Original subtitles

In the far reaches of the Pacific Ocean...

lies a land cut-off from the rest of the world...

since the time of the dinosaurs.

After 80 million years of isolation,

nature has gone its own way.

In this lost world, life plays by different rules.

Penguins in the forests...

parrots in the snow...

and predators from prehistory.

Their lives are dominated by the most powerful forces on earth.

When humans finally arrived, they discovered

nowhere is more strange and mysterious than New Zealand.

At the extreme southern tip of New Zealand,

the influence of the South Pole is surprisingly clear.

The Aurora Australis, the Southern Lights.

At 47 degrees south, the next stop is Antarctica.

At these latitudes in summer, the nights don't last long.

So there is only a brief window of opportunity

for the creatures who hunt by night.

Like this mysterious beachcomber.

He's only found in New Zealand

and very rarely seen.

He has stubby wings, but he's too heavy to fly.

A wild southern brown kiwi.

Just after sunset, the kiwi hits the beach in search of sand-hoppers.

He relies on his sense of smell and sniffs out the bugs through

nostrils at the end of his bill.

Kiwis come out at night to avoid daytime predators.

So it's rare to get such a good look at them.

Cold nights and meagre pickings mean that as the first rays of the sun

appear, this kiwi doesn't run and hide.

He keeps hunting into dawn.

The conditions here force the southern brown kiwi to stay out in daylight.

To live this far south, it has had to completely alter its normal routine.

Every creature who lives in this wild and remote part of the world

must come up with radical solutions to the challenges of living here.

New Zealand's closeness to the pole makes it vulnerable to storms,

particularly in the south, where they say you can feel the icy breath

of Antarctica.

New Zealand's southern beaches are a refuge for one incredible

subantarctic pioneer.

A New Zealand sea lion.

Possibly the rarest sea lion in the world.

Almost hunted to extinction 150 years ago.

But then, in 1993, one female returned and gave birth.

Over 20 years on, their descendants are still here.

An adult male can weigh about as much as four grown men.

It can take eight years to reach maturity.

SEA LION ROARS

Adult male sea lions are the rugby front row of the South Island.

During the breeding season, the beaches become their battleground.

Only the biggest and toughest will win the right to breed.

A female returning from a three-day fishing trip doesn't want to attract

the males' attention.

She has something else on her mind.

She might be able to dive deeper than any other sea lion on earth,

but hauling 160kg up over a sand dune is more of a struggle.

SEA LION CALLS

There is a reason for all this effort.

She's searching for something precious.

The centre of her world.

Her pup.

Only a couple of weeks old.

By hiding her baby in the woods, she avoids the bullyboys on the beach.

In the safety of the forest, he can suckle in peace.

All along the southern coast,

sea creatures come ashore to find shelter.

But living on land when you're meant to be at sea can bring problems of

its own.

On the Snares Islands,

penguins build their nests amongst the trees

because it's a safe place to breed.

But protection in these forests comes at a price.

BIRDS SQUAWK

Thousands of tiny feet turn the nesting ground into a quagmire.

They get covered in sticky mud,

not just their feet, but their precious feathers, too.

The mud not only ruins their looks, it could threaten their lives.

Their densely-packed plumage is their survival suit.

If their feathers are dirty,

they won't insulate as effectively

and the penguins will lose vital energy.

These are coastlines where risks cannot be taken.

So before he dives headfirst into the sea,

this penguin checks into the penguin spa.

The rock pool gives him a chance to wash and scrub up in safety.

He combs through his feathers...

then waterproofs them with a wax from an oil gland

at the base of his tail.

Not only does this wax help him stay warm,

it will also help glide through the water more efficiently.

Insulated and waterproof once more, he's now dressed for dinner.

Ready to tackle the wild ocean beyond.

The waters surrounding the South Island

are some of the most brutal on earth.

These are the Roaring Forties.

Gale force winds rage year-round,

churning up seas that batter the shores.

Fierce weather systems can arrive without warning.

Open ocean swells and storms charge up

from Antarctica and create massive waves up to eight metres high.

It's always a challenge.

The challenge of being able work the area.

You just have to be prepared all the time.

Tackling the tempest is a regular occurrence for Peter Young.

It's his commute to work.

But the view from his workplace makes up for it.

One of the most spectacular sights in New Zealand -

Fiordland.

This labyrinth of steep-sided fjords and inlets offers shelter to a whole

host of marine life.

For bottlenosed dolphins, it's a place to rest and feed.

And a nursery, where baby fur seals can build up their strength.

Peter is a ranger for the Department of Conservation.

He monitors and protects the wildlife here.

The diversity of Fiordland is something I love.

It's something that not a lot of people

in the world will ever get to do.

You sort of get a 40-tonne whale just come cruising up.

Right beside the boat, rolling over,

exposing their bellies to you as if they want a bit of a scratch.

Fiordland is the jewel of the South Island.

At almost 5,000 square miles, it's New Zealand's biggest national park.

This dramatic landscape was gouged out by glaciers

during the last ice age.

Creating incredibly deep saltwater inlets.

Here, two distinct worlds meet.

Fresh water from the land

mixes with saltwater from the ocean...

to create a unique ecosystem.

Fresh water arrives here from the forests,

rich in tannins from rotting vegetation,

turning it into a dark tea.

It pours off these cliffs to mix with the saltwater below.

Less dense than saltwater,

the stained fresh water floats above and blocks out the light...

creating a dark and cold underwater world.

Here, creatures that normally live in the inky depths of the ocean make

their home much nearer to the surface.

Black corals normally grow below 100 metres, but here,

underwater forests of them thrive in the shallows.

It may be known as black coral, but it appears white as it's covered in

millions of tiny coral polyps,

all feeding in the current.

Black corals are the slowest-growing corals in the world.

But here they grow a remarkable two centimetres a year.

To create a forest of them can take hundreds of years.

Prehistoric shellfish, brachiopods,

are relics from the time of the dinosaurs.

They, too, have crept up the cliff walls and into the shallows.

A unique mix of marine life has adapted to live here thanks

to the extraordinary way fresh and saltwater meet.

The south of New Zealand is one of the wettest places on earth.

Freezing winds from Antarctica collide with warm wet weather

from the north.

Huge volumes of moist air are forced to rise over the South Island's

mountains, where they cool and form vast banks of cloud.

The South Island's west coast and forests are drenched with rain for

more than 200 days a year.

The water sustains vast swathes of temperate rainforest.

Forests brought to life

by New Zealand's bizarre and beautiful birds.

Where tuis' complex calls echo through the canopy.

TUIS SING

Bellbirds trade nectar for a dusting of blue pollen.

And flightless weka skulk in the undergrowth.

It is the perfect environment for moisture-loving mosses and ferns.

Underneath them,

a humid forest floor of mucus and slime with a deadly secret.

It comes to life at twilight when the hunters come out.

Their lairs are in dark and damp forest overhangs where the extreme

moisture is put to good use.

These silken threads are the work of a tiny larva of a gnat.

Beautiful though they may appear, the threads have a sinister purpose.

The larvae use them to trap their prey.

Droplets of sticky mucus work like spider webs,

waiting to catch hold of flying insects.

Mayflies are a particular favourite.

As darkness settles,

the genius of their deadly traps is revealed in all its beautiful glory.

Gnat larvae are also known as glow-worms.

The bioluminescence is generated

by a chemical reaction within their tail.

Creating an irresistible lure.

The hungrier they are, the brighter they glow,

drawing in victims like moths to a flame.

And this glow-worm isn't alone.

Hundreds live side-by-side.

It's almost as if together they create their own starscape,

confusing navigating insects and luring them to their doom.

When the air itself becomes saturated

and the temperature is just right,

rare giants emerge.

A powelliphanta snail.

It can grow to the size of a man's fist.

So rare, they can only be filmed in captivity

where their extraordinary behaviour is revealed.

It's still a mystery as to exactly how they track down their food.

But one thing is for sure,

this snail has unusual tastes.

And revolting table manners.

Its mouth envelops and suffocates the earthworm.

It's sucked down like spaghetti.

For anything bigger, it's got 6,000 teeth ready to shred the next meal.

In this supersaturated environment,

this specialised snail is the ultimate predator.

BIRDS SING

Water dominates the land.

It thunders off the mountains, creating raging white-water rapids.

Some of the South Island's mountain rivers flow

at over 60,000 gallons a second.

This is no place to bring up a family.

But these parents have no choice.

Fortunately, blue duck chicks are born ready.

They have to navigate the churning currents

to reach the best feeding grounds.

And like their parents, they must dabble to feed.

The tastiest food is on the rocks.

Blue duck bills are specially-shaped to scrape

insect larvae from the riverbed.

The ducklings have a protective membrane to stop their bills

being rubbed raw.

It almost looks like fun.

But sudden storms or snowmelt can cause flash floods...

which can dislodge boulders, let alone a tiny ball of feathers.

But these blue duck chicks can motor through this powerful flow.

Their giant webbed feet are far too big on land,

but they are perfect in the torrent.

Allowing this violent river to become their playground.

There is more than one way to conquer these extremes.

Parrots are very intelligent birds.

But the kea is perhaps the smartest of them all.

When it comes to setting up home, they choose a warm,

dry burrow to keep their family safe from the elements.

HIGH-PITCHED SQUAWKING

The chicks huddle together for warmth and comfort

while their parents are away.

But nine weeks after they've hatched,

they hanker for something more.

Kea are famous for their insatiable curiosity.

THEY SQUAWK

With a little parental encouragement,

there's no holding these youngsters back.

On broad wings, they are led out from the forest...

into a whole new realm.

Kea have unusually agile minds.

Car parks and ski slopes are a smorgasbord of opportunity.

It's not just their minds that are flexible.

Their hooked beaks are a multi-tool.

Perfect for digging, twisting, and getting into all kinds of mischief.

It's this combination of beak and brain

that enables kea to tackle even the most hostile face of the mountains.

Its bill even serves as an ice axe.

The kea is the only parrot in the world to thrive above the snow line.

Of all the wild places in New Zealand,

the Southern Alps present the most extreme challenges of all.

They dictate the weather that rules all life here.

They tower almost 4,000 metres above sea level

and they're still rising.

These are some of the fastest-growing mountains in the world.

They might stand 20,000 metres high if they weren't battered down and

eroded by the elements.

It's a fractured, high altitude, frozen kingdom.

The most inhospitable of all New Zealand.

Up here, the grip of ice is impossible to escape.

Heavy snow falls on heavy snow.

It squeezes out the air, compacting into giant blocks of ice

to create immense glaciers.

Millions of tonnes of fresh water stored, frozen solid.

These powerful giants carve out valleys and deep glacial lakes.

They dominate the entire landscape and hold all life here in balance.

But the strength of the South Island's glaciers is slipping,

and one man has devoted his life's work to find out why.

Brian Anderson is a glacial scientist

who builds machines that help him look into the future.

I like to get out to the mountains.

I like to measure glaciers and try and understand how they work,

what's happening at the moment,

and then try and build a picture

of what glaciers might do in the future.

Brian's workplace has to be one of the most remote in the country.

His mission forces him into parts of the wilderness so cut-off,

he must take everything he needs with him.

Brian has to drive a stake eight metres down

into the icy heart of the glacier to reveal its deepest secrets.

And he does it with this portable steam drill.

For the steam drilling we use this backpack-mounted boiler.

You have to drill quite deep.

It might melt six or eight metres over the summer,

and so we need our stakes to be long enough

that they'll actually stay in.

By measuring the depth of snow through the year,

Brian can record how the glacier changes size,

building a picture of its long-term behaviour.

Glaciers move incredibly slowly,

so the only way to watch them is to speed up time itself.

And his handbuilt time-lapse units will let Brian do exactly that.

Or they will, providing he can get them into the best positions.

It all started with one camera and then I think I got seven cameras

looking at glaciers around the Southern Alps.

So the beauty of using a camera is that it's taking a photo every hour.

It gives us the kind of data

that you can't get from measuring on the ground.

And you can't really get from measuring from space, either,

because these glacier environments are often really cloudy.

Time-lapse cameras can condense a year into a few seconds.

But only if they survive the months of freezing conditions.

The results are worth it.

When you actually look at the photos,

like every hour over weeks or months or years,

you can actually see every little change in the glacier.

I always find things that I wouldn't have expected.

Glaciers are rivers of ice

and it's only in time-lapse that we really see them flow.

Some of the South Island's glaciers shift as much as seven metres a day.

The meltwater helps them move.

CREAKING

It carves its way through to the base of the glacier.

Where it lubricates the mass of ice,

allowing it to flow.

The huge weight carried by the water

grinds its way down the valleys in colossal cascades.

Brian is discovering that parts of New Zealand's frozen kingdom

are melting away.

Even the South Island's mightiest, the Tasman Glacier,

16 miles long and 600 metres deep, is retreating.

And the more they melt, the faster they flow.

Scientists estimate that the Southern Alps

have lost a third of their permanent snow and ice

over the last 40 years.

As the ice retreats, it reveals a broken landscape.

A challenging place to get a foothold.

But New Zealand has some remarkable mountaineers.

It's alpine buttercup.

At permanent risk of being destroyed by falling rocks.

The secret to its survival lies beneath the scree -

a snakelike stem which grows horizontally.

This is its underground larder.

If a stem is snapped, a whole new plant can still grow.

Creating a shower of sunshine across the grey mountainside.

And they aren't the only hardy plants up here.

Edelweiss has its own fleecy blanket as insulation against the cold.

And there is one plant which packs its leaves so tightly together

they become a dense living carpet.

Raoulia grows as low to the ground as possible, just off the rocks,

where it can be a few degrees warmer,

tucked away from the harsh mountain weather.

Antarctic storms bring a sudden drop in temperature.

Freezing conditions and gale-force winds bring death in their wake.

To survive here, you have to be prepared to die here.

But the sun can return as quickly as the storm arrived.

And a rise of just a few degrees is enough to spark a thaw,

even underground.

Frozen solid, a mountain stone weta.

It has the most extraordinary survival technique of all.

The ability to come back from the dead.

Only in a specialised filming chamber

can we capture its extraordinary talent.

The weta has developed special proteins which prevent

ice crystals from forming inside its cells.

A remarkable trick for a creature whose ancestors once lived in

prehistoric warm, wet forests.

But when New Zealand's mountains grew up beneath them,

around five million years ago,

they were forced to come up with this incredible ability to survive

near lethal temperatures.

Defrosting uses up a lot of energy.

So mountain snow berries are a welcome sight.

The weta needs to stock up while it can.

The next Antarctic storm could be the return of winter.

It can tolerate over 80% of its body freezing solid,

and can do so day-in and day-out for weeks at a time.

Nowhere else in New Zealand does life go to such extremes to survive.

Every living thing here must rise

to the challenges of this land's extremes.

In the face of adversity,

life has found unexpected and ingenious solutions.

But perhaps most striking of all is their resilience.

This is the true spirit of New Zealand's remarkable pioneers.

Visitors to New Zealand's Southern Alps

are likely to be confronted by a noisy welcoming party.

Kea are the boldest characters in the mountains.

Infamous for sticking their beaks into everything.

These mischievous vandals know how to charm.

But these entertaining encounters mask a worrying situation.

Kea are slowly disappearing.

One man is on a mission to find out why.

I think something that people are unaware of

is that kea are actually quite endangered, and there's not many.

Corey Mosen is a kea fanatic.

I think I like their inquisitive nature

and how they're really cheeky.

You know, they can outsmart you quite easily,

and working with them is interesting every day.

For nearly a decade, Cory has been trying

to understand the kea's decline,

and he doesn't do it alone.

He has an assistant.

Come here. Come here.

His name's Ajax.

I've been training the dog since he was a puppy.

I've trained him to find kea nests.

So he will follow a scent and lead me to where

a kea is going in and out of a hole.

Ajax is the only kea search dog in the world.

AJAX BARKS

He's pretty good company in the bush

and he can keep up with me.

Kea breed in some of the most remote parts of New Zealand.

Today, Corey and Ajax are on their annual kea nest checkup,

and have a two-day journey ahead of them.

Sometimes you have to walk over a couple of mountains and down into

valleys, and then up through some rivers and around some bluffs,

but eventually you'll find where they are.

But Corey's task is getting harder every year.

He starts by checking some closer nesting sites.

Which, a few years ago, would have been full of kea families.

Now they're empty.

Corey and Ajax are going to have to go further afield.

With the light fading, they make camp for the night.

My favourite thing is just being outside.

I am outside all the time, in the snow, in the rain, in the wind,

and it all just makes you feel alive.

Next day, they set off early.

And Ajax announces

AJAX BARKS

he's found exactly what they're looking for.

But this burrow is built for a kea, not for a kea tracker.

This is not comfortable.

To study them, Corey first needs to catch them.

A collar keeps Corey's fingers safe.

He carefully attaches a leg ring

and records the details.

A quick draw of blood adds to the genetic database for the species.

A final check, and he releases the bird back to the nest,

none the worse for wear.

But Corey has one more job to do.

During the three months kea nest underground,

they're extremely vulnerable.

We put a trail camera outside the kea nest

to monitor for predator visits.

So every time something moves outside the nest,

it'll take three photos,

and we can use those photos to determine,

you know, what's visiting the nests.

Whether it's just the keas

or whether stoats and possums and rats are annoying them, as well.

Corey's trail-cams provide a unique insight

into the private life of kea.

But they also reveal what is really going on.

Predatory mammals introduced from around the world

are decimating New Zealand's native birds.

Kea are easy prey for a stoat.

I fear that they might be approaching extinction

and that they will no longer be in the wild.

We need to find a way to control stoats.

Stoats are the big number-one pest that affect

all New Zealand's native birds

and if they weren't here, they'd do a lot better.

In areas where there are pest control,

the kea actually have a chance of producing young that make it out.

It's great to see them become adults,

flying around the same area where we tagged them as chicks.

Oh, I'd like to see kea everywhere.

Every time you go for a hike into the mountains

it would be nice to have an interaction with a kea

somewhere along the way

and to hear them screaming in the hills

and in the forest would be great.

Thanks to Corey's hard work

we are realising that despite their clever nature, kea need our help.

And only with our help will New Zealand's Alpine valleys

remain the realm of this cheeky mountain king.

KEA SQUAWKS

Next time...

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