Our Planet (2019) s02e03 Episode Script

1
A million wildebeest,
after 1,000 kilometers on the march,
are facing their greatest obstacle
on their annual migration.
Tanzania's Mara River.
Traveling with them are zebras.
Some, females with foals.
And waiting for them
crocodiles.
The smaller a foal, the lower its chances.
And he is one of the smallest.
He tries to stay
as close as possible to his mother.
Those that get separated
are unlikely to survive.
He's struggling to keep up.
All he can do is kick
while others take the fall.
The distractions last just long enough
to enable him to reach his mother
continuing their march
with the planet's largest herd.
Some animals give their young
the best start in life
by making truly astonishing journeys.
And it's not only where they go
that's important but when.
Mexico's Pacific Coast.
The beach looks deserted.
But beneath the sand,
thousands of animals are on the move.
Olive ridley turtle hatchlings.
In October, the sand is at exactly
the right temperature for an emergence.
The first to surface
stay still.
Any movement might attract attention.
They must wait for others.
They are about to start
on the most dangerous journey
of their lives.
And it's better to do that together.
For the hunters
this is the biggest feast of the year.
They take half
of the emerging hatchlings on the beach.
But the little turtles
keep arriving in such numbers
that the predators simply can't keep up.
And that is their only chance
of reaching the water.
The tide is going out.
Things are getting even more dangerous
for the little turtles.
Their only chance is to follow the others.
Some reach the shallows.
But even now, they're not safe.
Those that survive
will swim harder in the next 24 hours
than they will ever do again.
As they travel, they are imprinted
by the Earth's magnetic field.
A mental marker that will guide them back
when it's their time to breed.
Every olive ridley turtle
will spend the first 15 years
of its life in the Pacific,
feeding and growing alone.
Each will travel
hundreds of thousands of kilometers
until one day, they change course
and begin the long journey
back to the beach where they hatched.
For the first time in over a decade,
this teenage turtle
meets others of its own kind.
A quarter of a million of them.
The greatest gathering
of turtles on Earth.
Here she will mate,
then swim ashore to lay.
She is no longer a tiny hatchling.
But the shallows
are still just as daunting.
Land.
The first she's touched in 15 years.
Now she has urgent things to do.
Her eggs are ready to be laid,
and she must dig a nest for them.
If she deposits them below the tide line,
they would drown.
But too far up the beach,
and they could dry out.
So the middle ground is very popular.
As thousands more adults arrive,
as many as 80% of the eggs laid here
are accidentally destroyed
by other nesting females.
But so many eggs are laid
that millions will remain undamaged,
deep in the sand.
She lays a hundred or so.
And with that, her work is done.
But next year, at this same time,
she will return to this particular beach
to lay again
and will keep doing that
for the rest of her life.
Most of the journeys made
in order to breed
have barely changed for millennia.
In a remote part of the Atlantic,
east of South America,
lie the Falkland Islands.
Elephant seals
have been coming here to breed
for thousands of years.
Here on this beach, in late October,
there are only pups.
Their mothers left them weeks ago,
and now they must fend for themselves.
In a few days, they too will leave
and begin their lives
as ocean wanderers in the deep sea.
But they have yet to learn how to swim!
This sheltered beachside pool
would seem a good place to do that.
They get acquainted with the sea.
They make the right
swimming movements instinctively
but are, as yet,
unable to understand danger.
Orca.
Killer whales.
This is no passing pod.
They've traveled hundreds of kilometers
to get here at this precise time.
Twenty years ago,
the lead female discovered
when the pups go to their play pool.
And when, as the tide rises,
she too could reach it.
Until then, she must wait.
If she mistimes her attack,
she will get stranded on the rocks.
At half tide,
it's just deep enough for a killer whale.
The pups don't recognize the threat,
even when it's staring them in the face.
She needs a pup to be in the water,
but it's still
dangerously shallow for her.
A wrong turn
and she could get stuck.
The pups
are almost within reach.
She watches and waits
for one to come close enough to snatch.
She carries it, still alive, out to sea.
This female orca
is the only one who hunts in this way.
And she does so for her entire family.
The pup remains alive for hours.
These orcas have learned to take advantage
of the seals' annual journeys
here to breed.
And, perhaps equally remarkably,
know exactly when
they should come back every year.
Breeding in safety, for some animals,
means avoiding crowds.
New Zealand.
The last habitable landmass
to be reached by people.
To get here,
the Polynesians had to cross
thousands of kilometers of open ocean.
And so indeed does any animal.
But nonetheless, one visitor
makes a 6,000-kilometer journey
across the Southern Ocean every year
to the island's most secluded corners.
It's shy and mysterious.
Fiordland's tawaki penguin.
The jungle penguin.
He's looking after
his eight-week-old chick
while his partner is at sea finding food.
If he doesn't do so adequately,
she might leave him.
Penguin divorce rates are indeed high!
So he had better keep everyone away.
His partner has returned to the coast
after a busy day collecting food.
But getting ashore is not easy.
It's a question of timing.
Almost!
Nicely done.
To reach her hungry chick,
she has to travel over boulders,
roots,
and ravines.
This is Deliveroo, penguin-style.
Dad can only watch with envy.
As the chick grows,
so too does its appetite.
To keep up with the demand,
Mum must complete
the obstacle course through the jungle
again
and again.
To rear her chick,
she will walk the distance of a marathon
and swim over a thousand kilometers.
And she will lose
up to half of her body weight.
But that doesn't stop her.
And then, after ten long weeks,
she's finally had enough.
With the delivery service ended,
hunger drives the chick to the sea.
There's plenty of food
to be had just offshore,
but strangely, he swims away with others
and keeps going
for thousands of kilometers,
halfway to Antarctica.
It's the longest single journey
made by any penguin
and quite possibly pointless.
It's thought their ancestors
started doing this two million years ago
when their food was only found out here.
And it's clearly been
a hard routine to break.
In November,
an increase in the daily sunlight
heats the Indian Ocean
and kick-starts the monsoon.
In its path lies Christmas Island.
The rise in humidity it brings
awakens a sleeping army.
Christmas Island red crabs
now live almost entirely on land.
But to breathe,
they still need moisture in their gills
and the sea in which to lay their eggs.
So they make an annual trek to the coast,
as they have done for 200,000 years.
Lately, however, a lot has changed.
But help is now at hand.
Local people
have also built special bridges
that allow them to cross the busiest roads
at their own speed,
and a network of subways guides them.
They increase their pace,
for they must catch the high tide.
In a single night,
four million crabs reach the coast.
Each female shakes 100,000 eggs
into the surf.
They hatch immediately
and become free-swimming larvae.
Most years, the vast majority
are eaten or washed into the deep,
and none return.
But with luck,
on the next month's high tide,
they will be swept back
to the island's shores.
Thousands of kilometers further south,
another first journey is about to begin.
Late November,
midsummer, at the end of the world.
Patagonia, the southernmost tip
of the Americas.
Only one large land predator
lives as far south as this.
The puma.
This is Machito.
The gray one.
He is one year old and about to face
the biggest test of his life.
Not that he knows it.
He and his sister, Niña,
are at the age where they should separate,
and each find a territory of their own.
Competition between males
means Machito will have to travel
much further than his sister.
But now, each must learn to hunt.
Even for their mother,
there is no greater challenge
than catching an adult bull guanaco
three times her size.
But she's an expert.
The cubs watch closely.
To succeed,
she must get within a few meters.
And then hold on,
no matter how wild the ride.
The cubs should make the most
of the free meal.
Their easy living
is about to come to an end.
Their mother has done
all she can for them.
After a year together,
her territory is no longer theirs.
It's time for them to leave.
For several weeks,
the siblings stay close to each other.
But they will soon need
to go their separate ways.
Niña, the female,
will be allowed to live
close to her mother's home range.
Machito will not.
Male territories are much larger.
And to find enough space,
he may have to travel
for hundreds of kilometers.
For the first time in his life,
he is alone.
After weeks on the move,
he is starving.
He's seen how to hunt,
but has he learned enough?
Not quite.
To find food, he must keep moving,
heading deeper into unfamiliar lands.
He doesn't stop until
he picks up
the unmistakable scent of a fresh kill.
But it was made
by a huge male.
He's twice Machito's size
and could kill him in seconds.
But he's too hungry to give up now.
Remarkably, the old puma backs down
and allows the youngster to feed,
behavior that is very rare among males.
Machito's courage
may have bought him more time,
but his journey has only just begun.
Male pumas travel far and quickly.
As a consequence, very little is known
about their independent lives.
It's thought that few survive
their first year alone.
With luck,
he'll be one of them.
It's Christmas Eve,
and the shores of Christmas Island
are bright red.
Once in a decade,
the ocean currents
are just right for the crablets to return.
And this is one of the biggest ever seen.
Billions crowd the reefs
bewildering the locals.
They try to reach dry land
in whatever way they can.
They need to get to the forest
from where their parents came
and where they will be safe,
just two kilometers away.
But their parents
weren't the size of a pinhead.
Now they shed their shells,
changing their wetsuits
for something
in which it's easier to breathe.
Ready.
But before they've even left the beach
they are attacked by someone unexpected.
Mother?
Clearly, adult red crabs
are not very child-friendly.
Time to leave the beach, and quickly.
That requires climbing the seawall.
As formidable
as a skyscraper would be for us.
Once at the top,
they must creep through the town.
But it's hard
to keep a low profile
when you're part of an army
of several billion.
The world is very, very dangerous
when you're very, very small.
So they need to watch their step.
The forest edge.
Safety is in sight.
But it's too soon to relax.
Yellow crazy ants,
which eat crablets.
Those that make it through
are home for Christmas.
They will spend the next five years
feeding and growing
before making the return journey
to the sea
and then producing little crablets
of their own.
An animal's first journey
will almost always be
its most challenging.
But some are especially daunting.
Young demoiselle cranes
face one of the toughest migrations
made by any bird.
Fleeing frozen Mongolia,
they travel south
to spend the winter in India.
But the journey there
wasn't always as hard as this.
Forty-five million years ago,
the land beneath them
was comparatively flat.
It was then crushed and pushed upwards
into great folds,
creating what was to become
the highest mountain range on Earth.
The Himalayas.
To cross, the cranes must now ascend
to 8,000 meters above sea level.
The higher they fly, the lower the oxygen.
Exhausted, they're vulnerable to attack.
Golden eagles, lifted by the warm air
rising from the steep slopes,
soar above the cranes.
And then, they dive down towards them.
To bring down such large prey,
the eagles work as a pair.
This chick's first journey
has become its last.
There are lower, safer routes than this.
But the cranes' instinct
is to fly in the direction
they have always taken.
Until very recently, they faced hunting
and the loss of many
of their traditional feeding sites.
Then one small village in Northern India
changed their fortunes.
The people of Khichan
began to feed and protect the cranes.
More and more cranes arrived each winter.
Fifteen thousand of them
now visit Khichan every year.
It's the greatest gathering of the species
to be seen anywhere.
For the chicks,
their journey south
across the tallest mountain range on Earth
is finally over.
Until next year.
In this changing world,
animals on the move
need our help more than ever.
The tropical forests of Yunnan
are the last home
of the endangered wild elephants of China.
In March 2020,
the forest was hit by the biggest,
longest drought on record.
Trees died
and elephants starved.
With a new member of the family
about to be born
the herd decided to move.
But this was to be no ordinary journey.
Their story captured
the world's imagination.
Here was the largest land animal
trying to find somewhere to live
in the most populated country on Earth.
The family headed north
into a very different China
from the one they had left behind.
For eight months, they trekked through
strange new lands
but couldn't find anywhere to settle.
So their newest arrival
was born on the move.
That, for elephants, was highly unusual.
His start to life would be very tiring.
But the now 17-strong family
had to keep traveling.
And for those
who'd only just learned to walk,
every hurdle was a problem.
And every slope
a steep one.
They continued for another 400 kilometers.
And the further north they trudged,
the less they belonged.
To eat or drink,
they were forced to steal.
But remarkably,
instead of driving them away
people gave them safe passage
and allowed them to plunder.
After marching for a year,
they were exhausted.
Elephants usually sleep on their feet
and only lie down
when they are completely fatigued.
If we continue to change our planet,
more and more animals
will be forced to make new journeys
such as this.
But it was their next move
that would be
the most extraordinary of all.