Africa (2013): Season 1, Episode 5 - Sahara - full transcript
Over a few thousand years, climate change drove many species from an abundant part of (Northern) Africa to the coastal and mountain edges, where some population persist, as most turned into the Sahara. It's actually mostly stone, yet the fifth sand causes almost instant apocalyptic dangers: sand storms which swallow whole caravans or even villages in no time. Specialist species adapt admirably to drought, spots where the vast water reserve emerges are bountiful oases.
A F R I C A
North Africa.
High in Morocco's Atlas Mountains,
Barbary macaques shiver
in the icy cedars.
The ancestors of these monkeys
fled here
from a disaster that overwhelmed
their homeland.
Now, trapped in this isolated
corner of Africa,
there's no going back
to the land farther south.
Even in this snowy refuge,
there's a reminder
of what drove them here.
The unbridled power
of the African sun.
Under its intense gaze,
the snow can't last for long.
Melt water should bring life
to the lowlands.
Hundreds of torrents
cascade southwards.
But each is flowing
towards extinction.
Just 200 miles
south of the mountains,
the rivers are vaporised.
Life has been burnt off the land.
This was the apocalypse from which
the Barbary macaques fled.
The sudden and unstoppable advance
of the greatest desert
on the planet.
The Sahara transformed North Africa.
Today, it covers an area
the size of the United States.
One-third of the entire
African continent.
This is one of the hottest places
on Earth.
The merciless sun,
a colossal 15-million-degree
nuclear reactor,
blasted life from the surface
of the land.
It still wreaks havoc.
A faint breath of wind
can be the beginning of disaster.
Nomads tell of entire
villages being engulfed...
..camel trains disappearing,
and people buried alive
inside their tents.
A sandstorm can be
1,000 miles across.
It seems miraculous that anything
can survive such devastation.
The Saharan apocalypse
wiped out many creatures,
but, today, some still cling on,
in the lands around the margins
of the great desert.
It's very dry here.
Some years, the rains fail entirely.
A lone Grevy's zebra.
He weighs close to half a tonne,
and could go for three days
without drinking.
Like the macaques,
his forebears were refugees
from the advancing Sahara.
The land is scrubby and dry.
But this stallion has claimed it
as his own.
He's been waiting months
for visitors.
Female visitors.
If they like his territory,
they might stay a while.
It's his first chance to mate
for a very long time.
Hardly a success.
Perhaps his visitors are looking
for a more impressive partner.
There's another setback.
The females were being followed,
a posse of young males,
every one, a rival.
It's time to separate
the men from the boys.
One by one,
the stallion sees them off.
The females had ringside seats.
And his prowess has not gone
unnoted.
Machismo gives way to tenderness.
Around here, you have to take
every opportunity,
be it for food, for water
or for mates.
Female Grevy's are a fickle bunch.
The herd have decided to move on.
All of them.
The stallion may never
see them again.
But there's a chance
that one is now carrying his foal.
In this harsh land
THAT must count as a triumph.
The sun's power cannot, however,
reach far underground.
Below, in stark contrast,
conditions are stable and tolerable.
And home to one of the planet's
strangest mammals.
Meet the 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.
A 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.
Tough though they are,
such refugees living on the edges
of North Africa
cannot survive in the heart
of the Sahara.
And yet here, in southern Nigeria,
there are creatures preparing
to journey right across the centre
of that great desert.
Barn swallows.
They spent the winter roosting
in a forest of elephant grass.
But now, it's time
for them to leave.
All two million of them.
They're tiny, each weighing the same
as a couple of one pound coins,
yet the journey to their breeding
grounds in Europe
is over 3,000 miles long.
Ahead of them lies
a vast death trap.
The Sahara is too large
to go around.
The swallows have no choice
but to meet it head-on.
It will take one of nature's
greatest feats of navigation
to cross this lifeless wasteland.
A wilderness that stretches
not just to the horizon,
but almost beyond imagination.
It's an immense blank space
on the map.
In spite of the Sahara's reputation,
less than one-fifth of it is sand.
The rest is stone
and wind-scoured rock.
The sun not only bakes the land,
it warps its appearance.
The superheated air, rising
upward from the desert surface,
distorts the distant scene.
A reflection of the sky
shimmers on the sands a mirage.
The sun is an illusionist.
To thirsty travellers,
a mirage can resemble a lake
which agonisingly recedes
as it's approached.
And swaying camels
coming to the rescue
transform into dry, spiny
acacia trees.
To cross this confused,
shimmering landscape,
many swallows will need to find
real water amongst the mirages.
Even in the Sahara,
rain does sometimes fall
and that is sufficient
for plants to survive
providing they have
the right adaptations.
Rising from the sand,
a dried-out ball of twigs.
In strong winds, it can travel.
This plant may have been dead
for 100 years.
Yet its name suggests
that all is not lost,
for this is a resurrection plant.
Around here, rain might only fall
once or twice a year.
But if you're searching for decades,
that might be enough.
Dead limbs absorb water
and unfurl in a matter of minutes.
But the resurrection plant
needs one more miracle.
Rain must fall on its branches
before they dry out
and close up again.
Within hours, shoots emerge.
In just a few weeks, they flower
and develop seeds of their own.
Then, before they can grow
any larger,
the sun kills them.
But their seeds live on,
ready for when the rains return,
even if that is a century from now.
North Africa wasn't always
so brutal.
Scattered across the Sahara
are glimpses of life
before the apocalypse
swept over the land.
In the north, a petrified forest
trees turned to stone.
Remains from a far distant,
wetter past.
White sediments in the heart of the
Sahara are the dried-out remains
of what was once
the world's largest lake.
In the east, ruined cities
hark back to a time of plenty.
And here, deep inside Libya,
is Messak Settafet.
Carved here are hundreds of images
of animals, all drawn from life.
Ghosts from a greener time.
Remarkably, a remnant of this old
North Africa survives.
Bou-Hedma, in Tunisia,
is sustained by mountain rains.
It's a relic of the savannah
that once carpeted North Africa.
The vast grassland vanished
when a shift in the Earth's orbit
drove the rains south
and, in perhaps only
a matter of centuries,
the Sahara Desert overwhelmed
North Africa.
The evidence suggests this took
place around 6,000 years ago.
In evolutionary terms,
that's no time at all
and life has had little chance
to adapt to this new world.
Only a few tough specialists can
cope with life amongst the dunes.
Camels are sometimes called
"ships of the desert"
but, like the swallows,
they're really only visitors here.
These "ships" can certainly
cross the Sahara,
but even THEY can't make their home
in the harshest places.
Left to wander the desert
by themselves,
camels would not survive.
They depend on their human
navigators to find oases and wells.
Saharan folklore is full of tales
of caravans
that missed a well by a few hundred
metres and disappeared.
This is the White Desert, in Egypt.
The landscape is littered
with giant chalk pillars,
carved by innumerable sandstorms.
This glaring white oven
is lethally hot.
Food here is almost non-existent.
But there's a rare gift
from a passing camel.
The smell has lured dung beetles
from miles around.
For them, this is manna from heaven.
One dung ball could provide
enough food
to last this female beetle
the rest of her life.
But she has a problem.
To keep it fresh,
she must bury it in moist ground.
And that's not easy to find.
The temperature has already
risen ten degrees.
This lizard avoids
the roasting sand.
Only 30 centimetres
above the surface,
it's significantly cooler.
The 'reverse-pushing' technique
is certainly the fastest way
to keep the ball rolling.
But it does have one drawback.
You can't see where you're going.
Disaster!
Stuck between two dunes.
The dung ball is twice her weight,
but the urge to keep pushing
is inextinguishable.
Now, it's 41 degrees Celsius.
Soon, she'll be baked alive.
Her survival instinct, in the end,
over-rides her love for dung.
Much of the Sahara is uninhabitable,
but there are rare places
where there is
some possibility of survival.
Places where, by strange chance,
there is water.
Waw An Namus is an extinct volcano.
From space, it's a remote,
black scar on the Libyan Sahara.
Yet there are other colours here,
colours rarely seen
on the desert floor.
Blue and green.
Rain fell thousands of years ago,
when the Sahara was green
and percolated deep into the ground.
And here water from this vast,
ancient reservoir
rises to the surface.
These pools offer another
glimpse of the Sahara's past.
Wherever there's water
in North Africa,
living relics from this wetter time
have a chance to cling on.
This oasis is fed
by a hot volcanic spring.
Slightly away from the
stream of near-boiling water,
its cooler, and fish can live.
These are tilapia.
Hatchlings stick close
to their mother.
There are other dangers here
beside the scalding water.
Particularly at night.
The crocodiles are stealthy.
And the tilapia are almost blind
in the darkness.
In panic, they all leap to escape
the hunters' approach.
But this female
can't abandon her brood.
The crocodiles won't be thwarted.
They too can leap.
With first light, the crocodiles
lose the element of surprise,
and the battle is over, for now.
The mother fish has survived,
but where are her young?
All present and correct.
They spent the whole night
sheltering in her mouth.
The contest will be
repeated at sunset.
There is nowhere else to go.
Oases are always
sought by desert travellers,
but not all are as they seem.
This is the great Ubari Sand Sea,
in the heart of the Sahara.
These swallows have travelled
1,500 miles
since they left Nigeria.
Their superb powers of navigation
will eventually guide them
to Europe, but now they,
and other thirsty migrants,
need to find a speck of blue amidst
this ocean of sand.
And here it is.
Umm el Mar.
Here too, ancient groundwater
wells up to the surface.
But the birds need to be careful,
for the sun has played
a terrible trick.
This oasis is poisonous.
Intense evaporation over thousands
of years has left the water
saltier than the sea.
As if to underline the horror,
the place is infested
by vast swarms of flies.
But this plague
is a birds' salvation.
The flies are filled with
freshwater, filtered from the brine.
So, like a desert wanderer
squeezing a drink from a cactus,
the birds get all the water
they need from the flies' bodies.
More and more migrants join in.
Wagtails.
This is the birds' only stopover.
It gives them enough fuel to
escape from the Sahara and Africa.
Away from an oasis,
it seems remarkable
that anything can live at all.
The temperature of the sands
can exceed 70 degrees Celsius.
There's not the slightest
trace of water left at the surface.
And when that happens,
the Sahara itself cries out.
Billions of sliding grains
generate a hum
that echoes across miles
of empty desert.
These are the Sahara's legendary
singing dunes.
Over time, these avalanches add up.
If you watch the dunes
for long enough,
something remarkable is revealed.
One and a half years
flash past in a matter of seconds.
On this timescale,
the dunes are like a stormy sea.
An unstoppable tsunami of sand.
In this immense,
ever-shifting landscape,
it's easy to see how
a lost traveller could succumb
to what's been called
the Sahara's only endemic disease
madness.
Can anything survive
the North African desert
when the sun is at its fiercest?
It's approaching mid-day.
A fringe-toed lizard is hungry.
He's on a stake-out.
Flashy scales
reflect some of the sun's rays.
Nevertheless,
the heat is almost unbearable.
His prey hasn't left home all day.
The lizard is the last animal
still out on the dunes.
But even he can't take it any more.
To survive longer,
you would 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 heatstroke. 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.
Something has to change.
The silver ant is the hardiest
of all desert inhabitants.
Even so, it can only survive
outside in the middle of the day
for a matter of minutes.
Now, the desert belongs to
the sun alone.
The sun has scorched
life from the Sahara.
And yet the vast desert it created
is a source of life
half a world away.
The advancing Sahara
vaporised the world's largest lake,
leaving behind the silvery remains
of countless microscopic algae.
In winter, the wind carries away
700,000 tonnes
of this mineral-rich dust every day.
It blows from here all the way
to South America,
where, astonishingly, it fertilises
the Amazon rainforest.
A striking demonstration of the
reach of this mighty continent.
Throughout its long history, Africa
has influenced the entire planet.
It was the cradle of a remarkable
array of land animals that spread
across the globe, and, of course, it
was the ancestral home of all of us.
This is the tale of two
of the Africa team's
most challenging desert expeditions.
One focused on a miniscule creature
with an incredible turn of speed.
The other, on a subject so slow, to
film it in action would take years.
In both cases,
the Sahara would push crews
to the limit in pursuit
of the perfect shot.
In Tunisia, the mission is to
capture footage of moving
sand dunes, something that's never
been tried like this before.
Because the dunes move so slowly,
we'll have to leave cameras here
for about 20 months,
which means there's a huge
potential for things to go wrong.
And with film-making, if something
can go wrong, it usually will.
Two local shepherds,
Amur and Nasser,
have volunteered to tend
the equipment full-time.
The camera tower will be
the tallest structure
for as far as the eye can see.
And there are three other cameras
at lower angles.
All this toil will yield
surprisingly scant results.
They've programmed the cameras
to take one photo every day.
That's only 365 photographs
a year...
which, when you run it at
normal speed, just over 14 seconds.
I think it's taken longer to explain
what's going to happen
than the end result
will actually be.
The cameras are left to
the mercy of the sun, wind and sand.
In the meantime, crews are shooting
all across North Africa.
In Egypt, the challenge is to
get into the world of the most
heat-tolerant desert animal,
the silver ant.
They're really small,
they're really fast.
Like, you're not too sure
if you've seen an ant.
The crew have three weeks to gather
the footage they need.
We're going to try
a tracking shot on this ant nest.
Moving forward towards it,
as the ants pour out of the hole
in their millions.
Not only are these insects
super-fast,
they also keep antisocial hours.
The thing is,
we need to be out here in the middle
of the day to film these ants.
They don't do what they do
when it's nice and cool at seven,
eight o'clock in the morning.
I can't remember ever being
in a place where the wind was
so relentless
and the temperatures were so high.
The insufferable heat
is not the only problem.
Dangers are everywhere.
Ooh!
There's a really fat scorpion,
it's really big!
One, two, three.
This might kill.
Yeah? Yeah.
It's big and they have a lot
of poison in his dark thing.
What, that thing there?
Don't! Oh, my god!
Don't touch it!
The scorpion will be released far,
far away from the camp,
in a shady spot.
No such luck for the team.
They're back
to work in the midday sun.
This is, this is too much.
This is crazy.
This is crazy.
Indeed.
The heat seems to have given Kat and
Warwick a touch of Saharan madness.
The plan is to do an experiment,
to find out how fast
these little ants can run.
So we're going to lay this along
the floor, and hopefully an ant will
run alongside it and we can film it
at high speed.
And from that, calculate their...
their speed,
and perhaps try and relate it to
how fast that would be for a human.
Like me.
Silver ants are expert navigators,
using the angle of the sun
to calculate their position.
But for our team, even basic mental
tasks are becoming a challenge.
Count the seconds. See one running
and then count the seconds.
It's difficult to count a second,
isn't it? No, it's "one".
"One", yeah!
There he goes!
He's gone ten centimetres
in four seconds,
but we're running
at 500 frames a second,
which is 20 times normal time.
Yeah. So in fact, he's
covered those ten centimetres in...
We know that he does
half a metre in one second.
Half a metre per second, yep.
50 centimetres in one second,
roughly. Yeah.
So, how many body lengths is that?
He's maybe doing
five body lengths a second,
if he's two metres tall like I am.
Are you? Yeah. That's how much more
than a normal man I am.
Eventually, the duo decide that
if the silver ants were our size,
they'd be doing 280 miles an hour.
They're one of the fastest sprinters
in the animal kingdom.
No wonder we've been
struggling to film them.
It does explain a few things.
Ant-letics!
Knowing the exact speed of the ants
is all well and good, but there's
still a great deal of work to be
done before the shoot finishes.
However, in Tunisia, there's
no shortage of time, and hopefully,
no news is good news, as far as
Amur and Nasser are concerned.
The final week in Egypt,
and the crew seem to be adapting
to life in the oven.
Practice is making perfect,
and the sequence is coming together.
I think we've got some lovely shots.
Every single shot
has been really hard-earned.
But getting down in the ant's world
is now taking its toll on the kit.
It's running to stand still,
the business of blowing
dust off these things.
Oh, no!
It's got dust in it!
Ooh, crunch.
I think these ants
are stunning looking.
Near-impossible to film, I think,
because of the speed they had.
But, you know, I've come to love them
over the days and weeks.
With the sequence in the bag,
Warwick wants the final
traditional sunset shot.
It's the best time of day
to film sunsets, in the evening.
That's experience
that tells me that.
I've been doing this for years.
You learn these things.
Thanks to Warwick's experience,
including sunsets, he and Kat
have captured the extraordinary life
of the speedy silver ant.
Over a year later, in Tunisia,
it's time to take down
the sand dune cameras.
Bonjour!
Nasser, Amur. Hello again.
So how's it been, has it been good?
It's OK, but two days ago, we have
a little bit... small problem.
After surviving 600 days
in the desert,
the "small problem" is that
the cameras have been vandalised.
I'm really hot and bothered now,
it's 40 degrees,
and someone's smashed the cameras.
Not been a good start to the day,
to be honest.
There's no doubt the dunes
have moved.
But the question is
whether the equipment has survived.
That is amazing,
the camera's still here.
I guess maybe it just took them so long
to get through the toughened plastic,
that they felt they had made so much noise
they were worried about the guards coming,
because they only sleep
a couple of 100 metres away.
After almost two years of waiting,
it's the moment of truth.
We're going to find out,
find out whether or not
the cameras
have actually recorded anything.
It's just hugely stressful
because it's never been done before.
The footage is a surreal window
into a secret world
the private life of a sand dune.
The Africa team
struggled under the burning sun
and driving winds
that are hallmarks of the Sahara.
They went home with an enormous
admiration for the creatures that
spend their entire lives battling to
survive in this brutal desert world.
North Africa.
High in Morocco's Atlas Mountains,
Barbary macaques shiver
in the icy cedars.
The ancestors of these monkeys
fled here
from a disaster that overwhelmed
their homeland.
Now, trapped in this isolated
corner of Africa,
there's no going back
to the land farther south.
Even in this snowy refuge,
there's a reminder
of what drove them here.
The unbridled power
of the African sun.
Under its intense gaze,
the snow can't last for long.
Melt water should bring life
to the lowlands.
Hundreds of torrents
cascade southwards.
But each is flowing
towards extinction.
Just 200 miles
south of the mountains,
the rivers are vaporised.
Life has been burnt off the land.
This was the apocalypse from which
the Barbary macaques fled.
The sudden and unstoppable advance
of the greatest desert
on the planet.
The Sahara transformed North Africa.
Today, it covers an area
the size of the United States.
One-third of the entire
African continent.
This is one of the hottest places
on Earth.
The merciless sun,
a colossal 15-million-degree
nuclear reactor,
blasted life from the surface
of the land.
It still wreaks havoc.
A faint breath of wind
can be the beginning of disaster.
Nomads tell of entire
villages being engulfed...
..camel trains disappearing,
and people buried alive
inside their tents.
A sandstorm can be
1,000 miles across.
It seems miraculous that anything
can survive such devastation.
The Saharan apocalypse
wiped out many creatures,
but, today, some still cling on,
in the lands around the margins
of the great desert.
It's very dry here.
Some years, the rains fail entirely.
A lone Grevy's zebra.
He weighs close to half a tonne,
and could go for three days
without drinking.
Like the macaques,
his forebears were refugees
from the advancing Sahara.
The land is scrubby and dry.
But this stallion has claimed it
as his own.
He's been waiting months
for visitors.
Female visitors.
If they like his territory,
they might stay a while.
It's his first chance to mate
for a very long time.
Hardly a success.
Perhaps his visitors are looking
for a more impressive partner.
There's another setback.
The females were being followed,
a posse of young males,
every one, a rival.
It's time to separate
the men from the boys.
One by one,
the stallion sees them off.
The females had ringside seats.
And his prowess has not gone
unnoted.
Machismo gives way to tenderness.
Around here, you have to take
every opportunity,
be it for food, for water
or for mates.
Female Grevy's are a fickle bunch.
The herd have decided to move on.
All of them.
The stallion may never
see them again.
But there's a chance
that one is now carrying his foal.
In this harsh land
THAT must count as a triumph.
The sun's power cannot, however,
reach far underground.
Below, in stark contrast,
conditions are stable and tolerable.
And home to one of the planet's
strangest mammals.
Meet the 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.
A 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.
Tough though they are,
such refugees living on the edges
of North Africa
cannot survive in the heart
of the Sahara.
And yet here, in southern Nigeria,
there are creatures preparing
to journey right across the centre
of that great desert.
Barn swallows.
They spent the winter roosting
in a forest of elephant grass.
But now, it's time
for them to leave.
All two million of them.
They're tiny, each weighing the same
as a couple of one pound coins,
yet the journey to their breeding
grounds in Europe
is over 3,000 miles long.
Ahead of them lies
a vast death trap.
The Sahara is too large
to go around.
The swallows have no choice
but to meet it head-on.
It will take one of nature's
greatest feats of navigation
to cross this lifeless wasteland.
A wilderness that stretches
not just to the horizon,
but almost beyond imagination.
It's an immense blank space
on the map.
In spite of the Sahara's reputation,
less than one-fifth of it is sand.
The rest is stone
and wind-scoured rock.
The sun not only bakes the land,
it warps its appearance.
The superheated air, rising
upward from the desert surface,
distorts the distant scene.
A reflection of the sky
shimmers on the sands a mirage.
The sun is an illusionist.
To thirsty travellers,
a mirage can resemble a lake
which agonisingly recedes
as it's approached.
And swaying camels
coming to the rescue
transform into dry, spiny
acacia trees.
To cross this confused,
shimmering landscape,
many swallows will need to find
real water amongst the mirages.
Even in the Sahara,
rain does sometimes fall
and that is sufficient
for plants to survive
providing they have
the right adaptations.
Rising from the sand,
a dried-out ball of twigs.
In strong winds, it can travel.
This plant may have been dead
for 100 years.
Yet its name suggests
that all is not lost,
for this is a resurrection plant.
Around here, rain might only fall
once or twice a year.
But if you're searching for decades,
that might be enough.
Dead limbs absorb water
and unfurl in a matter of minutes.
But the resurrection plant
needs one more miracle.
Rain must fall on its branches
before they dry out
and close up again.
Within hours, shoots emerge.
In just a few weeks, they flower
and develop seeds of their own.
Then, before they can grow
any larger,
the sun kills them.
But their seeds live on,
ready for when the rains return,
even if that is a century from now.
North Africa wasn't always
so brutal.
Scattered across the Sahara
are glimpses of life
before the apocalypse
swept over the land.
In the north, a petrified forest
trees turned to stone.
Remains from a far distant,
wetter past.
White sediments in the heart of the
Sahara are the dried-out remains
of what was once
the world's largest lake.
In the east, ruined cities
hark back to a time of plenty.
And here, deep inside Libya,
is Messak Settafet.
Carved here are hundreds of images
of animals, all drawn from life.
Ghosts from a greener time.
Remarkably, a remnant of this old
North Africa survives.
Bou-Hedma, in Tunisia,
is sustained by mountain rains.
It's a relic of the savannah
that once carpeted North Africa.
The vast grassland vanished
when a shift in the Earth's orbit
drove the rains south
and, in perhaps only
a matter of centuries,
the Sahara Desert overwhelmed
North Africa.
The evidence suggests this took
place around 6,000 years ago.
In evolutionary terms,
that's no time at all
and life has had little chance
to adapt to this new world.
Only a few tough specialists can
cope with life amongst the dunes.
Camels are sometimes called
"ships of the desert"
but, like the swallows,
they're really only visitors here.
These "ships" can certainly
cross the Sahara,
but even THEY can't make their home
in the harshest places.
Left to wander the desert
by themselves,
camels would not survive.
They depend on their human
navigators to find oases and wells.
Saharan folklore is full of tales
of caravans
that missed a well by a few hundred
metres and disappeared.
This is the White Desert, in Egypt.
The landscape is littered
with giant chalk pillars,
carved by innumerable sandstorms.
This glaring white oven
is lethally hot.
Food here is almost non-existent.
But there's a rare gift
from a passing camel.
The smell has lured dung beetles
from miles around.
For them, this is manna from heaven.
One dung ball could provide
enough food
to last this female beetle
the rest of her life.
But she has a problem.
To keep it fresh,
she must bury it in moist ground.
And that's not easy to find.
The temperature has already
risen ten degrees.
This lizard avoids
the roasting sand.
Only 30 centimetres
above the surface,
it's significantly cooler.
The 'reverse-pushing' technique
is certainly the fastest way
to keep the ball rolling.
But it does have one drawback.
You can't see where you're going.
Disaster!
Stuck between two dunes.
The dung ball is twice her weight,
but the urge to keep pushing
is inextinguishable.
Now, it's 41 degrees Celsius.
Soon, she'll be baked alive.
Her survival instinct, in the end,
over-rides her love for dung.
Much of the Sahara is uninhabitable,
but there are rare places
where there is
some possibility of survival.
Places where, by strange chance,
there is water.
Waw An Namus is an extinct volcano.
From space, it's a remote,
black scar on the Libyan Sahara.
Yet there are other colours here,
colours rarely seen
on the desert floor.
Blue and green.
Rain fell thousands of years ago,
when the Sahara was green
and percolated deep into the ground.
And here water from this vast,
ancient reservoir
rises to the surface.
These pools offer another
glimpse of the Sahara's past.
Wherever there's water
in North Africa,
living relics from this wetter time
have a chance to cling on.
This oasis is fed
by a hot volcanic spring.
Slightly away from the
stream of near-boiling water,
its cooler, and fish can live.
These are tilapia.
Hatchlings stick close
to their mother.
There are other dangers here
beside the scalding water.
Particularly at night.
The crocodiles are stealthy.
And the tilapia are almost blind
in the darkness.
In panic, they all leap to escape
the hunters' approach.
But this female
can't abandon her brood.
The crocodiles won't be thwarted.
They too can leap.
With first light, the crocodiles
lose the element of surprise,
and the battle is over, for now.
The mother fish has survived,
but where are her young?
All present and correct.
They spent the whole night
sheltering in her mouth.
The contest will be
repeated at sunset.
There is nowhere else to go.
Oases are always
sought by desert travellers,
but not all are as they seem.
This is the great Ubari Sand Sea,
in the heart of the Sahara.
These swallows have travelled
1,500 miles
since they left Nigeria.
Their superb powers of navigation
will eventually guide them
to Europe, but now they,
and other thirsty migrants,
need to find a speck of blue amidst
this ocean of sand.
And here it is.
Umm el Mar.
Here too, ancient groundwater
wells up to the surface.
But the birds need to be careful,
for the sun has played
a terrible trick.
This oasis is poisonous.
Intense evaporation over thousands
of years has left the water
saltier than the sea.
As if to underline the horror,
the place is infested
by vast swarms of flies.
But this plague
is a birds' salvation.
The flies are filled with
freshwater, filtered from the brine.
So, like a desert wanderer
squeezing a drink from a cactus,
the birds get all the water
they need from the flies' bodies.
More and more migrants join in.
Wagtails.
This is the birds' only stopover.
It gives them enough fuel to
escape from the Sahara and Africa.
Away from an oasis,
it seems remarkable
that anything can live at all.
The temperature of the sands
can exceed 70 degrees Celsius.
There's not the slightest
trace of water left at the surface.
And when that happens,
the Sahara itself cries out.
Billions of sliding grains
generate a hum
that echoes across miles
of empty desert.
These are the Sahara's legendary
singing dunes.
Over time, these avalanches add up.
If you watch the dunes
for long enough,
something remarkable is revealed.
One and a half years
flash past in a matter of seconds.
On this timescale,
the dunes are like a stormy sea.
An unstoppable tsunami of sand.
In this immense,
ever-shifting landscape,
it's easy to see how
a lost traveller could succumb
to what's been called
the Sahara's only endemic disease
madness.
Can anything survive
the North African desert
when the sun is at its fiercest?
It's approaching mid-day.
A fringe-toed lizard is hungry.
He's on a stake-out.
Flashy scales
reflect some of the sun's rays.
Nevertheless,
the heat is almost unbearable.
His prey hasn't left home all day.
The lizard is the last animal
still out on the dunes.
But even he can't take it any more.
To survive longer,
you would 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 heatstroke. 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.
Something has to change.
The silver ant is the hardiest
of all desert inhabitants.
Even so, it can only survive
outside in the middle of the day
for a matter of minutes.
Now, the desert belongs to
the sun alone.
The sun has scorched
life from the Sahara.
And yet the vast desert it created
is a source of life
half a world away.
The advancing Sahara
vaporised the world's largest lake,
leaving behind the silvery remains
of countless microscopic algae.
In winter, the wind carries away
700,000 tonnes
of this mineral-rich dust every day.
It blows from here all the way
to South America,
where, astonishingly, it fertilises
the Amazon rainforest.
A striking demonstration of the
reach of this mighty continent.
Throughout its long history, Africa
has influenced the entire planet.
It was the cradle of a remarkable
array of land animals that spread
across the globe, and, of course, it
was the ancestral home of all of us.
This is the tale of two
of the Africa team's
most challenging desert expeditions.
One focused on a miniscule creature
with an incredible turn of speed.
The other, on a subject so slow, to
film it in action would take years.
In both cases,
the Sahara would push crews
to the limit in pursuit
of the perfect shot.
In Tunisia, the mission is to
capture footage of moving
sand dunes, something that's never
been tried like this before.
Because the dunes move so slowly,
we'll have to leave cameras here
for about 20 months,
which means there's a huge
potential for things to go wrong.
And with film-making, if something
can go wrong, it usually will.
Two local shepherds,
Amur and Nasser,
have volunteered to tend
the equipment full-time.
The camera tower will be
the tallest structure
for as far as the eye can see.
And there are three other cameras
at lower angles.
All this toil will yield
surprisingly scant results.
They've programmed the cameras
to take one photo every day.
That's only 365 photographs
a year...
which, when you run it at
normal speed, just over 14 seconds.
I think it's taken longer to explain
what's going to happen
than the end result
will actually be.
The cameras are left to
the mercy of the sun, wind and sand.
In the meantime, crews are shooting
all across North Africa.
In Egypt, the challenge is to
get into the world of the most
heat-tolerant desert animal,
the silver ant.
They're really small,
they're really fast.
Like, you're not too sure
if you've seen an ant.
The crew have three weeks to gather
the footage they need.
We're going to try
a tracking shot on this ant nest.
Moving forward towards it,
as the ants pour out of the hole
in their millions.
Not only are these insects
super-fast,
they also keep antisocial hours.
The thing is,
we need to be out here in the middle
of the day to film these ants.
They don't do what they do
when it's nice and cool at seven,
eight o'clock in the morning.
I can't remember ever being
in a place where the wind was
so relentless
and the temperatures were so high.
The insufferable heat
is not the only problem.
Dangers are everywhere.
Ooh!
There's a really fat scorpion,
it's really big!
One, two, three.
This might kill.
Yeah? Yeah.
It's big and they have a lot
of poison in his dark thing.
What, that thing there?
Don't! Oh, my god!
Don't touch it!
The scorpion will be released far,
far away from the camp,
in a shady spot.
No such luck for the team.
They're back
to work in the midday sun.
This is, this is too much.
This is crazy.
This is crazy.
Indeed.
The heat seems to have given Kat and
Warwick a touch of Saharan madness.
The plan is to do an experiment,
to find out how fast
these little ants can run.
So we're going to lay this along
the floor, and hopefully an ant will
run alongside it and we can film it
at high speed.
And from that, calculate their...
their speed,
and perhaps try and relate it to
how fast that would be for a human.
Like me.
Silver ants are expert navigators,
using the angle of the sun
to calculate their position.
But for our team, even basic mental
tasks are becoming a challenge.
Count the seconds. See one running
and then count the seconds.
It's difficult to count a second,
isn't it? No, it's "one".
"One", yeah!
There he goes!
He's gone ten centimetres
in four seconds,
but we're running
at 500 frames a second,
which is 20 times normal time.
Yeah. So in fact, he's
covered those ten centimetres in...
We know that he does
half a metre in one second.
Half a metre per second, yep.
50 centimetres in one second,
roughly. Yeah.
So, how many body lengths is that?
He's maybe doing
five body lengths a second,
if he's two metres tall like I am.
Are you? Yeah. That's how much more
than a normal man I am.
Eventually, the duo decide that
if the silver ants were our size,
they'd be doing 280 miles an hour.
They're one of the fastest sprinters
in the animal kingdom.
No wonder we've been
struggling to film them.
It does explain a few things.
Ant-letics!
Knowing the exact speed of the ants
is all well and good, but there's
still a great deal of work to be
done before the shoot finishes.
However, in Tunisia, there's
no shortage of time, and hopefully,
no news is good news, as far as
Amur and Nasser are concerned.
The final week in Egypt,
and the crew seem to be adapting
to life in the oven.
Practice is making perfect,
and the sequence is coming together.
I think we've got some lovely shots.
Every single shot
has been really hard-earned.
But getting down in the ant's world
is now taking its toll on the kit.
It's running to stand still,
the business of blowing
dust off these things.
Oh, no!
It's got dust in it!
Ooh, crunch.
I think these ants
are stunning looking.
Near-impossible to film, I think,
because of the speed they had.
But, you know, I've come to love them
over the days and weeks.
With the sequence in the bag,
Warwick wants the final
traditional sunset shot.
It's the best time of day
to film sunsets, in the evening.
That's experience
that tells me that.
I've been doing this for years.
You learn these things.
Thanks to Warwick's experience,
including sunsets, he and Kat
have captured the extraordinary life
of the speedy silver ant.
Over a year later, in Tunisia,
it's time to take down
the sand dune cameras.
Bonjour!
Nasser, Amur. Hello again.
So how's it been, has it been good?
It's OK, but two days ago, we have
a little bit... small problem.
After surviving 600 days
in the desert,
the "small problem" is that
the cameras have been vandalised.
I'm really hot and bothered now,
it's 40 degrees,
and someone's smashed the cameras.
Not been a good start to the day,
to be honest.
There's no doubt the dunes
have moved.
But the question is
whether the equipment has survived.
That is amazing,
the camera's still here.
I guess maybe it just took them so long
to get through the toughened plastic,
that they felt they had made so much noise
they were worried about the guards coming,
because they only sleep
a couple of 100 metres away.
After almost two years of waiting,
it's the moment of truth.
We're going to find out,
find out whether or not
the cameras
have actually recorded anything.
It's just hugely stressful
because it's never been done before.
The footage is a surreal window
into a secret world
the private life of a sand dune.
The Africa team
struggled under the burning sun
and driving winds
that are hallmarks of the Sahara.
They went home with an enormous
admiration for the creatures that
spend their entire lives battling to
survive in this brutal desert world.