Original subtitles

One of nature's masterworks

the ultimate long-distance athlete

At full speed it uses less energy than any animal its size

The Kangaroo is shaped by the land in which it lives

one of the most challenging places on earth

Australia is a vast ancient weathered land

isolated from all others for 40 million years

It is a place of extremes

more like another planet than another continent

Travelling over Australia's 3 million square miles

is like crossing an ocean of dry land

Primeval landscapes belie its rich resourceful life

Australia is almost equal in size to the continental United States

It is the driest vegetated continent on Earth

Surrounded by three oceans it is the world's largest island

It shares no border with any other country

Here some of the Earth's oldest rocks hold fossils from the dawn of life

In its heartland are mountain ranges that once rivalled Everest

built up and worn down over time

and remnants of a once vast inland sea

Most of Australia's native animals are unique

Their journey on this continental raft

has taken them through cool forests and fiery deserts

and changed them forever

The survivors have been refined by poverty and uncertainty

Some have climbed up out of adversity

Some have outrun all their predators

Most have adapted to hard fickle conditions

A few are unchanged since the days of the dinosaurs

Now sheer diversity of species

spreads the risk that life is required to bear

The story starts millions of years ago

when Gondwana the great super continent began to break apart

Africa South America and India were formed

but Australia and Antarctica were still joined as one last giant land

forested and lush

By 50 million years ago the breakup was complete

when Australia parted from Antarctica

A massive ocean current began to flow around the South Pole

and Antarctica's life perished under a blanket of ice and snow

Australia pushed northwards from the freezing latitudes

and remained isolated for the next 30 million years

It became an ark of survival for its cargo of ancient life

Searing winds began to dry the land

and its moist rainforest all but disappeared

At the centre the desert was taking over

Australia's plants and animals faced a choice

adapt to the drying conditions or retreat

Now the symbol of Australia's red heart is Uluru

the Earth's largest exposed rock

It commemorates the relationship between life and this land

Today Australia is the Earth's flattest continent

lts mountains were worn to their stumps millions of years ago

The Nullarbor plain on its southern coast

has the world's longest unbroken coastal cliffs

Once you could walk to Antarctica from here

If the dry Outback is a land ocean these parallel sand dunes are its waves

Stretching beyond the horizons they cover nearly half of the continent

Millions of years of rain and drying winds

long ago leached the goodness from most of its soil

In the red centre there is no regular predictable pattern of rainfall

Poor soils and a savage climate now challenge all life in this land

Nature responded to the changing conditions

The kangaroo started its journey as a marsupial possum

the size of a mouse

As forests contracted some kangaroos evolved to live in the trees

and others learned to eat grass

When food is plentiful the males are active

and courtship disputes are traditionally settled

with a round or two of kick-boxing

Mothers and babies sensibly keep out of the way

On most continents animals breed in response to the seasons

In Australia it is the availability of food

that prompts the kangaroo to reproduce

To capitalise on good times the mother can support a production line

one joey in the pouch one at foot

and another in the womb as an embryo

She can even supply her babies

with two different formulas of milk at the same time

one for each generation of young

The koala evolved from the same marsupial possum as the kangaroo

When the baby is big enough to leave the pouch

it rides on its mother's back

Like the kangaroo

the koala evolved in the moist rainforest

As the forest dried it adapted to live on the leaves of the gum tree

Now it drinks little water

and its digestive system can extract moisture

and nutrients from leaves that would be toxic to most other mammals

Koalas use as little energy as possible resting about 19 hours a day

Some members of the family however are active at any hour

When moving from tree to tree they normally descend backwards

Consequently tree top traffic jams can sometimes leave one out on a limb

For years on end much of the Australian inland receives little or no rain

Two thirds is classified arid and one half is desert

The Outback as it is called covers most of the continent

By rights nothing should live here

this ought to be a lifeless wasteland

But it is not

The closer we look the more we find that some of Australia's forest inhabitants

have met the desert's challenge with subtlety and resource

Now a diverse underworld of ants rodents marsupials and reptiles

are among the most successful desert dwellers on Earth

By day most life in this land ocean is hidden beneath the surface

Many of the desert animals come out to feed in the cool of night

These tiny hopping mice survive because they rarely need to drink

Most of the water they require is contained in the seeds they eat

In the heat of the day they huddle together in deep burrows

creating a humid atmosphere that helps to conserve moisture

In this arid region hardy mulga trees

provide food for one of Australia's four thousand species of ants

Six feet below the surface

honey ants hang like clusters of golden grapes in cool humid larder chambers

These specialised ants are living honey pots

They are force fed by worker ants on nectar

harvested from the sap of mulga trees growing above

When food is scarce

these honey pots feed the workers by regurgitating their nectar on demand

Their underground storehouse will see the whole colony through the toughest of times

Arid Australia is the land of the lizards

There can be up to forty seven different varieties in just one area

The Thorny Devil has a sticky tongue and it's picky about what it eats

Out here black ants are one food that never runs out

The devil is perfectly adapted to the desert

lts prickly skin collects moisture from the air

and a system of fine channels along its body

carries the water to its mouth

The biggest and most fearsome of the desert lizards is the perentie

which is both scavenger and predator

This lizard can exceed six feet in length and outrun a human

It hunts anything including the most aggressive

and deadly of Australia's many snakes the King Brown

Sometimes though the King Brown is more than even a perentie can manage

The venom from this snake's bite will kill a human in minutes

Luckily for the perentie it is immune

While much of Australia's life was adapting to the dry inland

some of its plants and animals retreated to the mountains of the east coast

Here moist valleys and cool peaks

provide a haven for Australia's living links with the past

In scattered pockets of primitive rainforest

descendants of Gondwana's original plants and animals thrive today

These Antarctic Beech trees began growing between 3 and 5 thousand years ago

but their roots are in the ancient super continent

Most of Australia's native plants and animals

began to evolve in wet cool forests like these

One of the most remarkable living links with that ancient world

is found in the creeks and freshwater rivers of the east coast

The Platypus suckles its young like a mammal

yet lays egg like a lizard

It hunts under water with its eyes shut

using electric sensors in its bill

The first Europeans to see it were dumbfounded

To them it was a living contradiction if not a practical joke

The Platypus though has survived for 120 million years

Today it exists nowhere else on earth

The nearest surviving relative of the Platypus

is the Echidna

With its tubular snout and long sticky tongue

it lives on ants and termites

Unlike the Platypus the Echidna moved out of the cool forests

and now ranges across the whole continent

When threatened it digs in rapidly

presenting an array of sharp spines to its attacker

Drought

It can last for months or years at a time

Long periods without rain push all life to the limit

The young and the old are first to feel the effects

Clear skies parched earth and searing heat become the rule of life

Some will perish before the next rains come

Now the kangaroos of the desert

call on another remarkable strategy for survival

The female can halt the growth of her developing embryo

keeping it in a state of suspension until conditions improve

Only then will she give birth

For the joey already born the future is now uncertain

But the unborn embryo will be ready when good times return

Surviving kangaroos will either move to new territory in search of food

or batten down near remaining waterholes while at least some grass remains

Emu families have a similar hard choice to make

Whatever they decide it will be a gamble

Relief from drought is unpredictable

and often arrives a long way from where it is needed

Each year the tropical wet season brings storms

and flooding to Australia's far north

As the monsoon unfurls curtains of rain a transformation begins

As the wetlands fill crocodiles emerge from scattered waterholes

where they've been confined during the dry season

They will build nests above the high water level

and lay up to 100 eggs

Vast networks of wetlands that have been dry since last season are flooded again

Sometimes this powerful event can also transform Australia's arid centre

In years when rains are heavier and more widespread than usual

the water flows inland to the parched interior

Slowly heading south water spreads across the plains

In six months or more it may reach the centre of the continent

Under cloudless skies the water creeps quietly inland

filling hundreds of dry waterways

In dry sandy creek beds millions of tiny drought resistant eggs

like seeds are waiting

Subterranean life that may have been dormant for years begins to stir

Stimulated by seeping water

the burrowing frog awakes from its long sleep

Carefully it parts the membrane that has kept it moist through the drought

Like the frog many creatures are primed

for the good times that are about to unfold

Alerted by an ancient program in their minds

Egrets arrive and take up feeding positions

Fish have already started reproducing in streams that until a week ago

were tracks of dry sand

Thousands of waterbirds join in a frenzy of feeding and breeding

that may happen only once or twice in a decade

Briefly the desert blossoms in a colourful tide of new life

One of the few large predators in this land also participates in the bonanza

Australia's wild dog the dingo

arrived from nearby Asia about four thousand years ago

lts pups will feed on the plentiful supply of rodents and reptiles

that are also multiplying in the abundant conditions

Tens of thousands of pelicans

are drawn by the irresistible call of inland water

Responding to reflections far away in the sky

the birds fly hundreds of miles to gather on the shores of newly filled desert lakes

With more than half a million nesting birds

colonies of this size are a rare event

Pelicans normally breed in small scattered communities

producing one chick a year

Here they'll produce five or more in quick succession

and go on doing so as long as the food supply lasts

Millions of years ago

pelicans were breeding in the vast lake system that covered much of the interior

Ancestral knowledge seems to draw them back to their primeval home range

The water ends its long journey at the centre of the continent in Lake Eyre

Nearly a million square miles

of the continent drains into the world's largest dry salt lake

It fills completely only about twice a century

Inevitably the flow of water stops

The earth and blasting sun suck away at the stagnant pools where life

newly born there is on borrowed time

Trapped by receding waters

some of these fish will provide a final feast for the birds

Millions more will return to the mud of the riverbed

enriching it for the next generation

With their food supply running low

the great flocks of pelicans become nomads once more

rising to search for that far flash of water over the horizon

Those who have left their run too late go back into the earth

The familiar desert will now reclaim this place

Suns will scorch it winds will dry it out

Most living creatures will dig in and take refuge underground

Some will flee to the gentler edges of this great land

And the hardy ones will await a new flood in some future year

In Australia life has struck an unlikely deal with an uncertain climate

The continent has been a ship of refuge

for an alternate order of ancient life

as it crept northward through the eons

its passengers have had to adapt again and again

In this land beyond time

life has learned to ride out the hard times and flourish in the good times

Far more than merely surviving life has triumphed in Australia