All language subtitles for Our Living World S01E04

On a river
in the American Pacific Northwest...

...the yearly salmon run
has collided with the modern world.

This floodplain used to be
easy passage for fish on a mission.

But a road has turned it
into a deadly gamble.

The salmon must take their chances...

...to reach their spawning grounds upstream.

They are driven
by an overwhelming instinct

to swim against the current.

So they've just gotta go.

And where one succeeds...

others can too.

Millions of migrating salmon
must today run a treacherous gauntlet.

From the open ocean...

...inland past tarmac, concrete,
and steel...

...these determined travelers
will stop at nothing to reach their goal.

If they succeed,

their migration will bring a pulse
of vital nutrients in their bodies

that nourishes a vast forest network
that spans the Pacific Northwest.

To stay healthy,

this forest and everything
that depends on it...

...needs its fish.

And these heroic salmon

are just one in a cast
of incredible creatures

all over the world...

...whose battles to survive...

...adapt, and reproduce

also have the power to help nurse
our ailing planet back to health.

They are our most powerful allies
on the Earth's road to recovery.

While they fight for their futures,

they are in fact fighting for ours.

Humans.

We've done some strange things
to this planet.

By attempting to build our dream homes...

...we've created a confusing world
for the neighbors.

Wherever we've spread,

the dangers we've introduced
are causing havoc.

But one creature
has been preparing for the worst...

his entire life.

Hunkered down in his Florida bunker...

the ultimate doomsday prepper.

Inside a rock-hard shell
six feet underground.

Now that's how you stay safe.

But even a recluse needs to eat.

For a gopher tortoise,
leaving your burrow may well be daunting.

But to find fresh shoots,
he needs to come out of his shell

and out of his comfort zone.

Come on, how scary can it be?

Here goes nothing.

The neighbors seem pretty harmless.

All busy keeping Florida's
longleaf pine forest in tip-top condition.

Pollinators.

Tree planters.

Even pest controllers.

But it's best to give some a wide berth.

For our play-it-safe tortoise,

coming out of his shell
seems to have paid off...

...with a midsummer feast.

But he can't let his guard down.

Because high summer is also

wildfire season.

It's nature's way
of making space for new life to grow.

If he can't get back to his burrow,

he'll be cooked in his own shell.

Time to put the pedal to the metal.

Burning at over 600 degrees...

...the fire claims an acre
every ten seconds.

Amazingly...

the tortoise has survived.

But how?

He didn't make it home.

But he has dug safety bunkers
all over this forest.

And his doomsday prepping
hasn't just saved his own skin.

Over 300 different species
seek shelter from summer wildfires

in the burrows of gopher tortoises.

He has saved his neighbors.

And as each animal
plays its own role in the forest,

together they'll help
their home to recover.

We will increasingly rely
on heroes like him

as the web of life on which we all depend...

...is threatened from all sides.

In 2020,

Australia suffered
its worst ever bushfire season.

One-fifth of all its forests
turned to ash.

Three billion animals killed or harmed.

But there may yet be a way
to heal this broken land.

A flying fox descends on Downtown Sydney...

...with thousands of other fruit bats.

Her forest destroyed, these refugees
are trying to survive in a new home.

This world is like
no forest she's ever seen.

A canopy of concrete.

Electric branches.

Razor blade undergrowth.

Nothing in 50 million years of evolution
has prepared her for this.

But she's learning fast.

And pinpoint night vision
helps her find food

even in the heart of the city.

She must eat her fill before dawn.

Because after the night shift,
she's got a day job to clock on to.

In a park nearby,

what used to be a rest stop
for migrating bats,

has now become a permanent roost.

Hiding something truly precious...

her hungry baby
waiting for his morning milk.

But the day shift
brings its own challenge.

Heat.

Sydney summers
now regularly top 110 degrees.

Far hotter than shaded forests.

And deadly for young bats.

But mom has
some neat tricks up her sleeve.

Blood flows through the thin skin
of her wings

so she can try to cool down.

And she can fan her pup.

But the temperature is still rising.

He's in trouble.

She must find a way to cool him down.

There's one thing left to try.

Water.

It calls for a daredevil descent.

The airspace is crowded...

...with fierce competition.

But it's nothing she can't handle.

A single dip soaks her fur.

Enough water to cool her pup...

...with a soggy, life-saving embrace.

Whatever this hostile place throws at her,
she will do her best to find a way.

And there's more
than just her baby's survival at stake.

Because fruit bats have the power
to shape the world around them.

Amazingly, each flying fox can pollinate
50 different species of tree...

and spread thousands of seeds
in a single night.

Even here in Sydney's parks,

there are signs that they are nursing
nature back to health.

Over time, if these bats
can return to their wilderness home...

...this vast tree-planting air force...

could help regrow their lost forest anew.

The healthier the Earth's wild places,

the harder they work
to the benefit of us all...

...protecting the air we breathe
and the water we drink.

The future health of our entire planet

may rest with
nature's last great strongholds...

...and their most important inhabitants.

This grandmother has
a growing family to support.

Every new baby, a blessing.

But also another mouth to feed.

Forest elephants have
demanding nutritional needs.

And there's only
so much grass you can stomach.

So, it's just as well
she has Africa's biggest drugstore

right on her doorstep.

The Congo rainforest.

Bulldozing their way through
the dense undergrowth is slow-going.

But there's a quicker way.

A path.

Generations of her ancestors
have walked these same routes...

creating thousands of miles
of elephant-sized corridors...

...making it far easier
to browse the aisles.

And this path leads...

...to a forest pharmacy.

The clay is rich in salts and minerals...

that help them survive
the sweltering heat.

Like an isotonic mud drink.

But to grow big and strong,
this family needs fresh vitamins.

And Grandma knows
every trick in the book to find them.

Elephants can hear
some of the lowest frequencies

of any animal.

And they can even use
the sensitive pads of their feet

to pick up the faintest of tremors.

And that is the sound of fresh fruit
hitting the shop floor.

Grandma has a bearing...

and she knows the quickest route there.

And in their quest for a healthy diet,

wherever this family roams,

they also boost the forest's health.

Each elephant spreads
over 200 pounds of mineral-rich compost...

...and weeds out several miles
of choking undergrowth...

...every single day...

...which gives the forest's
slow-growing saplings

the chance they need
to transform into giants.

Giants with the power to help save us all.

As humans drive up the amount
of carbon dioxide in our atmosphere,

this mighty elephant-grown tree
is drawing it down.

It then performs
one of nature's greatest magic tricks.

Transforming carbon dioxide into sugars

through the power
of sunlight on its leaves.

Locking planet-warming carbon safely away

into its branches, trunk, and roots.

The work of gardening elephants
allows Africa's tropical trees

to draw down an extra billion tons
of carbon every single year.

These giants could help us turn the tide
on rising carbon dioxide levels...

...and actually fight climate change.

While Grandma simply searches
for what she needs

to keep her family healthy.

But in the last 30 years,

we have lost three-quarters
of Africa's forest elephants to poaching.

With so little
of our planet's wilderness still intact,

we need its wildlife now more than ever.

Nature's greatest healers
are disappearing on our watch.

Species that do most
for our planet's health

are amongst those
most at risk of extinction.

And as everything is connected
to the vast web of life,

their fate could soon become ours.

But what if we could help
some of these vital animals...

to rise again?

Saiga antelope.

They once roamed the steppe
from Europe to China in their millions.

Grazing and spreading seeds,

these nomads maintained
the world's biggest grassland

for millennia.

Until the 1990s,

when rampant poaching
devastated their herds.

Their numbers fell faster
than any mammals in history.

And as the grazers disappeared,

so too did the grasslands
that depended on them.

But a decade later, saiga hunting
was banned throughout their range.

The future of the steppe
rested on whether a few survivors

could come back from the brink.

A new hope.

And one becomes three.

Tomorrow's grazers ready to roam.

And thankfully, they are not alone.

Other saiga mothers
have gathered at the nursery grounds.

At a year old, they give birth to twins,

and even triplets.

So with each yearly baby boom,

the herds nearly double in size.

In just 20 years,

a few thousand survivors
have become a force a million strong.

This new generation
is ready to reclaim their ancestral home.

Marching for thousands of miles
every year.

Breathing life into the grassland
wherever they spread.

And securing the future of the steppe
for everyone who lives here.

Scientists have calculated that supporting
the return of just 20 large mammal species

could help revive nearly a quarter
of all the land on Earth.

So today, a movement is gathering pace
across more than 70 countries worldwide...

to hand damaged landscapes
back to their natural caretakers

in a process called "rewilding."

In Argentina's IberáWetlands,
over a million acres of swamps, forests,

and grasslands once thronged
with over 4,000 species.

But centuries of cattle ranching
drove out the wildlife

leaving this rich tapestry
at risk of collapse...

...until the turn of the millennium...

when work began
to hand this land back to nature.

But now, one species is standing
in the way of complete recovery.

With the cattle gone,
clans of capybara are filling the vacuum.

Hundred-pound rodents...

mowing down any new shoots
that try to grow.

Which means Iberá's recovery
has hit the skids.

Not that these giant guinea pigs
seem worried.

They're so laid back...

...they're horizontal.

But all that is about to change.

This pen holds one of South America's
most feared predators...

...hunted out here over 70 years ago.

This rescued jaguar
could solve the capybara conundrum.

While her challenge
is feeding her twin daughters.

Everything now hinges
on whether this killer can learn to hunt...

...on the other side of the fence.

The first free-roaming jaguars
to set foot here since the 1950s.

It's all theirs for the taking...

if Mom can just tune
into her killer Instinct.

Stealth mode.

Keep low.

Get close.

Then wait for your moment.

These capybara have
only ever danced to their own tune.

Until now.

Her daughters witness a masterclass

and share the spoils.

They too will become agents of change...

...unlocking the full potential
of this vast landscape.

This family of assassins
will now bring fear wherever they tread.

The capybara will keep to the waterways
where they feel safer.

Keeping grazers on the move
gives more plants a chance to recover...

so pockets of new habitat can emerge.

And even more species
can return to this old cattle ranch...

...building their own connections,
making it more resilient to change.

Iberá's restored webs of life

will help it endure long into the future.

Thanks to the return
of one missing piece of the puzzle.

Empowering nature's healers

can protect us from many of the perils
of a changing planet.

Wildflower meadows boost bee populations...

...helping secure
a quarter of our food supplies

from increasingly unpredictable seasons.

Protecting sea otters
revives kelp forests...

which shield coastlines
from increasingly stormy seas.

And rising whale numbers
fertilize the oceans,

helping to feed blooms of plankton

that capture ten billion tons
of carbon every year.

As much as all our rainforests combined.

When we help nature, nature helps us.

The signs of a hopeful recovery
are there to see.

Across Washington State,

the paths
of the mighty salmon run are blocked

by more than 10,000 man-made obstacles.

Numbers of some salmon species
have crashed by up to 95%.

But as we begin to see the bigger picture,

today on one river...

things are about to change.

A campaign to tear down old dams

is transforming waterways
across North America.

So far, over 1,900 have been dismantled.

Thousands of miles of rivers
can once again run free.

So too can their salmon.

Finally, they can reach
their ancestral spawning grounds.

As they lay their eggs
in the cool, shaded streams...

their journey is complete.

But their legacy will endure.

An entire generation of salmon
give up their bodies.

And their death
pumps life back into the forest.

This vast transfer of nutrients
from ocean to land,

from one life to the next,

is the forest's lifeblood...

providing up to 80%
of the nitrogen it needs to grow.

The salmons' offspring
will travel downstream

to start their cycle anew.

With our help,
their numbers could flourish again,

sustaining an entire web of connections...

from mountain...

...to sea.

Bringing new hope
for everyone that relies on them.

Nature can help heal our world...

if we just give it a chance.

Every living being
is an invaluable link in the web of life...

on which, ultimately, we all depend.

In our connected world,
every action has consequences.

And the choices we make

really matter.

Armed with new knowledge,

we can take steps to help nature
nurse our planet back to health.

The time to act

is now.

Because it's no longer just a case
of whether we can still save nature,

but whether nature can still save us.