Africa.
In the four years of making this series,
we've been to some astonishing places,
and seen animals behaving in ways that have never been filmed before.
In this programme, we travel to the four corners of Africa.
From the jungles in the west, to the mountains of the east.
From the ancient south to the deserts of the north.
Revealing extraordinary landscapes.
Looking at them through the eyes of the animals that live here.
The continent's wildlife is the most celebrated on Earth,
but it still has plenty of surprises.
We start in the most ancient corner of the continent.
The Kalahari, in Africa's south west.
The land of great thirst.
And also a land of great emptiness.
Water and food is hard to find.
Only the resourceful and resilient can survive here.
Amongst the sand, scrub and salt pans there is water,
if you know where to look.
In a few exceptional places,
water wells up almost miraculously from deep underground.
It's so rare, it draws animals like a magnet.
A black rhinoceros, the Kalahari's most cantankerous resident.
They certainly don't like sharing a waterhole with lions.
But under the cover of darkness, at one secret
and very special waterhole, rhino abandon their normally
solitary life and come from all around to meet under the stars.
This young female seems nervous.
She senses other rhinos close by.
A mother appears from the shadows, with her calf.
Tentatively, they greet one another.
They may be ill-tempered by day
but now they become gentle and affectionate.
More and more arrive.
The female is excited about something or someone.
Here comes a really big male.
Who would have thought that rhino could be so flirtatious?
A different male tries to come between them.
Somehow or other, he's got a pair of antelope horns stuck on his nose.
It looks as if she's been won over by his eccentric style.
He leads her off, away from the party.
He may have style
but he's turning out to be something of a disappointment.
A girl can only put up with so much.
The only way she can get rid of him is to pretend she's asleep.
To see so many rhino in one place is a revelation
and that's the power water has here - the power to bring together
the greatest gathering of rhinos anywhere on Earth.
THUNDER SOUNDS
IT RAINS
Springbok have been roaming this desert for many months,
searching not for a waterhole,
but for one of these rare and highly localised downpours.
THUNDER AND LIGHTNING
Grass is sprouting for the first time in months.
Food at last.
And that is worth celebrating.
If you're a springbok, that means pronking.
We still don't know exactly why they do this.
The simplest answer is that they're dancing for joy.
Water has left its imprint on the land.
It once flowed here.
But now the Hoanib, one of Namibia's rivers, is a river of sand.
It's home to this bull desert giraffe.
The trees that line these sand rivers send roots down over
30 metres to tap water that lies deep beneath the river bed.
Even on tiptoe, he still needs a half-a-metre-long tongue
to reach the leaves he so badly needs.
He's ruled this stretch of the Hoanib for over a decade
and this prime territory is attracting females.
He waits confidently for her.
But they've got company,
a young male.
The old bull won't tolerate a rival.
Pushing and shoving, they size each other up.
The young rival seems to think he has a chance and attacks.
The first few blows usually settle things in such battles
but here the stakes are high.
Neither will back down.
The young male aims for the rump,
the old bull targets his rival's legs.
The old bull is down.
Is this the end of his reign?
He knows a knockout blow is coming.
But the old bull ducks.
And strikes a blow to his rival's underbelly.
Out for the count.
The old bull is victorious.
But only just.
The sand river remains his to rule.
It's a river that is about to be transformed.
Under clear blue skies, water floods down the Hoanib.
The welcome consequence of rain that fell hundreds of kilometres away.
The water may only flow for a matter of hours...
..but this miraculous flood is enough to provide a lifeline
for the trees and the giraffes of the Hoanib river.
It's what makes this place worth fighting for.
Rare waterholes, occasional downpours,
and short-lived rivers provide just enough water to get by
in this, the most ancient corner of Africa.
Journey up the coast towards the equator, and the vast Congo jungle
meets the sand, surf, and fresh sea air of the Atlantic Ocean.
Spray blows in from the sea, making the grass salty
and enticing rarely-seen animals to come out of the forest.
But this is not their home.
These animals belong inside the tropical rainforest
that cloaks Africa's centre.
The jungle is not an easy place to carve out a living.
Creatures are locked in a battle for food, space and light.
And more than anywhere, the landscape itself seems alive.
It's a crowded, tangled place.
LOW GROWLING
Only forest elephants can clear pathways through the forest.
They have a need to socialise, and in the Congo
there is a special place where they can meet and mingle.
A place that the elephants have created for themselves.
And this is it.
Dzanga Bai, the legendary "village of elephants".
As well as being a place where they can enjoy one another's company,
this great clearing satisfies another craving - for salts.
The salts lie deep under the mud so the elephants must mine for them.
Dawn reveals the arrival of new visitors.
Including this young bull elephant.
ELEPHANT TRUMPETS LOUDLY
He is in a state of musth, a kind of sexual fury.
ELEPHANT TRUMPETS AND SNORTS
HE ROARS
But will throwing his weight about impress the females?
The cows only become fertile once every two years
so opportunities to encounter one at the right time are not common.
This could well be the first chance this young male has had.
And there are no older bulls around to put him in his place.
Just for a moment, he is king of the Bai.
ELEPHANT RUMBLES LOUDLY
But his rule doesn't last for long.
Enter another lusty bull.
And a much bigger one.
But the young bull is still charged up with testosterone.
Bold or foolish, he's going in to battle.
TRUMPETING SOUNDS
He never really had a chance.
Dzanga Bai is a huge clearing
but it's still just a speck in this vast expanse of green.
Each hectare of forest produces, as vapour,
almost 190,000 litres of water a year.
So much that it creates its own weather.
WIND ROARS
LIGHTNING CRACKS
THUNDER RUMBLES
Each year, as many as 100 million lightning bolts strike
over the forest. That's more than anywhere else in the world.
And with the lightning comes the rain.
It's certainly perfect weather for frogs.
The big storm is the cue for the most important climb
of this frog's life.
It's a male, in search of a mate.
But if he is to find one, he has to get to the top.
He needs to keep his wits about him,
for the rain also brings out hunters.
Easy does it.
The top, at last.
But he's late to the party.
The higher a male sits, the further his voice will carry.
So the top slots are worth fighting for.
And he's won! He has the top place.
So now, it's time to sing.
CROAKS AND WHIRRS
CHEEPING
And a white-bellied female responds.
They join together to mate.
The loser will have to wait for the next storm
before he sings again.
She lays her eggs on a blade of a long leaf
and he, using his back legs, folds it over
and glues its two edges together, shutting the eggs inside.
This sealed nest is the safest place
these leaf-folding frogs can find to protect their precious brood.
Within days, the eggs are developing.
The timing is perfect.
The rain washes away the glue and the tadpoles
slip out of the leaves into the growing puddles below.
The forest once stretched unbroken from the west coast of Africa,
all the way to the Indian Ocean.
But as we travel east, the scene is very different.
The forests now give way to frozen summits.
Up here lies the largest glacier in Africa,
only a few miles north of the equator.
These, the Ruwenzoris, form part of a massive barrier.
It separates the ancient jungles
from what is now savanna in the east.
Below the highlands,
vast wetlands cut swathes through the open savanna.
Bangweulu Swamp is huge.
It's name means, "Where the water meets the sky."
Hidden amongst this maze of waterways
is a creature like no other.
A giant, pre-historic looking bird.
A shoebill.
Standing well over a metre tall,
she roams these swamps,
trying to catch catfish.
Not exactly what she was after.
Deeper into the swamp lies the reason for all this fishing.
This chick is just three weeks old and a little bit wobbly on its feet.
Its vast bill means it has trouble balancing.
It won't be able to fly or even walk properly for several weeks.
It's entirely reliant on its parents for food and water.
There is also a smaller chick, who isn't doing so well.
The larger chick pesters its mother for a drink.
While she goes off to fetch water,
it reveals a dark side to the relationship with its nest-mate.
It's three days older than the other chick
and has always won the race for food and attention.
This is more than just a scrap between two siblings.
As their mother returns, she sees what the larger chick has done.
The smaller chick seeks its mother's comfort.
But she has already made her choice.
Only her firstborn will get a drink.
Shoebills very rarely raise more than one chick.
The younger chick was only ever an insurance,
in case the elder didn't make it.
Now it's old enough, the adults know that they're better off
putting all their efforts
into bringing up just one fit and healthy youngster.
The swamp's changing water levels mean fishing is too unpredictable
for them to gamble on trying to raise two chicks.
Change is everywhere in east Africa.
Volcanic eruptions and fires periodically devastate the land.
But after destruction, comes regeneration.
Here in the savanna, strewn with fertile ash,
that means lush, green grass.
Today, savannas dominate the landscape of this vast continent.
They are also one of the most productive on earth.
With the grasses come animals in huge numbers.
Shadowed by hunters...
..of every size.
With the herds come flying insects, billions of them.
Food, if only they could catch them.
Time for a rethink.
This agama lizard has spotted an opportunity.
Only one thing attracts more flies than the wildebeest.
Lions that have eaten wildebeest.
Lions are famously bad-tempered.
They could swat the lizard like the flies he's hoping to ambush.
He will need to pick his target carefully.
Not her.
Or her.
Maybe...
..but no.
To be within striking distance, he's got to hold his nerve.
Got one.
Now he's getting his eye in.
But this might be a bit ambitious.
It may take courage to hunt on the back of a lion...
..but it takes sense to know when to run away.
The wildebeest won't stay for long and when they leave,
most of the flies will follow.
The boom and bust of Africa's savannas forces animals
to gamble with their lives.
To the north, the power of Africa's greatest desert
makes life almost impossible.
The merciless sun, a colossal 15 million degree nuclear reactor
scorches life from the surface of the land.
A faint breath of wind can be the beginning of disaster.
A sandstorm can be 1,000 miles across.
The constant battering of the land wears down the hard-baked ground.
The landscape is littered with giant chalk pillars,
carved by innumerable sandstorms.
This glaringly white oven is lethally hot.
It's 41 degrees, too much for most animals.
The sun and sandstorms cannot however reach far underground,
where conditions are stable and tolerable.
Meet one of the planet's strangest mammals.
Naked mole rats.
These sabre-toothed sausages wouldn't last a day in the desert.
Special filming tunnels allow us to see how well-adapted
they are to the subterranean life.
They can run equally well in both directions,
so tight space is no problem.
They have lost their fur
and most bizarrely
they live in social colonies much like termites or ants.
After time spent digging, the workers come together to relax.
But one here is very different from all the rest - their queen.
Twice as heavy as her subjects
and not afraid to throw her weight around.
She is the mother of every worker in the colony
and exists in a near-continuous state of pregnancy.
Even now, two dozen babies are pulsating within her swollen belly.
Just occasionally, one of her brood is raised differently.
A daughter becomes a princess.
Until now, this youngster's enjoyed a lazy, privileged life.
But not for much longer.
She has a destiny to fulfil.
The surface is a place where no naked mole rat can survive for long.
But a princess will risk everything to search for a partner.
The quest is urgent.
There's an enticing smell in the air.
The seductive scent draws her downwards to safety.
She's sniffed out a partner.
He too is alone and eager to start a new colony in his lonely burrow.
Two months later, the princess has become a queen
and a new tyranny begins.
Above ground, life continues to be tough.
It's approaching midday.
A fringe-toed lizard is hungry.
He's on a stakeout.
Flashy scales reflect some of the sun's rays.
Nevertheless, the heat is almost unbearable.
His prey hasn't left home all day.
He can't take the heat any more.
To survive longer, he'll need a spacesuit.
And in a way, that's what these insects have.
Silver ants' armoured skin reflects light.
They can tolerate temperatures that would kill any other land animal.
Even so, they can only survive
for less than ten minutes in the midday sun.
Time is precious.
The ants race to find food as soon as their predators go to ground.
They can't afford to waste a second getting lost,
so they spin to take a bearing from the sun.
They log every change of direction, every footstep,
in order to know exactly where they are and where their nest lies.
Only four minutes to spare
and they've found a victim of heat stroke, a meal.
But it's going to take a monumental effort to get it home.
Three minutes to go and they're nearing their maximum temperature -
an astounding 53 degrees Celsius.
But there are already casualties.
One minute left and they're not going to make it.
They must lighten their load.
The silver ant is the hardiest of all the desert's inhabitants -
maybe even the hardiest of all Africa's creatures.
From the Sahara to the southern tip and all across Africa,
animals have been forced to adapt and behave in extraordinary ways,
but life here is astonishingly resilient.
And it is Africa's most successful and adaptable species
that is having the biggest impact on the continent,
with the arrival of agriculture and the growth of big cities.
Africa's human population is growing at nearly double the global rate.
It has just exceeded one billion.
The future for Africa's wild places and wild life is uncertain.
The pressures on the land and the challenges ahead are formidable.
There is an increasing urgency to understand
and crucially, to conserve the celebrated wildlife
of this great continent.
Come on, here we are.
Nobody knows what the future has in store for this little calf,
nor indeed what changes will take place
on the great continent on which he lives.
But what we do know is that human beings have lived alongside
wildlife here for longer than anywhere else,
and Africa is still the greatest wilderness on Earth.
We don't yet know all there is to know about Africa
and there is still plenty to explore and enjoy.
But critically there is still plenty that must be protected
if it is to have a future.
Subtitles by Red Bee Media Ltd