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A million wildebeest,
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00:00:16,099 --> 00:00:18,810
after 1,000 kilometers on the march,
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are facing their greatest obstacle
on their annual migration.
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Tanzania's Mara River.
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Traveling with them are zebras.
Some, females with foals.
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And waiting for them...
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crocodiles.
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The smaller a foal, the lower its chances.
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And he is one of the smallest.
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He tries to stay
as close as possible to his mother.
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Those that get separated
are unlikely to survive.
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He's struggling to keep up.
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All he can do is kick...
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...while others take the fall.
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The distractions last just long enough
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to enable him to reach his mother...
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continuing their march
with the planet's largest herd.
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Some animals give their young
the best start in life
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by making truly astonishing journeys.
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And it's not only where they go
that's important but when.
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Mexico's Pacific Coast.
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The beach looks deserted.
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But beneath the sand,
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thousands of animals are on the move.
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Olive ridley turtle hatchlings.
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In October, the sand is at exactly
the right temperature for an emergence.
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The first to surface
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stay still.
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Any movement might attract attention.
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They must wait for others.
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They are about to start
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on the most dangerous journey
of their lives.
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And it's better to do that together.
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For the hunters...
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...this is the biggest feast of the year.
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They take half
of the emerging hatchlings on the beach.
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00:05:22,864 --> 00:05:26,743
But the little turtles
keep arriving in such numbers
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that the predators simply can't keep up.
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And that is their only chance
of reaching the water.
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The tide is going out.
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Things are getting even more dangerous
for the little turtles.
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Their only chance is to follow the others.
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Some reach the shallows.
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But even now, they're not safe.
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Those that survive
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will swim harder in the next 24 hours
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than they will ever do again.
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As they travel, they are imprinted
by the Earth's magnetic field.
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A mental marker that will guide them back
when it's their time to breed.
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Every olive ridley turtle
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will spend the first 15 years
of its life in the Pacific,
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feeding and growing alone.
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Each will travel
hundreds of thousands of kilometers
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until one day, they change course...
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and begin the long journey
back to the beach where they hatched.
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For the first time in over a decade,
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this teenage turtle
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meets others of its own kind.
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A quarter of a million of them.
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00:08:31,511 --> 00:08:34,472
The greatest gathering
of turtles on Earth.
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Here she will mate,
then swim ashore to lay.
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She is no longer a tiny hatchling.
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But the shallows
are still just as daunting.
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Land.
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The first she's touched in 15 years.
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Now she has urgent things to do.
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Her eggs are ready to be laid,
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and she must dig a nest for them.
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00:10:18,284 --> 00:10:20,995
If she deposits them below the tide line,
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they would drown.
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But too far up the beach,
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and they could dry out.
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So the middle ground is very popular.
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As thousands more adults arrive,
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as many as 80% of the eggs laid here
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are accidentally destroyed
by other nesting females.
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But so many eggs are laid
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that millions will remain undamaged,
deep in the sand.
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She lays a hundred or so.
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And with that, her work is done.
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But next year, at this same time,
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she will return to this particular beach
to lay again
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and will keep doing that
for the rest of her life.
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Most of the journeys made
in order to breed
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have barely changed for millennia.
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00:11:54,380 --> 00:11:58,342
In a remote part of the Atlantic,
east of South America,
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lie the Falkland Islands.
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Elephant seals
have been coming here to breed
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for thousands of years.
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Here on this beach, in late October,
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there are only pups.
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Their mothers left them weeks ago,
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and now they must fend for themselves.
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00:12:34,795 --> 00:12:37,131
In a few days, they too will leave
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and begin their lives
as ocean wanderers in the deep sea.
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00:12:46,599 --> 00:12:49,560
But they have yet to learn how to swim!
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This sheltered beachside pool
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would seem a good place to do that.
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They get acquainted with the sea.
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They make the right
swimming movements instinctively
101
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but are, as yet,
unable to understand danger.
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Orca.
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Killer whales.
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This is no passing pod.
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They've traveled hundreds of kilometers
to get here at this precise time.
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Twenty years ago,
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the lead female discovered
when the pups go to their play pool.
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And when, as the tide rises,
she too could reach it.
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Until then, she must wait.
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If she mistimes her attack,
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she will get stranded on the rocks.
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At half tide,
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it's just deep enough for a killer whale.
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The pups don't recognize the threat,
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even when it's staring them in the face.
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She needs a pup to be in the water,
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but it's still
dangerously shallow for her.
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A wrong turn
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and she could get stuck.
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The pups
are almost within reach.
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She watches and waits
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for one to come close enough to snatch.
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She carries it, still alive, out to sea.
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This female orca
is the only one who hunts in this way.
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And she does so for her entire family.
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The pup remains alive for hours.
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These orcas have learned to take advantage
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of the seals' annual journeys
here to breed.
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00:16:56,974 --> 00:16:59,643
And, perhaps equally remarkably,
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know exactly when
they should come back every year.
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Breeding in safety, for some animals,
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means avoiding crowds.
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New Zealand.
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The last habitable landmass
to be reached by people.
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To get here,
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the Polynesians had to cross
thousands of kilometers of open ocean.
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And so indeed does any animal.
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But nonetheless, one visitor
makes a 6,000-kilometer journey
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across the Southern Ocean every year
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to the island's most secluded corners.
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It's shy and mysterious.
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Fiordland's tawaki penguin.
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The jungle penguin.
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He's looking after
his eight-week-old chick
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while his partner is at sea finding food.
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If he doesn't do so adequately,
she might leave him.
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00:19:07,771 --> 00:19:10,691
Penguin divorce rates are indeed high!
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So he had better keep everyone away.
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His partner has returned to the coast
after a busy day collecting food.
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But getting ashore is not easy.
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It's a question of timing.
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Almost!
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Nicely done.
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To reach her hungry chick,
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she has to travel over boulders,
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roots,
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and ravines.
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This is Deliveroo, penguin-style.
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Dad can only watch with envy.
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As the chick grows,
so too does its appetite.
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To keep up with the demand,
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Mum must complete
the obstacle course through the jungle...
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...again
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and again.
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00:21:22,364 --> 00:21:25,951
To rear her chick,
she will walk the distance of a marathon
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and swim over a thousand kilometers.
167
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And she will lose
up to half of her body weight.
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But that doesn't stop her.
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And then, after ten long weeks,
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she's finally had enough.
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With the delivery service ended,
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hunger drives the chick to the sea.
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There's plenty of food
to be had just offshore,
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but strangely, he swims away with others
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and keeps going
for thousands of kilometers,
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halfway to Antarctica.
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It's the longest single journey
made by any penguin
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and quite possibly pointless.
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It's thought their ancestors
started doing this two million years ago
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when their food was only found out here.
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And it's clearly been
a hard routine to break.
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In November,
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00:23:06,551 --> 00:23:10,680
an increase in the daily sunlight
heats the Indian Ocean
184
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and kick-starts the monsoon.
185
00:23:15,227 --> 00:23:18,146
In its path lies Christmas Island.
186
00:23:21,191 --> 00:23:25,946
The rise in humidity it brings
awakens a sleeping army.
187
00:23:37,833 --> 00:23:39,709
Christmas Island red crabs
188
00:23:39,793 --> 00:23:42,587
now live almost entirely on land.
189
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But to breathe,
190
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they still need moisture in their gills
191
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and the sea in which to lay their eggs.
192
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So they make an annual trek to the coast,
as they have done for 200,000 years.
193
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Lately, however, a lot has changed.
194
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But help is now at hand.
195
00:24:29,092 --> 00:24:32,554
Local people
have also built special bridges
196
00:24:32,637 --> 00:24:36,725
that allow them to cross the busiest roads
at their own speed,
197
00:24:38,101 --> 00:24:40,979
and a network of subways guides them.
198
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They increase their pace,
199
00:24:48,904 --> 00:24:51,114
for they must catch the high tide.
200
00:24:55,702 --> 00:24:59,915
In a single night,
four million crabs reach the coast.
201
00:25:08,381 --> 00:25:12,802
Each female shakes 100,000 eggs
into the surf.
202
00:25:25,857 --> 00:25:30,111
They hatch immediately
and become free-swimming larvae.
203
00:25:34,032 --> 00:25:39,120
Most years, the vast majority
are eaten or washed into the deep,
204
00:25:39,788 --> 00:25:41,540
and none return.
205
00:25:44,292 --> 00:25:47,629
But with luck,
on the next month's high tide,
206
00:25:47,712 --> 00:25:50,924
they will be swept back
to the island's shores.
207
00:25:57,806 --> 00:26:00,183
Thousands of kilometers further south,
208
00:26:00,267 --> 00:26:02,978
another first journey is about to begin.
209
00:26:08,400 --> 00:26:09,609
Late November,
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00:26:10,151 --> 00:26:12,988
midsummer, at the end of the world.
211
00:26:15,490 --> 00:26:20,120
Patagonia, the southernmost tip
of the Americas.
212
00:26:26,418 --> 00:26:30,922
Only one large land predator
lives as far south as this.
213
00:26:33,592 --> 00:26:34,592
The puma.
214
00:26:41,099 --> 00:26:42,642
This is Machito.
215
00:26:42,726 --> 00:26:44,728
The gray one.
216
00:26:46,062 --> 00:26:50,609
He is one year old and about to face
the biggest test of his life.
217
00:26:51,985 --> 00:26:53,445
Not that he knows it.
218
00:27:02,370 --> 00:27:04,623
He and his sister, Niña,
219
00:27:05,248 --> 00:27:07,834
are at the age where they should separate,
220
00:27:07,917 --> 00:27:10,795
and each find a territory of their own.
221
00:27:21,348 --> 00:27:23,391
Competition between males
222
00:27:23,475 --> 00:27:27,646
means Machito will have to travel
much further than his sister.
223
00:27:31,441 --> 00:27:34,986
But now, each must learn to hunt.
224
00:27:44,788 --> 00:27:46,164
Even for their mother,
225
00:27:47,540 --> 00:27:49,542
there is no greater challenge...
226
00:27:52,462 --> 00:27:55,548
...than catching an adult bull guanaco
227
00:27:56,174 --> 00:27:58,343
three times her size.
228
00:28:00,595 --> 00:28:02,055
But she's an expert.
229
00:28:04,933 --> 00:28:06,935
The cubs watch closely.
230
00:28:15,360 --> 00:28:19,072
To succeed,
she must get within a few meters.
231
00:28:46,307 --> 00:28:49,936
And then hold on,
no matter how wild the ride.
232
00:29:19,591 --> 00:29:22,844
The cubs should make the most
of the free meal.
233
00:29:24,095 --> 00:29:27,766
Their easy living
is about to come to an end.
234
00:29:34,022 --> 00:29:36,983
Their mother has done
all she can for them.
235
00:29:40,737 --> 00:29:42,363
After a year together,
236
00:29:42,447 --> 00:29:45,492
her territory is no longer theirs.
237
00:29:54,793 --> 00:29:57,045
It's time for them to leave.
238
00:30:07,055 --> 00:30:10,850
For several weeks,
the siblings stay close to each other.
239
00:30:11,726 --> 00:30:14,854
But they will soon need
to go their separate ways.
240
00:30:16,606 --> 00:30:18,274
Niña, the female,
241
00:30:18,358 --> 00:30:21,653
will be allowed to live
close to her mother's home range.
242
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Machito will not.
243
00:30:30,870 --> 00:30:33,373
Male territories are much larger.
244
00:30:33,456 --> 00:30:35,333
And to find enough space,
245
00:30:35,416 --> 00:30:38,253
he may have to travel
for hundreds of kilometers.
246
00:30:49,597 --> 00:30:51,724
For the first time in his life,
247
00:30:52,642 --> 00:30:54,227
he is alone.
248
00:31:01,442 --> 00:31:03,111
After weeks on the move,
249
00:31:03,736 --> 00:31:05,154
he is starving.
250
00:31:15,874 --> 00:31:17,333
He's seen how to hunt,
251
00:31:18,334 --> 00:31:20,420
but has he learned enough?
252
00:31:31,806 --> 00:31:32,849
Not quite.
253
00:31:37,103 --> 00:31:39,772
To find food, he must keep moving,
254
00:31:40,815 --> 00:31:44,652
heading deeper into unfamiliar lands.
255
00:31:52,285 --> 00:31:54,996
He doesn't stop until...
256
00:31:57,373 --> 00:32:01,753
...he picks up
the unmistakable scent of a fresh kill.
257
00:32:10,470 --> 00:32:11,846
But it was made...
258
00:32:14,390 --> 00:32:16,100
...by a huge male.
259
00:32:46,673 --> 00:32:48,967
He's twice Machito's size...
260
00:32:52,804 --> 00:32:55,056
...and could kill him in seconds.
261
00:33:05,441 --> 00:33:08,361
But he's too hungry to give up now.
262
00:33:26,879 --> 00:33:29,424
Remarkably, the old puma backs down
263
00:33:30,675 --> 00:33:32,719
and allows the youngster to feed,
264
00:33:33,302 --> 00:33:36,514
behavior that is very rare among males.
265
00:33:38,850 --> 00:33:42,145
Machito's courage
may have bought him more time,
266
00:33:43,688 --> 00:33:46,774
but his journey has only just begun.
267
00:33:52,572 --> 00:33:55,658
Male pumas travel far and quickly.
268
00:33:56,492 --> 00:34:00,830
As a consequence, very little is known
about their independent lives.
269
00:34:06,002 --> 00:34:10,006
It's thought that few survive
their first year alone.
270
00:34:12,675 --> 00:34:13,675
With luck,
271
00:34:14,218 --> 00:34:15,386
he'll be one of them.
272
00:34:33,863 --> 00:34:35,740
It's Christmas Eve,
273
00:34:35,823 --> 00:34:39,494
and the shores of Christmas Island
are bright red.
274
00:34:42,872 --> 00:34:44,207
Once in a decade,
275
00:34:44,707 --> 00:34:48,544
the ocean currents
are just right for the crablets to return.
276
00:34:50,797 --> 00:34:53,633
And this is one of the biggest ever seen.
277
00:34:55,426 --> 00:34:57,470
Billions crowd the reefs...
278
00:35:04,352 --> 00:35:06,062
...bewildering the locals.
279
00:35:08,022 --> 00:35:10,525
They try to reach dry land
280
00:35:11,567 --> 00:35:13,236
in whatever way they can.
281
00:35:17,698 --> 00:35:21,077
They need to get to the forest
from where their parents came
282
00:35:21,160 --> 00:35:25,581
and where they will be safe,
just two kilometers away.
283
00:35:26,999 --> 00:35:30,378
But their parents
weren't the size of a pinhead.
284
00:35:33,464 --> 00:35:37,135
Now they shed their shells,
changing their wetsuits
285
00:35:37,218 --> 00:35:39,929
for something
in which it's easier to breathe.
286
00:35:43,891 --> 00:35:44,891
Ready.
287
00:35:45,393 --> 00:35:47,770
But before they've even left the beach...
288
00:35:50,398 --> 00:35:53,317
...they are attacked by someone unexpected.
289
00:35:58,865 --> 00:35:59,865
Mother?
290
00:36:04,912 --> 00:36:10,084
Clearly, adult red crabs
are not very child-friendly.
291
00:36:12,753 --> 00:36:15,798
Time to leave the beach, and quickly.
292
00:36:20,052 --> 00:36:23,598
That requires climbing the seawall.
293
00:36:25,558 --> 00:36:29,103
As formidable
as a skyscraper would be for us.
294
00:36:35,526 --> 00:36:39,030
Once at the top,
they must creep through the town.
295
00:36:46,037 --> 00:36:48,497
But it's hard
to keep a low profile
296
00:36:48,581 --> 00:36:52,001
when you're part of an army
of several billion.
297
00:37:09,852 --> 00:37:12,605
The world is very, very dangerous
298
00:37:12,688 --> 00:37:14,649
when you're very, very small.
299
00:37:16,025 --> 00:37:18,277
So they need to watch their step.
300
00:37:25,910 --> 00:37:27,411
The forest edge.
301
00:37:27,495 --> 00:37:29,455
Safety is in sight.
302
00:37:30,581 --> 00:37:32,416
But it's too soon to relax.
303
00:37:36,337 --> 00:37:38,297
Yellow crazy ants,
304
00:37:39,590 --> 00:37:41,509
which eat crablets.
305
00:37:45,012 --> 00:37:46,639
Those that make it through
306
00:37:47,390 --> 00:37:49,892
are home for Christmas.
307
00:37:53,771 --> 00:37:57,733
They will spend the next five years
feeding and growing
308
00:37:58,484 --> 00:38:01,612
before making the return journey
to the sea
309
00:38:02,238 --> 00:38:05,032
and then producing little crablets
of their own.
310
00:38:12,206 --> 00:38:14,000
An animal's first journey
311
00:38:14,083 --> 00:38:17,253
will almost always be
its most challenging.
312
00:38:18,713 --> 00:38:21,382
But some are especially daunting.
313
00:38:26,971 --> 00:38:28,931
Young demoiselle cranes
314
00:38:29,015 --> 00:38:32,893
face one of the toughest migrations
made by any bird.
315
00:38:37,481 --> 00:38:39,567
Fleeing frozen Mongolia,
316
00:38:39,650 --> 00:38:43,404
they travel south
to spend the winter in India.
317
00:38:45,781 --> 00:38:49,076
But the journey there
wasn't always as hard as this.
318
00:38:56,125 --> 00:38:57,918
Forty-five million years ago,
319
00:38:58,002 --> 00:39:00,629
the land beneath them
was comparatively flat.
320
00:39:01,630 --> 00:39:05,551
It was then crushed and pushed upwards
into great folds,
321
00:39:05,634 --> 00:39:09,638
creating what was to become
the highest mountain range on Earth.
322
00:39:11,724 --> 00:39:12,933
The Himalayas.
323
00:39:19,648 --> 00:39:24,862
To cross, the cranes must now ascend
to 8,000 meters above sea level.
324
00:39:27,823 --> 00:39:31,660
The higher they fly, the lower the oxygen.
325
00:39:40,378 --> 00:39:43,172
Exhausted, they're vulnerable to attack.
326
00:39:50,679 --> 00:39:55,351
Golden eagles, lifted by the warm air
rising from the steep slopes,
327
00:39:55,976 --> 00:39:58,354
soar above the cranes.
328
00:40:12,243 --> 00:40:14,995
And then, they dive down towards them.
329
00:40:32,012 --> 00:40:34,014
To bring down such large prey,
330
00:40:34,098 --> 00:40:36,058
the eagles work as a pair.
331
00:40:49,238 --> 00:40:50,823
This chick's first journey
332
00:40:52,450 --> 00:40:53,951
has become its last.
333
00:41:10,885 --> 00:41:13,804
There are lower, safer routes than this.
334
00:41:14,972 --> 00:41:16,849
But the cranes' instinct
335
00:41:16,932 --> 00:41:20,019
is to fly in the direction
they have always taken.
336
00:41:32,031 --> 00:41:34,992
Until very recently, they faced hunting
337
00:41:35,701 --> 00:41:38,996
and the loss of many
of their traditional feeding sites.
338
00:41:46,795 --> 00:41:50,633
Then one small village in Northern India
339
00:41:51,217 --> 00:41:53,010
changed their fortunes.
340
00:42:12,613 --> 00:42:17,785
The people of Khichan
began to feed and protect the cranes.
341
00:42:34,927 --> 00:42:38,180
More and more cranes arrived each winter.
342
00:42:46,897 --> 00:42:50,734
Fifteen thousand of them
now visit Khichan every year.
343
00:42:54,029 --> 00:42:58,075
It's the greatest gathering of the species
to be seen anywhere.
344
00:43:01,412 --> 00:43:02,412
For the chicks,
345
00:43:02,454 --> 00:43:06,083
their journey south
across the tallest mountain range on Earth
346
00:43:06,166 --> 00:43:07,585
is finally over.
347
00:43:08,502 --> 00:43:10,546
Until next year.
348
00:43:20,097 --> 00:43:22,099
In this changing world,
349
00:43:22,182 --> 00:43:25,978
animals on the move
need our help more than ever.
350
00:43:29,231 --> 00:43:31,275
The tropical forests of Yunnan
351
00:43:31,358 --> 00:43:35,988
are the last home
of the endangered wild elephants of China.
352
00:43:53,297 --> 00:43:55,132
In March 2020,
353
00:43:56,008 --> 00:44:00,888
the forest was hit by the biggest,
longest drought on record.
354
00:44:03,265 --> 00:44:04,725
Trees died
355
00:44:06,060 --> 00:44:07,978
and elephants starved.
356
00:44:15,444 --> 00:44:18,322
With a new member of the family
about to be born...
357
00:44:21,909 --> 00:44:24,745
...the herd decided to move.
358
00:44:27,831 --> 00:44:31,001
But this was to be no ordinary journey.
359
00:44:33,212 --> 00:44:36,715
Their story captured
the world's imagination.
360
00:44:39,551 --> 00:44:42,596
Here was the largest land animal
361
00:44:43,806 --> 00:44:45,849
trying to find somewhere to live
362
00:44:47,601 --> 00:44:50,688
in the most populated country on Earth.
363
00:44:57,361 --> 00:44:59,071
The family headed north
364
00:44:59,154 --> 00:45:03,492
into a very different China
from the one they had left behind.
365
00:45:06,787 --> 00:45:10,582
For eight months, they trekked through
strange new lands
366
00:45:11,208 --> 00:45:13,419
but couldn't find anywhere to settle.
367
00:45:15,087 --> 00:45:19,007
So their newest arrival
was born on the move.
368
00:45:22,094 --> 00:45:25,055
That, for elephants, was highly unusual.
369
00:45:27,683 --> 00:45:31,019
His start to life would be very tiring.
370
00:45:34,857 --> 00:45:39,486
But the now 17-strong family
had to keep traveling.
371
00:45:51,749 --> 00:45:54,918
And for those
who'd only just learned to walk,
372
00:45:55,002 --> 00:45:57,129
every hurdle was a problem.
373
00:46:00,424 --> 00:46:02,551
And every slope...
374
00:46:02,634 --> 00:46:03,719
...a steep one.
375
00:46:11,393 --> 00:46:15,147
They continued for another 400 kilometers.
376
00:46:18,233 --> 00:46:20,360
And the further north they trudged,
377
00:46:21,195 --> 00:46:22,905
the less they belonged.
378
00:46:28,452 --> 00:46:29,828
To eat or drink,
379
00:46:31,497 --> 00:46:33,499
they were forced to steal.
380
00:46:38,587 --> 00:46:40,172
But remarkably,
381
00:46:41,256 --> 00:46:43,467
instead of driving them away...
382
00:46:44,593 --> 00:46:46,887
...people gave them safe passage...
383
00:46:48,931 --> 00:46:51,308
...and allowed them to plunder.
384
00:47:01,276 --> 00:47:03,237
After marching for a year,
385
00:47:03,904 --> 00:47:05,489
they were exhausted.
386
00:47:13,956 --> 00:47:16,458
Elephants usually sleep on their feet
387
00:47:16,542 --> 00:47:21,171
and only lie down
when they are completely fatigued.
388
00:47:26,885 --> 00:47:29,638
If we continue to change our planet,
389
00:47:30,305 --> 00:47:31,890
more and more animals
390
00:47:31,974 --> 00:47:35,727
will be forced to make new journeys
such as this.
391
00:47:46,363 --> 00:47:48,991
But it was their next move
392
00:47:49,074 --> 00:47:51,702
that would be
the most extraordinary of all.