All language subtitles for Seven.Worlds.One_.Planet.S01E04.2160p.BluRay.Remux_.eng_

Australia -

an island continent

cast adrift
during the time of the dinosaurs.

Isolated from the rest of life on land
for millions of years,

the animals cast away here
are today like none elsewhere.

This is a land of survivors.

The jungles of northern Australia -
the oldest on our planet.

Unchanged for 180 million years.

The animals and plants here are armed...

...built to live alongside dinosaurs.

Now there is just one giant left.

With claws longer than a velociraptor
and nearly two metres tall...

...the cassowary rules this forest.

But the key to its success
is not its stature...

...it's the male's abilities as a parent.

This one's chicks are six weeks old,

and he will raise them by himself.

Every morsel of food is valuable

if his chicks are to grow up
tall and strong.

But in this forest,

most of the fruit
is too big for the chicks.

It must be cut up for them.

There is food to be gathered
throughout their territory...

...but it's not easy to find.

He shows them how to cross water.

But when your legs
are only ten centimetres long,

a stream like this is very deep.

One takes the plunge...

...but for the other,
this is too daunting.

He turns and goes back the way he came.

Out of sight and without
his father's protection,

he's vulnerable.

Only half of cassowary chicks
make it to adulthood...

...and for very good reason.

Australia's prehistoric forests
are still full of predators.

Many manage to survive here

by eating almost anything
that's smaller than they are.

He needs to find his father...

...and quickly.

The male hears his cries and answers...

...using a special call that carries well
through the thick forest.

And then, a glimpse
of some reassuring, bright colours.

Their bonds are stronger than their fears.

The male will guide and protect his chicks
for another eight months

before he mates again.

Australia was once part of
the vast supercontinent of Gondwanaland...

...covered in forest and full of life.

Dinosaurs dominated.

Mammals had only just appeared.

Then, Australia began to break away.

Cast adrift on this new island were
reptiles, birds and early mammals

that then evolved in isolation
from the rest of the world.

None could now leave this giant island,

and very few could get here...

...unless they could fly.

A little red flying fox.

Their ancestors flew here,

travelling along the chain
of volcanic islands

that links Asia to Australia.

But their huge wings, which stretch
from their fingers to their toes,

make it difficult for them
to walk or take off from the ground,

so, when they want to rest,
they hang upside down in trees.

But the bats have to drink every day.

And they do so on the wing.

They swoop just low enough
to wet their bellies

and then, back in their roosts,
they will suck out the water.

Each evening, 10,000 of them come here.

Not all of them return.

Every two metres of river, there is...

...a crocodile.

They were here long before the bats...

...survivors from
Australia's prehistoric past.

These dramas have been taking place
for millions of years...

...aerial agility...

...versus patience...

...and deadly speed.

Australia's forests are hostile places
in which to make your home.

As you move inland,
the forest thins, the air cools

and the land, as it gets higher,
changes dramatically.

The Great Dividing Range,
2,000 metres above the jungle.

To survive here, you must be able
to tolerate really harsh conditions.

Kangaroos, like nearly all
of the continent's native mammals,

are marsupials...

...mammals that rear their young
usually in a pouch on the mother's belly.

And the young up here
certainly need such shelter.

No kangaroos can survive for long,
higher than this.

But there is an even tougher marsupial
up here.

A wombat.

She usually shelters underground
in a burrow,

but now that is under a metre of snow,

together with all the grass
on which she lives.

She weighs as much a big dog

and has the legs of a small one -

not ideal for deep snow.

Fragments of bark hardly count
even as a snack...

...and she's hungry.

She needs grass.

But it's over a mile away,
across a frozen river.

Wombats might not be fast,

but then they don't need to be up here.

They can survive on next to nothing.

A few mouthfuls will be enough food
for over a week.

And there's not much competition for it
in this small corner of the continent.

Snowy peaks are hardly typical
of Australia,

but the Great Dividing Range is a remnant

of what were once some of
the longest mountain chains on Earth.

They connected Australia and Antarctica.

But then these sister continents
broke apart.

Antarctica, drifting southwards,
became locked in ice.

Australia drifted northwards
towards the equator

and became hotter and drier.

Woodlands developed,

and in places where rainfall was low -

open grasslands.

On these grassy plains,

animals had the space to thrive.

These are also eastern grey kangaroos,

and this is their true home.

Here, they are well fed and powerful.

Adults can stand over two metres tall
and travel as fast as a racehorse.

And on these open plains,
you need speed...

...because where there are large herds,
there will be predators.

Dingoes - descendants of wolves
that were brought here

over 4,000 years ago
by human visitors from Asia.

This pack is led by a white female...

...and they are hunting.

Creating panic tests the herd.

Mothers with young in their pouches
might be slower...

...but they can still outrun a dingo.

Maybe an ambush will work.

But even young, newly independent
kangaroos seem uncatchable.

Across these open, flat plains,

the dingoes are just not fast enough.

But what makes the white female
their leader is her stamina

and, particularly, her intelligence.

She has run 18 miles today,
but she still doesn't give up.

A different group of kangaroos,
this time on uneven ground.

It's what she's been looking for.

Driving them uphill,
she's struggling to keep up with them.

And as they hurtle down the other side,
the kangaroos pick up speed.

They will easily outpace her,
if they stay in control.

The white dingo has more than one reason
to be so relentless.

She's a mother.

This is a rare sight.

Dingo pups are hardly ever seen.

With so much effort for just one meal,

the open plains are tough places
on which to raise young.

These are gumtrees.

They have leaves
that are poisonous to most animals.

But not the koala.

They eat almost nothing else.

There are echidnas in these forests, too -

mammals that don't even have pouches
but lay eggs like reptiles.

And there is an assassin here
that has only recently been discovered.

A Jotus jumping spider.

She's only five millimetres long,

but nonetheless
she's a stealthy and ferocious hunter.

She searches for prey
among the grass stems.

She's single-minded
and focused on hunting.

But today might be different.

This is something new,

something fast...

...and a little trickier.

But what is it?

Is it food?

It's a male Jotus, looking for a mate.

He needs to catch her attention,

but female Jotus only mate once.

If she's mated before, she might kill him.

He will need to seduce her with care.

Waving his arms
makes his intentions clear.

He's a friend, not food.

No sign of an attack... yet.

But she doesn't seem
particularly impressed.

Time to try his best move...

...the double paddle.

That surely will do the trick.

One final wave...

...and he's tamed her.

She stays still for just long enough.

And then he retreats quickly,
before she has second thoughts.

If you travel still further
towards the centre of Australia,

the landscape changes yet again.

Trees and grass disappear.

The continent, throughout prehistory,
continued to drift north

and as it entered the tropics,
it got hotter and hotter.

Over thousands of years,
the grasslands of the centre dried

and lakes and rivers turned dust.

The rocks have been reduced to sand
by the hot, blasting winds.

Now Australia's centre is one vast desert.

Its immensity is almost impossible
to comprehend.

This train running north
is a half a mile long.

Travelling at nearly 50 miles an hour,

it takes almost three days
to get from one side to another.

Australia today is the driest
inhabited continent on Earth.

Rain hardly ever falls in 70% of it.

From space, the continent is seen
to be stained red by iron oxide -

rust from its disintegrating rocks.

In the surface are lines carved by winds
over millennia.

The very bones of the continent
are now stripped bare...

...the foundations of what once
were mountains.

At its heart,
stands the great rock mountain of Uluru...

...sacred to the first people
to arrive here 60,000 years ago.

There is almost no soil here,
few plants, few animals

and almost no permanent water.

It's a place
where only the toughest can survive.

This is the land of reptiles.

Australia has more species of them
than any other continent.

The perentie, two metres long,

is the biggest here, and he's thirsty.

It only rains here once or twice a year.

And when there isn't any rain,

perenties get their water
from eating lizards.

There are several kinds to choose from...

...bearded dragons...

...blue-tongued skinks...

...and thorny devils.

All are on the menu.

The thorny devil also gets its water
from its food.

It's only the size of a mouse,

but, even so, it must eat hundreds of ants
every day to get what it needs.

Most storm clouds pass by
without releasing any water.

But just sometimes,

there's a brief shower.

Everyone makes the most
of the opportunity.

It's so hot the droplets will disappear
within minutes.

But the thorny devil has a trick.

He's found a tiny puddle,

only a few millimetres deep,

and he dips his toe into it.

H is skin is like blotting paper.

It collects moisture by capillary action,

sucking it up along the inter-connecting
grooves until he glistens all over.

When the water reaches his mouth,

he can collect it...

...while still keeping his head up,
on the lookout for danger.

The perentie is 200 times the size
of a thorny devil...

tiny puddles and droplets
are of no use to him.

What he needs is a juicy lizard.

That was a bearded dragon
that wasn't quite quick enough.

Even the perentie sometimes
gets a chance to quench his thirst.

There is one species that has truly
conquered the Australian desert.

They don't wait for water to come to them.

They sometimes travel over 300 miles
in a single day to find it.

Australia's hardiest animal...

...the wild budgerigar...

...the most accomplished
of all desert nomads.

These have been travelling together
for weeks...

...and that has evidently caused
a few domestic arguments.

This is truly an immense community.

There are over 10,000 budgies
in this flock.

Every one of them is thirsty.

But although they've found
this billabong...

...they must be wary.

A hawk - and one that eats budgies.

As long as it remains on the ground,
the budgies will risk taking a drink.

Once it takes to the air, however,
the budgies are in danger.

And it's not the only bird of prey here.

The budgies have a simple
but very effective defence -

they all take to the wing at once.

An aerial hunter needs to lock on
to a single target for a few seconds

if it is to catch it,

but in this swirl, that's very hard to do.

Flying in a flock keeps the budgies safe,
but they're still desperate to drink.

As soon as a particularly brave one
takes the plunge, they all do.

But once on the water,
they are easier to target.

They must drink quickly
and stick together.

The last ones to leave
will be the ones in most danger.

Only one has been taken
from a flock of 10,000.

In a few days,
they will leave the area,

on their never-ending search

for the next brief opportunity
to feed and drink.

As the continent continued to drift north,

it eventually entered warm, tropical seas.

And here,
in the crystal-clear, sunlit water,

just a metre or two beneath the surface,

life proliferated.

Coral grows into reefs
in these shallow seas.

This is N ingaloo...

...today one of the richest
anywhere in the world.

Thousands of species of fish
and all kinds of other organisms

thrive in these coral cities.

And they have attracted
the most ancient of living predators.

Sharks.

They were around 200 million years
before the dinosaurs.

They're fast and agile,

well able to pick off
the small reef fish.

But they come here for bigger rewards.

These are fish from the open ocean,

and every so often, for some reason,
they swim over the reef.

The small fish swirl like the budgies,
and for the same reason.

It makes it harder for a hunter
to single out a particular target.

But, in fact, the sharks aren't trying
to catch them individually.

They're driving them closer to the shore,
penning them against the beach.

Slowly, the sharks drive
each new wave of fish into shallow water

and the bait ball grows.

More sharks arrive,
some from many miles away.

And still the sharks don't attack.

They're waiting...

...for the right moment.

Millions of fish are now trapped
in these shallow waters.

It only happens like this
once in every decade or so.

The time has come to strike.

For the sharks, this is a bonanza.

They work together.

Each shark now fills its stomach.

These shallow seas
are exceptionally rich in sharks.

There are more species here
than anywhere else on Earth.

Australia is not only fringed
by rich reefs

but girdled with islands -
some big, some small.

Off the south coast
lies by far the biggest of them.

Tasmania.

And that has its own special marsupial...

...one that seldom appears
until after dark.

The Tasmanian devil.

Many predators inhabit
a territory packed with prey.

But here,
there's nothing like that for them.

Each may travel for miles
night after night,

prepared to eat anything it can find,
dead or alive.

The shoreline is a good place to search.

There might be some small creatures
to catch here,

or maybe something
that the tide has brought in.

The carcass of a wallaby
has been washed ashore.

Tasmanian devils can eat
40% of their body weight in one session,

and they have hugely powerful jaws.

They tackle everything - even bones.

Back at the den,

there are other hungry mouths.

Her two youngsters are six months old.

They still rely on their mother's milk,
but they're feeling peckish!

There must be something solid
they could find for themselves,

while they're waiting for a drink.

Is this food?

That possum smells tasty...

...but it's a little high up.

This looks more promising.

At last, a giant stick!

Not bad for a first go.

Their mother will protect and feed
these youngsters for another three months.

Their survival is important to her,
but also for us...

...because these are one
of the last devil families in the world.

Tasmanian devils are now endangered...

...found in only a few places,

such as this remote islet
off the coast of Tasmania.

But they once lived
across the whole of Australia.

Evidence that this was so

can be seen nearly 2,500 miles away
from the devils' family den,

on Australia's northern coast.

This great stretch of boulders

is covered by the largest concentration of
prehistoric images anywhere in the world.

Over one million pictures of wildlife...

...and among them...

...a Tasmanian devil.

It was engraved on stone
60,000 years ago

by some of the first human beings
to reach the continent.

Then, just 200 years ago,

European settlers arrived
with guns and dogs, foxes and cats.

Together, they decimated
Australia's unique wildlife.

This was one of the continent's
biggest animal predators -

a marsupial wolf or thylacine.

The last-known remaining one
was filmed in 1936

in a zoo just before it died...

...and so brought the final extinction
of its species.

These rocks are now its memorial.

And they may become that
for the Tasmanian devil, as well.

Mammals in Australia are disappearing
faster than anywhere else on Earth.

They succeeded in adapting to life
as their home changed around them.

But now they face
their greatest challenge -

the change to their world
brought by humanity.

Which of its unique species
will survive the coming decades

now depends on us.

Next time -
a world transformed by mankind...

...where extraordinary animals
are found...

...in surprising places.

Europe.