All language subtitles for Planet.Earth.III.S01E05.WEB

Forests at first sight

may seem quiet and tranquil.

But today we can explore them
in new ways...

..and from a new perspective.

And, in fact, they're full of
unexpected connections,

relationships

and even secret messages.

Only now are we discovering

how strange and complex

forests actually are.

The rainforest of Borneo.

A pair of oriental pied hornbills
are renewing their partnership.

They mate for life.

And this year's nesting season
is just starting.

Before they face
the challenges ahead,

they reaffirm their bond.

And they do so with an
unusual ritual...

..at the entrance to a bat cave
that they know well.

This rather curious gift

isn't normally on their menu.

But it both demonstrates devotion

and reassures the female that
her mate will provide for her.

In the coming weeks,
she will depend on him

in the most extraordinary way.

Nesting is a dangerous time
for any bird.

The hole in this tree trunk

will provide vital protection.

Just what she wants.

Once settled inside...

..the female does something
truly bizarre.

She pulls out her flight feathers.

She is not going to need them

because she will be staying
in here for quite some time.

It's not only a little cramped,

it also lacks basic amenities.

Now her partner brings her
a beakful of mud.

And she begins to seal herself in.

She has turned the tree hole

into a predator-proof fortress.

But it's also...

..a prison.

Her partner, however,
is a regular visitor.

For the next two months,
he will deliver all her food

directly to her door.

But she can be fussy.

He's going to have his work cut out.

Delicious.

It may seem that he has been
doing all the work...

..But she, too,
has been fully occupied.

The food he has brought
has enabled her to produce

two precious eggs.

She will keep them safe
for another six weeks

until the young have grown
and fledged.

And then, both she and they

will break out of their confinement.

But until then...

..this devoted couple are
going to be very busy indeed.

The warmth and the moisture
of rainforests

enables their inhabitants
to flourish

in both numbers and variety.

And here, in the Amazon,
live many strange species.

This is a treehopper.

One of hundreds of different types
in this forest.

They not only have
a bizarre appearance...

..but they also communicate...

...in a remarkable way.

Vibrating their bodies,
they send signals

through the forest plants
they live on.

Most of these messages we can only
hear by using special microphones.

Each treehopper species has
its own repertoire.

And every sound...

..has its own particular meaning.

Whether it is to attract a mate...

..share information about food...

..or warn each other about the
arrival of predators.

This treehopper mother
communicates with her young,

encouraging them to stay together

so that she can protect them.

For there are plenty here
waiting to eat young treehoppers.

Ants...

..on the hunt.

Treehoppers know how to
defend themselves.

But not all threats are
so easily dealt with.

An assassin bug.

Armed with piercing mouthparts

and sticky front legs...

...capable of literally sucking
the life out of her entire brood.

She can try to block
the assassin's path.

But she can't guard them all.

She needs help from friends
in high places.

Bees.

They're very aggressive.

This is more than the assassin bug
bargained for.

Mission accomplished.

Her brood are safe.

The bees don't protect
the treehoppers for free.

A little tickle on
a treehopper's back...

..and they exude a sugary liquid.

Honeydew.

A sweet reward for protecting them.

It's just one of the countless ways

in which forest species
work together.

In the forests of India,

you can hear a unique and truly
extraordinary sound.

These are dholes...

..wild dogs that whistle.

Like treehoppers, they, too,
communicate in secret -

but for a different reason.

Hunting in a dense teak forest
is difficult...

...especially so if your prey is
three times your own size.

The only way for dholes to succeed

is to work as a team.

This family has four growing pups.

A chital deer could feed
the entire pack.

The pack must get close...

...without being detected.

But with eyes and ears everywhere...

...the deer are soon aware
of the dogs' presence.

The pack can't afford to give up.

They may have better luck here.

The vegetation is dense
and provides better cover.

But the dholes could easily
lose track of one another.

So they use their unique whistles.

Only dholes can understand

these quiet, unobtrusive calls.

Now they take up their
hunting positions...

...even though they can't
see each other.

With the deer surrounded...

...the dholes wait for the signal
to attack.

Some of the dholes split the herd...

..and drive a stag towards
others waiting in ambush.

The dholes' ability to
communicate so quietly

enables them to stay connected,

and so hunt successfully in
the tangle of their jungle.

The mountainous forests
of central China.

Until recently, these were among
the least known of forests.

They're full of swirling mists,

and few outsiders had any idea

of what they might contain.

Living in such dense vegetation,

it's difficult to make
yourself seen...

..even when you want to be.

And that's a problem for this
male Temminck's tragopan.

He has lived most of his life alone.

And this is his first mating season.

He needs to make himself conspicuous
in the gloom of the forest floor,

and he's found a clearing
where he might do so.

A female.

She, too, is looking for a mate.

This could be his moment.

Oh, dear.

Stage fright.

And who is this?

A male golden pheasant.

He, too, has come to
this clearing...

...to attract a female.

And he seems a little
more confident.

So that is how it's done.

The tragopan might still
have a chance.

Here is a new female.

But is she interested?

It's time to be bold.

He pumps up a pair of horns

and a multicoloured bib.

It's a sight to be wondered at.

And it has never before been
filmed in the wild.

Not today.

How deflating.

The temperate rainforests
of western Canada.

Some of the trees here
are 1,000 years old.

It's autumn, and the beginning
of a spectacle that each year

transforms this forest
and all that lives in it.

After years at sea,
thousands of Pacific salmon

are returning to these streams
to breed.

And they attract the forest's
rarest resident.

A spirit bear.

A white variant of the black bear.

Fewer than 150 exist,

and they're found only here.

This female has fished for salmon
here for 20 years.

Get your timing right...

..and there can be great rewards.

In her youth, she was, in fact,
even more successful

than the black bears.

Perhaps her pale coat makes it
difficult for the fish to see her

against the bright sky,

and that could give her
an advantage.

But now she is old,

and this year she's finding it hard.

Her fishing skills, however,
haven't totally deserted her.

This annual feast helps
her to fatten,

ready for the winter ahead.

But it also helps the patch of
forest where she lives.

This female has an unusual
relationship with the forest.

Every fish carcass
she leaves behind decays,

releasing nutrients that soak
into the soil.

And there...

..they are collected by
a network of fungi.

The threads attach themselves
to the trees' roots.

And nutrients from the fish,
collected by the fungi,

are then passed on to the trees.

As a consequence,
the forest around the river

grows three times faster
than elsewhere.

And some trees here become
as tall as any in the world...

..and provide spirit bears
with a healthy forest home.

We now know that such relationships
exist in forests all over the world.

At the heart of these
many connections

stand giant trees, like this one.

A kapok.

It started life as a seed
some 200 years ago.

Now it towers 60 metres above
the forest floor...

..and transports 1,000 litres
of nutrient-filled water

from its roots up to its canopy
every day.

So this giant gives life to others.

A whole community of animals
and plants

depends on the wellbeing
of this one tree.

A single cut made in
just a few moments

has broken thousands of
long-established connections.

Across the world's forests,

this story is being repeated
endlessly.

15 billion trees

are cut down every year.

Every one of these trees is,
in itself,

an intricate ecosystem.

But here in Brazil,
they're being replaced

by plantations of a single
species of tree.

Originally from Australia...

..these eucalypts are unable
to build relationships

with most of the native plants
and animals.

And, worse, these newcomers
grow so rapidly

they extract nutrients from the soil

faster than they can be replaced.

And what was once a rich
and complex world...

..becomes little more than
a green desert.

And at just five years of age...

..their lives are ended.

They're felled and taken away.

Their wood is then pulped
to make paper.

And all that remains of
the rich rainforest

are a few tiny patches.

Patches so small that few of
the original inhabitants

are able to survive in them.

Uganda, East Africa.

This small group of chimpanzees

have a detailed knowledge
of the forest territory

that they inherited from
previous generations.

They know the best places
to shelter,

to raise their young...

..and to feed.

This fruiting tree

cannot by itself sustain
the chimps for long.

The alpha male signals
that it's time to move on.

Where he goes, others will follow.

He leads them not to
another fruiting tree...

..but into a new world.

This road, only recently built,

has cut through their territory.

The alpha male is cautious.

His own mother was killed
on this road.

He makes sure it's clear
before crossing

with the slower members
of his family.

If the group is to get
what they need...

..they will have to go against
their natural instincts...

..and approach humans.

But their new neighbours
are friendly.

And they allow the chimps
to collect...

..jackfruit,

the largest of all tree fruits.

Jackfruit grow all year round
in people's gardens.

And they're more nutritious

than the limited amount of wild food

the chimps can now find in what
remains of their forest.

But this is a new world...

..and a new relationship.

New boundaries need to be
established.

Some of the chimps start
to help themselves

to people's crops.

They have outstayed their welcome,

and the alpha male decides
that it's time to leave.

The chimps make this dangerous
journey every day.

But these highly
intelligent animals,

our closest living relatives,

have managed, just about,

to carve out a place
for themselves

in this changing world.

Animals have maintained

a long-established relationship
with forests.

But as we continue to break
our connections with them,

the question is,

for how much longer will
they survive?

Surely, the time has come
to rebuild them.

Over many years,

I've been lucky enough to watch
chimps in their natural home,

such as here in the thick forests
of West Africa.

Chimpanzees.

A peaceful scene of jungle harmony.

The experienced male...

..is sitting right there.

But the lives of
many chimpanzees

are now changing dramatically.

Here, in Uganda,
over the last decade,

they have lost over 80%
of their forest home.

They don't live in a protected area.

To survive here,
they have to live alongside

the 200 or so human families
who farm here.

The chimps always come
from the forest.

They come to eat jackfruit
from my land.

They know us by our faces,

as we know them by their faces,
as well.

To tell the story of this
remarkable chimp group,

the Planet Earth team are working
with these residents.

Who was that, Tom?

This one was Araali.

Tom is part of the Bulindi
Chimpanzee and Community Project.

He's been studying the chimps every
day for the last 15 years...

..and has seen the change
first-hand.

Very many things have changed.

When chimpanzees were seeing people,
they would run.

Run very quickly and go.

But now they just stand.

Because everywhere they go,

they find a person.

Chimps are normally tricky
to film in the wild.

But in this human world,
the crew are surprised

by how easy it is to approach them.

Another one
coming up the path.

But back in the forest,

it's a different story.

Here, the chimps seem wary
of the newcomers.

There's a ditch there.

All the crew get to see...

..is a lot of bottoms.

This afternoon, the chimps have been
taking us on a wild-goose chase.

They've crossed the river
and then they've crossed back,

gone past us
while we're in the woods,

and then now
they've disappeared again.

When we don't have chimps...

..we film goats!

Here, in the chimps' forest home,

it's going to take time
to earn the group's trust...

I think they found Moses.

..and get to know one another.

This is Jack.

After two weeks, things are
improving on the ground.

But what will the chimps think
of the crew up in the trees?

I can see a bunch of
chimp faces looking up at me.

This is a new experience
for them.

I doubt they've ever seen a human
in a tree before.

So, hopefully, they accept me.

After hours of waiting...

..success!

All the chimps that were
on the ground looking up at me

are now happily in the tree,

which is a really good sign
that they've accepted me.

It's the first time that we've been
able to see at their level

while they're feeding.

For the crew,
it has taken a long time

to gain the chimps' acceptance.

But, in fact, the chimps here
have shown that they can

respond quickly to the presence
of people.

Chimpanzees are highly intelligent.

If you cut down the forest,

well, chimps will start
eating human crops.

If you divide their range up
with roads and, you know...

Well, chimps will end up just
learning to cross the roads.

The animals can adapt to an
increasingly human environment.

The question is, can people
accommodate an animal like a chimp?

Chimpanzees can be dangerous.

Living alongside them is
a mixed experience.

The local community and the project
have been working together

to try to decrease the impact
of these problems.

Over the last eight years,

Lilian and her family

have planted native seedlings
on her land

and left her patch of forest
to regrow.

If we cut it, they come and
sleep in our houses,

so we should leave that place
for them.

If you leave them and
you don't disturb them,

they are peaceful animals.

With other residents following suit,

more of the forest is showing
positive signs of return.

There is a long way to go,

and the future for these chimps
remains uncertain.

But where peaceful coexistence
can be built,

there is hope.

Next time...

..animals battle the elements
in a world of extremes...

..where life exists on
a knife edge...

..in Earth's greatest
natural wonders.

Habitat Explorer brings animals
and their habitats to life.

Explore this free interactive,
and make origami animals.

Go to bbc.co.uk/planetearth3

and follow the links to
the Open University.

Or to order a free printed version,

visit the website or call
the numbers on the screen.