Planet Earth (2006) s01e02 Episode Script

1
Human beings venture into the highest
parts of our planet at their peril.
Some might think that
by climbing a great mountain
they have somehow conquered it,
but we can only be visitors here.
This is a frozen alien world.
This is the other extreme —
one of the lowest hottest places on Earth.
It's over a 100 meters
below the level of the sea.
But here a mountain is in gestation.
Pools of sulphuric acid
are indications
that deep underground
there are titanic stirrings.
This is the Danakil Depression
in Ethiopia,
lying within a colossal rent
in the earth's surface
where giant land masses
are pulling away from one another.
Lava rises to the surface through
this crack in the crust
creating a chain of young volcanoes.
This one, Erta Ale,
is today the longest continually
erupting volcano on the planet,
a lake of lava that has been
molten for over a 100 years.
These same volcanic forces
also created Ethiopia's highlands.
70 million years ago
this land was just as flat
and as deep
as the Danakil Depression.
Molten lava rising
from the earth's core
forced up a huge dome
of rock 500 miles wide,
the roof of Africa.
Over millennia,
rain and ice carved the rock
into a landscape
of spires and canyons.
These summits, nearly 3 miles up,
are home to some very
remarkable mountaineers —
Gelada baboons.
They are unique
to the highlands of Ethiopia.
The cliffs where they sleep
are for expert climbers only,
and Gelado certainly have
the right equipment.
The strongest fingers
of any primate
and an utterly fearless disposition.
But you need more than a head
for heights to survive up here.
A day in a Gelado's life reveals
how they've risen to the challenge.
For all monkeys,
morning is grooming time,
a chance to catch up with friends.
But, unlike other monkeys,
Gelados chatter constantly
while they do it.
It's a great way to network
while your hands are busy.
But these socials can't go on
for too long.
Gelados have
a busy daily schedule
and there's work to be done.
Most monkeys couldn't live up here.
There's no food
and few insects to feed on.
But Gelados are unique —
they're the only monkeys in the world
that live almost entirely on grass.
They live in the largest assemblies
formed by any monkeys.
Some groups are 800 strong
and they crop the high meadows
like herds of wildebeest.
The Gelados graze
alongside Walia Ibex,
which are also unique
to these highlands.
These rare creatures
are usually very shy
but they drop their guard
when the Gelados are around.
You might expect that grazers would
avoid each other's patch
but this is a special alliance
from which both partners benefit.
It's not so risky
to put your head down
if others are on the lookout.
Ethiopian wolves —
they won't attempt an attack
in broad daylight.
But at dusk the plateau becomes
a more dangerous place.
With the grazing largely over
there's a last chance to socialize
before returning to the sleeping cliffs.
An early warning system
puts everyone on the alert.
Their day ends as it began,
safe on the steep cliffs.
The Ethiopian volcanoes are dormant,
but elsewhere others still rage.
Volcanoes form the backbone of the
longest mountain chain on our planet —
the Andes of South America.
This vast range stretches 5,000 miles
from the Equator down to the Antarctic.
It formed as the floor
of the Pacific Ocean
slid beneath the South American
continent, buckling its edge.
At the southern end
stand the mountains of Patagonia.
It's high summer,
but the Andes have the most unstable
mountain weather on the planet
and storms can erupt without warning.
Temperatures plummet
and guanacos and their newborn young
must suddenly endure a blizzard.
Truly, all seasons in one day
A puma —
the lion of the Andes.
Pumas are usually
solitary and secretive.
To see a group walking boldly
in the open is extremely rare.
It's a family — a mother with 4 cubs.
She has just one brief summer
in which to teach them
their mountain survival techniques.
Rearing 4 cubs to this age
is an exceptional feat,
but she does have
an excellent territory,
rich in food and water.
Although the cubs are now
as large as their mother,
they still rely
on her for their food.
It will be another year before
the cubs can hunt for themselves.
Without their mother's
skill and experience,
they would never survive
their first winter.
Battered by hurricane force winds,
these slopes are now lifeless.
Further north,
they hold other dangers.
Moving at 250 miles an hour,
an avalanche destroys
everything in its path.
In the American Rockies,
a 100,000 avalanches devastate
the slopes every winter.
This huge mountain chain
continues the great spine
that runs from Patagonia to Alaska.
The slopes of the Rockies,
bleak though they are,
provide a winter refuge
for some animals.
A mother grizzly emerges
from her den
after 6 months dozing underground.
Her 2 cubs follow her
and take their first steps
in the outside world.
These steep slopes provide
a sanctuary for the cubs.
A male bear would kill
and eat them given the chance.
But big animals find it difficult
to get about here.
Males may be twice
the size of a female
and even she can have problems.
Her cubs, however,
make light of the snow
and of life in general.
But the mother faces a dilemma:
It's 6 months since she last fed
and her milk is starting
to run dry.
She must soon leave the safety
of these nursery slopes
and lead her cubs away
from the mountain.
If she delays,
the whole family will risk starvation.
Summer reveals the true nature
of the Rockies.
Stripped of snow,
the peaks bear their sculpted forms.
Only now can mountaineers
reclaim the upper reaches.
2 miles up, the crumbling precipices
seem devoid of life.
But there are animals here —
a grizzly bear.
It seems to be an odd creature
to find on these high rocky slopes.
It's hard to imagine
what could have attracted it here.
At this time of the year, bears should
be fattening up for the winter.
Yet they gather in some numbers
on these apparently barren slopes.
They're searching
for a rather unusual food —
moths.
Millions have flown up here
to escape the heat of the lowlands,
and they're now roosting
among the rocks.
Moths may seem
a meager meal for a bear,
but their bodies are rich in fat
and can make all the difference in a
bear's annual struggle for survival.
Another battle is being waged here
but on a much longer timescale.
These loose boulders are
the mountain's crumbling bones.
The Rockies are no longer rising
but slowly disintegrating.
All mountains everywhere are being
worn down by frost, snow and ice.
The Alps were raised
some 15 million years ago
as Africa, drifting northwards,
collided with the southern edge of Europe.
These spires are the eroded
remains of an ancient seabed
that once stretched
between the two continents.
But these are just
the Alpine foothills.
The range at its center
rises to 3 miles high
and is crowned with permanent snows.
The Matterhorn,
its summit too steep
to hold a snow field.
Mont Blanc — the highest peak
in Western Europe.
The distinctive jagged shapes
of the Alps
were carved by those great
mountain sculptors —
the glaciers.
Immense rivers of moving ice,
laden with rock,
grind their way
down the mountains,
gouging out deep valleys.
They're the most powerful
erosive force on our planet.
A moulin — a shaft in the ice
opened by melt water
as it plunges
into the depths of the glacier.
Like the water running through it,
the ice itself is constantly moving,
flowing down the valley
with unstoppable force.
Alpine glaciers may seem immense,
but they're dwarfed
by those in the great ranges
that divide the Indian
subcontinent from Tibet.
This is the boulder strewn snout
of the giant Baltoro glacier in the
Karakoram mountains of Pakistan.
It's the biggest mountain glacier
on Earth —
43 miles long and over 3 miles wide.
This huge ice-filled valley
is so large
it's clearly visible from space.
This is the greatest concentration
of peaks over 5 miles high
to be found anywhere on Earth.
They're the most
dangerous mountains of all.
K2 and her sister peaks have claimed
more lives than any others.
The peaks here rise so precipitously,
the glaciers are so steep
and crevassed
that few except the most skilled
mountaineers can penetrate these ranges.
Markhor gather for their annual rut.
Males must fight
for the right to breed,
but on these sheer cliffs any slip
by either animal could be fatal.
A snow leopard —
the rarest of Himalayan animals.
It's a female returning to her lair.
These are the first intimate images
of snow leopard ever filmed in the wild.
She greets her 1-year old cub.
Her den is well chosen.
It has exceptional views
of the surrounding cliffs.
On these treacherous slopes
no hunter other
than the snow leopard
would have a chance
of catching such agile prey.
A female with young
makes an easier target.
Her large paws give
an excellent grip
and that long tail
helps her balance.
Silently, she positions herself
above her prey.
She returns with nothing.
Golden eagles patrol these cliffs
in search of the weak or injured.
With a 2 meter wing span
this bird could easily
take a young markhor.
Eagles hunt by sight
and the thickening veil
of snow forces them to give up.
For the leopard,
the snow provides cover
and creates an opportunity.
The worsening weather dampens
the sound of her approach
allowing her to get
within striking distance.
It was an act of desperation
to try and catch such a large animal.
Wolves have made a kill
giving other hunters
a chance to scavenge.
The worst of the blizzard brings
success for the snow leopard,
but having descended so far
to make the kill
she has a grueling climb
to get back to her lair.
The cub must be patient.
It'll be a year before it has
the strength and skill
to kill for itself
on these difficult slopes.
The snow leopard is
an almost mythical creature,
an icon of the wilderness,
an animal few humans
have ever glimpsed
for its world is one we seldom visit.
The Karakoram lie
at the western end of a range
that stretches
across a tenth of our planet —
the Himalayas.
These, the highest mountains
of the world,
like other great ranges,
were created by the collision
of continents.
Some 50 million years ago
India collided with Tibet
thrusting up these immense peaks,
which are still rising.
This vast barrier of rock and ice
is so colossal
it shapes the world's climate.
Warm winds from India,
full of moisture,
are forced upwards by the Himalayas.
As the air rises so it cools,
causing clouds to form
and the monsoon is born.
At high altitudes,
the monsoon rains fall as snow.
Here, at the far eastern end
of the range in China,
one inhabitant endures
the bitter winters out in the open.
Most other bears would be
sleeping underground by now,
but the giant panda can't
fatten up enough to hibernate.
Its food, bamboo,
on which it totally relies
has so little nutritional value
that it can't build up
a store of fat like other bears.
Most of the creatures here move up or
down the slopes with the seasons
but the panda is held
captive by its diet
for the kind of bamboo it eats
only grows at this altitude.
But these forests hold
fewer challenges for the more mobile.
The golden snap-nosed monkey,
like the giant panda, lives only in China.
Their thick fur allows them to survive at
greater altitudes than any other monkey
and when the cold bites, they have
these upper slopes to themselves.
Even if you have a warm coat
it apparently helps to surround yourself
with as many layers as possible.
But at least these monkeys
have a choice —
if they tire of tree bark
and other survival food
they can always descend
to lower warmer altitudes
and not return until spring.
As the snows retreat
trees come into bloom.
Cherry blossom.
Rhododendrons —
here in their natural home
they form great forests
and fill the landscape
with the covers of a new season.
These forests are host to a
rich variety of springtime migrants.
Beneath the blooms — another display.
It's the mating season
for oriental pheasants,
Himalayan monal,
tragopan,
and blood pheasant.
Musk deer make the most
of a short flash of spring foods.
This male smells a potential mate.
The red panda,
rarely glimpsed in the wild.
It was once considered
a kind of raccoon,
but is now believed
to be a small mountain bear.
By midsummer its larger, more famous
relative, has retreated into a cave.
A giant panda nurses
a tiny week old baby.
Her tender cleaning
wards off infection.
She won't leave this cave
for 3 weeks,
not while her cub
is so utterly helpless.
Progress is slow
for milk produced on a diet
of bamboo is wretchedly poor.
4 weeks old
and the cub is still blind.
Its eyes do not fully open
until 3 months after birth,
but the chances of the cub
reaching adulthood are slim.
The struggle of a giant panda
mother to raise her cub
is a touching symbol of the precariousness
of life in the mountains.
On the highest summits
of our planet
nothing can live permanently.
The highest peak of all,
Mount Everest, five and a half
miles above sea level
and still rising —
the roof of our world.
Of those humans
who've tried to climb it
1 in 10 have lost their lives.
Those that succeed can stand for
only a few moments on its summit.
The Nepalese call it: "A mountain
so high no bird can fly above it."
But each year
over 50,000 demoiselle cranes
set out on one of the most
challenging migrations on Earth.
To reach their over-wintering
grounds in India
they must cross the Himalayas.
By late morning ferocious winds
are roaring past the peaks.
The cranes must gain height
to avoid the building storm.
They've hit serious turbulence.
They must turn back
or risk death.
A new day
and a new opportunity.
The flock stay in close contact
by calling one another.
Weak from lack of food and water,
they use thermals, rising columns
of warm air, to gain height.
For many, this is their first journey
across the Himalayas.
For some, it will be their last.
The golden eagles
have been expecting them.
The eagles work in pairs to separate
a young crane from the flock.
It escapes the touches of one,
and is caught by another.
But even a young crane
is a heavy prize
and the eagle has
to struggle to control it.
The mother can wait no longer —
this is a desperate race
against worsening weather.
The rest of the flock battle on.
In the final ascent every wing beat
becomes an exhausting struggle.
At last, they are over the highest
barrier that lies in their way.
But like all who visit
the world of the high mountains
they dare not linger.