All language subtitles for The.Great.Rift.Africas.Wild.Heart.1of3.720p.HDTV.x264_Subtitles01.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.

Millions of years of erosion

have created isolated islands
of alpine terrain

supporting strange
and unique creatures
found nowhere else on earth.

MONKEYS CHIRP

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.

BABOON GRUNTS

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...

SQUEAKS

..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.

MOLE RAT SQUEAKS

There's every reason to be cautious.

This foxy-looking Ethiopian wolf

preys almost exclusively
on giant mole rats.

MOLE RAT SQUEAKS, WOLF GROWLS

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.

HYRAXES CALL

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.

BIRD CHIRPS

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.

CHAMELEONS HISS

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.

HYRAXES SQUEAK

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.

HYRAX SQUEAKS

An augur buzzard.

BUZZARD CRIES

SQUEAKS

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 2½ 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.

ELEPHANTS GROWL

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.

SHEEP BLEAT

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.

ANIMATED CHATTER, LAUGHTER

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.

BABOONS CHATTER

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.

Rockclimbing 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 Ruppell'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.

GROWLS

ZEBRA BARKS

ZEBRA YELPS

Vultures have a clear pecking order.

SCREECHES

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.

WILDEBEEST LOW

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.

CHIRPS

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 Tempel'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.

INSECTS CHIRP

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.

KIPUNJIS CALL

LAUGHTER, CONVERSATION

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...

GORILLA GRUNTS

..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.

GORILLA GRUNTS

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.

JUSTIN: 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 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.
JEREMIAH LAUGHS

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

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.'

MASAI MEN SING, WHOOP

The Masai know of a concealed
entrance

which should give Justin
the chance to sneak in unseen.

MEN SING IN MASAI

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 tons of droppings,

'they also share the cave
with less welcome inhabitants.'

Oooh, look.
Look at these millions of fleas.

No, they are. 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...

ALARM SOUNDS

ALARM STOPS
Ah.

ALL LAUGH

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 GRUNTS

'Justin is in total darkness,

'filming himself in infra-red light,

'which neither he
nor the baboons can see.'

BATS CHIRP

(I've found
my guide string now,

(which leads me
to the last bit of the hide.)

PEBBLE FALLS

BABOON BARKS

(I think a baboon's seen me.)

BABOON BARKS

BABOON BARKS

BARKS CONTINUE

Right. I've made it into my hide.

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

BARKS

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

BABOON BARKS
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.

BABOON SCREECHES

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

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

BABOON SQUEALS

'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.

ALL LAUGH

'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.'

Subtitles by Red Bee Media Ltd