All language subtitles for The Great Rift (2010) - S01E01 - Fire (1080p BluRay x265 Silence)_track3_[eng]

The Ethiopian highlands.

The roof of Africa.

30 million years ago,

this was a vast high-altitude plateau
the size of Spain.

Since then,
the elements have carved the landscape

into Africa's equivalent
of the Grand Canyon.

have created isolated islands
of alpine terrain

supporting strange and unique creatures
found nowhere else on Earth.

The gelada baboon
needs a head for heights,

where a single slip
would mean certain death.

Geladas are exclusive
to this chilly plateau,

kept warm by a long fur coat.

They are the highest-dwelling primates
on the planet,

ranging up to 4,500 metres.

But what's really surprising
is their sheer numbers.

Geladas are the most sociable monkeys
on Earth.

Like the game herds of the Serengeti,
they are vegetarians.

In these high pastures,
they take the place of grazing antelopes.

But geladas aren't the only peculiar
creatures up here on the roof of Africa.

This is a giant mole rat...

...a specialised grass-eater
that's unique to the Ethiopian highlands.

The mole rat lives underground,

emerging at dawn and dusk
to snatch mouthfuls of grass,

which it drags back to its burrow
to munch at leisure.

There's every reason to be cautious.

This foxy-looking Ethiopian wolf

preys almost exclusively
on giant mole rats.

Despite the wolf's best efforts,
mole rats are incredibly common.

It's estimated there may be
more than 15,000 of them

in each square mile of grassland.

Yet despite their high numbers,
mole rats and geladas never meet.

So, how can that be?

The answer is this.

Dividing geladas on one side
from mole rats on the other,

the Great Rift Valley
runs through Ethiopia,

slicing the roof of Africa in two.

But it doesn't stop there.

Extending 3,000 miles further south,

the Great Rift shapes and defines
the entire landscape of East Africa,

creating intense hot spots of evolution.

All along the Rift Valley,
soaring above the hot, dusty plains,

isolated mountain peaks
harbour unique wildlife communities.

A kaleidoscope of strange
and remarkable creatures.

As well as extraordinary wildlife,

there's something else that's special
about these mountains.

They all share a common origin

that is key to understanding
how the rift was formed...

...and why it has had such a far-reaching
impact on this part of Africa.

The first clue lies here,

at the very northern margin
of the Great Rift Valley.

Ethiopia's Danakil Depression.

This is Erta Ale,

Africa's most active volcano.

It contains
the world's only permanent lava lake.

Like a window into
the fiery heart of the earth,

Erta Ale provides a terrifying glimpse
of the inner workings of our planet.

A cauldron of molten rock
beneath our feet.

In geological terms, Erta Ale's volcano
is still in its infancy.

But 1,000 miles to the south,

another Rift Valley volcano has been
growing for at least a million years.

Rising to the east
of the Great Rift Valley,

snow-capped Kilimanjaro
towers nearly four miles high.

It's Africa's loftiest peak

and the tallest
free-standing volcano on Earth.

Kilimanjaro and Erta Ale are just
two links in a long chain of volcanoes

that runs the length of the Great Rift.

In fact, all the mountains
along the rift are volcanic,

born deep beneath the Earth's surface.

Scientists believe that
a plume of superhot lava

has been rising up
beneath the crust of East Africa

for millions of years.

The thick crust above the plume
has been lifted more than a mile high,

causing cracks to appear
around its margins.

The Eastern and Western Rift Valleys
mark the fractured edges

of the uplifted East African Plateau,

with further branches extending outwards.

And wherever molten rock
has seeped through from below,

huge volcanoes have grown up.

It's estimated that
over the last 30 million years,

the rift's volcanoes have poured out
enough molten rock

to bury an area the size of Wales
to a depth of 15 miles.

Mount Kenya's 5,200-metre-high summit
is an eroded lava plug,

suggesting it was once even taller.

Below the summit,

a belt of strange and unique alpine plants
clings to the slopes.

Even on the equator,
mountain weather is unpredictable.

Just a few miles away,

lions and zebra are sweltering
under a blazing African sun,

yet here, on Mount Kenya,
a sudden squall can bring snow,

creating a winter wonderland.

This extreme climate
poses a real challenge

to the mountain's wild inhabitants.

Highland rock hyraxes are found
only on Mount Kenya.

High mountain hyraxes
have evolved to cope with the cold.

They are much larger
than lowland hyraxes

and have exceptionally dense fur,

which allows them to maintain
their core temperature

in freezing mountain conditions.

When the sun reappears,
the hyraxes save energy by sunbathing.

Giant alpine plants insulate their
delicate buds from frost damage

by wrapping them
in a protective duvet of leaves,

which unfurl one by one
as the temperature rises.

The giant ostrich plume lobelia
has evolved a peculiar life cycle.

After several years of growth,
it sprouts a huge flower spike,

containing hundreds of tiny flowers
swathed in a mass of furry insulation.

Up here, over two and a half miles
above sea level,

insect pollinators are scarce,

so the lobelia has developed
an alternative partnership.

The plant attracts high-flying sunbirds
with a rich supply of nectar.

The sunbirds use the lobelia
as a fuelling depot,

a social meeting point

and a sunbathing perch.

In return, the lobelias get pollinated
and set seed.

Further down the mountain,
at around 3,000 metres,

lives perhaps Mount Kenya's
strangest resident -

the side-striped chameleon.

This cold-blooded reptile
is uniquely adapted for mountain life,

far above the altitude
where reptiles normally survive.

As dawn breaks,
it creeps onto an exposed perch,

where it lines up its body
at right angles to the rising sun.

Then, flushing its skin
with dark pigment,

it soaks up the rays like a solar panel.

It takes only minutes to raise its
temperature 30 degrees Celsius.

Once warmed,
it changes to normal daytime colour.

The male chameleon
is fiercely territorial.

If another male has the nerve
to set foot on his bush,

there's bound to be a fight.

A sneaky bite clinches the bout...

...and the loser slinks off
to nurse his bruises.

Further up the mountain,

the hyraxes have also completed
their morning sunbathe.

Though it looks like
a short-eared rabbit,

the hyrax has some peculiar features

which suggest a much stranger kinship.

The layout of its toes is practically
identical to those of an elephant.

Its teeth and bones are also similar,
though scaled down a little.

The life of a baby hyrax looks cosy.

But sunbathing out in the open makes them
a tempting target for predators.

An augur buzzard.

40 miles west of Mount Kenya,

the Aberdares Mountains
are the legacy of an older volcano

that's been severely eroded but still
towers over two and a half miles high.

In the frosty alpine grassland,
a rare predator is on the prowl.

At lower altitudes,
servals have a spotted coat,

but up here, many of them are black.

Some scientists believe

that a dark coat may help the cats
to absorb heat on cold, bright days.

In the cool mountain conditions,
giant heathers form a dense carpet -

food for Africa's highest
resident elephants...

...including one of the biggest tuskers
in the world.

Unlike most herbivores, elephants can
process almost any plant they find,

including tough heather bushes.

A century ago, elephants migrated freely
between the Aberdares and Mount Kenya.

But as the human population
has increased locally,

the herd has become marooned
in its upland enclave with nowhere to go.

In these mountain forests,

one of Africa's rarest antelopes,
the mountain bongo,

is making a last stand.

Bongos are extremely shy and secretive,

staying in dense, shady forest
during daylight hours.

Human pressures have now reduced
their numbers to around 100

within the Aberdares National Park.

And these have been bred for release
into the wild.

The Aberdares lie along the eastern
escarpment of the Kenyan Rift Valley,

which here is up to 100 miles across.

Right in the centre of this landscape
sits a remarkable volcano,

virtually untouched by the outside world.

Mount Suswa is home
to Masai pastoralists,

who graze their herds
on the flat crater floor.

But Suswa is no ordinary volcano.

At its centre,
steep cliffs plunge 500 metres

into a ring-shaped Rift Valley
in miniature.

Around 100 families
from the Red Trees Masai community

share the resources
of Suswa's grassy crater.

Cattle are at the centre of Masai life -
the measure of a family's wealth.

With a six-month dry season

and no permanent streams or lakes
anywhere inside the crater,

keeping a supply of drinking water
is a constant challenge.

But the Masai have found
an ingenious solution to the problem.

A system of metal pipes condenses steam
from volcanic vents.

At the centre of the crater,

Mount Suswa's unique circular moat

encloses a lava plateau
two miles across -

a miniature lost world
protected by a ring of cliffs.

It's thought that Suswa's volcano
last erupted

just a couple of hundred years ago,

and parts of the "lost world"
are still smouldering.

The Masai consider this
wild, tangled jungle a sacred place,

where no hunting or grazing is allowed.

When Suswa's volcano last erupted...

...this moat was a cauldron
of molten rock.

The liquid lava has since
cooled and solidified,

but along the moat's rim,
the volcano still hides a dark secret.

This sunlit boulder pile was formed

when the rock collapsed
above an underground cavern,

opening a window
into the volcano's main artery,

where molten lava once flowed unseen
beneath the skin of the mountain.

Once the volcano stopped erupting
and the lava drained away,

it left behind a vast network
of empty passages,

some big enough to drive a bus through.

Cave explorers have mapped
over six miles of massive tunnels

beneath this single lava flow.

But humans weren't the first creatures
to discover this hidden world.

As dusk creeps up the flanks
of Mount Suswa,

a troop of baboons
is gathering for the night.

Most baboons roost in the treetops

to avoid night-prowling
leopards or lions.

But these baboons are heading downwards.

Their destination
is an underground chamber

known locally as
the baboons' parliament.

As they enter the underworld,

the baboons cross with bats
on their way out.

Filming them here
requires an infra-red camera

and lights invisible to the baboons.

The walls of the baboon parliament
have been worn glassy-smooth

by the hands and feet
of generations of baboons.

Rock-climbing in the dark
on polished holds

could be considered a hazardous sport,

but presumably,
these baboons find it less scary

than sleeping outside with the leopards.

The baboons' final destination

is a series of small ledges
high up on the cave wall.

Safe beyond the reach of predators
and protected by a roof of solid rock,

the cave dormitory stays warm and dry,

even at the height of the rainy season.

As the last light fades from the sky,
the bat exodus intensifies.

This is the world's largest colony
of giant mastiff bats.

It's made up entirely of females
who have just given birth.

Their pups - thousands of them -
can't fly yet

and are completely dependent
on their mothers.

But the mother bats
must leave their cave to feed.

Packed tightly together for warmth,

the deserted pups are left
in a wriggling, squeaking creche.

In all this confusion,

a baby bat has lost its grip
and fallen to the cave floor.

The tunnel is alive with
creepy creatures of all kinds.

Many are partial to
the flesh of a baby bat.

As dawn breaks over the volcano,
the baboons leave their sleeping cave.

After a hard night's insect-catching
in the skies above the Rift Valley,

the bats return home to roost.

Somehow,
in the chaos of fluttering adults

and thousands of squeaking babies,

each mum must track down her own infant
to give it its morning feed.

She does this

firstly by remembering where
she parked her baby the night before,

then, as she gets closer,
by recognising its voice and unique scent.

Like all mammals,
baby bats depend on their mothers' milk.

Her little wriggling pup
is frantic for its morning feed.

While bats and baboons seek sanctuary

in the protective environment
of Mount Suswa's lava caves,

a very different kind of creature
has chosen

what must be the Rift Valley's
most exposed habitat.

The sheer 500-metre-high cliffs
of Mount Ololokwe

are constantly buffeted by strong winds
rising from the valley below.

This precarious location

is home to Kenya's largest
nesting colony

of Rüppell's griffon vultures.

Vultures thrive in the rift

because the steep valley walls
create updraughts,

which they can use to get airborne.

Gliding effortlessly
from one thermal to the next,

a vulture can cover 200 miles in a day,

soaring seven miles high
with scarcely a wing flap.

From their lofty lookout
above the African plains,

nothing escapes their notice.

Out in the Serengeti grassland,
the game herds are on the move.

This is what the vultures
have been waiting for.

Vultures have a clear pecking order.

The heavy-billed lappet-faced vultures
are best equipped to open up a carcass,

so they get the greatest respect.

Once they're finished, the white-backed
and griffon vultures pile in

and squabble over the spoils.

The Serengeti is home
to the world's greatest game herds.

Most of it lies on
the East African Plateau,

perched around a mile above sea level,

the result of uplift by the same
lava plume that created the Rift Valley.

But it has another,
even more intimate connection

with the rift's fiery origins.

The Serengeti borders
Tanzania's most active volcano -

Ol Doinyo Lengai.

In 2007,

Ol Doinyo Lengai produced a spectacular
eruption that lasted almost a year...

...throwing out
thousands of tons of ash...

...which fell on the surrounding savanna.

As volcanic ash breaks down,

it creates a dense, fertile soil

which is hard for tree roots to penetrate

but is perfect for grass.

The great grass plains of the Serengeti
can support over a million wildebeest

only because of the fertility
of the vast volcanic ash deposits

on which they grow.

South of the Serengeti,
in southern Tanzania,

the Rift Valley's eastern
and western branches converge.

Close to their meeting point lies
one of the Great Rift's best-kept secrets.

The alpine grassland
of the Kitulo Plateau,

known locally as God's Garden.

It provides the stage

for one of Africa's most spectacular
floral displays.

The Kitulo meadows are serviced by
some unusual insect pollinators.

This is a monkey beetle,
a hairy-coated living fossil.

During the ice ages,
when Africa was much cooler,

monkey beetles were widespread,

but now they survive
only in a few high-altitude meadow lands.

The spectacular plumed
mountain marsh widowbird

is another local specialty.

On the slopes of the Kitulo Plateau,

a line of protea sugar bushes marks the
transition between meadow and forest.

Their blooms produce a feast
of pollen and nectar,

but for the monkey beetles,
it's a dangerous prize.

Once in place, the Temple's chameleon,

an insect hunter
peculiar to this corner of Tanzania,

hardly needs to move.

Chameleons are unique among reptiles

in having the ability
to swivel their eyes independently.

When they line them up,

the stereo image allows them
to launch their sticky tongue

exactly the right distance
to nail their victim

every time.

Below the line of sugar bushes,
where the chameleons stalk their prey,

a belt of dense jungle clings to
rain-drenched mountain slopes.

The cool, humid climate
fosters ancient tree ferns

and towering hardwood trees.

Isolated from other mountain forests

by the converging arms
of the Great Rift Valley,

Mount Rungwe's forests
are home to unique creatures.

The area has recently become
the focus for scientific research

and new species are being discovered
all the time...

...even up in the treetops.

This is a kipunji,

first discovered in 2005
and never filmed before.

In looks and behaviour,
the new monkey resembles a mangabey.

But its DNA is similar to a baboon's.

For now, the evolutionary origins
of the charismatic kipunji

remain shrouded in mystery.

Kipunjis are particularly fond of
this sticky orange cucumber fruit,

which sprouts from vines
in the treetops.

They're known to feed on
over 100 different plants

and play a crucial role
in dispersing their seeds.

But even while scientists
begin to uncover their secret lives,

kipunjis are teetering
on the verge of extinction.

As the isolated forests
around Mount Rungwe

are cleared for farming and firewood...

...the kipunjis' unique forest habitat
is shrinking.

With a mere 1,000 individuals
remaining in the wild,

they are already
the rarest monkeys in Africa.

There may be little time left
to study them.

Fortunately, kipunjis do have friends,

and a project is now under way
to safeguard a part of their forest home

and involve local people
in their protection.

North-west of the kipunjis'
mountain home,

a branch of the Great Rift curves between
Tanzania and the Congo.

The valley floor contains
vast deepwater lakes,

while to the west
lies a series of volcanic mountains

up to three miles high.

And the most spectacular are here,

in the Virungas National Park.

The Virungas volcanoes are home to
Africa's largest and rarest great ape...

...the mountain gorilla.

Mountain gorillas
evolved from lowland gorillas,

which colonised the Virungas
less than half a million years ago,

soon after these volcanoes formed.

They responded to the challenge
of high-altitude living

by becoming larger and furrier
than their lowland cousins,

enabling them to cope with
the permanently cold, miserable weather.

A combination of fertile volcanic soil
and two metres of annual rainfall

encourages a profusion of plants
on the mountain slopes...

...ideal fodder
for giant vegetarian apes.

In response to their fibrous diet,

the gorillas have developed
extra-large chewing teeth

and extra-powerful jaw muscles

anchored to a prominent ridge of bone
on the crown of their head.

Gorilla society is well ordered,

with each band of females
and their young

protected by a huge silver-backed male.

With few natural enemies prepared
to brave the wrath of a silverback,

young gorillas can play
to their hearts' content.

The unique characteristics

that separate mountain gorillas
from their lowland cousins

evolved as a result of their isolation

on just a handful of volcanoes
along the Great Rift.

It makes them vulnerable,
especially to poaching -

though, fortunately,
they have many human allies

fighting to ensure their survival.

Mountain gorillas are, without doubt,

one of the Great Rift's
most remarkable creatures,

their evolution uniquely shaped by
the volcanic terrain in which they live.

That terrain has itself been moulded
and shaped by the fiery rocks beneath,

creating a complex
of valleys and volcanoes

spanning the length of East Africa.

For those animals and plants

which were able to adapt
to the changing conditions,

the Great Rift has promoted
a remarkable burst of evolution.

In this turbulent landscape,

volcanic fire has proved to be
less a destroyer,

but more a creator of new life.

And that is what is so special
about Africa's Great Rift.

One of the Great Rift team's
most difficult assignments

took them deep into
Mount Suswa's volcanic crater,

home to a troop of very unusual baboons.

Instead of spending the night in trees,
they have taken to sleeping down caves.

Cameraman Justin Maguire
is here to film them.

Masai elder Jeremiah Ole Tanin
will be Justin's guide.

He hopes that the baboons will attract
visitors to Mount Suswa,

generating income for his community.

Wow. That's pretty impressive.

- Yeah.
- Fantastic cave.

So, this is where the baboons
come and sleep, is it?

Yeah. It is where they spend
during the night.

With the baboons
out foraging for the day,

Justin has a chance to recce the cave.

Jeremiah warns that
when they return at dusk,

they will be wary and easily spooked,

and baboons can be dangerous.

Justin will have to be on his guard.

- So, how many baboons use this cave?
- Over 100.

100 baboons? That's incredible.
And I'm going to be in there with them?

- So it's going to make 101 baboons?
- Oh, yeah.

- You think they'll be frightened of me?
- Yeah, yeah.

Well, I'm hoping I can be a bit like
a baboon and they'll be relaxed with me.

Justin's problem is that
if he tries to climb down here at night,

he'll wake any baboons
sleeping close to the entrance.

Luckily, Jeremiah has a cunning plan.

The Masai know of a concealed entrance

which should give Justin
the chance to sneak in unseen.

Before venturing down at night,

he decides to go
for a daylight run-through.

- That is one bendy ladder.
- Yeah.

OK. Here goes. Freak!

To film in such a tricky situation,
Justin has an experienced team with him.

OK. I'm sending your bag down, OK?

Phil Chapman is the director,
but he is also an experienced caver.

Once inside, it becomes apparent

that getting both them and the equipment
through the cave

is not going to be as easy
as they first thought.

It looks tiny, Jeremiah.
- Yeah.

- Can we really get through there?
- Yeah, yeah.

I can hear bats.
Are there bats in there?

I do like these things.

OK.

That's quite good.
That's fine for them to crawl through.

Oh, watch your head.
Very sharp stalactites.

Inside, the team find thousands of bats
preparing for a night's hunting.

Not only do the bats
produce tonnes of droppings,

they also share the cave
with less welcome inhabitants.

- Oooh, look.
- Look at these millions of fleas.

I can feel them
crawling up my trouser leg.

That is quite amazing.

I'm absolutely covered in fleas.
Look at my leg.

Finally, they reach the baboons'
sleeping chamber,

and Jeremiah was right.

The signs of baboons are everywhere.

As you can just see,
all the rocks are smooth.

Very smooth. Shiny.

- Just feel it.
- Yeah, that's incredibly smooth.

- Very smooth and shiny.
- Yeah.

It's just because of rubbing
of their bottom, the... baboons...

Right. So, these have got...

They're smooth because of...

the baboons' bottoms have rubbed
on these for many years?

- Yeah, yeah. They've been rubbed...
- I can see baboon poo on the top.

- Oh, yeah. See?
- OK.

Knowing that baboons are here in numbers
is great news for filming,

but poses Justin with another problem.

Baboons could be extremely dangerous
in the confined space of the cave,

so Justin needs some way to
scare them off if they come too close.

The BBC, in their thoughtfulness,
have provided me with a rape alarm,

in case I have trouble
with any of the baboons.

There are some big males, aren't there?

- Oh, yeah.
- I'm hoping I'm not going to have to...

Ah.

I'm hoping I'm not going to get
to the stage they're attacking me.

Oh, yes.

Not only will the team
have to build a hide,

they also have to rig up special lights
producing infra-red,

which the baboons can't see.

But it's close to sunset,
and the baboons are already on their way.

We don't have enough time.
That's the big problem.

No, seriously, we're very close
to not being able to light this.

We're going to have to start now.

If the baboons return early
and find the team,

they may desert the cave,
scuppering any chance of filming.

It's 5.50, and the sun will be setting
pretty soon.

We've run out of time and we don't want to
be here whilst the baboons return.

Phil, I think you guys should really go.

OK.

- Plug that one in.
- I'll plug that one in, yeah.

With the lights rigged,

the team leave to allow the baboons
to settle in for the night.

We've just got down into the cave now.
Um, it's night.

It's one thing walking through the cave
with all the guys,

another walking through it at night
with 60 baboons,

which I am a little bit nervous about.

Justin is in total darkness,

filming himself in infra-red light,

which neither he
nor the baboons can see.

I've found
my guide string now,

which leads me
to the last bit of the hide.

I think a baboon's seen me.

Right. I've made it into my hide.

And, uh... I've definitely been spotted by
one baboon.

I think the baboon that spotted me
has fallen asleep, so, hopefully...

No.

He's still barking.

Incredibly quiet.
I'm really amazed how quietly they sleep.

The only thing that's changing
is the bat sounds.

There's more and more bats in the cave,

which is a clear signal
that dawn is approaching,

and soon the baboons
are going to wake up, I think.

It seems like a defining sound of the
morning are the babies squealing.

It sounds like any...
any household, really.

Justin's perseverance has revealed
for the first time

the underground behaviour
of these unique baboons.

And back at camp, he can share
these glimpses with the team.

I have never seen a baboon sleeping.

In the past, baboons were persecuted
for killing livestock.

However, attitudes are slowly changing.

They will not be killing them.

We want now to start to conserve them,

to... to get a relationship
between baboons and human beings,

because their community
can benefit from them.

Justin's filming quest
has been a success,

and as interest in Mount Suswa increases,

the Masai will be able
to share with others

their unique cave-dwelling baboons.