0:00:45 > 0:00:48ROARING YAWN
0:01:20 > 0:01:25I'm flying over the Great Rift Valley in East Africa.
0:01:25 > 0:01:29And below me, is a landscape in turmoil,
0:01:29 > 0:01:34torn apart by the twisting and buckling of the Earth's crust.
0:01:35 > 0:01:41It's also a landscape of huge and unpredictable change,
0:01:41 > 0:01:45that forces animals, day by day, season by season,
0:01:45 > 0:01:48to gamble with their lives.
0:01:48 > 0:01:50But for those that win,
0:01:50 > 0:01:55this is one of the most fertile landscapes on Earth.
0:02:31 > 0:02:36Nyiragongo, the largest lava lake in the world...
0:02:38 > 0:02:41..bubbling up from nearly ten miles beneath the surface.
0:02:48 > 0:02:51Nowhere takes you closer to the fiery heart of the planet.
0:02:58 > 0:03:02Mount Nyiragongo is one of the most active volcanoes in Africa.
0:03:04 > 0:03:06Its eruptions can be seen from space.
0:03:14 > 0:03:17As magma churns below the Earth's crust,
0:03:17 > 0:03:20the land to the east of here is being torn apart.
0:03:41 > 0:03:46Volcanoes like this are continually changing the face of Eastern Africa.
0:03:58 > 0:04:01The volcanoes here may have a violent side...
0:04:03 > 0:04:06..but life flows from these infernos.
0:04:16 > 0:04:20Fertile ash from countless eruptions carpets the land...
0:04:23 > 0:04:27..creating the ideal conditions for grasses to flourish,
0:04:27 > 0:04:29on an immense scale.
0:04:35 > 0:04:42And with the grasses come animals in numbers found nowhere else on Earth.
0:04:42 > 0:04:43Wildebeest.
0:04:47 > 0:04:49Nothing stands in their way.
0:05:07 > 0:05:10All this, just to reach fresh grass.
0:05:12 > 0:05:14WILDEBEEST GRUNT
0:05:27 > 0:05:31The ever-travelling herds are only one element of life here.
0:05:35 > 0:05:38Look closer and there are new stories to tell.
0:05:42 > 0:05:46Living on the savanna is about making the most of the hand
0:05:46 > 0:05:48the landscape deals you.
0:05:49 > 0:05:54But here, it's always a gamble - everything may change tomorrow.
0:05:55 > 0:05:58From their vantage point, agama lizards
0:05:58 > 0:06:02wait for the arrival of the herds, ready to seize their moment.
0:06:05 > 0:06:08It's payday - over a million wildebeest on their doorstep.
0:06:15 > 0:06:20And with the wildebeest come flying insects - billions of them.
0:06:20 > 0:06:23BUZZING
0:06:23 > 0:06:26Food - if only they could catch them!
0:06:52 > 0:06:54Time for a rethink.
0:07:03 > 0:07:07This agama lizard has spotted an opportunity.
0:07:19 > 0:07:22Only one thing attracts more flies than the wildebeest...
0:07:25 > 0:07:28..lions that have eaten wildebeest.
0:07:34 > 0:07:36Lions are famously bad-tempered -
0:07:36 > 0:07:39they could swat the lizard like the flies he's hoping to ambush.
0:07:50 > 0:07:52He will need to pick his target carefully.
0:07:56 > 0:07:58LOW GROWL
0:08:07 > 0:08:09Not her.
0:08:17 > 0:08:18Or her.
0:08:22 > 0:08:24Maybe?
0:08:26 > 0:08:28But no.
0:08:28 > 0:08:31LIONESS GRUMBLES
0:08:33 > 0:08:38To be within striking distance, he's got to hold his nerve.
0:08:42 > 0:08:43Got one!
0:08:51 > 0:08:53Now he's getting his eye in.
0:09:00 > 0:09:04LIONESS GRUMBLES
0:09:07 > 0:09:09But this might be a bit ambitious.
0:09:30 > 0:09:33It may take courage to hunt on the back of a lion...
0:09:36 > 0:09:38LION GRUMBLES
0:09:41 > 0:09:44..but it takes sense to know when to run away!
0:09:50 > 0:09:53The wildebeest won't stay for long, and when they leave,
0:09:53 > 0:09:55most of the flies will follow.
0:09:57 > 0:10:00Change is everywhere in East Africa.
0:10:03 > 0:10:06This grassland was once covered by a forest that ran
0:10:06 > 0:10:08unbroken from west coast to east coast.
0:10:13 > 0:10:15Today, high above the plains,
0:10:15 > 0:10:20swirling clouds hide mountains that tower three miles into the sky.
0:10:35 > 0:10:39These frozen summits now form part of a mountainous barrier separating
0:10:39 > 0:10:44the ancient jungles in the west from the savannahs of the east.
0:10:54 > 0:10:57Up here, lies the largest glacier in Africa,
0:10:57 > 0:11:00just a few miles north of the equator.
0:11:15 > 0:11:19These are the legendary Mountains of the Moon.
0:11:30 > 0:11:34The height of these peaks means they create their own weather.
0:11:43 > 0:11:47The local name for these mountains is "Rwenzori" -
0:11:47 > 0:11:48"the rain maker".
0:11:56 > 0:12:02WATER DRIPPING
0:12:12 > 0:12:15Meltwater flows down from the glaciers.
0:12:22 > 0:12:27And on the lower slopes, all this water supports thick jungle...
0:12:27 > 0:12:31PIPING AND TRILLING BIRDSONG
0:12:33 > 0:12:35..remnants of the dense,
0:12:35 > 0:12:41steamy forests that once dominated the whole of East Africa.
0:12:44 > 0:12:47But driven by a drying climate beyond the mountains,
0:12:47 > 0:12:50the forests began to wither away.
0:12:52 > 0:12:56Today, only small pockets of upland jungle remain -
0:12:56 > 0:13:00home to animals who once roamed the ancient forests.
0:13:05 > 0:13:07The largest living primates on Earth.
0:13:07 > 0:13:09GORILLA GRUNTS
0:13:11 > 0:13:13Mountain gorillas.
0:13:21 > 0:13:25GORILLA BABY SQUEALS
0:13:35 > 0:13:40This little one's ancestors have lived in forests like these
0:13:40 > 0:13:42for millions of years.
0:13:59 > 0:14:04But all around, the world has changed to swamp and savanna.
0:14:14 > 0:14:17This is the furthest these mighty giants
0:14:17 > 0:14:19now venture into Eastern Africa.
0:14:22 > 0:14:26They're marooned on their islands in the African sky.
0:14:43 > 0:14:45Below the highlands,
0:14:45 > 0:14:49vast wetlands cut swathes through the open savanna.
0:14:52 > 0:14:56BIRDS CHIRRUP
0:15:15 > 0:15:19Bangweulu Swamp is huge -
0:15:19 > 0:15:22its name means, "where the water meets the sky".
0:15:28 > 0:15:32Hidden amongst this maze of waterways
0:15:32 > 0:15:34is a creature like no other.
0:15:59 > 0:16:03A giant, prehistoric-looking bird.
0:16:05 > 0:16:07A shoebill.
0:16:10 > 0:16:14Standing well over a metre tall...
0:16:14 > 0:16:17she roams these swamps...
0:16:18 > 0:16:21..trying to catch catfish.
0:16:41 > 0:16:44Not exactly what she was after.
0:16:52 > 0:16:56Deeper into the swamp, lies the reason for all this fishing.
0:17:03 > 0:17:08This chick is just three weeks old and a little bit wobbly on its feet.
0:17:10 > 0:17:14Its vast bill means it has trouble balancing.
0:17:14 > 0:17:17It won't be able to fly, or even walk properly for several weeks.
0:17:21 > 0:17:23HONKING CALL
0:17:23 > 0:17:27It's entirely reliant on its parents for food and water.
0:17:27 > 0:17:29SQUEAKING CALL
0:17:37 > 0:17:40There is also a smaller chick,
0:17:40 > 0:17:42who isn't doing so well.
0:17:46 > 0:17:49CHICK'S LOW HONKING CALLS
0:17:52 > 0:17:55The larger chick pesters its mother for a drink.
0:18:06 > 0:18:09While she goes off to fetch water,
0:18:09 > 0:18:14it reveals a dark side to the relationship with its nest mate.
0:18:29 > 0:18:32It's three days older than the other chick,
0:18:32 > 0:18:35and has always won the race for food and attention.
0:18:39 > 0:18:42This is more than just a scrap between two siblings.
0:18:59 > 0:19:03As their mother returns, she sees what the larger chick has done.
0:19:13 > 0:19:16The smaller chick seeks its mother's comfort.
0:19:16 > 0:19:19CHICK SQUAWKS
0:19:21 > 0:19:24But she has already made her choice.
0:19:35 > 0:19:37Only her first-born will get a drink.
0:19:47 > 0:19:51Shoebills very rarely raise more than one chick.
0:19:57 > 0:20:01The younger chick was only ever an insurance,
0:20:01 > 0:20:03in case the elder didn't make it.
0:20:14 > 0:20:17Now it's old enough, the adults know that
0:20:17 > 0:20:19they're better off putting all their efforts
0:20:19 > 0:20:23into bringing up just one fit and healthy youngster.
0:20:27 > 0:20:30The swamp's changing water levels mean fishing
0:20:30 > 0:20:32is too unpredictable for them
0:20:32 > 0:20:35to gamble on trying to raise two chicks.
0:20:45 > 0:20:49Nothing here stays the same for long.
0:20:53 > 0:20:58This is the time of year when Eastern Africa is beginning to dry.
0:20:58 > 0:21:02HIPPOS SNORT AND ROAR
0:21:02 > 0:21:06The rivers and waterholes are shrinking.
0:21:12 > 0:21:14The land continues to dry out.
0:21:18 > 0:21:20Tensions rise.
0:21:44 > 0:21:47Hippos seek what relief they can.
0:21:52 > 0:21:55This time of relentless drying
0:21:55 > 0:22:00is also when another force of change ravages the land.
0:22:15 > 0:22:19Without warning, fires rip through these tinder-dry plains.
0:22:28 > 0:22:34The flames sweep across the savanna at 50mph...
0:22:34 > 0:22:37reaching temperatures of nearly a thousand degrees,
0:22:37 > 0:22:39consuming everything in their path.
0:22:43 > 0:22:46Each year, an area larger than Britain goes up in smoke.
0:23:24 > 0:23:28But this destruction can bring opportunity,
0:23:28 > 0:23:30if you're prepared to take a risk.
0:23:48 > 0:23:51Drongos, bee-eaters
0:23:51 > 0:23:55and rollers bravely pluck fleeing insects from amongst the flames.
0:24:12 > 0:24:16There's little better than a char-grilled grasshopper.
0:24:24 > 0:24:27These fires may appear devastating, but they are, in fact,
0:24:27 > 0:24:32part of a natural cycle that is essential for the regeneration
0:24:32 > 0:24:34of East Africa's grasslands.
0:24:41 > 0:24:45But sometimes the cycle is broken, just when a change is most needed.
0:25:11 > 0:25:16Here, on the plains of Amboseli, in the shadow of Mount Kilimanjaro,
0:25:16 > 0:25:19the seasonal rains have failed for the last two years.
0:25:24 > 0:25:27And this year, they are already long overdue.
0:25:30 > 0:25:33It's the hardest drought for half a century.
0:25:39 > 0:25:42ELEPHANTS TRUMPET
0:25:56 > 0:25:59ELEPHANTS TRUMPET
0:26:06 > 0:26:09Amboseli is usually a haven for elephants.
0:26:12 > 0:26:15These plains should be green and covered with grass.
0:26:17 > 0:26:20Now there is nothing but dust.
0:26:27 > 0:26:30This family is forced to travel
0:26:30 > 0:26:31constantly,
0:26:31 > 0:26:33searching for anything they can eat.
0:26:34 > 0:26:36ELEPHANTS GRUNT
0:26:36 > 0:26:42The young must keep up, sometimes there's not even time to suckle.
0:26:42 > 0:26:44ELEPHANT BABY SQUAWKS
0:26:53 > 0:26:54With the grass gone,
0:26:54 > 0:26:59all the elephants can scratch from the dust is withered twigs.
0:27:05 > 0:27:09The adults might just survive on this,
0:27:09 > 0:27:12but it will not support a calf for long.
0:27:36 > 0:27:38Every mother in the herd
0:27:38 > 0:27:41is struggling to provide milk for her calf.
0:27:48 > 0:27:52The search for food is increasingly urgent.
0:27:58 > 0:28:03As the herd moves on, this female faces a terrible choice.
0:28:07 > 0:28:10To carry on with her family,
0:28:10 > 0:28:12or stay behind with her calf,
0:28:12 > 0:28:14who's becoming too weak to even stand.
0:28:22 > 0:28:24They will soon be out of sight.
0:28:28 > 0:28:30But her instinct is to stay.
0:28:37 > 0:28:39CALF SQUEALS
0:28:39 > 0:28:41MOTHER ELEPHANT BAYS
0:29:00 > 0:29:02She won't abandon her baby.
0:29:05 > 0:29:08CALF SQUEAKS
0:29:17 > 0:29:21MOTHER ELEPHANT BAYS
0:29:32 > 0:29:35MOTHER ELEPHANT BAYS
0:30:05 > 0:30:08MOTHER ELEPHANT BAYS
0:30:14 > 0:30:17BABY ELEPHANT WHEEZES SOFTLY
0:30:19 > 0:30:24With the calf's last breath, she knows that her battle is lost.
0:30:45 > 0:30:50MOTHER ELEPHANT RUMBLES
0:31:26 > 0:31:31There ARE places even more hostile than the dust-choked plains.
0:31:38 > 0:31:42These alien landscapes are actually the sun-baked salt crusts
0:31:42 > 0:31:46of a chain of lakes that run through East Africa.
0:31:49 > 0:31:52The face of these soda lakes changes day by day,
0:31:52 > 0:31:56as the sun evaporates the water, leaving the salts behind.
0:32:00 > 0:32:05The waters here are toxic, poisoned by volcanic springs.
0:32:08 > 0:32:11But life does exist, even here.
0:32:12 > 0:32:15The strange colours are created by algae,
0:32:15 > 0:32:18specially adapted to live in this corrosive liquid.
0:32:20 > 0:32:23And it is these algae that attract
0:32:23 > 0:32:27one of the most astonishing animals found in East Africa.
0:33:08 > 0:33:10SQUAWKING
0:33:14 > 0:33:18WATER LAPS NOISILY
0:33:33 > 0:33:36Among the steaming geysers of Lake Bogoria,
0:33:36 > 0:33:41over a million lesser flamingos bathe and feed in the caustic water.
0:33:46 > 0:33:50They gather whenever the algae bloom.
0:33:50 > 0:33:53LOUD SQUAWKING
0:33:59 > 0:34:01These huge numbers
0:34:01 > 0:34:04create one of the greatest wildlife spectacles on Earth.
0:34:26 > 0:34:29Almost all the world's lesser flamingos
0:34:29 > 0:34:31live on this chain of lakes,
0:34:31 > 0:34:35moving from one lake to another as the amount of algae in each changes.
0:35:06 > 0:35:10All along the lake shore, volcanic vents are a reminder
0:35:10 > 0:35:13of the forces that continue to change this land.
0:35:18 > 0:35:21And a streak of colour on the horizon
0:35:21 > 0:35:25signals that relief for the parched plains is on its way.
0:35:30 > 0:35:33THUNDERCLAPS
0:35:33 > 0:35:35RAIN FALLS
0:35:37 > 0:35:41At last, countless storms drench the thirsty ground.
0:35:48 > 0:35:52Rain changes everything, yet again.
0:35:52 > 0:35:54LIGHTNING CRACKLES
0:35:54 > 0:35:56THUNDERCLAPS
0:36:07 > 0:36:09A crowned eagle has been desperately waiting
0:36:09 > 0:36:12for what she hopes the rain will bring...
0:36:12 > 0:36:15CHIRPING
0:36:15 > 0:36:17..food for her hungry chick.
0:36:19 > 0:36:21Nesting here has been her biggest gamble.
0:36:24 > 0:36:27Her chick's life depends on the arrival of creatures
0:36:27 > 0:36:31from the far rainforests of the Congo.
0:36:31 > 0:36:34THUNDERCLAPS
0:36:39 > 0:36:43Her wait will soon be over.
0:36:43 > 0:36:47The largest mammal migration in Africa is on the move.
0:36:47 > 0:36:49HIGH-PITCHED SQUEAKING
0:37:09 > 0:37:12Ten million fruit bats are drawn to this tiny forest,
0:37:12 > 0:37:14on the edge of the eastern savanna.
0:37:17 > 0:37:20The bats flock here to gorge themselves on fruit.
0:37:26 > 0:37:29It's what the crowned eagle and her chick have been waiting for.
0:37:32 > 0:37:33But they're not alone.
0:37:33 > 0:37:36Other eagles have flown in from miles around...
0:37:38 > 0:37:39..fish eagles,
0:37:39 > 0:37:41martial eagles,
0:37:41 > 0:37:43and they're all after the bats.
0:38:00 > 0:38:03HIGH-PITCHED SQUEAKING
0:38:18 > 0:38:21SQUEAKING, WING FLAPPING
0:38:52 > 0:38:56The gamble the crowned eagle took months ago by nesting here
0:38:56 > 0:38:57has paid off.
0:39:04 > 0:39:08She is the only eagle to actually nest in this forest.
0:39:08 > 0:39:10CHIRPING
0:39:19 > 0:39:22The only one who took the risk to breed here,
0:39:22 > 0:39:26well before the trees came into fruit and the bats flooded in.
0:39:37 > 0:39:40She only breeds once every two years,
0:39:40 > 0:39:42so her timing must be perfect.
0:40:00 > 0:40:03HIGH-PITCHED SQUEAKING
0:40:03 > 0:40:05In a few months, the bats will leave,
0:40:05 > 0:40:07but her gamble means her chick
0:40:07 > 0:40:09will have the best possible start in life.
0:40:17 > 0:40:20These grasslands have been grazed and burned
0:40:20 > 0:40:24and have endured the harshest drought in generations...
0:40:27 > 0:40:29FLIES BUZZ
0:40:29 > 0:40:33..but with the rains, they're beginning to recover.
0:40:33 > 0:40:36GRUNTING
0:40:41 > 0:40:44WATER LAPPING
0:40:44 > 0:40:46GRUNTING
0:40:48 > 0:40:51CHIRPING
0:40:59 > 0:41:00THEY GROWL
0:41:00 > 0:41:04And on the once dust-choked plains of Amboseli,
0:41:04 > 0:41:07there's a return to the good times.
0:41:36 > 0:41:38ELEPHANTS BELLOW
0:41:38 > 0:41:41The drought here killed hundreds of elephants,
0:41:41 > 0:41:44but the survivors are now returning home.
0:41:48 > 0:41:51And with them, there's a surprise.
0:41:51 > 0:41:53HIGH-PITCHED GRUNTING
0:41:55 > 0:41:57A newborn.
0:42:00 > 0:42:02ELEPHANT BELLOWS
0:42:02 > 0:42:05LOW-PITCHED GRUNTING
0:42:13 > 0:42:15HIGH-PITCHED SQUEAL
0:42:22 > 0:42:24Surrounded by food,
0:42:24 > 0:42:27the youngster can concentrate on more important things...
0:42:32 > 0:42:34..like chasing egrets.
0:42:34 > 0:42:36HIGH-PITCHED SQUEAL
0:42:37 > 0:42:40BIRDS SQUAWK
0:43:11 > 0:43:16LOW-PITCHED BELLOW
0:43:16 > 0:43:18The bulls also return.
0:43:18 > 0:43:21LOW-PITCHED GROWLING
0:43:26 > 0:43:29THEY GROWL AND HISS
0:43:36 > 0:43:38This bull has waited many years
0:43:38 > 0:43:41for his chance to father the next generation.
0:43:46 > 0:43:49Now, he must fight his way to the top.
0:43:49 > 0:43:51LOW-PITCHED GROWL
0:43:52 > 0:43:54But his rival is massive.
0:43:56 > 0:43:58Each of their heads weighs as much as a car.
0:44:01 > 0:44:04They have been duelling for days.
0:44:04 > 0:44:06GRUNTING
0:44:08 > 0:44:10LOW-PITCHED GROWLING
0:44:18 > 0:44:22Now in its third day, the contest is reaching a climax.
0:44:28 > 0:44:31ROARING
0:44:38 > 0:44:41Soon, one will be forced to concede.
0:44:55 > 0:44:57GRUNTING
0:45:05 > 0:45:08LOW-PITCHED HOWLING
0:45:12 > 0:45:16The power of these clashes can even shatter tusks.
0:45:16 > 0:45:18CRASHING AND CREAKING
0:45:22 > 0:45:25GROWLING
0:45:34 > 0:45:37Three days of battle is at an end.
0:45:40 > 0:45:43The victor has won the right to the females.
0:45:49 > 0:45:53The process to replace what the drought took away has begun.
0:45:58 > 0:46:02Soon, the elephants will be at full strength again.
0:46:13 > 0:46:17Every day, the animals of Eastern Africa gamble with their lives,
0:46:17 > 0:46:21but despite the continual changes they face,
0:46:21 > 0:46:23their extraordinary adaptability
0:46:23 > 0:46:27just tips the odds of survival in their favour.
0:46:34 > 0:46:37East Africa may seem very cruel,
0:46:37 > 0:46:41but there's nowhere else that provides such rich opportunities
0:46:41 > 0:46:44for those that are prepared to take them.
0:46:44 > 0:46:47And in the end, it was these ever-changing savannahs
0:46:47 > 0:46:51that produced the most adaptable species of all...
0:46:51 > 0:46:53ourselves.
0:46:54 > 0:46:57ENGINE REVS
0:47:40 > 0:47:42Filming in East Africa
0:47:42 > 0:47:46would take the team on both a physical and emotional journey
0:47:46 > 0:47:48through the extremes of this landscape.
0:47:51 > 0:47:55These are the legendary Mountains of the Moon,
0:47:55 > 0:47:58towering over 5,000 metres into the African sky.
0:48:01 > 0:48:02Just miles from the equator,
0:48:02 > 0:48:05they're the highest mountain range on the Continent
0:48:05 > 0:48:08and home to the largest glacier in Africa.
0:48:13 > 0:48:16To reach the summits, the team had to travel on foot,
0:48:16 > 0:48:20the same way as climbers did when they first reached the top
0:48:20 > 0:48:22just over 100 years ago.
0:48:27 > 0:48:29It would take more than two weeks,
0:48:29 > 0:48:32climbing over 3,000 metres from the valleys below.
0:48:36 > 0:48:39Six days into their trek, still well below the summits,
0:48:39 > 0:48:43the team come to realise why Rwenzori, the mountains' other name,
0:48:43 > 0:48:46means "the rain makers".
0:48:47 > 0:48:51Just after we set off, it started raining, then it started hailing,
0:48:51 > 0:48:54and the idea had been that we'd stop here for an hour or two
0:48:54 > 0:48:57and do some shots. But as you can probably see,
0:48:57 > 0:48:59there's not a great deal of view.
0:48:59 > 0:49:03Brilliant shots of rain and hail and fog.
0:49:03 > 0:49:07Beyond that, we're pretty stuffed, so it's becoming a bit of a theme.
0:49:07 > 0:49:10For the crew and over 75 guides and helpers,
0:49:10 > 0:49:14it's hard going carrying nearly a tonne of kit
0:49:14 > 0:49:15through the marshy valleys.
0:49:17 > 0:49:19Mud, mud,
0:49:19 > 0:49:21and just a little bit more mud.
0:49:23 > 0:49:26But it's not just the bogs they have to deal with.
0:49:26 > 0:49:30There was a small, but slightly disconcerting, earthquake last night,
0:49:30 > 0:49:33so let's hope we don't get any of those below any rocks.
0:49:35 > 0:49:40The team continue to climb and, before long, the rain turns to snow.
0:49:45 > 0:49:47They eventually arrive at the highest hut,
0:49:47 > 0:49:50surrounded by ice and nearly three miles up.
0:49:50 > 0:49:54This will be base camp for the crew.
0:49:54 > 0:49:55We've got a kitchen over there.
0:49:57 > 0:49:58Um...
0:49:58 > 0:50:04over there, down a really treacherous precipice, is the toilet,
0:50:04 > 0:50:06which is just a shack with a big hole in the floor.
0:50:10 > 0:50:13From here, they'll make the hardest part of the ascent
0:50:13 > 0:50:14right up to the glaciers.
0:50:21 > 0:50:25Well, this is, believe it or not, one of the better viewpoints
0:50:25 > 0:50:29so...probably going to hang around here for a little while,
0:50:29 > 0:50:31wait till the fog clears.
0:50:31 > 0:50:34But the weather isn't on their side.
0:50:37 > 0:50:41So much for hoping the weather was going to get better.
0:50:41 > 0:50:44All that optimism now seems completely ill-founded.
0:50:46 > 0:50:51With the storm clouds closing in, the team are forced to retreat.
0:50:51 > 0:50:54THUNDERCLAPS
0:50:56 > 0:50:59This enormous weather front's come in, as isn't entirely unusual.
0:50:59 > 0:51:03So we're just coming down as the thunder bursts around us.
0:51:03 > 0:51:06So, glad to get back and go and get inside the hut
0:51:06 > 0:51:08and hopefully weather it out.
0:51:10 > 0:51:13After days of climbing and finding the peaks hidden by fog,
0:51:13 > 0:51:17filming the summits is looking increasingly impossible.
0:51:18 > 0:51:20It can be pretty frustrating at times.
0:51:20 > 0:51:24There's a group of maybe 70 people that we've involved directly.
0:51:24 > 0:51:26You get all the way up here,
0:51:26 > 0:51:29and then we can't film anything because of the weather.
0:51:29 > 0:51:31So, it is just a matter of sitting it out and waiting.
0:51:31 > 0:51:34You have to sort of hope that things come right in the end.
0:51:36 > 0:51:39The "rain makers" are certainly living up to their name,
0:51:39 > 0:51:41but by complete contrast,
0:51:41 > 0:51:44other parts of East Africa were gripped by drought.
0:51:46 > 0:51:50At the beginning of the production, Mark Deeble travelled to Amboseli,
0:51:50 > 0:51:53just a few hundred miles from the Rwenzoris,
0:51:53 > 0:51:55to film the plight of the animals there.
0:51:57 > 0:51:58I mean,
0:51:58 > 0:52:01I've never seen anything quite as bad as that drought.
0:52:04 > 0:52:06And we talked to some of the Masai elders.
0:52:06 > 0:52:09They said it was the worst drought they'd seen in 50 years.
0:52:11 > 0:52:14Amboseli is famous for its huge herds of elephant,
0:52:14 > 0:52:17but the drought had dispersed them far and wide.
0:52:17 > 0:52:21Those that remained were struggling to find what little food was left.
0:52:25 > 0:52:27When we first saw the group, we could tell instantly
0:52:27 > 0:52:30that they were in a really serious condition.
0:52:32 > 0:52:35They were thin and obviously starving.
0:52:35 > 0:52:37ELEPHANT BAYS
0:52:37 > 0:52:42Mark knew that many of the calves would not survive.
0:52:42 > 0:52:44Although desperately painful to witness,
0:52:44 > 0:52:48nothing would convey the cruel power of the drought
0:52:48 > 0:52:51more than this mother's struggle to keep her baby alive.
0:52:56 > 0:52:58The thing about filming a situation like that...
0:52:58 > 0:53:01You know, when an elephant calf dies,
0:53:01 > 0:53:03is that when you're actually filming it,
0:53:03 > 0:53:04you're so caught up in the moment.
0:53:04 > 0:53:07ELEPHANT BAYS
0:53:07 > 0:53:08But it was only after filming,
0:53:08 > 0:53:10when I put the camera away and I looked there,
0:53:10 > 0:53:14and there was this dead calf and the mother standing there grieving,
0:53:14 > 0:53:16that the full impact of what I'd just filmed hit me.
0:53:22 > 0:53:23People often say to me, you know,
0:53:23 > 0:53:26"Could you not have intervened in a situation like that?"
0:53:28 > 0:53:30There are times when you CAN help,
0:53:30 > 0:53:33but in that time in Kenya there WAS no food available.
0:53:33 > 0:53:36Now, you have to also consider the mother.
0:53:36 > 0:53:39If we'd gone in there and tried to...to take the calf away,
0:53:39 > 0:53:42it would have been absolute mayhem, she'd have got incredibly stressed,
0:53:42 > 0:53:45and that would probably have jeopardised her survival.
0:53:46 > 0:53:50In that particular situation, when everything around us was dying,
0:53:50 > 0:53:52there was absolutely nothing we could do
0:53:52 > 0:53:53to help that young elephant.
0:53:58 > 0:54:00Although too late to save the calf,
0:54:00 > 0:54:04a few months later, the rains did finally return.
0:54:11 > 0:54:16When we returned, it was amazing. It was lush and green again.
0:54:16 > 0:54:18And the elephants in the rains, they all tend to come together,
0:54:18 > 0:54:21so it was like all these groups which had been dispersed,
0:54:21 > 0:54:24which had been just somehow coping on their own,
0:54:24 > 0:54:25all got back together again,
0:54:25 > 0:54:27so it was almost a sort of festival type atmosphere.
0:54:27 > 0:54:30GRUNTING
0:54:36 > 0:54:39That was when, essentially, they come together,
0:54:39 > 0:54:42they mate and then, after that, lots of young calves are being born.
0:54:45 > 0:54:47Since the end of the drought,
0:54:47 > 0:54:50over 220 calves have been born in Amboseli,
0:54:50 > 0:54:52and that number is still rising.
0:54:54 > 0:54:57It's the biggest elephant baby boom on record.
0:54:59 > 0:55:02I think what's lovely to see in that situation
0:55:02 > 0:55:06is that having been through such a terrible drought,
0:55:06 > 0:55:09to see the way in which, you know, if you let things alone,
0:55:09 > 0:55:12you know, they do have incredible capacity to bounce back.
0:55:21 > 0:55:24Back in the mountains, and several failed ascents later,
0:55:24 > 0:55:27the team were still battling through the white out.
0:55:28 > 0:55:30They try one last time.
0:55:32 > 0:55:34There's cloud below us and cloud above us.
0:55:34 > 0:55:38It somehow seems slightly like we're heading nowhere slowly.
0:55:42 > 0:55:48Then, as they reach the top, finally, the clouds begin to part.
0:55:48 > 0:55:50MUSIC: "Outro" by M83
0:55:52 > 0:55:57# I am the king of my own land. #
0:56:01 > 0:56:03It was absolute magic here.
0:56:03 > 0:56:05We've just come through the densest, densest cloud,
0:56:05 > 0:56:09having absolutely no idea what's surrounding us.
0:56:09 > 0:56:13The past few days have just been rain and cloud and rain and cloud,
0:56:13 > 0:56:18and, as if by magic, there's the most spectacular view
0:56:18 > 0:56:21of ice and glaciers and mountains,
0:56:21 > 0:56:23that you just wouldn't think was on the equator.
0:56:23 > 0:56:24It's just amazing.
0:56:48 > 0:56:51It's the most spectacular mountain scenery I've seen,
0:56:51 > 0:56:54and to think it's in Africa is just mind-boggling.
0:57:02 > 0:57:07These mysterious mountains have finally unveiled their secrets,
0:57:07 > 0:57:08and on the plains beyond,
0:57:08 > 0:57:11the elephants have returned to their home.
0:57:13 > 0:57:17Despite having been explored by film-makers for over a century,
0:57:17 > 0:57:22East Africa still has the power to enchant and surprise us all.