Planet Earth (2006) s01e01 Episode Script

1
A 100 years ago
there were one and a half
billion people on Earth.
Now, over 6 billion
crowd our fragile planet.
But even so, there are still places
barely touched by humanity.
This series will take
to the last wildernesses
and show you the planet
and its wildlife
as you have never seen them before.
Imagine our world without sun.
Male Emperor Penguins are facing the
nearest that exists on planet Earth:
Winter in Antarctica.
It's continuously dark
and temperatures drop
to -70 degrees centigrade.
The penguins stay when all other
creatures have fled
because each guards a treasure:
A single egg rested
on the top of its feet
and kept warm beneath
the downy bulge of its stomach.
There is no food
and no water for them,
and they will not see
the sun again for 4 months.
Surely, no greater ordeal
is faced by any animal.
As the sun departs
from the Antarctic,
it lightens the skies
in the far north.
It's March
and light returns
to the high Arctic,
sweeping away 4 months of darkness.
A polar bear stirs.
She has been in her den
the whole winter.
Her emergence marks
the beginning of spring.
After months
of confinement underground,
she toboggans down the slope;
perhaps to clean her fur,
perhaps for sheer joy.
Her cubs gaze out
of their bright new world
for the very first time.
The female calls them,
but this steep slope is not the
easiest place to take your first steps.
But they are hungry
and eager to reach their mother,
who's delayed feeding them
on this special day.
Now she lures them
with the promise of milk,
the only food the cubs have known
since they were born
deaf and blind beneath the snow
some 2 months ago.
Their mother has not eaten
for 5 months
and has lost half her body weight.
Now she converts the last of her fat
reserves into milk for her cubs.
The spring sun brings warmth,
but also a problem for the mother.
It starts to melt the sea ice.
That is where she hunts for the seal
she needs to feed her cubs.
And she must get there
before the ice breaks up.
For now though,
it's still -30 degrees
and the cubs must have
the shelter of the den.
It's 6 days
since the bears emerged
and spring is advancing rapidly.
But even now, blizzards
can strike without warning.
Being so small,
the cubs are easily chilled and they will
be more comfortable resting in the den.
But their mother must keep them
out and active.
She's becoming weak from hunger
and there's no food
on these nursery slopes.
The sea ice still holds firm,
but it won't last much longer.
Day 10,
and the mother has led
her cubs a mile from the den;
it's time to put them to the test.
They've grown enormously in confidence,
but they don't have
their mother's sense of urgency.
At last, it seems that they're
ready for their journey,
and they're only just in time,
for a few miles from the coast,
the ice is already splitting.
Now the mother can start hunting
for the seals they must have,
but she's leading her cubs
into a dangerous new world.
Nearly half of all cubs die
in their first year out on the ice.
Summer brings 24 hours
of sunlight
and the thawing shifting landscape.
Further south, the winter snows have
almost cleared from the Arctic tundra.
Northern Canada's wild frontier.
Here, nature stages
one of her greatest dramas —
Every year, 3 million caribou
migrate across the Arctic tundra.
The immensity of the herd can only
be properly appreciated from the air.
Some herds travel over 2,000 miles
a year in search of fresh pastures.
This is the longest overland
migration made by any animal.
They're constantly on the move.
Newborn calves have to be up and
running the day they are born.
But the vast herds
do not travel alone.
Wolves.
Packs of them, 8 - 10 strong,
shadow the migration.
And they are hungry.
It's the newly born calves
that they are after.
Running directly at the herd
is a ploy to generate panic.
The herd breaks up
and now it's easier
to target an individual.
In the chaos, a calf is
separated from its mother.
The calf is young,
but it can outrun the wolf if only
it manages to keep its footing.
At this stage, the odds are even —
either the caribou
will make a mistake,
or after a mile,
the wolf will give up.
Midsummer on the tundra
and the sun does not set.
At these latitudes,
the sun's rays are glancing
and not enough of their energy
reaches the ground
to enable trees to grow.
You'll need to travel
500 miles south from here
before that is possible.
These stunted shrubs
mark the tree line —
the beginning
of the boreal forest —
the taiga.
The needle-shaped leaves of the
conifers are virtually inedible,
so this forest supports
very little animal life.
It's a silent place
where the snow is unmarked
by footprints.
In the Arctic winter,
snow forms a continuous blanket
across the land.
But as spring creeps up
from the south,
the taiga is unveiled.
This vast forest
circling the globe
contains a third
of all the trees on Earth,
and produces so much oxygen
it changes the composition
of the atmosphere.
As we travel south,
so the sun's influence
grows stronger
and at 50 degrees of latitude,
a radical transformation begins.
Summers here are long enough for
broadleaf trees to replace conifers.
Broadleaves are much easier
to eat and digest,
so now animals can collect
their share of the energy
that has come from the sun.
It's summer
and these forests
are bustling with life.
But the good times will not last.
Broad leaves must be shed in winter
for their damage by frost.
As they disappear,
so the land becomes barren
with little for animals to eat.
The inhabitants must migrate,
hibernate,
or face months of near starvation.
The Amur leopard —
the rarest cat in the world.
Here, in the deciduous forests
of eastern Russia,
the winter makes hunting
very difficult.
Prey animals are scarce,
and there's no concealing vegetation.
The cub is a year old
and still dependent on its mother.
Deer are frequent casualties
of the harsh winter
and these leopards are not above
scavenging from a corpse.
African leopards could
never survive here,
but the Russian cats have thick fur
to shield them from the cold.
There are only 40 Amur leopards
left in the wild
and that number is falling.
Like so many creatures,
the cats have been pushed
to the very edge of extinction
by hunting and the destruction
of their habitat.
The Amur leopard symbolizes the
fragility of our natural heritage.
The future of an entire species
hangs on survival
of a tiny number of mothers
like this one.
All animals, rare or common,
ultimately depend
for their energy on the sun.
In Japan, the arrival
of the cherry blossom
announces the beginning of spring.
The sun's energy brings
color to the landscape.
The earth, as it makes its annual
journey around the sun,
spins on a tilted axis.
And it's this tilt
that creates the seasons.
The advance of the seasons
brings constant change.
As the sun's influence
diminishes in the north,
so the deciduous forests of America
begin to shut down
losing their leaves in preparation
for the dark cold months ahead.
One season hands over to another.
Some organisms thrive on decay,
but most must make special
preparations for winter
and a life with little sun.
Whole populations of animals
are now forced to travel great distances
in pursuit of food and warmth.
300,000 Baikal teal gather to
escape from the Siberian winter
by migrating south to Korea —
the world's entire population
in a single flock.
But there are parts of the world
that have no seasons.
In the tropics the sun's rays
strike the earth head on
and their strength is
more or less constant all year round.
That is why the jungle
grows so vigorously
and supports so much life.
This forest covers only 3%
of the planet's surface,
but it contains more than 50%
of all its plants and animals.
The canopy is particularly rich.
There are monkeys, birds
and millions of species of insects,
exactly how many — we have no idea.
The character of the forest
changes as we descend,
becoming ever darker and damper,
favoring different kinds
of animals and plants.
Less than 2% of the sunlight
reaches the floor,
but even here, there is
extraordinary variety.
In the great island
of New Guinea,
there are 42 different species
of birds of paradise,
each more bizarre than the last.
This forest is so rich
that nourishing food
can be gathered very quickly.
That leaves the male
six-plumed bird of paradise
with time to concentrate
on other matters,
like tidying up his display area.
Everything must be spick and span.
All is ready.
Very impressive,
but no one is watching.
The superb bird of paradise
calls to attract a female.
And he has more luck.
But what does he have to do
to really impress her?
She retires to consider her verdict.
It's hard not to feel deflated
when even your best
isn't good enough.
The sun influences life in the oceans
just as it does on land.
Its richest parts are those
where waves and currents
bring fertilizing nutrients
to surface waters
that are bathed in sunlight.
The seas off the Cape in South Africa
have this magic recipe
and are hugely productive.
Summer is the time of plenty
and it's now that the seals
start to breed.
The strike of a great white shark
lasts a mere second.
Slowing it down forty times
reveals the technique
and immense strength
of this massive predator.
If surprise fails,
there will be a chase.
The shark is faster
on a straight course
but it can't turn
as sharply as the seal,
its agility versus power.
Once the seals
have finished breeding,
the giant sharks will move on.
It's now becoming clear
that great whites migrate thousands
of miles across the oceans
to harvest seasonal abundances
in different seas.
The sun, beating down
on tropical waters,
powers the weather systems
of the globe.
Moisture evaporates
from the warming ocean
and rises to create great storms.
The winds generated out at sea
sweep inland across the continents.
As they travel across the Sahara,
they create the biggest
of all sand storms,
blowing sand halfway
round the world
to fertilize the Amazon jungle.
Winds blowing
across the Indian Ocean
collect moisture and sweep northwards
towards the Himalayas.
As the air rises, so it cools.
The water it carries
condenses into clouds
and then falls as the life giving
rains of the monsoon.
So air currents
powered by the sun
carry wet air
to the middle of continents.
Without water,
there can be no life,
but its distribution
over the land is far from even.
Deserts cover one third
of the land's surface
and they're growing bigger
every year.
This is the Kalahari Desert
in Southern Africa.
It's the dry season
and thousands of elephants
have started to travel
in desperate search for water.
All across Southern Africa, animals
are journeying for the same reason.
Buffalo join the great trek.
Nowhere else on Earth are so
many animals on the move
with the same urgent purpose.
They're all heading
for the swamps of the Okavango,
a vast inland delta.
At the moment, it is dry,
but water is coming.
The travelers are hampered
by dangerous dust storms.
Females and calves can easily get
separated from the main herd.
For this pair, sanctuary lies in the
patch of woodland a few miles ahead.
They can't rest until they reach it.
The main herd has already
got there safely.
Finally, the stragglers
emerge from the dust.
The exhausted calf is
still blinded by sand.
Its mother does
everything possible to help it.
The storm is now subsiding,
but not all the elephants
have been so lucky.
One youngster has got lost.
Thirsty and exhausted,
it follows the tracks
of its mother,
but sadly,
in the wrong direction.
At the peak of the dry season
in the Kalahari,
water arrives in the Okavango.
It fell as rain a 1,000 miles away
in the highlands of Angola
and has taken nearly
5 months to reach here.
The water drives out insects
from the parched ground,
which are snapped up by plovers.
Catfish, traveling with the flood,
collect any drowning creatures
the birds have missed.
It's a seasonal feast
for animals of all kinds.
Birds are the first
to arrive in any numbers —
wattled cranes,
then black storks.
Behind the birds come buffalo.
After weeks of marching
their trek is coming to an end.
As the water sweeps
into the Okavango,
a vast area of the Kalahari is
transformed into a fertile paradise.
Nowhere on our planet is the life-giving
power of water so clearly demonstrated.
The Okavango becomes
criss-crossed with trails
as animals move into its heart.
The new arrivals open up
paths like arteries
along which water flows,
extending the reach of the flood.
This is an Africa rarely seen —
a lush water world.
Some creatures are completely
at home here.
These are lechwe —
antelope with hooves
that splay widely,
enabling them to move
its speed through the water.
For others, the change
is far less welcome.
Baboons are somewhat
apprehensive bathers.
The water brings a season
of plenty for all animals.
Hunting dogs.
These are now among
the rarest of Africa's mammals,
but then nonetheless the continent's
most efficient predators.
Their secret is teamwork.
Impala are their favorite prey.
They start to hunt
and the pack splits up.
An aerial viewpoint gives
a new insight into their strategy.
As the dogs approach their prey,
they peel off to take up separate
positions around their target.
They seem to form
a cordon around the impala.
Moving in total silence,
they take up their positions.
Those ears can detect
the slightest rustle.
The hunt is on.
Three dogs close in
on one impala.
Missed.
The lead dog drives the impala
towards the hidden flankers.
Anticipating their line,
the leader cuts the corner
and joins a flanker
for the final assault.
It's all or nothing.
One on one.
The dog has stamina,
the impala has speed.
Leaping into the lake
is an act of desperation —
impala can barely swim.
The dogs know their prey
must come out or drown —
now it's a waiting game.
The rest of the pack are calling.
They've made a kill
in the forest
and this is an invitation
to join in the meal.
The impala is in luck.
A pack this size kills once a day
and everything is shared.
And this impala is reprieved.
The elephants are nearing
the end of their long journey.
After weeks of marching,
they're desperately tired.
The matriarch can smell water
and encourages the herd
to make one last effort.
The youngsters are exhausted
but their mothers have made
this journey before
and they know
that they're close to water.
After many hundreds of miles,
they've arrived.
The lives of these elephants are dominated
by the annual rhythm of wet and dry,
a seasonal cycle
created by the sun.
At the southern end of the earth,
after 4 months of total darkness,
the sun once more
rises over Antarctica.
Now at last the Emperor penguins
abandon their huddle.
The males are still carrying
the precious eggs
that they've cherished
throughout the Antarctic winter.
With the returning sun,
the eggs hatch.
Other birds have not even arrived.
But the Emperors by enduring
the long black winter,
have given their chicks
a head start.
These youngsters are now
ready and eager
to make the most
of the brief Antarctic summer.