Planète Animale

This is our planet's hothouse. The jungle.

The tropical rainforest.

Forests like these occupy only three percent of the land

yet they're home to over half of the world's species.

But how do so many different kinds of plants and animals

find the space here to live alongside one another?

On the dark, humid forest floor the jungle appears to be lifeless.

Often the only signs of life are what you hear.

A male blue bird of paradise is advertising for a mate.

It's quite a performance

but he's not the only bird of paradise here keen to make an impression.

There are nearly forty different kinds on the island of New Guinea

each with a display seemingly more bizarre than the rest.

A riflebird of paradise.

Like many jungle animals, birds of paradise avoid competing with each other

and these do so by living in different parts of this jungle covered island.

The six plumed bird of paradise displays in his special clearing, on the forest floor.

The magnificent bird of paradise favors the low branches of bushes.

His female is modestly dressed.

The male has a good set of lungs

but he'll have to do more than flutter his eyelids, if he wants to impress her.

It'll all depend on his performance.

The females may be dull looking but they're very picky

and it's time for a really close inspection.

His right side looks fine... but what about his left?

Pretty impressive, but is he magnificent enough?

Oh dear. Her departure says it all.

Generations of choosy females have driven the evolution

of these remarkable displays.

The more extravagant a male is, the more likely he'll be noticed.

New Guinea lies in a warm tropical belt that girdles our planet around the equator.

With abundant rainfall and twelve hours of daylight

three hundred and sixty five days a year, it's here that rainforests flourish.

Surprisingly only two percent of the sunlight filters down to the forest floor.

Down here seedlings struggle to grow

but the gloom is not eternal.

The death of a forest giant is always sading

but it has to happen if the forest is to remain healthy.

The sudden blaze of sunlight will bring life to the forest floor.

A single hectare of rainforest may contain as many as 250 species of tree.

That's nearly ten times the number that grow in Britain

and the thirst for light triggers a race for a place in the sun.

There's no time to waste.

A seed that may have fallen only a few days ago, now bursts through the leaf litter.

With so many competitors, getting a good start is critical

but each plant has it's own particular strategy

for making the most of this rare opportunity.

The seeds of hardwoods are quick to germinate

but, like the fabled tortoise, their strategy is to be slow and steady.

Vines and other climbers put all their energy into rapid vertical growth, rather than girth

though they'll need to be well supported.

The climbers' strategy looks chaotic but there's method in their madness.

Their growing tips circle like lassoes, searching out anchors for their spindly stems.

They put coils in their tendrils

so that if their support moves, they will stretch and not snap.

But the frontrunners at this stage, the first to fill the clearing,

are pioneers like the macaranga.

Their immense leaves capture huge amounts of sunlight, so fueling their growth.

As a result the macarangas grow a remarkable eight meters a year

surging ahead of almost all their rivals.

In the race for the top sport hundreds will start

yet few will ever reach the finishing line, their growth cut short by the diminishing light.

In less than four years, the gap will have gone

but that's not the end of the race.

The ultimate winners are the tortoises, the slow and steady hardwoods.

When the short lived pioneers have fallen

it's the hardwoods that take their place, and a fifty meter giant, like this one,

may keep it's place in the sun for another two hundred years.

At the top, is the canopy, the engine room of the jungle.

It's up here that most of the animal life in the rainforest can be found

But despite the apparent abundance of vegetable food, gathering it is seldom easy.

With no real seasons

each tree flowers or fruits at a different time of the year

which means that food is very widely spaced.

Monkeys, like these tamarinds, must search the canopy for all kinds of food

if they're to survive.

but across the world's rainforests there's one type of fruiting tree

that always delivers: the fig.

Wherever they grow, figs are a magnet for the great diversity of animals.

In the Amazon, the first to appear are the spider monkeys.

These large primates are big fig eaters

But they won't have the tree to themselves for long. Others will want a share.

like the diminutive emperor tamarinds.

The tamarinds love figs too, but being petite means they're easily scared off.

Squirrel monkeys are also small but they have strength in numbers.

Their timeshare on the tree may be short, so their tactics are more smash and grab.

Capuchin monkeys are the bully boys in these forests

and they want the ripe figs for themselves.

Figs are one of the few trees that fruit the year round

so when other food is scarce, these fruits are always available somewhere or other.

Even for leaf eaters, like howler monkeys the ripe figs are just too good to miss.

And howlers are too big for the capuchins to chase off.

Figs are so popular, that as many as 44 different kinds of bird and monkey

have been seen working a shift system on a single tree.

Because fruiting trees are so valuable, many monkeys are territorial

And if you live in the treetops

there's perhaps no better way of staking your claim to a territory, than this.

The calls of the siamang gibbons begin as a duet

between the dominant male and female.

The rest of their families soon join in, and it results in a frenzy of activity.

The calls can carry over a mile, and their message is clear.

They tell any neighboring siamangs this is our territory. Keep out.

Up here the calls of siamang gibbons seem to dominate the airwaves

but with the jungle's incredible diversity

there are countless others trying to be heard too.

Every layer seems to beat to a different tune.

In the early morning the forest's chorus is particularly rich.

Sounds travel further in the cooler air

But few calls can penetrate as far through the dense vegetation as this one

the deep bass solo of a male orangutan.

In the middle of the day little stirs in the jungle

and the hot dense air muffles the sound.

As the afternoon wears on, a different set of players begin to warm up.

Insects work in harmony, timing their calls to fall between the notes of others.

Many singers stick to precise schedules

and right on cue the six o'clock cicada.

Night brings out a whole new orchestra.

The cacophony of competing calls seems deafening to us

but frogs ears are tuned to hear only the calls of their own kind.

The songs of courtship echo from all around.

Male gliding leaf frogs leap from the treetops.

To slow their descent, they use their huge webbed feet as parachutes.

These large tree frogs spend most of their lives in the high canopy

and only come down when it's time to breed.

Once settled, they begin to serenade their unseen females.

Now it's time for the females to make their move.

There's no shortage of suitors, but this female has already made her choice.

She's heading towards the loudest call, because loud calls come from big frogs

and big is best, but to reach him she must run the gauntlet of a gang of smaller suitors.

Their only chance of mating is to make a sneaky interception.

He's scored.

But with more females arriving all the time, it's not over until the fat frog stops singing.

Feet, so vital for gliding, are now put to other uses.

Two's company, three's inconvenient

but in any case, all male frogs are equipped with dry thumbs

which enable them to get a vice like grip on their moist partners.

It's a case of first come first served.

Living in such a humid environment, means jungle frogs are less tied to puddles and pools

and these even lay their eggs out of water.

There's little chance of them drying out

and up here they're safer from predators.

Surprisingly, it doesn't rain every day in the rainforest

but more still falls here than anywhere else on Earth.

On average, over two meters a year.

A single tree can suck up hundreds of tons of water each year

But the trees can't use all this water

so, much of it returns to the air as vapor, forming mist and clouds.

In the Amazon, the largest unbroken stretch of rainforest in the world,

half of all the rainwater that falls, comes from clouds produced by the trees themselves.

With so much rain, it's not surprising that many of the worlds largest rivers

are found in rainforests.

Inside the forest, the high humidity

creates the perfect conditions for a strange world, where life is built on decay.

Amoeba like slime molds cruise the surface, feeding on bacteria and rotting vegetation.

Fungi also flourish on decay.

These are the fruiting bodies of the fungi, the only visible sign