Our Planet

Just 50 years ago,

we finally ventured to the moon.

For the very first time, we looked back at our own planet.

Since then, the human population has more than doubled.

This series will celebrate the natural wonders that remain

and reveal what we must preserve

to ensure people and nature thrive.

This is a tropical forest.

A rain forest.

The richest habitat on Earth.

Exactly how many species rain forests contain is unknown,

but it runs into millions.

And new ones are discovered every week.

There are some, like this clouded leopard, we still know virtually nothing about.

Although they cover just seven percent of the world's land area,

jungles play a vital role in the health of the planet.

In the heart of Africa lies the Congo.

It is our planet's youngest rain forest, a mere 18,000 years old,

and it's the jungle with more big animals than any other.

A family of lowland gorillas.

They're led by this silverback, the dominant male.

He's as tall as a man, but twice the weight.

His family depend on him for survival.

As their guardian, he must keep a lookout for danger.

A rival male might usurp him and tear his family apart.

But there is one threat beyond his control.

In the last 20 years,

poaching for bushmeat has halved the Congo's gorilla population.

His kind are now critically endangered.

It's only a forest elephant, which needn't concern the silverback.

But the elephant has reason to be wary of poachers too.

Their long straight tusks are even more sought after

than those of their grassland cousins.

He follows paths

made by generations of elephants before him,

searching for food.

Like the elephant, the silverback's family will travel several kilometers a day,

looking for fruits and seeds.

They and the elephants are the gardeners of this jungle.

The seed dispersers.

And many of the trees here

owe their existence to these large animals.

Here, all paths eventually lead to Mbeli Bai.

Open areas like this are a unique feature of the Congo's jungles,

and there are more than a hundred dotted throughout the forest.

Known as bais, these clearings attract many of the jungle's inhabitants.

The silverback cautiously leads the way,

but his family are close behind.

The gorillas come to feed on aquatic plants rich in salt,

a mineral in short supply inside the forest,

but crucial to their survival.

Elephants mine salts from the mud using their trunks.

Or just drink the mineral-enriched water.

The silverback's family are not the only gorillas here.

Nearly 200 others also use this bai,

as well as more than 530 elephants,

a measure of Mbeli's importance.

For the elephants, the bais have another vital role.

Most of their lives are spent

roaming the vast forested interior on their own,

so it's only here they get a chance to meet others.

Unlike most of the Congo's other bais, Mbeli is well protected,

making it a refuge from poaching.

It's only when they leave that the danger returns.

And as the Congo's main seed dispersers,

the loss of its megafauna could have a far-reaching impact

on the future of our planet's second-largest rain forest.

Jungles may look the same,

but each is home to a unique cast of characters.

New Guinea is the world's largest jungle-covered island,

and more than half of its plants and animals

are found nowhere else on Earth.

Its turbulent geological past has shaped this vast island

into a dramatic landscape of mountains and valleys.

A process that isolated one species from another.

Separated in this way,

New Guinea's animals have become truly bizarre.

The male twelve-wired bird-of-paradise

is the only bird in the world that has tail ornaments like this,

used to tickle the face of a prospective mate.

From one crow-like ancestor,

birds-of-paradise have evolved into 40 different kinds.

Every corner of this island has its own version.

Meet the black sicklebill of New Guinea's highlands...

...able to morph into some very un-birdlike shapes.

Each male bird-of-paradise has a unique display for attracting mates,

and none is more extraordinary

than the one that takes place on this stage.

For the owner, a western parotia, there's work to be done first.

Every morning, he clears his court of the night's fallen debris.

It's a vital chore if he wants to attract a mate.

Females only visit the tidiest courts,

so one rogue leaf might ruin his chances.

Perfect.

His obsessive housework pays off,

and a female drops in for a closer look.

Now is his chance to really impress,

but it won't be easy.

Females are very fussy,

and she'll expect his carefully choreographed routine

to be faultless.

He opens with a bow.

Next, his blue eye must flash yellow.

So far, so good.

He has all the moves.

Fancy footwork.

The whirling dervish.

The head plume shuffle, with spin.

Her erect head feathers and quivering wings

are a very encouraging sign.

His sidestep and head bob look good from any angle,

but his crowning glory

can only be appreciated from her perspective.

Wait for it.

There it is. A flash of his iridescent throat patch.

Her excitement grows. His performance has been a triumph,

and he wins her approval.

New Guinea's isolation has created a unique variety of animals,

but the age of a forest has an even greater impact

on the diversity of life it contains.

The jungles of Borneo, in Southeast Asia,

have grown here for nearly 130 million years,

making them the oldest on Earth.

This limestone mountaintop in Borneo's highlands

was originally formed under the sea.

Time and rain has slowly shaped this jungle fortress

into these 40-meter towers.

The great age of this island's jungle is best illustrated

by one of the oldest predators on Earth.

A velvet worm.

Completely at home on the humid forest floor.

They've been here since the age of the dinosaurs,

and have remained virtually unchanged.

It detects its insect prey through vibration and touch.

But with no turn of speed,

how does it capture these fleet-footed critters?

The answer is stranger than fiction.

Glue guns.

The sticky slime hardens on impact,

trapping the luckless insect.

The velvet worm will inject the cockroach with digestive saliva,

and then suck out its insides.

The high humidity of the forest floor isn't just good for velvet worms.

It's perfect for fungi, too,

and Borneo's ancient jungles are rich in species.

By decomposing the dead,

the slime molds and fungi recycle scarce nutrients.

Time has made Borneo's jungles extraordinarily rich and diverse.

Here, in just a few hectares of forest,

there may be more kinds of plants than in the whole of Europe,

including some of the most specialized on Earth.

Over several weeks,

these growing tips inflate to form jugs or pitchers.

There are 39 kinds of pitcher plant in Borneo,

and most are found nowhere else.

To get the nutrients they need to survive, pitcher plants rely on animals,

often in surprising ways.

This is the mountain treeshrew, an animal found only in Borneo.

Every morning, the treeshrew visits his neighborhood pitchers.

It depends on the sugary solution

that exudes from hairs on the pitcher's lid.

When he's licked this lid dry, he'll move to another.

And then another.

Eventually, all that sugar can have only one result.

In return for the free food, the treeshrew leaves a gift.

Fertilizer for the plant.

All that's needed is an afternoon shower

to flush the shrew poo into the pitcher's bowl.

Without these added nitrates, the plant couldn't survive.

And the quest for nutrients has led some pitchers down a sinister path.

A gracilis pitcher plant

attracts ants to the underside of its lid with drops of nectar.

But what do the ants give in return?

It's a story that also depends on rain.

The force of the raindrops

make it impossible for the ants to hold on.

It's the plant world's only springboard trap.

This pitcher plant feeds on ant bodies.

All pitcher plants depend on animals for survival,

and one has even gone into business with a bat.

The woolly bat finds hemsleyana pitchers

because the plant's broad back wall reflects the bat's ultrasound.

The tube-like pitchers are the perfect roosting site.

The pitcher provides secure accommodation

and the plant is enriched by its guest's deposits.

Relationships like these have taken millions of years to evolve,

but many could be gone in a decade.

In the last 50 years, Borneo has lost over half of its jungle.

And it's even worse

on the neighboring islands of the Philippines.

Here, 90 percent of the primary rain forest has gone.

What's left is the last refuge for the world's rarest bird of prey.

The mighty Philippines eagle.

With just 400 pairs remaining,

a chick on a nest is a very scarce sight.

Scientists have tracked the mother since she was a year old.

Now aged ten, this is her first chick.

It's four months old, already nearly a meter tall,

and increasingly confident.

Although Mother still likes to give a helping hand.