Original subtitles

(EPIC MUSIC)

NARRATOR: Off the eastern coast of Australia,

K'gari.

Also known as Fraser Island.

It's the largest sand island in the world

with its own tropical rainforest.

Little wonder K'gari means 'paradise'.

But don't be fooled.

Life can be tough on this island of sand.

It's a daily struggle to survive. (DINGOES HOWL)

From the Arctic... (BEAR GROWLS)

(SEALS CHUFFING)

..to the tropics... (ELEPHANT TRUMPETS)

..islands are wild laboratories...

..where unique rules apply... (SQUAWKS)

..and nature puts life...

(SNAKE HISSES) (MONKEYS CHATTER)

..to the ultimate test.

(HYENA WHOOPS) (BEARS GROWL)

Although K'gari is made of sand,

it has many different ecosystems.

Rainforest. (CREATURES CHIRPING)

Scrub. (BIRDS TWEETING)

Wetlands. (FROGS CROAKING)

And, of course... (WAVES CRASHING)

..the beach.

(SOFT MUSIC) (WATER LAPPING)

Any beach is a point of entry...

..for new arrivals on an island.

For 20 years, this loggerhead turtle has been at sea...

..criss-crossing the Pacific Ocean.

Now, the island is calling her home.

Back to the very beach where she was born...

..so that she can give birth.

She lays up to 100 eggs at a time.

(TURTLE HUFFS)

(SOFT SQUELCHING)

But it's the island that will determine the sex of her babies...

..by the temperature of its sand.

Below 29 degrees, they'll be male.

Above 29, female.

This mother will not stay around to find out.

(GULLS SQUAWKING)

As soon as she is done, she returns to her life at sea...

..leaving her eggs behind...

..protected by the island.

Many islands are the tops of underwater mountains,

sticking out above the waves.

But K'gari is different.

This island has been formed over hundreds of thousands of years.

Wind eroded rock on the mainland,

creating sand, which it carried far away,

only to be washed back by waves...

..building an island of giant parallel sand dunes.

K'gari's newest sand gathers on the east coast...

..at Seventy-Five Mile Beach.

This beach is patrolled day and night by wild dogs.

Wongari.

Or dingoes.

They've lived here for at least 5,000 years.

Cut off from the mainland,

they never get to mate with domestic dogs.

So, genetically,

they're the purest dingoes in the world.

(UNEASY MUSIC)

The dingo is an opportunist...

..finding food wherever it can...

(DINGO GROWLS, BARKS)

..even on this empty beach.

(SNIFFING)

With an acute sense of smell...

..he works out where the green turtles have buried their eggs.

(GRUMBLES)

(GROWLS)

It is thought that 80% of all green turtle nests on K'gari

are raided in this way.

(SNIFFING)

But this is the first time a raid has been caught on camera.

He works his way from nest to nest...

..clearing them out before other scavengers arrive.

(EGG CRACKING)

Tonight, he'll sleep with a full belly.

(BIRDS CHIRPING)

Inland from the sea,

K'gari's beach gives way to its thick, primary rainforest...

(BIRDS TRILLING)

..8,000 hectares of it.

Here, life thrives

in all its diversity.

(SQUAWKS)

But still,

it can be tricky finding food.

The competition is intense.

On the forest floor...

(OMINOUS MUSIC)

..a predator has set a trap.

A silky burrow of trip wires...

..guarded over...

..by a funnel-web spider.

(GENTLE CLICKING)

Such spiders exist across Australia...

..but on K'gari, they're especially deadly.

(HISSES)

Like dingoes, they've been genetically isolated

for thousands of years...

..and have evolved in their own way.

So now, their venom is six times more powerful

than that of their mainland cousins.

A wolf spider is the next critter to walk into the trap.

Smaller and less venomous than the funnel-web,

it's in trouble.

(TENSE MUSIC)

Although the funnel-web is lethal,

it's not as agile as other spiders.

Such are the pitfalls of evolution.

Sunrise on Seventy-Five Mile Beach.

The carcass of a marine turtle,

washed ashore.

(WAVES CRASHING)

The dingo is the first scavenger on the scene...

..his reward for patrolling the beach day and night.

On an island where food is in short supply...

..it pays to make the most of every opportunity.

(BIRD SQUAWKS)

NARRATOR: K'gari is an island made of sand...

..and at its heart, there is a rainforest.

(BIRDS CHIRPING)

But between beach and forest, there's the scrub.

(INTENSE MUSIC)

Nutrients are blown onto K'gari's scrub by sea spray...

..allowing coastal grasses to take root.

Around which tough and thorny plants can grow,

creating the scrub where the dingoes live.

(HIGH-PITCHED YAPS)

This terrain offers protection

for a litter of pups.

The youngsters are three months old.

They will stay in the family den for another month or so...

..looked after by Mum and Dad.

(WHINING)

(GROWLING AND YAPPING)

The scrubland is also their playground.

Such rough-and-tumble is their way of getting stronger

and establishing rank within the litter.

(WHINING)

As they get older,

the most dominant pups will have the best chance of survival.

With so many mouths to feed, the parents are always on the move.

(BARKS)

They rack up 30km at a time...

..hoping to find a meal for the family.

(GRUMBLES)

(PUPS HOWLING)

Back in the den, the pups wait...

..impatiently.

(HOWLING CONTINUES)

When they're hungry, they don't bark like dogs...

(HOWLING)

..they howl like wolves...

..revealing the origin of their species.

(BIRDS CHIRPING)

In K'gari's rainforest, giant trees stretch up,

competing for sunlight.

(SOOTHING MUSIC)

While long roots reach down,

seeking out nutrients.

(CRICKETS SINGING)

In the soil,

a network of mycorrhizal fungi breaks down organic matter...

..to extract nitrogen,

essential for all plants to grow.

The fungi deliver the nitrogen direct to the tree roots.

In return,

they get glucose from the trees.

It's a win-win situation...

..creating a lush wonderland.

(OWL HOOTING)

At night, the fungi put on a show.

(ETHEREAL MUSIC)

Not underground but attached to the trees.

Bioluminescent mushrooms.

No-one knows why they have evolved to glow like this.

Maybe it is to attract insects,

which scatter their spores.

Or maybe it is just a happy and colourful accident of nature.

While fungi play a lead role in sustaining the island's forest...

(MUSIC INTENSIFIES)

..they get valuable support...

..from the giant burrowing cockroach.

The heaviest cockroach in the world.

Known locally as 'the litter bug'...

..it gathers up dead leaves from the forest floor to feed off.

And its droppings release nutrients into the soil.

And when she is done foraging,

this mother cockroach returns to her burrow...

to feed her youngsters.

Here, way below the surface,

her nymphs stay put for their first six months.

Like dingo pups,

they're dependent on parental care in early life.

But every time their mother leaves the burrow...

..she's vulnerable.

(OMINOUS MUSIC)

The giant centipede...

up to 20cm long.

The only centipede in Australia

capable of killing such a big cockroach.

(TENSE MUSIC)

The chase is on.

(MUSIC INTENSIFIES)

(MUSIC FADES)

The cockroach makes it home...

..back to her nymphs.

(CRICKET CHIRPING)

(RUSTLING)

(OMINOUS MUSIC)

The giant centipede still manages to make a kill on the forest floor...

but it's hardly the super-sized feast it was after.

(PUPS HOWLING)

(SNIFFING)

(PUP YAPS)

At last, the pups get to eat.

(GROWLING)

Their father delivers them the remains of a bandicoot.

The dominant pups take as much as they can...

(GROWLING)

..while the runt has to make do with the scraps.

(RUNT YAPPING)

(GROWLS, BARKS) (RUNT WHIMPERS)

He is smaller and weaker than the others...

..bullied by his siblings.

(YAPPING, WHINING)

A dingo family doesn't stay together.

Soon, this runt will have to fend for himself...

(GROWLS, YAPS) ..finding his own food...

..on this island of sand.

(BIRDS CHATTERING)

For an island surrounded by salt water...

..K'gari has an amazing number of freshwater lakes.

(BIRDS TWITTERING)

Boorangoora,

also known as Lake McKenzie.

Its crystal-clear waters...

(GIRL YELPS, LAUGHS) (INDISTINCT CHATTER)

..are a tourist attraction.

They're so clear because there are no nutrients.

Nothing grows here.

It's simply a basin of fresh rainwater,

known as a perched lake.

(STONE CRACKING)

Underneath, the sand is packed so tight,

it has formed a crust, like cement,

so rainwater stays perched on the surface

with nowhere to go.

Half of all the perched lakes in the world are on K'gari.

(DREAMY MUSIC)

But the real miracle

is the amount of fresh water underground.

There's 20 trillion litres of it,

contained within a giant dome-shaped reservoir.

Any rain not trapped by the perched lakes

filters through the island to keep this hidden miracle topped up.

Some of the aquifer's water breaks its way back out

in rivers and creeks.

And some of it seeps through the sand...

..to form K'gari's swamps and bogs.

(CREATURES CHIRPING, WARBLING)

The water here is so mixed up with decaying organic matter

that it becomes acidic.

Too acidic for most creatures.

But not the Cooloola sedge frog.

It manages to balance its own pH levels

to tolerate the acid. And tonight...

..this male frog...

is looking for love.

(CROAKS)

(PLAYFUL MUSIC)

(CROAKS)

(REEDS CRACKLE)

He sings to attract a mate.

But, he has a rival...

..also trying to impress the females.

(CROAKING)

Time for a sing-off.

(HIGH-PITCHED CROAK)

(CROAKS)

(BOTH CROAKING)

To the victor go the spoils.

He awaits his mate.

(LOW, CONTINUOUS CROAKING)

But an intruder crashes the party.

A cane toad with a taste for sedge frogs.

(SINISTER MUSIC)

(FROG CROAKS) Time to leave.

(OMINOUS MUSIC)

In 1935,

cane toads were introduced to Australia from Hawaii...

..to control parasitic cane beetles.

Now, there are 200 million of them,

spread across the north and east of the country.

Even on K'gari. (WATER SPLASHES)

Twice a year, females lay up to 30,000 eggs at a time.

Within only a couple of days,

the eggs become tadpoles...

..and the next generation of cane toads is born.

It's an invasive species...

..upsetting the delicate balance of this island...

..eating whatever it wants. (LOW, CONTINUOUS CROAKING)

(GULLS SCREECHING)

It's so poisonous, it's off the menu

for almost every other animal on K'gari.

But not the keelback snake.

It is immune to the cane toad's toxin...

..having evolved in Asia alongside similar toads.

But it would take an army of keelbacks

to make a dent in the cane toad population.

(LOW, CONTINUOUS CROAKING)

(SNORTS)

(FLIES BUZZING)

(SNIFFS, SNORTS)

(WHINES)

The dingo pups have now left their family den.

They're on their own.

(PANTING)

The runt of the litter has to find food for himself.

Sand berries are one of the island's hidden treats,

but they won't go far.

They're not enough for a young dingo to survive on K'gari.

(YAPPING)

Just like his parents,

he sets out on beach patrol,

hoping to find something more substantial.

(CAR APPROACHING)

(SOMBRE MUSIC)

But he's hit a roadblock.

The beach is used as the island's highway.

Working out how to co-exist with humans

is one of the most important lessons for any dingo pup.

(OMINOUS MUSIC)

(FIRE CRACKLES)

Humans have lived on K'gari for thousands of years,

managing this wild landscape through the use of fire.

The Butchulla people have always burned areas of bush...

..to create space for new trees and plants to grow.

Today, rangers tap into that ancient wisdom

to carry out their own prescribed burns...

..while providing escape routes for animals.

(FLAMES CRACKLING)

But not all fires on K'gari are prescribed.

And some have raged out of control.

In 2020, an illegal campfire

was the spark for an inferno.

High winds and dry conditions

meant the fire burned for months.

Affecting half the island.

Destroying ancient habitats.

With climate change, animals on the island will have to adapt...

..as the risk of wildfire grows ever greater.

But, amazingly,

K'gari finds a way of bouncing back.

(OPTIMISTIC MUSIC)

Burned areas are reborn.

Grass trees bloom.

Their stems underground are insulated against the heat of a wildfire.

And, as soon as the fire is over,

they take advantage of the soil,

now fertilized with ash...

..and bloom.

A testament to the island's resilience.

(BIRDS CHIRPING)

(WIND WHISTLES)

K'gari is an island that has changed over millennia.

Impacted by wind...

..waves...

and fire.

But there are changes that occur on this island twice a day...

..brought about by the ebb and flow of its tides.

For anything to survive in the island's intertidal zone,

it needs to adapt to life above and below the waves.

Hunkering down to avoid predators when the tide is high...

..finding food when it is low.

(CLICKING)

(INTENSE MUSIC)

An army of blue soldier crabs.

Instead of scuttling sideways, like most crabs,

they march forwards,

seeking out anything edible washed ashore by the tide.

They are working against the clock...

..because once the tide turns...

..it is time to return underground.

Out of harm's way.

But this game of hide-and-seek

doesn't fool everyone.

(WHOOSHING)

Even though the crabs are under 20cm of sand...

..this stingray can find them.

Like its shark cousins,

it can detect bioelectric signals generated by its prey.

Using its pectoral fins,

it traps the soldier crab...

..and sucks it up into its mouth.

(WATER LAPPING)

In the far north of the island,

baby sea turtles see daylight for the first time.

Eight weeks after their mother laid her eggs...

..it's time to hatch

and make a dash for the sea.

But they're heading straight into the line of fire.

The white-bellied sea eagle.

The largest raptor on K'gari.

Like every other animal on this island,

it's always on the lookout for food.

(BIRDS SQUAWKING)

And baby turtles

are irresistible.

(TENSE MUSIC)

Only one in a thousand sea turtles makes it to adulthood.

(SOFT MUSIC)

But among the survivors,

there are females who will return to K'gari in 20 years' time...

..to lay eggs of their own...

and give birth to the next generation of sea turtles.

(INTRIGUING MUSIC)

The little dingo pup

is growing up fast.

Hunting and scavenging on his own.

(CRUNCHING)

Learning the ways of this island.

And today,

there's something on the air catching his attention.

(FAINT HOWL)

(SNORTS)

A familiar scent

and sound.

(DISTANT HOWLING)

His father.

(SNARLING)

Father and son haven't forgotten eachother.

(SNARLS)

But the reunion doesn't last long.

The young dingo will not return to his parents.

His search for food will continue...

alone.

A nomad on K'gari.

(UPBEAT MUSIC)

K'gari,

the name means 'paradise'.

(CREATURES CHIRP AND WARBLE)

But this island of sand

throws down challenges at every turn.

(SQUAWKS)

You've got to be resourceful...

..strategic...

..and lucky to make it...

..in paradise.

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