1
00:00:36,000 --> 00:00:37,480
North Africa.


2
00:00:55,880 --> 00:00:59,160
High in Morocco's Atlas Mountains,


3
00:00:59,160 --> 00:01:03,200
Barbary macaques shiver
in the icy cedars.


4
00:01:12,800 --> 00:01:15,720
The ancestors of these monkeys
fled here


5
00:01:15,720 --> 00:01:19,360
from a disaster that overwhelmed
their homeland.


6
00:01:21,600 --> 00:01:25,160
Now, trapped in this isolated
corner of Africa,


7
00:01:25,160 --> 00:01:28,560
there's no going back
to the land farther south.


8
00:01:31,720 --> 00:01:33,960
Even in this snowy refuge,


9
00:01:33,960 --> 00:01:35,120
there's a reminder


10
00:01:35,120 --> 00:01:36,520
of what drove them here.


11
00:01:42,800 --> 00:01:46,400
The unbridled power
of the African sun.


12
00:01:54,120 --> 00:01:56,640
Under its intense gaze,


13
00:01:56,640 --> 00:01:58,560
the snow can't last for long.


14
00:02:05,400 --> 00:02:09,280
Melt water should bring life
to the lowlands.


15
00:02:12,560 --> 00:02:15,760
Hundreds of torrents
cascade southwards.


16
00:02:18,040 --> 00:02:21,760
But each is flowing
towards extinction.


17
00:02:26,600 --> 00:02:29,680
Just 200 miles
south of the mountains,


18
00:02:29,680 --> 00:02:32,120
the rivers are vaporised.


19
00:02:38,520 --> 00:02:41,600
Life has been burnt off the land.


20
00:02:50,000 --> 00:02:54,160
This was the apocalypse from which
the Barbary macaques fled.


21
00:02:55,920 --> 00:02:58,800
The sudden and unstoppable advance


22
00:02:58,800 --> 00:03:01,840
of the greatest desert
on the planet.


23
00:03:14,480 --> 00:03:17,560
The Sahara transformed North Africa.


24
00:03:19,320 --> 00:03:21,080
Today, it covers an area


25
00:03:21,080 --> 00:03:23,360
the size of the United States.


26
00:03:23,360 --> 00:03:26,360
One-third of the entire
African continent.


27
00:03:32,480 --> 00:03:36,320
This is one of the hottest places
on Earth.


28
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The merciless sun,


29
00:03:46,200 --> 00:03:50,440
a colossal 15-million-degree
nuclear reactor,


30
00:03:50,440 --> 00:03:53,200
blasted life from the surface
of the land.


31
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It still wreaks havoc.


32
00:03:59,680 --> 00:04:03,120
A faint breath of wind
can be the beginning of disaster.


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00:04:49,040 --> 00:04:53,160
Nomads tell of entire
villages being engulfed...


34
00:04:54,720 --> 00:04:56,760
..camel trains disappearing,


35
00:04:56,760 --> 00:05:01,000
and people buried alive
inside their tents.


36
00:05:50,680 --> 00:05:55,280
A sandstorm can be
1,000 miles across.


37
00:05:58,600 --> 00:06:04,000
It seems miraculous that anything
can survive such devastation.


38
00:06:07,720 --> 00:06:12,400
The Saharan apocalypse
wiped out many creatures,


39
00:06:12,400 --> 00:06:15,160
but, today, some still cling on,


40
00:06:15,160 --> 00:06:18,440
in the lands around the margins
of the great desert.


41
00:06:23,040 --> 00:06:24,480
It's very dry here.


42
00:06:25,640 --> 00:06:28,800
Some years, the rains fail entirely.


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00:06:38,000 --> 00:06:41,040
A lone Grevy's zebra.


44
00:06:43,240 --> 00:06:46,080
He weighs close to half a tonne,


45
00:06:46,080 --> 00:06:49,320
and could go for three days
without drinking.


46
00:06:54,560 --> 00:06:56,160
Like the macaques,


47
00:06:56,160 --> 00:06:59,480
his forebears were refugees
from the advancing Sahara.


48
00:07:05,200 --> 00:07:07,560
The land is scrubby and dry.


49
00:07:13,040 --> 00:07:15,800
But this stallion has claimed it
as his own.


50
00:07:18,120 --> 00:07:20,560
He's been waiting months
for visitors.


51
00:07:22,080 --> 00:07:23,560
Female visitors.


52
00:07:32,280 --> 00:07:34,160
If they like his territory,


53
00:07:34,160 --> 00:07:35,920
they might stay a while.


54
00:07:40,800 --> 00:07:45,320
It's his first chance to mate
for a very long time.


55
00:07:57,280 --> 00:07:58,760
HE BRAYS


56
00:07:58,760 --> 00:08:00,120
Hardly a success.


57
00:08:02,240 --> 00:08:06,000
Perhaps his visitors are looking
for a more impressive partner.


58
00:08:09,280 --> 00:08:11,240
There's another setback.


59
00:08:13,040 --> 00:08:15,080
The females were being followed,


60
00:08:15,080 --> 00:08:17,560
a posse of young males,


61
00:08:17,560 --> 00:08:19,480
every one, a rival.


62
00:08:25,520 --> 00:08:28,800
It's time to separate
the men from the boys.


63
00:08:38,920 --> 00:08:40,520
HE SNORTS


64
00:08:44,440 --> 00:08:45,720
HE BRAYS


65
00:08:51,000 --> 00:08:52,800
HE BRAYS


66
00:08:54,520 --> 00:08:57,800
One by one,
the stallion sees them off.


67
00:09:04,960 --> 00:09:06,720
HE BRAYS


68
00:09:21,560 --> 00:09:24,080
The females had ringside seats.


69
00:09:26,000 --> 00:09:29,640
And his prowess has not gone
unnoted.


70
00:09:36,720 --> 00:09:39,680
Machismo gives way to tenderness.


71
00:09:56,880 --> 00:10:00,440
Around here, you have to take
every opportunity,


72
00:10:00,440 --> 00:10:03,920
be it for food, for water
or for mates.


73
00:10:14,880 --> 00:10:18,120
Female Grevy's are a fickle bunch.


74
00:10:18,120 --> 00:10:20,320
The herd have decided to move on.


75
00:10:22,080 --> 00:10:24,080
All of them.


76
00:10:24,080 --> 00:10:25,440
HE NEIGHS


77
00:10:25,440 --> 00:10:28,480
The stallion may never
see them again.


78
00:10:28,480 --> 00:10:32,760
But there's a chance
that one is now carrying his foal.


79
00:10:35,040 --> 00:10:39,320
In this harsh land
THAT must count as a triumph.


80
00:10:48,240 --> 00:10:52,560
The sun's power cannot, however,
reach far underground.


81
00:10:54,560 --> 00:10:56,920
Below, in stark contrast,


82
00:10:56,920 --> 00:10:59,880
conditions are stable and tolerable.


83
00:11:02,240 --> 00:11:05,800
And home to one of the planet's
strangest mammals.


84
00:11:10,320 --> 00:11:12,760
Meet the naked mole rats.


85
00:11:18,960 --> 00:11:24,240
These sabre-toothed sausages
wouldn't last a day in the desert.


86
00:11:25,760 --> 00:11:28,160
Special filming tunnels
allow us to see


87
00:11:28,160 --> 00:11:31,240
how well adapted they are
to the subterranean life.


88
00:11:31,240 --> 00:11:34,200
They can run equally
well in both directions,


89
00:11:34,200 --> 00:11:36,240
so tight space is no problem.


90
00:11:41,240 --> 00:11:43,040
They have lost their fur.


91
00:11:45,360 --> 00:11:48,680
And, most bizarrely,
they live in social colonies,


92
00:11:48,680 --> 00:11:51,800
much like termites or ants.


93
00:11:55,600 --> 00:11:57,320
After time spent digging,


94
00:11:57,320 --> 00:11:59,680
the workers come together to relax.


95
00:12:11,680 --> 00:12:15,520
But one here is very different
from all the rest.


96
00:12:17,560 --> 00:12:18,720
Their queen.


97
00:12:20,600 --> 00:12:22,840
Twice as heavy as her subjects,


98
00:12:22,840 --> 00:12:25,840
and not afraid to throw
her weight around.


99
00:12:30,000 --> 00:12:33,360
She is the mother of every
worker in the colony,


100
00:12:33,360 --> 00:12:37,200
and exists in a near-continuous
state of pregnancy.


101
00:12:39,960 --> 00:12:44,680
Even now, two dozen babies are
pulsating within her swollen belly.


102
00:12:50,680 --> 00:12:52,240
Just occasionally,


103
00:12:52,240 --> 00:12:54,840
one of her brood
is raised differently.


104
00:12:56,040 --> 00:12:59,120
A daughter becomes a princess.


105
00:13:03,200 --> 00:13:08,120
Until now, this youngster's enjoyed
a lazy, privileged life.


106
00:13:08,120 --> 00:13:10,000
But not for much longer.


107
00:13:15,120 --> 00:13:17,960
She has a destiny to fulfil.


108
00:13:25,520 --> 00:13:29,960
The surface is a place where no
naked mole rat can survive for long.


109
00:13:37,800 --> 00:13:42,280
But a princess will risk everything
to search for a partner.


110
00:13:51,240 --> 00:13:53,080
The quest is urgent.


111
00:13:59,520 --> 00:14:00,960
IT SNIFFS


112
00:14:00,960 --> 00:14:03,760
There's an enticing smell
in the air.


113
00:14:12,520 --> 00:14:16,680
A seductive scent draws her
downwards, to safety.


114
00:14:28,800 --> 00:14:31,040
She's sniffed out a partner.


115
00:14:34,440 --> 00:14:36,320
He too is alone,


116
00:14:36,320 --> 00:14:40,040
and eager to start a new colony
in his lonely burrow.


117
00:14:43,400 --> 00:14:45,000
Two months later,


118
00:14:45,000 --> 00:14:47,360
the princess has become a queen.


119
00:14:47,360 --> 00:14:49,720
And a new tyranny begins.


120
00:14:57,600 --> 00:14:59,640
Tough though they are,


121
00:14:59,640 --> 00:15:03,880
such refugees living on the edges
of North Africa


122
00:15:03,880 --> 00:15:07,280
cannot survive in the heart
of the Sahara.


123
00:15:11,840 --> 00:15:14,600
And yet here, in southern Nigeria,


124
00:15:14,600 --> 00:15:18,240
there are creatures preparing
to journey right across the centre


125
00:15:18,240 --> 00:15:19,880
of that great desert.


126
00:15:24,760 --> 00:15:26,640
Barn swallows.


127
00:15:31,840 --> 00:15:34,760
IT SINGS


128
00:15:34,760 --> 00:15:38,240
They spent the winter roosting
in a forest of elephant grass.


129
00:15:41,160 --> 00:15:44,000
But now, it's time
for them to leave.


130
00:15:49,080 --> 00:15:51,760
All two million of them.


131
00:16:14,680 --> 00:16:20,040
They're tiny, each weighing the same
as a couple of one pound coins,


132
00:16:20,040 --> 00:16:23,240
yet the journey to their breeding
grounds in Europe


133
00:16:23,240 --> 00:16:25,160
is over 3,000 miles long.


134
00:16:27,960 --> 00:16:31,080
Ahead of them lies
a vast death trap.


135
00:16:34,600 --> 00:16:37,640
The Sahara is too large
to go around.


136
00:16:37,640 --> 00:16:42,080
The swallows have no choice
but to meet it head-on.


137
00:16:53,800 --> 00:16:57,120
It will take one of nature's
greatest feats of navigation


138
00:16:57,120 --> 00:16:59,480
to cross this lifeless wasteland.


139
00:17:01,920 --> 00:17:06,040
A wilderness that stretches
not just to the horizon,


140
00:17:06,040 --> 00:17:08,760
but almost beyond imagination.


141
00:17:17,760 --> 00:17:21,480
It's an immense blank space
on the map.


142
00:17:28,920 --> 00:17:31,800
In spite of the Sahara's reputation,


143
00:17:31,800 --> 00:17:34,040
less than one-fifth of it is sand.


144
00:17:37,240 --> 00:17:40,040
The rest is stone


145
00:17:40,040 --> 00:17:41,840
and wind-scoured rock.


146
00:17:51,600 --> 00:17:55,160
The sun not only bakes the land,


147
00:17:55,160 --> 00:17:57,280
it warps its appearance.


148
00:18:00,520 --> 00:18:04,680
The superheated air, rising
upward from the desert surface,


149
00:18:04,680 --> 00:18:06,800
distorts the distant scene.


150
00:18:11,040 --> 00:18:16,000
A reflection of the sky
shimmers on the sands - a mirage.


151
00:18:22,360 --> 00:18:24,960
The sun is an illusionist.


152
00:18:28,640 --> 00:18:30,600
To thirsty travellers,


153
00:18:30,600 --> 00:18:32,320
a mirage can resemble a lake


154
00:18:32,320 --> 00:18:36,160
which agonisingly recedes
as it's approached.


155
00:18:44,400 --> 00:18:47,640
And swaying camels
coming to the rescue


156
00:18:47,640 --> 00:18:51,360
transform into dry, spiny
acacia trees.


157
00:19:02,360 --> 00:19:06,240
To cross this confused,
shimmering landscape,


158
00:19:06,240 --> 00:19:11,080
many swallows will need to find
real water amongst the mirages.


159
00:19:17,960 --> 00:19:22,400
Even in the Sahara,
rain does sometimes fall


160
00:19:22,400 --> 00:19:25,760
and that is sufficient
for plants to survive


161
00:19:25,760 --> 00:19:28,520
providing they have
the right adaptations.


162
00:19:29,760 --> 00:19:31,920
Rising from the sand,


163
00:19:31,920 --> 00:19:34,120
a dried-out ball of twigs.


164
00:19:41,760 --> 00:19:44,160
In strong winds, it can travel.


165
00:20:01,920 --> 00:20:04,720
This plant may have been dead
for 100 years.


166
00:20:08,640 --> 00:20:12,640
Yet its name suggests
that all is not lost,


167
00:20:12,640 --> 00:20:15,160
for this is a resurrection plant.


168
00:20:23,320 --> 00:20:27,120
Around here, rain might only fall
once or twice a year.


169
00:20:31,040 --> 00:20:33,480
But if you're searching for decades,


170
00:20:33,480 --> 00:20:35,240
that might be enough.


171
00:20:42,160 --> 00:20:44,560
Dead limbs absorb water


172
00:20:44,560 --> 00:20:47,320
and unfurl in a matter of minutes.


173
00:20:49,920 --> 00:20:53,600
But the resurrection plant
needs one more miracle.


174
00:20:57,120 --> 00:20:59,560
THUNDER


175
00:21:00,760 --> 00:21:03,960
Rain must fall on its branches


176
00:21:03,960 --> 00:21:06,560
before they dry out
and close up again.


177
00:22:04,320 --> 00:22:07,560
Within hours, shoots emerge.


178
00:22:23,720 --> 00:22:26,800
In just a few weeks, they flower


179
00:22:26,800 --> 00:22:28,880
and develop seeds of their own.


180
00:22:35,880 --> 00:22:38,880
Then, before they can grow
any larger,


181
00:22:38,880 --> 00:22:41,440
the sun kills them.


182
00:22:47,080 --> 00:22:48,800
But their seeds live on,


183
00:22:48,800 --> 00:22:50,880
ready for when the rains return,


184
00:22:50,880 --> 00:22:53,840
even if that is a century from now.


185
00:22:58,280 --> 00:23:01,640
North Africa wasn't always
so brutal.


186
00:23:01,640 --> 00:23:04,920
Scattered across the Sahara
are glimpses of life


187
00:23:04,920 --> 00:23:08,120
before the apocalypse
swept over the land.


188
00:23:11,520 --> 00:23:14,200
In the north, a petrified forest -


189
00:23:14,200 --> 00:23:16,040
trees turned to stone.


190
00:23:16,040 --> 00:23:19,480
Remains from a far distant,
wetter past.


191
00:23:24,160 --> 00:23:28,560
White sediments in the heart of the
Sahara are the dried-out remains


192
00:23:28,560 --> 00:23:31,880
of what was once
the world's largest lake.


193
00:23:35,560 --> 00:23:39,320
In the east, ruined cities
hark back to a time of plenty.


194
00:23:47,520 --> 00:23:50,280
And here, deep inside Libya,


195
00:23:50,280 --> 00:23:52,160
is Messak Settafet.


196
00:23:56,800 --> 00:24:02,920
Carved here are hundreds of images
of animals, all drawn from life.


197
00:24:07,120 --> 00:24:09,920
Ghosts from a greener time.


198
00:24:15,280 --> 00:24:20,200
Remarkably, a remnant of this old
North Africa survives.


199
00:24:24,400 --> 00:24:29,800
Bou-Hedma, in Tunisia,
is sustained by mountain rains.


200
00:24:34,560 --> 00:24:36,200
It's a relic of the savannah


201
00:24:36,200 --> 00:24:38,440
that once carpeted North Africa.


202
00:24:51,000 --> 00:24:52,960
The vast grassland vanished


203
00:24:52,960 --> 00:24:57,480
when a shift in the Earth's orbit
drove the rains south


204
00:24:57,480 --> 00:25:00,480
and, in perhaps only
a matter of centuries,


205
00:25:00,480 --> 00:25:03,400
the Sahara Desert overwhelmed
North Africa.


206
00:25:08,160 --> 00:25:12,600
The evidence suggests this took
place around 6,000 years ago.


207
00:25:12,600 --> 00:25:15,680
In evolutionary terms,
that's no time at all


208
00:25:15,680 --> 00:25:19,880
and life has had little chance
to adapt to this new world.


209
00:25:26,520 --> 00:25:31,920
Only a few tough specialists can
cope with life amongst the dunes.


210
00:25:40,360 --> 00:25:41,760
THEY GRUNT


211
00:25:47,280 --> 00:25:49,120
THEY GRUNT


212
00:25:50,160 --> 00:25:54,040
Camels are sometimes called
"ships of the desert"


213
00:25:54,040 --> 00:25:55,200
but, like the swallows,


214
00:25:55,200 --> 00:25:57,760
they're really only visitors here.


215
00:25:59,160 --> 00:26:02,400
These "ships" can certainly
cross the Sahara,


216
00:26:02,400 --> 00:26:06,440
but even THEY can't make their home
in the harshest places.


217
00:26:11,560 --> 00:26:14,080
Left to wander the desert
by themselves,


218
00:26:14,080 --> 00:26:16,920
camels would not survive.


219
00:26:16,920 --> 00:26:21,640
They depend on their human
navigators to find oases and wells.


220
00:26:28,480 --> 00:26:32,200
Saharan folklore is full of tales
of caravans


221
00:26:32,200 --> 00:26:36,400
that missed a well by a few hundred
metres and disappeared.


222
00:26:51,240 --> 00:26:54,920
This is the White Desert, in Egypt.


223
00:27:00,120 --> 00:27:04,560
The landscape is littered
with giant chalk pillars,


224
00:27:04,560 --> 00:27:08,200
carved by innumerable sandstorms.


225
00:27:12,400 --> 00:27:16,200
This glaring white oven
is lethally hot.


226
00:27:19,000 --> 00:27:22,240
Food here is almost non-existent.


227
00:27:25,560 --> 00:27:29,000
But there's a rare gift
from a passing camel.


228
00:27:29,000 --> 00:27:32,720
The smell has lured dung beetles
from miles around.


229
00:27:35,040 --> 00:27:37,920
For them, this is manna from heaven.


230
00:27:45,320 --> 00:27:48,080
One dung ball could provide
enough food


231
00:27:48,080 --> 00:27:51,400
to last this female beetle
the rest of her life.


232
00:27:53,440 --> 00:27:55,040
But she has a problem.


233
00:27:56,280 --> 00:27:57,520
To keep it fresh,


234
00:27:57,520 --> 00:28:00,120
she must bury it in moist ground.


235
00:28:00,120 --> 00:28:02,480
And that's not easy to find.


236
00:28:10,960 --> 00:28:14,600
The temperature has already
risen ten degrees.


237
00:28:20,480 --> 00:28:23,480
This lizard avoids
the roasting sand.


238
00:28:24,960 --> 00:28:27,160
Only 30 centimetres
above the surface,


239
00:28:27,160 --> 00:28:29,440
it's significantly cooler.


240
00:28:37,440 --> 00:28:40,760
The 'reverse-pushing' technique


241
00:28:40,760 --> 00:28:42,360
is certainly the fastest way


242
00:28:42,360 --> 00:28:43,840
to keep the ball rolling.


243
00:28:49,360 --> 00:28:51,800
But it does have one drawback.


244
00:29:00,760 --> 00:29:02,680
You can't see where you're going.


245
00:29:07,400 --> 00:29:08,800
Disaster!


246
00:29:10,080 --> 00:29:12,760
Stuck between two dunes.


247
00:29:20,960 --> 00:29:23,680
The dung ball is twice her weight,


248
00:29:23,680 --> 00:29:27,800
but the urge to keep pushing
is inextinguishable.


249
00:30:11,440 --> 00:30:15,920
Now, it's 41 degrees Celsius.


250
00:30:15,920 --> 00:30:18,680
Soon, she'll be baked alive.


251
00:30:22,680 --> 00:30:28,440
Her survival instinct, in the end,
over-rides her love for dung.


252
00:30:39,840 --> 00:30:44,240
Much of the Sahara is uninhabitable,
but there are rare places


253
00:30:44,240 --> 00:30:47,240
where there is
some possibility of survival.


254
00:30:47,240 --> 00:30:51,560
Places where, by strange chance,
there is water.


255
00:30:55,600 --> 00:30:59,080
Waw An Namus is an extinct volcano.


256
00:31:00,080 --> 00:31:05,240
From space, it's a remote,
black scar on the Libyan Sahara.


257
00:31:12,240 --> 00:31:15,000
Yet there are other colours here,


258
00:31:15,000 --> 00:31:18,160
colours rarely seen
on the desert floor.


259
00:31:19,880 --> 00:31:23,480
Blue and green.


260
00:31:36,000 --> 00:31:40,440
Rain fell thousands of years ago,
when the Sahara was green


261
00:31:40,440 --> 00:31:43,240
and percolated deep into the ground.


262
00:31:44,400 --> 00:31:47,000
And here water from this vast,


263
00:31:47,000 --> 00:31:50,200
ancient reservoir
rises to the surface.


264
00:31:52,560 --> 00:31:57,320
These pools offer another
glimpse of the Sahara's past.


265
00:32:03,920 --> 00:32:06,600
Wherever there's water
in North Africa,


266
00:32:06,600 --> 00:32:11,200
living relics from this wetter time
have a chance to cling on.


267
00:32:14,400 --> 00:32:19,440
This oasis is fed
by a hot volcanic spring.


268
00:32:24,400 --> 00:32:28,120
Slightly away from the
stream of near-boiling water,


269
00:32:28,120 --> 00:32:31,080
its cooler, and fish can live.


270
00:32:31,080 --> 00:32:33,680
These are tilapia.


271
00:32:36,280 --> 00:32:39,640
Hatchlings stick close
to their mother.


272
00:32:39,640 --> 00:32:43,360
There are other dangers here
beside the scalding water.


273
00:32:47,800 --> 00:32:51,040
Particularly at night.


274
00:33:01,120 --> 00:33:04,280
The crocodiles are stealthy.


275
00:33:12,200 --> 00:33:17,320
And the tilapia are almost blind
in the darkness.


276
00:33:22,760 --> 00:33:26,600
In panic, they all leap to escape
the hunters' approach.


277
00:33:33,480 --> 00:33:37,360
But this female
can't abandon her brood.


278
00:33:44,760 --> 00:33:48,800
The crocodiles won't be thwarted.
They too can leap.


279
00:34:33,120 --> 00:34:38,040
With first light, the crocodiles
lose the element of surprise,


280
00:34:38,040 --> 00:34:40,520
and the battle is over, for now.


281
00:34:42,240 --> 00:34:47,160
The mother fish has survived,
but where are her young?


282
00:34:50,880 --> 00:34:54,080
All present and correct.


283
00:34:54,080 --> 00:34:58,320
They spent the whole night
sheltering in her mouth.


284
00:34:59,600 --> 00:35:02,560
The contest will be
repeated at sunset.


285
00:35:03,600 --> 00:35:05,880
There is nowhere else to go.


286
00:35:11,240 --> 00:35:14,880
Oases are always
sought by desert travellers,


287
00:35:14,880 --> 00:35:17,320
but not all are as they seem.


288
00:35:25,160 --> 00:35:31,600
This is the great Ubari Sand Sea,
in the heart of the Sahara.


289
00:35:35,280 --> 00:35:39,600
These swallows have travelled
1,500 miles


290
00:35:39,600 --> 00:35:41,520
since they left Nigeria.


291
00:35:43,440 --> 00:35:47,400
Their superb powers of navigation
will eventually guide them


292
00:35:47,400 --> 00:35:51,160
to Europe, but now they,
and other thirsty migrants,


293
00:35:51,160 --> 00:35:55,960
need to find a speck of blue amidst
this ocean of sand.


294
00:36:00,560 --> 00:36:03,160
And here it is.


295
00:36:03,160 --> 00:36:05,400
Umm el Mar.


296
00:36:13,520 --> 00:36:17,720
Here too, ancient groundwater
wells up to the surface.


297
00:36:37,680 --> 00:36:40,240
But the birds need to be careful,


298
00:36:40,240 --> 00:36:43,600
for the sun has played
a terrible trick.


299
00:36:51,040 --> 00:36:54,440
This oasis is poisonous.


300
00:36:56,920 --> 00:37:01,240
Intense evaporation over thousands
of years has left the water


301
00:37:01,240 --> 00:37:03,400
saltier than the sea.


302
00:37:05,960 --> 00:37:08,040
As if to underline the horror,


303
00:37:08,040 --> 00:37:12,000
the place is infested
by vast swarms of flies.


304
00:37:16,440 --> 00:37:19,760
But this plague
is a birds' salvation.


305
00:37:23,960 --> 00:37:29,080
The flies are filled with
freshwater, filtered from the brine.


306
00:37:35,040 --> 00:37:39,120
So, like a desert wanderer
squeezing a drink from a cactus,


307
00:37:39,120 --> 00:37:44,000
the birds get all the water
they need from the flies' bodies.


308
00:37:51,520 --> 00:37:54,560
More and more migrants join in.


309
00:37:56,720 --> 00:37:59,000
Wagtails.


310
00:38:14,200 --> 00:38:16,680
This is the birds' only stopover.


311
00:38:18,320 --> 00:38:24,480
It gives them enough fuel to
escape from the Sahara and Africa.


312
00:38:27,400 --> 00:38:29,240
Away from an oasis,


313
00:38:29,240 --> 00:38:33,000
it seems remarkable
that anything can live at all.


314
00:38:37,600 --> 00:38:41,560
The temperature of the sands
can exceed 70 degrees Celsius.


315
00:38:43,880 --> 00:38:48,120
There's not the slightest
trace of water left at the surface.


316
00:38:53,200 --> 00:38:58,200
And when that happens,
the Sahara itself cries out.


317
00:39:02,760 --> 00:39:05,440
LOUD HUMMING


318
00:39:33,960 --> 00:39:37,480
Billions of sliding grains
generate a hum


319
00:39:37,480 --> 00:39:40,720
that echoes across miles
of empty desert.


320
00:39:42,120 --> 00:39:46,640
These are the Sahara's legendary
singing dunes.


321
00:40:12,120 --> 00:40:15,680
Over time, these avalanches add up.


322
00:40:19,840 --> 00:40:22,080
If you watch the dunes
for long enough,


323
00:40:22,080 --> 00:40:24,640
something remarkable is revealed.


324
00:40:27,280 --> 00:40:31,480
One and a half years
flash past in a matter of seconds.


325
00:40:40,400 --> 00:40:44,640
On this timescale,
the dunes are like a stormy sea.


326
00:40:51,200 --> 00:40:55,040
An unstoppable tsunami of sand.


327
00:41:03,160 --> 00:41:06,560
In this immense,
ever-shifting landscape,


328
00:41:06,560 --> 00:41:09,800
it's easy to see how
a lost traveller could succumb


329
00:41:09,800 --> 00:41:14,760
to what's been called
the Sahara's only endemic disease -


330
00:41:14,760 --> 00:41:16,520
madness.


331
00:41:34,600 --> 00:41:38,520
Can anything survive
the North African desert


332
00:41:38,520 --> 00:41:41,360
when the sun is at its fiercest?


333
00:41:47,080 --> 00:41:50,440
It's approaching mid-day.


334
00:41:50,440 --> 00:41:53,680
A fringe-toed lizard is hungry.


335
00:41:54,760 --> 00:41:57,080
He's on a stake-out.


336
00:42:05,360 --> 00:42:09,600
Flashy scales
reflect some of the sun's rays.


337
00:42:11,240 --> 00:42:15,080
Nevertheless,
the heat is almost unbearable.


338
00:42:19,200 --> 00:42:22,400
His prey hasn't left home all day.


339
00:42:34,760 --> 00:42:39,480
The lizard is the last animal
still out on the dunes.


340
00:42:43,480 --> 00:42:46,600
But even he can't take it any more.


341
00:42:48,040 --> 00:42:51,680
To survive longer,
you would need a spacesuit.


342
00:42:55,120 --> 00:42:59,040
And in a way,
that's what these insects have.


343
00:43:02,200 --> 00:43:06,280
Silver ants'
armoured skin reflects light.


344
00:43:06,280 --> 00:43:11,040
They can tolerate temperatures that
would kill any other land animal.


345
00:43:12,720 --> 00:43:16,800
Even so, they can only
survive for less than ten minutes


346
00:43:16,800 --> 00:43:18,480
in the midday sun.


347
00:43:27,600 --> 00:43:30,160
Time is precious.


348
00:43:30,160 --> 00:43:34,880
The ants race to find food as soon
as their predators go to ground.


349
00:43:43,920 --> 00:43:47,040
They can't afford to waste
a second getting lost,


350
00:43:47,040 --> 00:43:50,320
so they spin to take
a bearing from the sun.


351
00:43:51,440 --> 00:43:55,120
They log every change of direction,
every footstep,


352
00:43:55,120 --> 00:43:58,880
in order to know exactly where
they are and where their nest lies.


353
00:44:05,040 --> 00:44:06,960
Only four minutes to spare,


354
00:44:06,960 --> 00:44:11,520
and they've found
a victim of heatstroke. A meal.


355
00:44:15,080 --> 00:44:18,800
But it's going to take a
monumental effort to get it home.


356
00:44:33,040 --> 00:44:36,920
Three minutes to go and they're
nearing their maximum temperature,


357
00:44:36,920 --> 00:44:39,720
an astounding 53 degrees Celsius.


358
00:44:48,640 --> 00:44:51,400
But there are already casualties.


359
00:45:01,840 --> 00:45:04,920
One minute left,
and they're not going to make it.


360
00:45:04,920 --> 00:45:06,920
Something has to change.


361
00:45:53,920 --> 00:45:59,040
The silver ant is the hardiest
of all desert inhabitants.


362
00:45:59,040 --> 00:46:03,240
Even so, it can only survive
outside in the middle of the day


363
00:46:03,240 --> 00:46:04,640
for a matter of minutes.


364
00:46:09,880 --> 00:46:14,520
Now, the desert belongs to
the sun alone.


365
00:46:17,360 --> 00:46:21,720
The sun has scorched
life from the Sahara.


366
00:46:21,720 --> 00:46:26,200
And yet the vast desert it created
is a source of life


367
00:46:26,200 --> 00:46:28,280
half a world away.


368
00:46:32,360 --> 00:46:38,040
The advancing Sahara
vaporised the world's largest lake,


369
00:46:38,040 --> 00:46:43,880
leaving behind the silvery remains
of countless microscopic algae.


370
00:46:46,600 --> 00:46:51,600
In winter, the wind carries away
700,000 tonnes


371
00:46:51,600 --> 00:46:54,760
of this mineral-rich dust every day.


372
00:46:57,320 --> 00:47:01,200
It blows from here all the way
to South America,


373
00:47:01,200 --> 00:47:06,400
where, astonishingly, it fertilises
the Amazon rainforest.


374
00:47:12,160 --> 00:47:18,120
A striking demonstration of the
reach of this mighty continent.


375
00:47:28,040 --> 00:47:33,840
Throughout its long history, Africa
has influenced the entire planet.


376
00:47:33,840 --> 00:47:37,920
It was the cradle of a remarkable
array of land animals that spread


377
00:47:37,920 --> 00:47:42,960
across the globe, and, of course, it
was the ancestral home of all of us.


378
00:48:13,560 --> 00:48:17,280
This is the tale of two
of the Africa team's


379
00:48:17,280 --> 00:48:19,920
most challenging desert expeditions.


380
00:48:24,480 --> 00:48:29,240
One focused on a miniscule creature
with an incredible turn of speed.


381
00:48:32,160 --> 00:48:36,520
The other, on a subject so slow, to
film it in action would take years.


382
00:48:38,480 --> 00:48:41,360
In both cases,
the Sahara would push crews


383
00:48:41,360 --> 00:48:44,400
to the limit in pursuit
of the perfect shot.


384
00:48:49,000 --> 00:48:52,840
In Tunisia, the mission is to
capture footage of moving


385
00:48:52,840 --> 00:48:57,360
sand dunes, something that's never
been tried like this before.


386
00:48:57,360 --> 00:49:01,240
Because the dunes move so slowly,
we'll have to leave cameras here


387
00:49:01,240 --> 00:49:02,280
for about 20 months,


388
00:49:02,280 --> 00:49:04,960
which means there's a huge
potential for things to go wrong.


389
00:49:06,200 --> 00:49:10,520
And with film-making, if something
can go wrong, it usually will.


390
00:49:12,000 --> 00:49:15,040
Two local shepherds,
Amur and Nasser,


391
00:49:15,040 --> 00:49:18,000
have volunteered to tend
the equipment full-time.


392
00:49:20,720 --> 00:49:23,920
The camera tower will be
the tallest structure


393
00:49:23,920 --> 00:49:26,040
for as far as the eye can see.


394
00:49:29,640 --> 00:49:33,160
And there are three other cameras
at lower angles.


395
00:49:34,960 --> 00:49:39,960
All this toil will yield
surprisingly scant results.


396
00:49:39,960 --> 00:49:44,080
They've programmed the cameras
to take one photo every day.


397
00:49:44,080 --> 00:49:47,880
That's only 365 photographs
a year...


398
00:49:47,880 --> 00:49:51,400
which, when you run it at
normal speed, just over 14 seconds.


399
00:49:51,400 --> 00:49:56,360
I think it's taken longer to explain
what's going to happen


400
00:49:56,360 --> 00:49:58,920
than the end result
will actually be.


401
00:49:58,920 --> 00:50:02,800
The cameras are left to
the mercy of the sun, wind and sand.


402
00:50:04,680 --> 00:50:09,040
In the meantime, crews are shooting
all across North Africa.


403
00:50:11,880 --> 00:50:15,720
In Egypt, the challenge is to
get into the world of the most


404
00:50:15,720 --> 00:50:19,480
heat-tolerant desert animal,
the silver ant.


405
00:50:19,480 --> 00:50:22,400
They're really small,
they're really fast.


406
00:50:22,400 --> 00:50:25,080
Like, you're not too sure
if you've seen an ant.


407
00:50:26,920 --> 00:50:30,960
The crew have three weeks to gather
the footage they need.


408
00:50:32,280 --> 00:50:35,120
We're going to try
a tracking shot on this ant nest.


409
00:50:35,120 --> 00:50:38,440
Moving forward towards it,


410
00:50:38,440 --> 00:50:41,840
as the ants pour out of the hole
in their millions.


411
00:50:41,840 --> 00:50:44,840
Not only are these insects
super-fast,


412
00:50:44,840 --> 00:50:47,440
they also keep antisocial hours.


413
00:50:47,440 --> 00:50:48,840
The thing is,


414
00:50:48,840 --> 00:50:52,480
we need to be out here in the middle
of the day to film these ants.


415
00:50:52,480 --> 00:50:55,840
They don't do what they do
when it's nice and cool at seven,


416
00:50:55,840 --> 00:50:58,000
eight o'clock in the morning.


417
00:50:58,000 --> 00:51:01,160
I can't remember ever being
in a place where the wind was


418
00:51:01,160 --> 00:51:03,960
so relentless
and the temperatures were so high.


419
00:51:07,000 --> 00:51:10,640
The insufferable heat
is not the only problem.


420
00:51:10,640 --> 00:51:12,680
Dangers are everywhere.


421
00:51:12,680 --> 00:51:15,120
Ooh!


422
00:51:15,120 --> 00:51:18,520
There's a really fat scorpion,
it's really big!


423
00:51:18,520 --> 00:51:20,040
One, two, three.


424
00:51:24,040 --> 00:51:25,280
This might kill.


425
00:51:25,280 --> 00:51:27,360
Yeah? Yeah.


426
00:51:27,360 --> 00:51:31,720
It's big and they have a lot
of poison in his dark thing.


427
00:51:31,720 --> 00:51:33,880
What, that thing there?


428
00:51:33,880 --> 00:51:35,280
Don't! Oh, my god!


429
00:51:35,280 --> 00:51:36,720
Don't touch it!


430
00:51:36,720 --> 00:51:40,600
The scorpion will be released far,
far away from the camp,


431
00:51:40,600 --> 00:51:43,320
in a shady spot.


432
00:51:43,320 --> 00:51:45,360
No such luck for the team.


433
00:51:45,360 --> 00:51:49,000
They're back
to work in the midday sun.


434
00:51:49,000 --> 00:51:53,440
This is, this is too much.
This is crazy.


435
00:51:53,440 --> 00:51:54,880
This is crazy.


436
00:51:54,880 --> 00:51:55,960
Indeed.


437
00:51:55,960 --> 00:52:00,000
The heat seems to have given Kat and
Warwick a touch of Saharan madness.


438
00:52:01,680 --> 00:52:03,960
The plan is to do an experiment,


439
00:52:03,960 --> 00:52:08,600
to find out how fast
these little ants can run.


440
00:52:08,600 --> 00:52:13,480
So we're going to lay this along
the floor, and hopefully an ant will


441
00:52:13,480 --> 00:52:16,760
run alongside it and we can film it
at high speed.


442
00:52:16,760 --> 00:52:20,080
And from that, calculate their...
their speed,


443
00:52:20,080 --> 00:52:24,400
and perhaps try and relate it to
how fast that would be for a human.


444
00:52:24,400 --> 00:52:26,640
Like me.


445
00:52:26,640 --> 00:52:29,080
Silver ants are expert navigators,


446
00:52:29,080 --> 00:52:32,600
using the angle of the sun
to calculate their position.


447
00:52:32,600 --> 00:52:37,720
But for our team, even basic mental
tasks are becoming a challenge.


448
00:52:37,720 --> 00:52:41,120
Count the seconds. See one running
and then count the seconds.


449
00:52:41,120 --> 00:52:44,480
It's difficult to count a second,
isn't it? No, it's "one".


450
00:52:46,360 --> 00:52:48,680
"One", yeah!


451
00:52:53,160 --> 00:52:54,680
There he goes!


452
00:52:56,760 --> 00:52:59,400
He's gone ten centimetres
in four seconds,


453
00:52:59,400 --> 00:53:02,800
but we're running
at 500 frames a second,


454
00:53:02,800 --> 00:53:04,600
which is 20 times normal time.


455
00:53:04,600 --> 00:53:08,880
Yeah. So in fact, he's
covered those ten centimetres in...


456
00:53:12,760 --> 00:53:16,000
We know that he does
half a metre in one second.


457
00:53:16,000 --> 00:53:18,440
Half a metre per second, yep.


458
00:53:18,440 --> 00:53:22,240
50 centimetres in one second,
roughly. Yeah.


459
00:53:22,240 --> 00:53:25,040
So, how many body lengths is that?


460
00:53:26,920 --> 00:53:29,440
He's maybe doing
five body lengths a second,


461
00:53:29,440 --> 00:53:31,040
if he's two metres tall like I am.


462
00:53:31,040 --> 00:53:34,400
Are you? Yeah. That's how much more
than a normal man I am.


463
00:53:40,200 --> 00:53:45,320
Eventually, the duo decide that
if the silver ants were our size,


464
00:53:45,320 --> 00:53:49,160
they'd be doing 280 miles an hour.


465
00:53:52,000 --> 00:53:55,600
They're one of the fastest sprinters
in the animal kingdom.


466
00:53:55,600 --> 00:53:58,280
No wonder we've been
struggling to film them.


467
00:53:58,280 --> 00:53:59,920
It does explain a few things.


468
00:54:01,800 --> 00:54:03,960
Ant-letics!


469
00:54:07,480 --> 00:54:11,120
Knowing the exact speed of the ants
is all well and good, but there's


470
00:54:11,120 --> 00:54:14,680
still a great deal of work to be
done before the shoot finishes.


471
00:54:16,440 --> 00:54:21,320
However, in Tunisia, there's
no shortage of time, and hopefully,


472
00:54:21,320 --> 00:54:25,680
no news is good news, as far as
Amur and Nasser are concerned.


473
00:54:30,240 --> 00:54:32,800
The final week in Egypt,


474
00:54:32,800 --> 00:54:36,200
and the crew seem to be adapting
to life in the oven.


475
00:54:39,520 --> 00:54:43,680
Practice is making perfect,
and the sequence is coming together.


476
00:54:46,880 --> 00:54:49,120
I think we've got some lovely shots.


477
00:54:49,120 --> 00:54:51,600
Every single shot
has been really hard-earned.


478
00:54:51,600 --> 00:54:55,880
But getting down in the ant's world
is now taking its toll on the kit.


479
00:54:55,880 --> 00:54:57,560
It's running to stand still,


480
00:54:57,560 --> 00:55:00,240
the business of blowing
dust off these things.


481
00:55:01,840 --> 00:55:03,480
Oh, no!


482
00:55:03,480 --> 00:55:05,320
It's got dust in it!


483
00:55:05,320 --> 00:55:06,520
CRUNCH


484
00:55:06,520 --> 00:55:08,080
Ooh, crunch.


485
00:55:10,640 --> 00:55:12,760
I think these ants
are stunning looking.


486
00:55:12,760 --> 00:55:15,720
Near-impossible to film, I think,
because of the speed they had.


487
00:55:15,720 --> 00:55:19,520
But, you know, I've come to love them
over the days and weeks.


488
00:55:21,480 --> 00:55:23,200
With the sequence in the bag,


489
00:55:23,200 --> 00:55:26,800
Warwick wants the final
traditional sunset shot.


490
00:55:27,800 --> 00:55:31,200
It's the best time of day
to film sunsets, in the evening.


491
00:55:32,800 --> 00:55:34,880
That's experience
that tells me that.


492
00:55:34,880 --> 00:55:37,720
I've been doing this for years.
You learn these things.


493
00:55:37,720 --> 00:55:42,280
Thanks to Warwick's experience,
including sunsets, he and Kat


494
00:55:42,280 --> 00:55:47,280
have captured the extraordinary life
of the speedy silver ant.


495
00:55:50,280 --> 00:55:52,840
Over a year later, in Tunisia,


496
00:55:52,840 --> 00:55:56,440
it's time to take down
the sand dune cameras.


497
00:55:57,480 --> 00:55:59,600
Bonjour!


498
00:55:59,600 --> 00:56:03,880
Nasser, Amur. Hello again.


499
00:56:03,880 --> 00:56:05,720
So how's it been, has it been good?


500
00:56:05,720 --> 00:56:10,960
It's OK, but two days ago, we have
a little bit...small problem.


501
00:56:10,960 --> 00:56:13,760
After surviving 600 days
in the desert,


502
00:56:13,760 --> 00:56:17,880
the "small problem" is that
the cameras have been vandalised.


503
00:56:20,720 --> 00:56:23,360
I'm really hot and bothered now,
it's 40 degrees,


504
00:56:23,360 --> 00:56:27,280
and someone's smashed the cameras.


505
00:56:27,280 --> 00:56:30,000
Not been a good start to the day,
to be honest.


506
00:56:31,040 --> 00:56:33,560
There's no doubt the dunes
have moved.


507
00:56:33,560 --> 00:56:37,240
But the question is
whether the equipment has survived.


508
00:56:40,400 --> 00:56:42,600
That is amazing,
the camera's still here.


509
00:56:42,600 --> 00:56:46,200
I guess maybe it just took them
so long to get through
the toughened plastic,


510
00:56:46,200 --> 00:56:49,920
that they felt they had made
so much noise they were worried
about the guards coming,


511
00:56:49,920 --> 00:56:52,640
because they only sleep
a couple of 100 metres away.


512
00:56:52,640 --> 00:56:57,680
After almost two years of waiting,
it's the moment of truth.


513
00:57:00,000 --> 00:57:03,320
We're going to find out,
find out whether or not


514
00:57:03,320 --> 00:57:06,200
the cameras
have actually recorded anything.


515
00:57:06,200 --> 00:57:09,920
It's just hugely stressful
because it's never been done before.


516
00:57:12,360 --> 00:57:16,000
The footage is a surreal window
into a secret world -


517
00:57:16,000 --> 00:57:18,760
the private life of a sand dune.


518
00:57:28,560 --> 00:57:31,480
The Africa team
struggled under the burning sun


519
00:57:31,480 --> 00:57:35,280
and driving winds
that are hallmarks of the Sahara.


520
00:57:40,960 --> 00:57:45,120
They went home with an enormous
admiration for the creatures that


521
00:57:45,120 --> 00:57:50,520
spend their entire lives battling to
survive in this brutal desert world.


522
00:57:58,440 --> 00:58:02,040
Next time, we'll be looking towards
the future of Africa


523
00:58:02,040 --> 00:58:03,840
and its wildlife.


524
00:58:03,840 --> 00:58:09,880
Meeting the remarkable Elvis
and his highly endangered family.


525
00:58:09,880 --> 00:58:13,080
Diving with Shella,
who's learning to swim again.


526
00:58:14,360 --> 00:58:17,840
Africa's wildlife
is at a critical point


527
00:58:17,840 --> 00:58:20,200
as it faces its greatest threat.


528
00:58:21,480 --> 00:58:23,280
As this battle between man


529
00:58:23,280 --> 00:58:27,360
and wildlife happens, in most cases,
wildlife is on the losing end.


530
00:58:31,320 --> 00:58:35,040
But there is hope as the
new generation takes on the task


531
00:58:35,040 --> 00:58:39,960
of protecting Africa's animals
for the 21st century and beyond.


532
00:58:39,960 --> 00:58:44,080
Join me
next time for the future of Africa.


533
00:59:01,120 --> 00:59:03,400
Subtitles by Red Bee Media Ltd