Original subtitles

(WAVES CRASH)

NARRATOR: Sun-drenched coastlines.

Vast forests of eucalyptus.

Rolling grasslands.

The animals that thrive in this Australian wilderness...

(HOWLS)

...are some of the most iconic...

(SNARLS)

...and deadly, on Earth.

(BIRDSONG)

But a great shift is underway.

Born of climate change,

wildfires and flooding

are hammering the continent.

(THUNDER RUMBLES)

The ancient status quo has been disrupted,

allowing new leaders to emerge.

Along a small stretch of coastline,

the shifting conditions create new opportunities

for those bold enough to take them.

A chance for animal gladiators to conquer new territory...

settle old scores...

and to fight to survive.

Among the coastal grasslands,

an Australian icon is on the move.

His kind have existed here for 15 million years.

Eastern Gray Kangaroo.

A large and muscular marsupial.

But this male has fallen on tough times.

Last year a wildfire ripped through his territory,

forcing him and his mob to flee

and take shelter in this new valley.

The dominant male, who ruled over the mob

didn't make it.

He was in charge of maintaining harmony

in this highly social group.

He kept the other males in check

and was the mob's main protector.

So now a new leader must rise through the ranks.

And Gray has his eye on the top job.

But he's not the only one with his sights on the crown.

Several other bucks also fancy themselves for the role.

Whoever succeeds

will carry the safety of the mob on their shoulders,

because their new valley is fraught with danger.

(HOWLING)

(HOWLING)

(HOWLING, BARKING)

Dingoes. (HOWLING)

The wily gangsters of these coastal grasslands.

Fierce carnivores.

And one of the few natural enemies of kangaroos.

Two of the dingoes break from the pack

and move to ambush the kangaroos from the thick scrub.

Gray's cat-like hearing, senses their approach.

(BIRDS CALL)

It's an opportunity for him to prove his worth

and protect the group.

Thumping the ground with his hind feet,

he signals to the mob to flee.

Gray races off

and the mob follows.

But the dingoes try to slow them

by funnelling them up a steep valley.

They're looking to pick off a young straggler.

Huge tendons in Gray's hind legs work like springs,

they absorb energy with each foot strike,

and release it with explosive force.

He picks a safe route for the mob to follow.

Dingoes can reach speeds close to 50 kilometres an hour.

But in open terrain kangaroos can do 65.

Gray's clawed feet pound the ground like a jackhammer,

guiding the group past the rocky scrub

and into the open valley.

From here, it's a footrace.

The dingoes have no chance.

Gray's quick thinking has shown he has the makings of a leader.

But his greatest battle is yet to come.

Across this arena,

animals of all kinds are adapting to life after the fire.

But one in particular,

the extreme conditions have worked in its favour.

The hollow where she lives

is littered with the spoils of past battles.

Victims seized as they fled the wildfires.

She's perhaps the most iconic of all Australian arachnids.

Redback.

One of the most venomous spiders in the world.

As this stretch of coast has become hotter and more hostile,

redbacks have rolled with the punches.

Originating in the deserts of Western Australia,

they've quickly adapted to the shifting climate

by pushing into new territory here.

Redback is a newcomer in this arena,

and she's on a campaign to increase her stake on this land.

Right now, she's hatching her plan.

She's brewing a chemical weapon.

In the glands around her mouth,

she's combining a deadly concoction of enzymes and toxins.

When injected, this venom will cause extreme pain and paralysis.

But Redback is no larger than a pea,

and she'll remain in the same spot for most of her adult life.

So, her plan is to get an unsuspecting victim

to come to her.

(BIRDSONG)

(BIRDSONG)

NARRATOR: As fires and rising temperatures blight the land,

the effects are being felt in the waters too.

A warming ocean and overfishing

have made food harder to find here,

making the battle for resources underwater tougher than ever.

Even for one of the most efficient hunters.

Great White Shark.

Evolution made his kind such effective predators

that they've remained unchanged for millions of years.

But the world around him is shifting.

With fewer fish in the ocean,

the seal colonies he hunts have shrunk.

So he's travelled thousands of kilometres through open water,

to find better hunting grounds.

He's come to the right spot.

An exposed stretch of rugged coastline.

This is home to another elite predator.

Fur Seal.

She was born on this beach 15 years ago.

The changing ocean has affected her too.

She must swim ever further offshore

to reach increasingly depleted fish stocks.

The shallows close to shore are Fur Seal's safe place.

But 30 metres out,

a steep drop-off gives way to a labyrinth

of kelp beds and dark gullies.

The best food is beyond here.

But so too is Great White Shark.

And he's already on her tail.

Fur Seal's scent is irresistible.

Great White's nose is the most powerful of all sharks'.

Other exacting senses draw him closer still.

Detectors around his nose

feel the electromagnetic currents emitted by Fur Seal's muscles.

And as he draws closer still,

he zeros in on the pulsing of her heart.

Fur Seal is equipped to avoid him.

Like a cat, the linings of her large eyes

reflect and amplify weak light.

Flexible joints between her vertebrae

enable her spine to bend back on itself.

She beats her powerful front flippers

to propel herself away from the shark

and rockets to the safety of the shallows.

Perhaps this isn't the best time to go fishing.

But sooner or later she'll have to.

It's not just her own survival at stake.

Up on the rocks, her three-month-old pup.

(BARKS)

There's no shortage of dangers up here, either.

Aggressive breeding males

have a careless attitude towards the colony's young.

This amped-up bull could easily crush Fur Seal's pup.

(SNARLING)

She moves to draw his attention away

from her vulnerable youngster.

The male is over three times her weight.

But what Fur Seal lacks in bulk

she makes up for in know-how and bravery.

She throws open her jaws

to give the male a full show of her curved canines.

His thick blubber acts like body armour.

But the male has an Achilles heel.

Fur Seal sinks her canines into his exposed neck.

(SNARLS)

Her painful bite has the desired effect.

With her pup watching,

Fur Seal has demonstrated a vital rule.

Bigger doesn't always mean better.

As the tougher conditions continue to put pressure on this arena,

there's a resourceful wanderer in the tree line

who has reaped great benefits.

This is Bull Ant.

After the fire blazed through here,

it left an abundance of dead insects for her colony to dine on.

With each day, she's getting stronger, fitter and bigger.

Evolving in Australia's extremes for millions of years

Bull Ant is a giant of the ant world,

a full four centimetres long.

And she's endowed with an impressive armoury.

Up front, giant scythe-like mandibles.

At the back, a venom-loaded stinger.

Most ants have poor vision

but Bull Ant's huge compound eyes give her superior eyesight,

exceptional for navigating and finding food

in all light levels.

Her vision rivals that of a dog.

She uses her extra-large eyes

to scan and memorize landmarks in her environment,

and spot her next meal from up to a metre away.

It's one of her favourites.

Packed with energy.

But the larvae in her colony need protein to grow.

She needs to find something a little... meatier.

She must tread carefully.

There are bigger predators prowling the woodland.

Ant's jaws are on a hair-trigger.

A thousand fast-twitch muscle fibres fire together

to clamp its mouthparts tightly around the moth.

But the moth fights back.

It sheds a cloud of dusty scales to throw Bull Ant off her stride.

She's temporarily blinded,

But she rallies,

and uses her superior strength

to get the moth just where she wants it.

Then, she triggers her needle-sharp hypodermic stinger

to deliver a deadly shot of venom.

The moth isn't dead, just paralyzed.

Bull Ant must drag it back to the colony,

where she'll pull it apart and feed it to the larvae.

It weighs three times more than she does.

But Bull Ant is a power-lifter.

She can carry loads up to 50 times her own weight.

She drags the catch back to her nest.

Beyond the tree line...

(SNORTS)

...Gray is gaining stature within the mob.

But it's a rival buck that makes the first move.

The flex is an unmistakable display of dominance.

In the searing 40-degree heat, everyone is on edge.

Gray must keep his cool.

Resting kangaroos can't sweat,

so they pant rapidly, and lick their arms.

(FLIES BUZZ)

Worse still, the extreme temperature

has unleashed a wave of pestering flies.

The cracks in the mob are beginning to show.

They need a new leader to bring calm and security

now more than ever.

Even the rookies are flexing their muscles.

They're not long out of Mum's pouch,

but already they're eager to prove their grit

to anyone...

or anything.

A kick here.

A jab there.

Extra points if your opponent runs away.

Scuffles like this are just play fights.

A way to practice their boxing skills

and build their muscles.

These joeys are still a long way from leader material.

But Gray carries the hallmarks of a real mob boss.

He's big, with bulging biceps

and bags of attitude.

He weighs 70 kilograms, half of which is pure muscle,

and stands close to two and a half metres tall.

But so does this opponent.

(GROWLS)

Gray emits a low guttural growl,

an attempt to state his dominance.

The rival retorts with a full body flex,

trying to scare Gray into submission.

If Gray is to become leader...

(BARKS)

...it's clear he must get physical with this challenger.

(GROWLS)

This won't be a play fight.

(GROWLS)

The fighters go toe-to-toe.

Gray, in the left corner,

attempts to stare down his competition.

But the challenger holds his gaze

in a bid to intimidate him.

Neither is willing back down.

(GROWLS)

It's time for Gray to be smart.

He pushes the challenger backwards,

trying to assert his heavyweight credentials.

But he mustn't commit too soon.

These dominance battles can last for days.

And the challenger's low kicks show that he's game for a fight.

As darkness falls, the fighters disengage.

But their battle is just getting started.

(WIND WHISTLES)

(SEALS BARK)

From the safety of dry land,

Fur Seal has been diligently raising her pup

over the first four months of his life.

Her milk is some of the most nutritious

in the entire animal kingdom.

But to keep producing it, Fur Seal must eat.

But the bony fish, squid, and octopus she hunts

are harder to find

and further from shore than ever.

To reach them,

she must run the gauntlet against Great White.

(BARKS)

On land, Fur Seal is ungainly and cumbersome.

(BARKS)

But in water...

she's an athlete.

On a single foraging trip,

she can travel 200 kilometres from her home base.

Her plan is to sneak past Great White,

feed up on fish and squid, and return safely to her pup.

She passes the drop-off.

Her single breath will last close to ten minutes.

After that, she'll need to break for air.

It's when she'll be most exposed.

The kelp beds provide ideal cover for Great White.

His dark upper body blends with the shadowy depths,

making him hard to see from above.

So, his tactic is to find distracted seals near the surface

and ambush them from below.

Fur Seal stays close to the sea floor.

She's memorized foraging routes

past every boulder and gully in these kelp beds.

It's like a built-in GPS

and it allows her to find a safe path through.

She's past the first hurdle.

But to return to her pup,

she'll need to slip past the shark a second time.

She catches her breath.

And now it's time to feed.

In the deeper water, she locates a huge shoal.

Her thick, wiry whiskers,

packed with nerve endings at the base,

are highly sensitive to movement

allowing her to home in on a single fish

and make millimetre adjustments to make the kill.

After an hour of feeding,

it's time for her to head back to shore.

But Great White is on high alert,

and this time he picks up on Fur Seal's approach.

He's precision engineered for this scenario.

Tiny structures all over his skin work to reduce drag,

enabling him to swim fast and silently.

To avoid getting caught in the open water,

Fur Seal weaves amongst the gullies.

Keeping low makes her less exposed

to a surprise ambush.

But her air supply's dwindling.

She must break for the surface soon.

From deep below,

Great White spots her.

As he accelerates, it creates a pressure wave.

Fur Seal senses it,

weaves in a zig-zag

and dodges the shark's jaws by a few centimetres.

Great White's muscular body gives him deadly speed,

but he's not built for endurance.

His failure to kill with his first strike

has slashed his chance of success.

Fur Seal makes a bolt to the shallows.

But she's in a dead end, with no place to haul out.

The shark has her cornered.

So she uses the underwater landscape to her advantage.

She keeps close to the rocks.

Great White can see her,

but he's too big to manoeuvre this close to the jagged shore.

If she can stay out of reach, she'll tire out the shark,

and he will be forced to give up.

But she goes one step further.

She circles round and swims in Great White's blind spot.

Great White is disorientated and losing energy.

It gives Fur Seal the chance she needs

to make a break through the shallows

along the coast, to a safe place to haul out.

Great White resets.

And, in the deeper water,

turns his attention to a group of less experienced seals.

Four huge muscles do the work to clamp his jaws shut,

as 50 serrated teeth puncture the seal's body.

Fur Seal is reunited with her pup.

(SEAL CALLS)

Great White may have vanquished one from the colony,

but Fur seal has shown that her kind can best a bigger, stronger foe.

And by safely delivering another rich meal to her pup,

Fur Seal is helping ensure

that her colony continues to grow and thrive along this coast.

(BIRDSONG)

Back inland,

among the dry coastal woodland,

Redback's strategy is entering its next stage.

She starts to spin silk.

Rappelling down, she pulls her thread behind

and fixes it in place,

then returns to the roof

and attaches the other end of the line.

Line after line, she weaves her tangle web.

By the time she's done,

she's laid 70 tripwires.

It's a finely engineered trap.

Bull Ant is on another foray to feed her colony's young.

Redback's lair is the sort of place a meal could be lurking.

Impelled to forage for her colony,

she tries to pick her way through the labyrinth of wires.

The trap springs like elastic.

She's snared.

The high-tensile lines are tougher than Kevlar

and coated in liquid silk

that acts as an instant glue, fixing it to the ant's body.

The vibrations tell Redback her trap has been sprung.

By sheer strength,

Bull Ant is able to pull free of some of the lines.

But Redback's trap is too extensive.

Redback goes on the offensive.

Ant tries to grab her with her mandibles,

but runs into another sticky snare.

She braces against the line with her clawed feet.

It's stuck fast.

Redback lunges.

A chance for Ant to grasp the spider with her jaws.

But Redback smothers them with silk.

Combing out the thread with her back legs,

she binds Ant's mouthparts, like a muzzle on a dog.

Each new strand wraps Ant's mandibles tighter,

neutralizing her primary weapon.

But Ant still has her deadly sting.

She arches her back, trying to reach the spider.

She can inject six times as much venom as a bee

if she can get close enough.

But she's tiring.

Escape is all but impossible.

Bull Ant tries to land a fatal sting as her final move.

But she's overwhelmed with silk.

Only now can Redback move closer,

to deliver a fatal bite.

With two pin-sharp fangs,

she injects her neurotoxic cocktail.

Its effect on Bull Ant's nervous system is almost instant.

Slowly, Redback begins to feed.

Her reward,

a vital meal that will keep her going over the coming weeks.

And as the southern coast's climate becomes increasingly extreme,

Redback's kind will continue to expand their range here.

(BIRDSONG)

(HAWK CALLS)

While Redback is tasting victory,

Gray is preparing to go another round.

(LOW GROWLS)

The previous night was a chance for Gray's challenger to back down.

But today, he's back

and even more fired up for the fight.

An all-out battle for dominance is now unavoidable.

The prize, to become the undisputed champion...

(GROWLS)

...and take the title of Mob Boss.

Gray's opponent makes the first advance.

But Gray countermoves, with a burst of flying kicks

and a volley of punches.

(SNARLS)

Their muscular forepaws, tipped with sharp claws,

are nature's knuckledusters.

If Gray lands one right,

he can blind his opponent.

But the challenger throws back his head

to keep it out of reach.

So Gray changes tack.

He moves to grapple his opponent...

(GROWLING)

...and throw him off his feet.

His opponent shrugs it off, so Gray steps it up a gear.

Using his metre-long tail for support,

Gray lashes out with both legs.

His double-barrelled kicks hit with the force of a heavyweight boxer.

Just one of these clawed kicks could disembowel a human.

But thickened belly skin enables his opponent

to withstand multiple strikes.

So Gray picks his moment

and delivers a gut-crushing shot.

(GROWLING)

His opponent is left reeling.

Gray in the left corner has the upper hand,

but he must keep up the pressure.

It's now a battle of attrition, a true test of grit.

Gray's opponent is wounded from the belly shot and tiring.

(GROWLS)

But still, he won't back down.

So Gray goes in for a final strike.

And this time, it's too much for his rival.

(BARKS)

Gray has won the title of Mob Boss.

The loser must decide whether to get in line

as a lower-ranked male

or leave and move elsewhere.

The power vacuum has been filled.

With Gray now in charge,

security and order can return to this group.

(BIRDSONG)

Along this stretch of wild Australian coastline,

brave animals have risked it all.

(SEAL BARKS)

An underdog seal has outwitted its ancient foe.

A champion boxer has been crowned.

And Redback's patient strategy overwhelmed her quarry.

Extreme conditions and hunger

will continue to challenge all who live here.

But they've proven themselves true survivors...

(GULLS CRY)

...earning the right to live and fight another day...

(HOWLING)

...in the badlands of wild Australia.