[somber music playing]
[David Attenborough] A million wildebeest,
after 1,000 kilometers on the march,
are facing their greatest obstacle on their annual migration.
[bleating]
Tanzania's Mara River.
Traveling with them are zebras. Some, females with foals.
And waiting for them...
crocodiles.
[music becomes dramatic]
The smaller a foal, the lower its chances.
- [foal whinnying] - And he is one of the smallest.
[music intensifies]
[music abates]
[music intensifies]
He tries to stay as close as possible to his mother.
Those that get separated are unlikely to survive.
- [music intensifies] - [foal whinnying]
He's struggling to keep up.
[foal whinnying anxiously]
All he can do is kick...
[snorting]
...while others take the fall.
[music continues]
[buffalo bellows]
[foal snorts, whinnies]
[groans]
[music ends abruptly]
The distractions last just long enough
to enable him to reach his mother...
continuing their march with the planet's largest herd.
[rousing music playing]
[music abruptly trails off]
[theme tune playing]
[music fades out]
[gentle classical music fades in]
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.
[music becomes optimistic]
Mexico's Pacific Coast.
[music abates]
The beach looks deserted.
But beneath the sand,
thousands of animals are on the move.
[subdued classical music playing]
[music becomes optimistic]
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.
[music becomes dramatic]
[music crescendoes]
[music ends]
[music reprises]
- For the hunters... - [turtle chirping]
...this is the biggest feast of the year.
[music intensifies]
[chirps]
- [muffled chirp] - [music fades out]
They take half of the emerging hatchlings on the beach.
[tense music playing]
But the little turtles keep arriving in such numbers
that the predators simply can't keep up.
[hatchlings chirping]
And that is their only chance of reaching the water.
[music intensifies]
[caws loudly]
[gulls squawks]
[chirps]
[music ends abruptly]
[snorts softly]
[somber music playing]
[music becomes tense]
- The tide is going out. - [snarling]
Things are getting even more dangerous for the little turtles.
Their only chance is to follow the others.
[music becomes urgent]
[birds squawking]
[music abates]
Some reach the shallows.
But even now, they're not safe.
[whimsical music playing]
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.
[music becomes rousing]
A quarter of a million of them.
The greatest gathering of turtles on Earth.
[music intensifies]
Here she will mate, then swim ashore to lay.
She is no longer a tiny hatchling.
But the shallows are still just as daunting.
[optimistic music playing]
[gasps]
Land.
- [growls softly] - The first she's touched in 15 years.
- [gasps, sighs] - 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.
[music becomes rousing]
As thousands more adults arrive,
as many as 80% of the eggs laid here
are accidentally destroyed by other nesting females.
[music abates]
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.
[stillness]
[thunder rumbling]
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.
[making fart-like noises]
Here on this beach, in late October,
there are only pups.
[trills]
Their mothers left them weeks ago,
and now they must fend for themselves.
[barking softly, making fart-like sounds]
In a few days, they too will leave
and begin their lives as ocean wanderers in the deep sea.
[making fart-like sounds]
But they have yet to learn how to swim!
This sheltered beachside pool
would seem a good place to do that.
[growls softly]
[honks]
- [growls] - [honks]
[blowing]
They get acquainted with the sea.
[croaks]
They make the right swimming movements instinctively
but are, as yet, unable to understand danger.
[menacing music playing]
Orca.
Killer whales.
[music abates]
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.
[pup barking]
Until then, she must wait.
[menacing music reprises]
If she mistimes her attack,
she will get stranded on the rocks.
[music abates]
At half tide,
it's just deep enough for a killer whale.
[menacing music reprises]
[music becomes dramatic]
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.
[music abates]
[low voice] The pups are almost within reach.
She watches and waits
for one to come close enough to snatch.
[disquieting music playing]
[seal barking]
[music climaxes]
[seal trills]
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.
[birds squawking]
[birds chirping]
[spiritual music playing]
Breeding in safety, for some animals,
means avoiding crowds.
New Zealand.
The last habitable landmass to be reached by people.
[music intensifies]
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.
[bird call]
[quirky music playing]
[chirruping]
It's shy and mysterious.
[peeping]
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.
[music continues]
[chick chirping]
Penguin divorce rates are indeed high!
So he had better keep everyone away.
- [squawks] - [cheeps]
[squawks]
His partner has returned to the coast after a busy day collecting food.
But getting ashore is not easy.
[somber dramatic music playing]
[music abates]
It's a question of timing.
[music reprises]
[music abates]
Almost!
[music reprises]
[music abates]
[music fades out]
Nicely done.
[whimsical music playing]
To reach her hungry chick,
she has to travel over boulders,
roots,
and ravines.
[chirping]
[peeping]
[chick chirping]
This is Deliveroo, penguin-style.
[mother chirping]
- [chick peeps] - Dad can only watch with envy.
[music fades out]
[mother chirping]
As the chick grows, so too does its appetite.
To keep up with the demand,
Mum must complete the obstacle course through the jungle...
[quirky music playing]
...again
and again.
[mother chirping]
To rear her chick, she will walk the distance of a marathon
and swim over a thousand kilometers.
[music continues]
And she will lose up to half of her body weight.
- [squawking] - [peeping]
But that doesn't stop her.
[lively percussion playing]
[high-pitched chirps]
[music ends abruptly]
- [chick cheeping] - [spiritual music playing]
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.
[ambient music playing]
In November,
an increase in the daily sunlight heats the Indian Ocean
and kick-starts the monsoon.
In its path lies Christmas Island.
[quirky electronic music playing]
The rise in humidity it brings awakens a sleeping army.
[music becomes dramatic]
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.
[car horn hoots]
But help is now at hand.
[music intensifies]
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.
[rapid squeaking]
They increase their pace,
for they must catch the high tide.
[music ends abruptly]
[waves gently crashing]
In a single night, four million crabs reach the coast.
[optimistic ambient music playing]
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.
[music fades out]
Thousands of kilometers further south,
another first journey is about to begin.
[atmospheric panpipe music playing]
Late November,
midsummer, at the end of the world.
Patagonia, the southernmost tip of the Americas.
[music becomes rousing]
Only one large land predator lives as far south as this.
The puma.
This is Machito.
- [growls softly] - The gray one.
He is one year old and about to face the biggest test of his life.
Not that he knows it.
[rousing music playing]
[Machito snarls]
[brown puma vocalizing]
He and his sister, Niña,
are at the age where they should separate,
and each find a territory of their own.
[music fades out]
Competition between males
means Machito will have to travel much further than his sister.
- But now, each must learn to hunt. - [snorts]
[subdued tense music playing]
[prey grunts]
Even for their mother,
there is no greater challenge...
[music intensifies, abates]
...than catching an adult bull guanaco
three times her size.
But she's an expert.
The cubs watch closely.
[disquieting music playing]
To succeed, she must get within a few meters.
[music intensifies]
[music becomes dramatic]
And then hold on, no matter how wild the ride.
[puma snarls]
[music builds]
[guanaco whinnying]
[guanaco bellowing]
[silence]
The cubs should make the most of the free meal.
Their easy living is about to come to an end.
[whimsical music playing]
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.
[music becomes nostalgic]
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.
[music climaxes, fades]
After weeks on the move,
he is starving.
[guanaco whinnies]
[apprehensive music playing]
He's seen how to hunt,
but has he learned enough?
[music accelerates]
[guanaco shrieking]
Not quite.
[music abates]
To find food, he must keep moving,
heading deeper into unfamiliar lands.
[music reprises]
He doesn't stop until...
[sniffs]
...he picks up the unmistakable scent of a fresh kill.
[snarling]
But it was made...
[ominous music playing]
...by a huge male.
[music fades out]
[gentle growling]
[tense string music playing]
[gentle snarling]
[snorting]
[growling]
He's twice Machito's size...
[growling]
[music intensifies]
...and could kill him in seconds.
- [growls] - [snarls]
[soft growling]
But he's too hungry to give up now.
[soft growling]
[growling]
[snorts]
[silence]
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.
[poignant music playing]
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.
[ambient music playing]
[chirping]
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.
[optimistic music playing]
And this is one of the biggest ever seen.
Billions crowd the reefs...
[music speeds up]
...bewildering the locals.
[music slows]
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.
- [music speeds up] - [squeaking]
Now they shed their shells, changing their wetsuits
for something in which it's easier to breathe.
Ready.
- [squeaking] - But before they've even left the beach...
[big crab growls]
...they are attacked by someone unexpected.
[music abruptly ends]
Mother?
[quirky music playing]
Clearly, adult red crabs are not very child-friendly.
Time to leave the beach, and quickly.
[squeaking]
That requires climbing the seawall.
[music speeds up]
As formidable as a skyscraper would be for us.
[music speeds up]
[music abates]
Once at the top, they must creep through the town.
[music intensifies]
[woman speaking English]
[Attenborough] But it's hard to keep a low profile
when you're part of an army of several billion.
[music intensifies]
The world is very, very dangerous
when you're very, very small.
[squeaking]
So they need to watch their step.
The forest edge.
Safety is in sight.
[music ends]
But it's too soon to relax.
[shrieking string music playing]
[music subsides]
Yellow crazy ants,
which eat crablets.
Those that make it through
are home for Christmas.
[squeaking]
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.
- [optimistic music playing] - [squawking]
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.
[music ends]
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.
[dramatic music playing]
The Himalayas.
To cross, the cranes must now ascend to 8,000 meters above sea level.
[cawing]
The higher they fly, the lower the oxygen.
[music becomes suspenseful]
Exhausted, they're vulnerable to attack.
[music fades out]
Golden eagles, lifted by the warm air rising from the steep slopes,
soar above the cranes.
[cranes squawking]
[menacing music playing]
And then, they dive down towards them.
[tense music playing]
To bring down such large prey,
the eagles work as a pair.
[music climaxes, slowly fading out]
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.
[poignant music playing]
[squawking]
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.
[optimistic music playing]
The people of Khichan began to feed and protect the cranes.
[squawks]
More and more cranes arrived each winter.
Fifteen thousand of them now visit Khichan every year.
[music becomes rousing]
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.
[cawing]
[squawks]
[music fades out]
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.
[elephants roar, growl]
[snarls]
In March 2020,
the forest was hit by the biggest, longest drought on record.
Trees died
and elephants starved.
[growling]
With a new member of the family about to be born...
[snorts, growls]
...the herd decided to move.
But this was to be no ordinary journey.
[rousing music playing]
Their story captured the world's imagination.
[growls]
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.
[barks]
That, for elephants, was highly unusual.
His start to life would be very tiring.
But the now 17-strong family had to keep traveling.
[music intensifies]
And for those who'd only just learned to walk,
every hurdle was a problem.
[growls]
- And every slope... - [trumpets]
...a steep one.
[music abates]
They continued for another 400 kilometers.
And the further north they trudged,
the less they belonged.
[roars]
To eat or drink,
they were forced to steal.
But remarkably,
instead of driving them away...
[roars]
...people gave them safe passage...
[trumpets]
...and allowed them to plunder.
[snorting]
[growls]
After marching for a year,
they were exhausted.
[snoring]
[poignant music playing]
Elephants usually sleep on their feet
and only lie down when they are completely fatigued.
[snoring]
If we continue to change our planet,
more and more animals
will be forced to make new journeys such as this.
[music intensifies]
But it was their next move
that would be the most extraordinary of all.
[music intensifies]
[music fades out]
[theme tune playing]
[music crescendoes]
[music fades out]