All language subtitles for Planet.Earth.III.Ep04.Freshwater.2023.1080p.BluRay.x264.Atmos.TrueHD7.1-WiKi.English

DAVID ATTENBOROUGH:
Beneath the Yucatan Peninsula

of Mexico...

...lies another world.

A labyrinth of caves...

...carved by freshwater.

An essential for life on Earth.

Freshwater shapes the land

and the creatures
that live in it...

...in the most surprising ways.

(BIRDSONG)

The rainforest of Costa Rica.

As you might expect,
it rains most days.

(THUNDER RUMBLES)

But it's only during
the wet season

that the rains
become torrential.

And with them...

...comes
a most remarkable creature.

Gliding tree frogs.

Thousands drop in...

...together,
at this newly formed pond.

They all have an urgent need.

To breed.

This female
needs to find a leaf

and lay her eggs.

(CHORUS OF CROAKING)

The breeding frenzy
will only last one day...

...so she needs
to get a move on.

There are lots of eager males.

Nine for every female.

And all are ready
to spring into action.

So for her, getting a partner
is no problem.

But the other males
are desperate.

For this female,
mating is rather chaotic.

Things are getting out of hand.

There is one way
to deal with this.

A few well-placed kicks...

...usually does the job.

Problem solved.

She and her partner
can now finally mate...

...in relative peace.

(BOING)

The eggs are positioned
perfectly...

...directly overhanging
the pond.

(SQUELCH)

(SPLASH)

This is the ideal nursery
for tadpoles.

For now,

her work here is done.

She'll be back next year
when the heavy rains return.

As quickly
as freshwater appears...

...it can vanish.

(CRACKING)

Southeast Sri Lanka.

(FLIES BUZZ)

It's the middle of the dry
season.

(WIND WHOOSHES)

This is
the only remaining water hole

for miles around.

(BIRD CALLS)

(HIGH-PITCHED HONK)

Mugger crocodiles.

Giants. Five metres long.

Dozens are hiding

beneath the surface.

And others...

...are on their way.

This male has been travelling
for hours.

The water hole
is the only place

where he has a chance
to catch a deer.

A single adult would be enough
to feed him

for the entire dry season.

But hunting prey
that knows you're here...

...requires something
truly remarkable.

He creates...

...a trap.

He digs down into the mud.

Deep enough to hide
beneath the vegetation.

Perfect camouflage.

He has built his trap
right on the water's edge.

So it's the first place

that thirsty deer will
come to drink.

(RAPID SQUAWKING)

(FLIES BUZZ)

(SNIFFS)

These crocodiles
have learned to exploit

the deer's desperate
need for freshwater.

(TRICKLING)

Freshwater transforms

not only the lives
of animals...

...but entire landscapes.

Every year,
over a trillion litres of water

flow into the Kalahari Desert.

It has travelled
a thousand miles

from where it fell as rain.

And on arrival...

...it turns the Kalahari

into a vast oasis.

(SQUAWKING)

The Okavango Delta.

These waters attract
millions of animals.

And for some,

now is the perfect time
to raise a family.

(GENTLE SPLASH)

A lily-trotter.

(CRACKING)

And he is a father...

- (CHIRPS)
- ...on duty.

(ALARMED CHIRPING)

He has not just one...

...but four
newly hatched chicks.

(SQUEAKING)

They won't be able to fly
for another six weeks.

So, until then,
he alone is their protector.

Walking on water
is not straightforward.

(CHIRPS)

So he must show them
how to be a lily-trotter.

The floodwaters make
the perfect training ground.

And in two weeks...

...his chicks not only double
in size...

...they grow in confidence.

(SQUEAKING)

But this is a dangerous place
to stray.

(WARBLES)

He sounds the alarm,

and his chicks
instantly freeze.

They can't yet fly to safety.

But there is one thing he can
do to protect them.

(BURST OF RAPID CHIRPING)

And it's risky.

(SHRILL CHIRPING)

Get close enough to distract...

...and hopefully divert
the crocodile.

(CHIRPING)

(BURST OF RAPID CHIRPING)

(CHIRPS)

Mission accomplished.

(LONG CHIRP)

He signals the all-clear.

(SQUEAKS)

(CHICKS SQUEAK)

But one chick is missing.

(SHRILL CHIRPING)

(CHIRPING)

(CHIRPING)

His calls go unanswered.

(CHIRPS)

(CHIRPING)

(SOFT CHIRPING)

A little bedraggled,
but alive and well.

(LONG CHIRP)

His chick just hadn't heard
his call.

And when danger threatens,

it's always better to be safe
than sorry.

He's brought his chicks,
all four of them,

to the verge of independence.

Whilst lily-trotters
are well adapted to life

in this flooded world...

(PANTING)

...these residents of the delta
are not.

African painted dogs.

Normally, they are
remarkably successful hunters,

but this pack of five
hasn't eaten in days.

(PANTING)

(DISTANT BELLOWS)

Finding prey isn't the problem.

This herd of lechwe is only
a few hundred metres away.

But between them is deep water.

(NERVOUS YIPPING)

(DEEP BELLOWING)

(HIPPO HONKS AND BELLOWS)

It's not safe to cross here.

(HIGH-PITCHED SQUEAL)

(GRUNTS)

On dry land, the dogs can run
at over 40 miles an hour.

But when threatened,

lechwe always seek
the safety of water.

With their splayed hooves
and long hind legs,

they can power their way
through the water.

The dogs can't.

The pack won't be able
to outswim the lechwe.

But they do have a strategy.

The dogs drive the lechwe
to where

they have the advantage.

Back towards dry land.

Now the pack
can regain lost ground.

(LECHWE WHIMPERS)

Success today,

but tomorrow the pack
will need to hunt again.

In the Okavango,

animals must always adapt
to the coming and going

of freshwater.

But there are
a few rare places,

as here in Lake Malawi,

where freshwater has lain
for millions of years.

And that has enabled life
to evolve

into a dazzling diversity
of species.

There are over a thousand
different kinds of fish here.

More than any other lake
on Earth.

Competition in these waters
is intense.

Meet Nimbochromis livingstonii.

A master of deception

that tricks other fish
into thinking it's dead.

Its mottled colouration
mimics decaying flesh.

But to appear dead...

...one must at least act dead.

This juvenile
is fooling no-one.

Perhaps faking his death
will be more believable.

Blown it.

A more subtle performance
will be needed.

This is more convincing.

But his aim must be
better than that.

Nearly.

It seems
he's overstayed his welcome.

In a final effort,

he appears
to even hold his breath.

Success at last.

All it took was a million years
of evolution...

...and the unique stability
of this ancient lake.

Off the western coast
of equatorial Africa

lies the volcanic island
of Bioko.

(THUNDER RUMBLES)

Freshwater here
has a turbulent nature.

Few venture into such waters,

but for those that do,

there can be great rewards.

After months feeding
and growing out at sea,

these gobies
are ready to breed.

And the safest place
to lay their eggs

is somewhere that
ocean predators can't reach.

The top of this waterfall.

Surely an impossible journey
for a fish.

But over the coming days,

the gobies
transform themselves.

They change colour.

Their mouth rotates and acts
like a kind of suction cup.

Which they will certainly need.

Because the only way...

...is up.

It is 30 metres to the top.

They are only an inch long.

This is the equivalent

of a human being
scaling a waterfall

over a mile high.

Millions attempt the climb...

...but less than 1 %
will make it.

This goby has been climbing
for days.

Made it!

Those that reach the top
can now prepare to breed.

And when the time comes,

their young will be washed
back out to sea.

The extraordinary power
of flowing water

makes it our planet's
greatest architect.

This may look like the surface
of an alien planet.

But these strange patterns
are channels of freshwater...

...flowing towards the sea.

For 3.8 billion years,

ever since
the first rains fell...

...freshwater has been making
this journey.

But today, two thirds
of our world's great rivers

no longer reach the sea.

(DEEP CREAKING)

There is a finite amount
of freshwater on Earth.

(ECHOING CREAKS)

So humans have devised
extraordinary means

to ensure
that it is always available

to meet our every demand.

(GEARS GRINDING)

We now control freshwater

on a colossal scale.

The largest irrigation system
on Earth

has been built here,
in Pakistan.

(HONKING)

A vast network of dams
and canals...

...that diverts and drains
the great Indus River.

It's used to irrigate an area
the size of England.

This man-made freshwater world

provides water and a livelihood

for millions of people.

(LAUGHING)

But at a cost
to the natural world.

A rare creature
has become stranded

in this irrigation canal.

And the water
will soon be gone,

used to supply
the surrounding land.

Endangered, they number fewer
than 2,000 individuals.

An Indus river dolphin.

This female dolphin
is 150 miles

from the main river.

She can't return on her own.

So the only option

is for this rescue team
to take her.

(EXCITED CHATTER)

Out of water,
she cannot survive for long.

The journey back to the river
will take hours.

Her life now depends
on these people.

(EXCITED CHATTER)

Nearly 30 dolphins
had to be rescued

in one month alone.

Freshwater is not only
a resource for humans...

...it is the home
for countless species

that simply cannot survive
without it.

Freshwater is the lifeblood...

...of Planet Earth.

DAVID: To film the story

of the most endangered
freshwater dolphin,

the Planet Earth team joined
the world's leading expert,

Uzma Khan.

The first time I saw
an Indus dolphin,

I was just amazed.

It's a beautiful creature,
you know?

It's like love at first sight.
It's so unique.

Uzma has been studying
the last remaining population

for over 20 years.

There's a dolphin
that surfaced

just right there.

Indus river dolphin
can only live in freshwater.

It is only found in Pakistan
and nowhere else,

and we only have
about 2,000 of them left

in the Indus River.

So, you know,
each individual is special.

Following the dolphins
in the murky water

is extremely challenging.

They only surface
for a split second,

and that makes protecting them
difficult, too.

Their greatest threat
is becoming trapped

in the irrigation canals.

But Uzma may have a solution,

and teams up with a rescue unit

to attempt something
never done before.

This is the first time
we'll be putting satellite tags

on river dolphins in Asia.

Since this has not been tested
on this species,

there's a little bit
of anxiety,

but if they work,

then it's going
to be a breakthrough

for conservation.

(SIRENS WAIL)

Uzma has been developing
a suitable tag

for over ten years,

and hopes it will help her
collect critical data

on how the dolphins are moving
through the dams and canals.

But in order to tag,

she will first need
a successful rescue.

UZMA KHAN:
I'm usually very concerned

when a rescue is happening.

You know the divers,
they are very experienced,

but a part of me
is always very worried.

They are wild animals
that have never been handled.

NICK EASTON:
It's really quite a risky thing

that they're undertaking here.

There's a good chance
the dolphin might die.

But, of course,
they're balancing that

against the fact
that they definitely will die

if they stay in here.

So it's a risk
they have to take.

CREW: Have they got
the dolphin?

Yeah, I think so.
They've got it.

DAVID: Now, speed is key.

NICK: We're now bombing
across the field

on the way to the release site.

And I think Uzma went ahead
of us, so I'm really hopeful

that she'll get her opportunity
to tag the dolphin.

But rescue missions
don't always go to plan.

(POP)

(AIR HISSES)

(HONKING)

A puncture.

The dolphin is quickly moved
to the film crew's truck.

But with no roof for shelter,

the dolphin is at greater risk
of dehydration.

ABDULLAH: Stakes are high
right now.

It's a cute little animal,
and we don't want it to die.

The team re-route
to the closest release site.

There can be no more delay.

Uzma calls off the tagging.

It's unfortunate
because we were all prepared.

We were very excited
since morning, all geared up,

but hopefully
we'll get an opportunity

to tag the next rescue.

A few days later,
Uzma finally gets her chance.

UZMA: It's a very exciting day
for us.

RESCUER: It's OK.

The moment that we have been
waiting for over ten years.

UZMA: Just stay calm.

OK. It's good to go.

Congratulations, Mubarak.
Well done.

I am very happy, very happy.

I think
it's a great accomplishment.

It's the happiest moment
of my life.

(RESCUERS CLAP)

DAVID: Within a few weeks,

the tags begin to reveal
some new insights.

UZMA: They are moving
quite a lot,

which we never expected.

So one of the dolphins
actually went

about 46 kilometres upstream

from the release site.

And the other thing is that
we thought that they will stay

in the main river stream,

but they are using
side channels.

It is extremely interesting.

Tracking the movement
of the tagged dolphins

will help Uzma
better understand

when and where
they become trapped,

helping safeguard the future
of this most endangered animal.