All language subtitles for BBC.Natures.Microworlds.12of13.Australias.Red.Centre.720p.HDTV.x264.AAC.MVGroup.org Eng

Our planet is the greatest
living puzzle in the universe.

A collection of worlds
within worlds.

Each one a self-contained
ecosystem bursting with life.

But how do they work?

The intricate web of relationships

and the influence of natural forces,

makes each microworld
complex and unique.

So to discover their secrets, we
need to explore them one by one,

untangle their interlocking pieces

and ultimately reveal
the vital piece -

the key to life itself -

hidden deep within each of
nature's microworlds.

In the heart of the Australian
continent lies a vast red desert.

Isolated for millions of years,

its timeworn landscapes are
instantly recognisable.

Most of its animals and plants do
not exist anywhere else on Earth.

It is a world of extraordinary
beauty and diversity,

but also a land of surprises.

70 per cent of Australia
is classed as desert -

an area larger than Europe.

At the very heart of this
vast arid region

is an area known as the Red Centre.

Millions of years of baking sunshine

have oxidized iron deposits
in the soil, turning them red.

It is - in effect - rust.

The Red Centre's most iconic
landmark is Uluru,

previously known as Ayers Rock,

but the vast majority
of this microworld

consists of spinifex
grass and sand dunes.

It is a harsh, hot, dry place,
parched by the sun,

scorched by fire and prone to
unpredictable flooding.

The first explorers to travel here
thought it a godforsaken place

where no life could possibly exist.

How wrong they were.

22 species of mammal,

60 species of lizard,

200 species of bird

and countless insects inhabit the
arid centre of this continent.

For somewhere so remote and dry,
it teems with life.

A whole host of marsupial mammals
live here,

from the tiny planigale

to Australia's largest herbivore -
the red kangaroo.

But it is the reptiles that
dominate.

Thorny devils,
goannas, dragons, skinks and geckos

all thrive in the Red Centre as does
the world's most venomous snake -

the inland taipan.

Even more extraordinary is that here

in one of the world's
driest deserts,

water-loving amphibians
live and breed.

The question is why?

How come so many unique animals
thrive in a place

where the odds are so clearly
stacked against them?

To answer that,
we must travel back in time.

Before it became an island,

Australia was part of a
supercontinent called Gondwana.

This enormous landmass consisted of
Africa, South America,

India and Antarctica.

When Gondwana broke up,

Australia drifted away and its
plants and animals

were left to evolve in complete
isolation for 50 million years.

The results speak for themselves.

Take a look at the red kangaroo.
There is nothing like it on Earth.

They're the largest of
all marsupials.

Males can stand up to two metres
tall and weigh almost 90 kilos.

It's an unusual mode of transport,

but red kangaroos can hop at speeds
of over 56 kilometres an hour.

With a single bounce, they can cover
eight metres of ground

and leap over two metres
into the air.

Red kangaroos are mostly
active early and late in the day.

Temperatures here regularly exceed
40 degrees,

so they conserve energy
by resting in the shade.

They also have a unique trick of
licking their forelegs

allowing their blood to cool through
a special network of capillaries.

As the day comes to an end, they
move out into the open again.

Play-fighting is common among males.

They are constantly jostling
for dominance.

To show who's boss, they push
themselves up on their strong tail

to make themselves look
as tall as possible.

However, if that doesn't intimidate
an opponent,

then a fight breaks out.

Their powerful back legs and claws
could easily inflict serious injury,

but most of these bouts are
friendly.

As well as kangaroos, there are many
other unique animals

living in the microworld
of the Red Centre.

Not only are they unique,
they're amazingly diverse.

Why is this?

To understand this, we have to look
at a series of events

that have had a profound effect
on Australia,

making it what it is today.

We can see evidence for one of these
300 kilometres from Uluru itself.

These are the MacDonnell Ranges,

the remains of mighty mountains
eroded to little more than hills.

On the rare occasions
that rain falls,

it is soaked into these porous rocks
and at their base,

permanent springs form,

creating oases in the middle
of this vast desert.

Here in an isolated gorge, it's wet
enough for palm trees to flourish -

red cabbage palms.

The only other populations
of these trees

are found 1,000 kilometres away

in a rainforest on another part
of the continent.

But their seeds cannot disperse over
large distances.

So how could these palms possibly
have colonized areas

so far from each other?

The clue is in their age.

Cabbage palms have been in Australia
for tens of millions of years.

The isolated pockets found today
were once all part of the same
population.

Australia was at one time completely
covered in lush forest.

But as the continent
travelled north,

it moved into a zone south of the
equator dominated by high pressure,

and the once plentiful rains
stopped,

creating the desert we see today.

The ancestors of all the animals
now living in the Red Centre

came from this ancient rainforest.

That is why there is such a big
variety here.

But why didn't they just die out
as the land dried?

How do they all survive here?

The water holes around the central
ranges are a haven for life.

For flocks of birds,
desert water is a lifesaver.

Corellas, galahs, budgerigars and
zebra finches flock here.

But it is not without risk.

Thirsty zebra finches find safety in
numbers, but they have to be wary.

To increase their chances of
catching a meal,

these brown falcons work in pairs to
cause panic and confusion.

Even so, a meal is hard won...

..and in this case lost
to a white-necked heron.

Trees lining the banks attract

large numbers of red-tailed
black cockatoos.

Travelling in flocks,
these sociable birds are
intelligent and long-lived.

50 years is not an unusual lifespan.

The characteristic hollows
found in red gum trees
make excellent nesting sites.

Every year, a pair of black
cockatoos rears just a single chick.

Both parents are kept very busy.

It will be three months before it
can leave the nest.

The ancestors of Australia's birds
lived in the large lush forest

that covered the continent more than
20 million years ago.

As the continent dried, they have
evolved into different forms

specialising in feeding on different
fruit and seeds.

Permanent desert springs
are a welcome oasis

but they only make up
a tiny area of the Red Centre.

Elsewhere in our microworld,
things are very different.

The Red Centre is dominated
by high pressure.

Skies are cloudless and
water is a very precious commodity.

However, it does rain here.

But there is no way of predicting
when that might happen.

Australia is under the influence of
El Nino from the Pacific.

And El Nino is responsible for
dramatic and random changes in
pressure over the continent.

The results can be spectacular.

Rain - and a lot of it.

So unlike most deserts with a
predictable wet season,

the wet periods in the Red Centre
can be years apart and completely
unpredictable.

Even in the face of such
uncertainty,

animals have evolved to cope.

Some you would never even know are
there until it rains.

Spadefoot toads.

The ancestors of these toads were
tied firmly to water...

..but over millions of years
of drying, they have adapted

to live in the most hostile
of places.

They have only a short time
to find food and mate

before the relentless sun bakes
the desert soil hard again.

Kangaroos, too,
take advantage of the good times.

During intense periods of drought,
kangaroos do not breed at all.

All their energy is put
into survival.

But when the rain falls and there is
plentiful greenery to feed on,

their minds turn to breeding.

During the good times, a female
kangaroo might be attending

to three young at one time.

A joey out of the pouch,

a young joey in the pouch,
and one in her womb.

Because events can turn so
quickly,

a female kangaroo can keep an embryo
in suspended animation in her womb

until a good food source
comes along.

When Europeans arrived and started
pumping well water to the surface,

the kangaroo population exploded
out of control.

The number of kangaroos is currently
estimated to be approaching
30 million -

larger than Australia's
human population.

Despite the lack of desert water

there's a surprising amount of
vegetation in the Red Centre.

Like the animals, the plants
found here are very unique.

A quarter of Australia
is covered in spinifex grass.

European settlers thought it
represented a fantastic
opportunity to graze livestock.

They were sorely mistaken.

In other deserts of the world,

plants have evolved water storage
mechanisms

to survive between rainy seasons.

Such plants are known as succulents,
cactus being a typical example.

There are no succulents
in the Red Centre.

Because of the sheer
unpredictability of rainfall,

storing water is
out of the question,

so plants here are dry,
tough and fibrous.

WIND HOWLS

The baking sun and wind also means
that nutrients are not recycled

and are leached away.

It is a dusty,
impoverished environment.

So not only are the
desert plants tough -

they contain very little
in the way of nutrition.

Spinifex is a typical
Australian plant -

indigestible and nutrient poor.
No good for grazing livestock.

Elsewhere in the world,
great grasslands

are associated with herds
of large grazing mammals -

wildebeest and zebra in Africa, or
bison and reindeer in North America.

A vital link in the food chain.

In the Red Centre,
large herds of grazing mammals

are conspicuous by their absence.

Australia's biggest grazer, the red
kangaroo, won't touch spinifex.

Instead it lives a nomadic
life roaming large areas

looking for patches of
fresh green shoots

and the leaves of desert shrubs.

And this requires fuel economy
on a grand scale -

solving one of Australia's great
mysteries - why kangaroos hop.

Hopping is the most energy efficient
way of getting around.

Tendons in the legs act like
large pieces of elastic,

so that once they are moving,
less energy is needed per hop.

In this way kangaroos can cover
huge distances

while expending the minimum
of energy.

So for kangaroos,
spinifex is like fool's gold.

It looks like the real thing, but it
doesn't deliver the goods.

Despite this, spinifex grass is home
to a surprising number of creatures.

To escape the burning heat
of the day,

most of them only ever come out
at night.

They are generally small but all
very unusual in their own way.

They all have very
Australian names too -

spinifex hopping mouse...

..bandicoot...

and mala wallaby.

One of the most unusual
is the bilby -

Australia's very own
version of the rabbit.

During the day, it lives in a cool
burrow under the sand

but at night, it comes out
to forage.

The mulgara lives almost
entirely on a diet of insects.

Like many desert mammals, it has
developed specialised kidneys.

It never has to drink, gaining all
the moisture it needs from its food.

The planigale is tiny,
weighing only 11 grams,

but will happily take on
prey as large as itself.

It is almost completely fearless.

Well, almost.

The inland taipan.

The most venomous snake on Earth.

One bite carries enough venom to
kill several humans.

Highly efficient venom
has evolved here

because meals can be few
and far between.

A swift-acting venom
makes sure that nothing gets away.

Being so small, the planigale
is able to squeeze

into tiny cracks in the ground.

A lucky escape.

The taipan will have to look
elsewhere.

Venomous snakes aren't the only
challenge to life in the Red Centre.

Dry spinifex is a perfect place
for fires to start.

Occasionally large areas
of desert burn,

reducing the vegetation cover
to cinders.

While the fires blaze,
everything runs for cover -

back to the safety of their burrows.

Paradoxically, the destructive
force of fire

is a good thing for the Red Centre.

Many desert plants release their
seeds after fire

and sprout fresh shoots.

The ash left behind by fires puts
vital nutrients back into the soil.

Some creatures rely
on frequent burning.

The mala wallaby needs fresh green
shoots to live

and bilbies flourish after fires,
thanks to the abundance of seeds.

When humans first arrived in
Australia 40,000 years ago,

they soon learned that animals were
attracted to recently burned areas.

So they started
lighting fires deliberately.

This practise is known as
fire-stick farming,

and has been shown to increase
numbers of desert animals
such as bilby.

And this animal -
the desert skink.

Researchers found that the
desert skink thrived in areas

where fire-stick farming
was a regular occurrence.

The desert skink is unique among
lizards in that it lives communally
with its siblings.

They cooperate as a family to dig a
complex series of tunnels safe from
predators and fires.

Such social interaction is very
unusual behaviour for a lizard.

Desert skinks aren't
the only lizard living here.

There are more lizards per
square metre of the Red Centre

than anywhere else on Earth.

Lizards are built for the
Australian desert.

They regulate their metabolism
very differently to mammals

and as a result, do not
have to eat constantly.

They are really good at switching
off almost completely and can live
on next to nothing.

In the tough and uncompromising
Australian desert,

economy is everything.

The goanna is the
largest Australian lizard.

There are over 20 species of these
monitor lizards in Australia.

They can reach lengths
of over two metres.

Goannas are active and
intelligent hunters.

Their powerful front legs allow them
to dig in search of food

and they will eat almost anything.
Even scorpions.

But this has to be
the most unusual desert lizard.

The thorny devil.

The thorny devil has evolved
a unique way of coping
with the lack of water.

The thorns on its back are not only
a deterrent to predators,

they are interspersed with complex
ridges and channels that act

as a capillary mechanism,

enabling it to literally suck up
moisture from the ground.

Thorny devils exist entirely
on a diet of ants.

They have a leisurely
approach to feeding.

Sitting alongside an ant trail,

its food is delivered
straight to the door.

To prevent the ants picking up on
its presence, it holds its breath
between meals.

In this way, it can eat thousands
of ants in one sitting.

The large number of mammals
and lizards living amongst
the vast areas of spinifex

are tiny compared to the countless
numbers of insects.

There are over 1,000 species of ant
in the Red Centre.

Meat ants get their name from their
ability to pick a carcass clean.

They are the most numerous species
of ant in the desert

and also the most aggressive
carnivore.

Insects are high on their menu.

A large grasshopper is
quickly dismembered

and carried into an
underground nest.

Their interconnected nests are huge

and can extend for hundreds of
metres under the desert floor.

For an indigestible plant containing
very little nutrition,

spinifex supports a huge number
of animals.

Far more than can possibly be
explained through unpredictable
periods of fire and flood.

So what is the key to all the
abundance in our microworld?

What converts all this plant energy
into animals?

Well, there are spinifex eaters
here.

Millions and millions of them,

and their handiwork litters
the Red Centre.

You just have to think small.

Termites.

Termites make short work
of spinifex,

converting a huge amount of plant
material into body tissue.

Termites are crucial to the health
of the desert.

They act as bioengineers constantly
turning over the soil,

excavating, building, breaking down
and aerating.

This increases the turnover of
precious nutrients and improves the
soil's water-holding properties.

Their gut bacteria also
fix nitrogen from the atmosphere.

This ultimately ends up in the soil,

encouraging the growth of more plant
material - including spinifex.

So termites and spinifex are
dependent upon each other.

Termite mounds are a fortress
against desert extremes.

In the face of this unpredictable
environment, they remain constant.

The carefully crafted network of
tunnels maintains a steady
temperature.

There's a myriad of squatters
and freeloaders living

in the complex
tunnel system of the mound.

Spiders enjoy the cool conditions.

Centipedes enjoy a diet of termites

and the knob-tailed gecko enjoys
a diet of centipedes.

So, termites are the basis
of the food chain.

They support a huge
number of animals.

It's not just about food either.

Goannas lay their
eggs in termite mounds.

A perfect incubator and a safe haven
from predators.

When the time is right,
they just break out.

In all likelihood, the total number
of termites in Australia

weigh more than all the kangaroos.

This is environmental engineering
on a vast scale.

Without the unique relationship
between termites and spinifex,

our microworld would be nothing more
than sand.

Instead, life thrives here.

Millions of years of isolation,
drying and uncertainty have shaped
the Red Centre.

It is the most extraordinary
of environments,

home to a cast of equally
extraordinary animals and plants.

Despite having all the odds
stacked against it,

the red heart of Australia
continues to beat

through heat, drought,
fire and flood,

bringing us a unique collection
of awe-inspiring landscapes
and wildlife.