equally important, if not even more so, it is
the consumption of carry on are already deceased animals that
we talked about earlier. Any animal that is part of
nature cleanup crew, consuming dead and decaying things helps prevent
(09:03):
the spread of disease and helps move along the process
of the life cycle. And it's worth noting ebony. With
the recent reintroduction of the species back on mainland Australia,
biologists and ecologists are both expecting to see a rebalancing
of the forest ecology, much of which has been out
of balance in the past due to introduce cats, foxes
and other invasive species. Rick, you mentioned reintroduction. The Tasmanian
(09:26):
devil population is endangered unfortunately, and some scientists predict extinction
could be inevitable. What's the Tasmanian devils like major threat
to survival? Well, unfortunately, for decades, this sort of really
kind of horrible facial cancer has been decimating the Tasmanian
devil population, spreading from animal to animal. When these stocky
(09:49):
raccoon sized marsupials bite each other, and it's worth noting
they don't just randomly bite each other. Part of these
sort of group feedings we were talking about, where the
dominant ones pushed back the less dominant ones. You know,
this is done through biting, just sort of a normal
way that they communicate with each other. And it is
said when this face cancer didn't exist yet, that sure
it would leave scars, but it wouldn't really damage them
(10:09):
too much. Unfortunately, now this transmits this cancer and it
kills up to the devils in Tasmania. They're only a home.
For quite a long time, some researchers saw extinction as
inevitable as you said, eany until recently. In fact, the
cancer was spreading exponentially like a pandemic across the population
of Tasmanian devils. But geneticists have calculated that each infected
(10:31):
devil now transmits the tumor self to just one or
fewer other devils, and that could mean the disease may
disappear over time. There's also an interesting fact that they
have found some populations that were free of this disease,
and they were able to isolate them and send them
away from the island to help prevent them from catching
this disease. So they have created some safe populations and
(10:52):
they're also monitoring this very closely. In coming up, we'll
talk more about how teams at the San Diego Zoo
Wildlife Alliance are working with partners to address other Tasmanian
devil conservation efforts. The first this now it's time for
the San Diego Zoo Minute, an opportunity for you to
(11:13):
learn what's new at the zoo and Safari Park. The
San Diego Zoo has one of the largest colonies of
Gallas tortoises in the world. We have had these giants
in our care since, making them the oldest residents at
the Zoo. That's the year when Charles Townsend of the
New York Zoological Society began his efforts to save the
(11:35):
tortoise from extinction by collecting juvenile tortoises and setting up
colonies for them in North American zoos. Did you know
Tasmanian devils sneeze to help avoid a fight. It's true.
These are known as bluff behaviors or behaviors that are
an attempt to scare an opponent before a real scuffle starts. Oh,
(11:57):
and get this, Tasmanian devil's travel a long distance each
and every night in their pursuit of food, sometimes covering
as much as ten miles. We're continuing our conversation about
the Tasmanian devil and the cancer that threatens to wipe
(12:17):
it out. Joining the conversation now is Corrus Singleton, a
senior veterinarian with San Diego Zoo Wildlife Alliance High Cora
hi Aberty. In scientific terms, what is the devil facial
tumor disease? Devil facial tumor disease is a transmissible or
contagious cancer, and that's very different than the cancers that
(12:39):
we typically think of, which develop within an individual and
stay within that one individual. Devil facial tumor can be
transmitted from one devil to another, just like an infection.
And you've probably never heard of a contagious cancer because
they're very rare, and there are only three that are
known to infect mammals in the entire world. Of those
three Tasmanian devils, of two of them, So how are
(13:02):
Tasmanian devils transmitting this cancer and what's happening to them
once that happens. Facial tumors are spread mostly by biting,
which is a common behavior among Tasmanian devils. As their
meeting and as they're feeding, devils bite each other on
the head in the neck, so the tumors are observed
to grow mostly around the mouth. And these tumors can
(13:24):
grow very large and make it very difficult for the
devils to feed, so many of them die from starvation.
So what a researchers know about the history of this disease.
Is it known how or or where it originated. Yes,
researchers do know how and where the devil facial tumor
disease originated. This disease was first documented in in northeastern
(13:48):
Tasmania actually by a wildlife photographer, and this disease is
spread rapidly south and west across the island and over
the past twenty five years, population numbers have declined by
almost across the island of Tasmanian. The second Tasmanian devil
facial tumor disease was diagnosed in so there are two
(14:09):
different transmissible tumors that devils have, and can this transmissible tumor?
Can it be transferred to other animals? Can another animal
be infected by this disease? No, devil facial tumor can
only affect Tasmanian devils. Other animals, including people, have an
immune system that's able to recognize tumor cells as invaders
(14:33):
and kill those tumor cells. So if we were to
contact a tumor from a Tasmanian devil, our body would
recognize that that was abnormal and would not allow it
to grow. But the reason that this tumor can infect
so many devils is that the devil immune system is
unable to recognize those tumor cells as foreign invaders, so
the devil's body allows the tumors to grow. Is this
(14:55):
tumor a threat to the population at the st Ago Zoo.
That's a great question, Ebony, because it's a really scary
disease and we're lucky that the answer to that is no.
Because facial tumor disease is a cancer of wild devils only,
and as this disease in the wild caused populations to
get smaller, conservationists agree that it would be really important
(15:16):
to protect populations of devils that are free from the disease.
So some wild devils were brought into human care, and
part of that process involved really long observation periods where
they were able to monitor devils for several years to
make sure that they didn't have the facial tumor disease
before they entered these protected populations. So the three Tasmanian
(15:37):
devils who live at San Diego Zoo were born within
these protected populations and are free from this horrible disease.
So what is the case of the Tasmanian devil and
the Tasmanian devil facial tumor disease? What does that say
about the importance of genetic diversity when it comes to conservation.
(15:58):
By studying genetics of Tasmanian devil, researchers hope to better
understand how this disease and the devil are evolving together
so that we can focus our conservation work to help
the devil survive this threat. In speaking of conservation work,
what has the San Diego Zoo Wildlife Alliance done to
address this problem? At the San Diego Zoo Wildlife Alliance,
(16:22):
we focus our conservation efforts in eight hubs around the world,
one of which is the Australian forests, where we work
to conserve the Tasmanian devil as well as koalas and platypus,
and we're partnering with governmental conservation and research groups to
learn more about why the devil has this cancer as
well as how we can help conserve the devil populations
in the wild. And specifically we've partnered with the Save
(16:45):
the Tasmanian Devil Foundation and the Australasian Wildlife Genomics Group
at the University of Sydney to learn more about the
genetics of the devil. During these conversations, we've talked about
human behavior being the driver of extinction for some animals,
but in this case, the Tasmanian devil populations have been
devastated by cancer. Someone my question, if human intervention is
(17:09):
therefore the appropriate response, given that this is a non
human cause problem, what would you say to that, Yes, definitely,
of any that can be a difficult question to tackle,
but really there aren't really any ecosystems around the world
that are untouched by human behaviors via either climate change
or pressures of development, or introduced species such as foxes
(17:31):
and feral cats in Tasmania. So while the facial tumor
disease is not a problem caused by humans, we have
altered the ecosystem and the climate in ways that make
it more difficult for the devil to adapt to this disease,
and human behavior directly contributed to the extinction of another
apex predator on Tasmania, the Tasmanian tiger, leaving the devil
to fill this important ecosystem role. So humans depend on
(17:54):
healthy ecosystems and our behaviors threatened this delicate balance. So
I see it as our responsibility as environmental stewards to
help the devil fight this disease. From a veterinarian's perspective,
does anything about that has Menian devil in particular stand out?
Does it require any sort of special care? Tasmanian devils
(18:14):
are really interesting. First off, they're very charismatic animals and
it's really enjoyable to work with them. But interestingly, from
a biology standpoint, they have a really short lifespan for
a mammal, and in the wild they only live up
to about five years, and in human care that can
live to be seven or eight years of age. And
while devils and zoos do not have devil facial tumor disease,
(18:37):
they do develop cancers, many different types of cancers, at
a higher rate than many other animals. So since we
know this about devils, we've designed a healthcare program specifically
for the Tasmanian devil that helps us to detect and
to treat cancers early. And it's really rewarding to see
the work that we do help an animal live a
longer and healthier life. What would you say is the
(19:00):
best part of your role as a senior veterinarian with
a San Diego Zoo Wildife Alliance, I feel fortunate to
be part of a conservation organization with a one health
approach where I can channel my passion for animals and
my skills in support of conservation. And one health refers
to the interdependence of wildlife health, ecosystem health, and human health,
(19:23):
And for me, each day at work is interesting and
full of variety. In the morning, I might be called
upon to help an injured insect or an ill elephant,
and then in the afternoon I'll work with a global
team of conservation allies to help devils or koalas or
platypus in Australia, and I know that what I do
here at San Diego's a Wildlife Alliance helps the animals
(19:43):
living in our care as well as helps the animals
in their habitats worldwide. What would you say to a
kid who wanted to one day be a veterinarian? Any advice?
M Yeah, lots of advice. So why do most kids
say that they want to be a veterinarian Because they
love animals. They love animals and they want to help animals.
(20:04):
That's right, and veterinarians do help animals in many different ways,
sometimes by doing exams and giving treatments and performing surgery,
but also sometimes by studying animals in their habitats or
by doing health research in a lab. And at its core,
being a veterinarian is about science and service service to
both animals and people. So hard skills like science and
(20:25):
math are just as important as soft skills like communication
and teamwork. And while I think that being a clinical
veterinarian is fantastic, kids should know that there are many
different ways that they can help animals and many different
ways that they can help and work with animals. My
best advice is to be curious and explore all the
different ways that they could work with animals, find out
(20:46):
where their passion for animals overlaps with the things they're
really good at and the things that they really like
to do. So maybe you're passionate about wildlife and you
like to work with computers, Or maybe you're passionate about
wildlife and you like to take pictures and make video
those or write stories, or maybe you like to design things.
Are you like to organize and lead teams? All of
(21:06):
these people work at San Diego's a Wildlife Alliance helping animals,
And for me, my passion is wildlife and conservation. I'm
good at biology, learning how systems work and solving problems,
and I like to work directly with individual animals and
populations of animals. So being a wildlife veterinarian is perfect
for me. And I think if kids can explore and
(21:28):
be curious, they can find those places where their passions,
their skills, and their interests overlap in support of animals.
Great advice. We've been talking to Cora Singleton, a senior
veterinarian with the San Diego Zoo Wildlife Alliance. Thanks Cora,
thank you. Thanks for listening. We hope you enjoyed learning
(21:49):
about the largest marsupio carnivore in the world, the Tasmanian Devil,
and being sure to subscribe and tune into next week's episode,
in which will be jumping into the story of one
of the more recognizable marsupials from Australia. I'm Ebony Money
and I'm Rick Schwartz. Thanks for listening. If you would
(22:12):
like to find out more about San Diego Zoo Wild
Lack Alliance, please visit sdz w a dot org. Amazing
Wildlife is a production of I Heart Radio. Our producer
is Nikkia Swinton and our executive producer is Marcia to Peanut.
Our audio engineer and editor is Sierra Spreen. For more
shows from My Heart Radio, check out the I Heart
Radio app, Apple podcast, or wherever you listen to your
(22:34):
favorite shows.
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