04x05 - Koalas and Wombats: The Untold Story

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Martin and I are here
in australia...

About to head off
into the bush

To find two of australia's
most distinctive animals--

The koala

And the wombat.

As soon as we get
our creature jeep fixed,

We'll be ready to roll.

[Martin]
heads up!

Hey, what about
the jeep?

I thought we'd try

A more reliable form
of transportation.

We're going to explore
the world of koalas and wombats

And clear up a lot
of confusion about them.

For instance,
a koala isn't a bear...

And a wombat isn't a bat.

But something they both are
is related to one another.

Let's hit
the dusty trail

On this episode of--

Hey, I think
we have to ride off
before the opener.

Hyah! Whoo!

Iarriba!
Iandale! Iandale!

Chris? Martin?

All kinds of creatures,
but no chris or martin.

Last time they checked in,

They were taking off
from tasmania,

But that doesn't
tell me anything.

They could be anywhere.

[Martin]
hey, al!

Where are you guys?

We're in australia,
checking out two creatures

Unique to this part
of the world--the koala...

And the wombat.
They're both marsupials,

But koalas and wombats
are two totally
different creatures.

One lives underground
in burrows,

And the other
hangs out in trees...

Which makes it
hard to believe

That they're
virtually brothers.

Brothers?
Are you sure?

Yeah. Let's
check them out.

Hyah!

Brothers? Chris and martin
may be related,

But koalas, wombats?

That's amazing.

The only problem is, they don't
look anything alike to me.

How can they be related?

[Ttark]
divergent
evolution, al.

Divergent evolution?
What's divergent evolution?

It's easy.

[Allison]
wait a minute.

Maybe there issomething there,
but what is it?

Say you got one creature
who lives on a grassy plain--

A guy who's perfectly adapted
to his plain old grassy habitat.

Then suddenly
his surroundings change.

Trees with fruit sprout up.
Lakes with fish appear.

We're talking new food
and new opportunities.

It's time to adapt,

And thatmeans
a family split.

Ee-yah!

Pretty handsome guy, huh?

So he goes his way,
and I go mine.

A few million years pass,
and next time you meet...

Kazowee!

Have you changed--

And I mean more than
putting on a little weight!

That's divergent
evolution.

I get it. Koalas and wombats
aren't exactly brothers

Like chris and martin,

But they have a common ancestor,
which means they're related.

Guys?

Hey, where did you come from?

Who are you?

Wait a minute. I bet I know
exactly who you are.

You're a dingo--
the wild dog of australia.

These dogs are australia's
number-one land predator.

I know they might look like dogs
you'd see in a pet store,

But you can't judge a book
by its cover.

They're wild dogs,

And humans have been trying
to control them for years.

[Dingoes barking]

Did you know that
in the 1960s

They completed
australia's dingo fence,

Which stretched as far across
as 3,700 miles?

That's almost three states.

It was twice as long
as the great wall of china

And can be seen
from outer space.

That's one big dog fence.

They built it
to protect their sheep,

But it didn't control them.

So, dingoes prey on all sorts
of australian creatures

And even manage to spook
creatures larger than them,

Such as horses.

[Horse whinnies]

Horses? Uh-oh.

The dingoes of australia
are one of the animals

That can really
spook a horse.

When horses
are spooked,

All you can do
is hang on.

See you, martin!

See you, chris!

[Allison laughs]

Ttark, remember the time
they ran out of air

In their hot air balloon
or fell out of the plane?

Add this one to the list.

Something tells me we're not
going to see koalas or wombats.

Chris, look out!

Ooh!

When riding a horse,

It's important to always
keep your eye out

For overhanging branches.

Otherwise you might end up
in the tree with...

A koala!

It's great
hanging with the koalas.

I wonder
what happened to martin.

[Whinnying]

Martin, look out!

When you're riding a horse,

It's always important
to keep your eye on the terrain

Because you'll be thrown
if your horse almost steps

In a wombat burrow.

Wombats!

What are they
going to do?

They're separated,
they've got no transportation

And no food.

If chris
is really hungry,

All he has to do is
ask his tree mate

If he can stay
for dinner.

Humans can't eat
eucalyptus like the koala

Because some eucalyptus leaves
are full of toxins.

But a koala has
a special digestive system,

And eucalyptus
is its main meal.

Koalas even smell
like eucalyptus.

A lot of people
come to australia

Just to watch koalas.

They're one of the stars
of the creature world

But also one of the most
misunderstood.

O.k., Myth number one--
koalas are lazy.

Do they look lazy?

Check it out.

These guys are busy,

But they do try
to conserve energy.

They have to.

It takes a lot of energy
to digest eucalyptus leaves.

You know what's weird?

Just how many creatures can eat
poisonous stuff without dying.

There are a million more
than I ever imagined.

Just check them out.

In africa, colobus monkeys
can eat poisonous plants, too.

And talk about
an iron stomach--

The turkey vulture
eats rotten meat.

It's loaded
with toxic bacteria.

Back in australia,

Tasmanian devils
also eat rotten meat.

And don't forget
the african hyena,

Not the pickiest of eaters.

And howler monkeys
eat leaves

That other creatures
couldn't handle.

Wow! Then there's animals
who carry poisons.

You can look,

But don't touch
these poison arrow frogs

From costa rica

Because they have poison
in their skin.

Cane toads
are australian frogs

That are also
seriously poisonous.

O.k. So here's
what I figure.

Koalas are related
to wombats,

And koalas eat
eucalyptus leaves, right?

So wombats must also
eat eucalyptus leaves.

[Martin]
not exactly.

What you eat
is about where you live

And how you're built.

What does that say
about the wombat?

A wombat is the ultimate
ground marsupial.

She's built
low to the ground,

She lives underground,

And she eats
a lot of grass,

Clipping it right down
to the ground.

Get your own grass,
over there.

Watch these wombats.

They eat while they walk.

A bunch of wombats
can clear a field

Better than any lawn mower.

And here's something
wombats really dig...

Moss!

For a wombat,
this is better

Than a burger
and fries.

Hey, cats,
check that out!

Hey, daddy-o...

How about sharing some
of that moss with us?

Yeah, sure.

Cool.

Look at that baby wombat
following his mom.

By sticking close
to his mom,

He learns what to eat--

Hey, I didn't know wombats
ate with their hands--

And he learns how
to dig a burrow.

[Chris]
imagine if you were a baby koala



You'd hang on tight, too.

A good grip
keeps him from falling,

And it also keeps him
close to mom,

So he can learn the ropes.

He's hitching
a piggyback ride from mom,

But he's also learning how
to get around, koala style.

And now he's trying it himself.

Mom's taught him the basics,
like how to get around

And how to find
good eucalyptus.

Now he's got to master them.

You might be thinking
koalas spend all their time

Just eating leaves, right?

Truth is, not exactly.

[Chris]
koalas don't spend
all day eating.

They eat whenever
they feel like it.

And even all that eating
has nothing to do

With the belching sound
they make.

[Belching]

It would be great
to be a koala.

You could hang out
in the trees all day,

And you don't
get hassled if you belch.

[Belching]

But a koala belch
isn't a burp.

It's a call,

And this guy knows
exactly what it means.

He's looking
for a new tree,

But the other koalas
are saying...

[Belching]

"This tree is mine.

Get lost!"

Did you know
a koala call

Can be heard
for half a mile?

So one of the reasons
koalas bellow

Is to claim their territory.

Actually,
when you think about it,

Why do so many
different creatures

Make different noises?

[Ttark]
why do howler
monkeys howl?

Why do rails sing?

Communication.
Protecting turf.

Warning of danger.

[Honk honk]

Danger!

Danger.

What exactly
is dangerous to a koala--

Or should I say who?

Our old friend the dingo.

How do creatures
like koalas and wombats

Get away
from somebody like him?

When danger's around,

Koalas just sit tight
high up in the trees.

[Dingoes howling]

The dingoes are
on the prowl,

But the koala's not scared.

It doesn't matter
how many dingoes are out there.

He's safe.

He's safe because he knows
that dingoes can't climb.

Hanging around in a tree
is great for the koala,

But how does
a wombat protect itself?

The reason for the blindfold
and the earplugs

Is that I'm trying
to get a better sense

Of what it's like
for the wombat.

A wombat doesn't have

A very good sense
of hearing or eyesight.

They have to depend
mainly on smell.

But even so,

Wombats are great at avoiding
predators like the dingoes.

If you're a wombat,

Of course you don't
climb trees,

But you have to be fast
on the ground.

Wombats are great sprinters.

When there's danger around,
a wombat bolts to its hole.

Dingo alert!

Head for the burrows, dude!

Whew!

Coast is clear.

Time to exit the burrow
and get back to grazing.

You know, the wombat's
not the only burrow digger.

There are lots of examples
from around the world.

How about the meerkat?

In the deserts of africa
where meerkats live,

It gets hot,

So they dig burrows
that get really cool.

It's like underground
air conditioning,

And that's how
the meerkats chill out.

And how about
the north american red fox?

This mother fox
hides her pups in a burrow.

That way, they're safe
when she goes hunting.

And check out this crab.

He has to be careful

When he leaves the safety
of his burrow,

Or a bird may swoop him up.

And what about

Australia's
blue fairy penguin?

Would you believe
they dig burrows?

They'll be safe there
for the night.

But burrows
aren't for everybody.

A cave or a tree
can be a safe place, too.

The best time for a dingo
to catch a koala

Is when it comes down
to the ground,

Which makes crossing
from one tree to the next

More than a walk
in the park for a koala.

It's dangerous down here.

Careful. Careful.

Go, buddy, go!

The crossing
is dangerous enough,

But climbing a tree
would be a lot easier

If I were a koala.

That's because
it's all in the hands.

Look at his claws.

They dig right into the bark.

He's got a sure grip
on that tree.

Another advantage
is the shape of his hands.

See how they're split
in the middle?

That's like
having two thumbs,

And that's great
for climbing.

When a pack of dingoes
is around,

Having a good set
of claws comes in really...

Well, handy.

This would be a lot easier

If I had the front claws
of a wombat.

Now, a wombat burrow
isn't just a hole.

It's a series of holes

Connected
by underground tunnels

Which run from one hole

To another.

You could think
of wombat burrows

As marsupial
superhighways.

That's all right.

[Ttark]
it's more than all right.

What do you mean?

Ricocheting rumpshields!

It's also part
of their defense strategy.

If something's
after the old wombat,

He just sticks himself
into whatever hole he's got,

And bang!
Use that old rumpshield

To get rid of whoever's
on your tail.

Hey, I've seen it
a thousand times.

Let me get this straight.
The rumpshield thing--

That's something
a wombat can do

That a koala
can't do, right?

So that's something that
happened after they diverged,

Which proves there's more
to why creatures diverge

Than finding food.

Who said it was
only about food?

You did.

Well, a creature has to adapt
for all sorts of reasons.

That's what I'm saying.

Some creatures might diverge
as they adapt to predators.

He never listens.

Different creatures
find different ways

To protect themselves
from enemies.

Koalas found protection
from dingoes

Up here in the trees.

Wombats found protection
with a well-dug hole

And the solid rumpshield.

Each creature specializes
and carves out its own turf.

O.k. So when
two related creatures

Specialize in different ways,
they diverge.

They become different
to live different lifestyles.

That's what divergent
evolution is all about.

And some more examples
from around the world?

How about
the african elephant?

He's built for
getting food on land...

And he's big--

Big enough
to knock down trees.

He's got a long trunk to pull
leaves and bark off branches,

But get this--

He's actually related
to the manatee.

Talk about going
in different directions!

Manatees are built for
getting food in the water.

They have flippers,
they're streamlined,

And they can hold their breath
for 20 minutes.

Strange things happen
in the creature world,

But elephants
and manatees related?

Then there's porcupines...

And beavers.

They're both rodents,
and they both eat tree bark,

But one lives in the water
and the other on land,

So they have different ways
of protecting themselves.

Don't go near this guy,
or you may get a sharp surprise.

A porcupine protects
himself with quills.

The beaver,
on the other hand,

Protects herself by
hanging out in the water.

She builds a lodge
to hide out in,

And she's a good swimmer.

So in the water,
she's hard to catch.

Then there's wolves,

Big dogs because
they hunt big prey,

Unlike their relatives...

[Howling]

The fox, smaller hunters
that hunt small prey

Like moles and mice.

So that's divergent evolution--

When two related
creatures evolved

Into two very different
creatures.

So there must be
something opposite--

Two totally
different creatures,

Unrelated,
evolve into something similar.

Didn't I say
that already?

No. I just figured it out.

It's simple, al.

Take two creatures
who never even
met each other.

Over a few centuries,

They wind up
eating the same food,

Living in the same type
of places.

Then before you know it,

Two creatures
so much alike...

They're almost the same.

[Allison]
you're talking about

Convergent evolution,
like african hyenas

And tasmanian devils.

They look similar,

But hyenas are related
to mongooses

And genets...

While tazzy devils
are cousins to kangaroos

And koalas.

Tazzy devils and hyenas
aren't related,

But check out
how similar they are.

How about sea creatures?

Here's a shark,
who isa fish...

And a spotted dolphin,
who's nota fish,

But look how similar
they look.

But the shark
is closely related

To fish like stingrays...

And the dolphin evolved
from cowlike mammals.

Now here's a weird one--
the costa rican toucan.

He eats fruit high up
in the trees

And is similar to flying foxes,

A family of australian bats

Who eat the same food
as toucans.

But let's get back
to divergent evolution,

Because
the burrow-digging wombat

And the tree-hugging koala

Are a perfect example
of divergent evolution.

But you know what?

Both these guys
are threatened--

Threatened by
loss of habitat.

[Martin]
losing your living space

Is devastating
to any creature.

[Chris]
man-made forest fires

Claim the lives
of many koalas, wombats,

And other animals
every year.

[Martin]
but it's not just forest fires.

A huge thr*at
is the destruction of habitat

To make way
for cities and farms.

And the biggest thr*at
to a wombat

Is cattle and sheep
eating all of their grass.

Hey!

You look familiar.

[Chris]
hey, martin!

Where have you been?

I've been looking
all over for you.

Liars! They looked
pretty happy diverged.

Looking at the koala
and the wombat,

We can see what happens

When creatures go
their separate ways.

And looking
at the tasmanian devil

And the hyena,

You can see what happens
when two different creatures

Start to resemble
each other.

Two creatures that
resemble one another?

Guys, that's not
news to me.

Come on.

Come on.

Come on, martin.
Let's split!

Like koalas and wombats,

Some creatures
become different

As they adapt
to new opportunities.

That's called divergence.

Other creatures
become similar

As they adapt
to similar opportunities.

That's called convergence.

And still other creatures...

Never get together at all?

That doesn't make
any sense, does it?

Where are
all the wombats?

Hmm...

I don't see any.

Where are the wombats?

Hey, chris,
have you seen any wombats?