This is The Americas,
an extraordinary journey across Earth's great supercontinent.
The widest variety of life on the planet.
The untold story...
...of our home.
Tonight on The Americas...
The Caribbean.
The tropical paradise
at the heart
of the supercontinent.
This is a voyage
across sparkling, deep seas,
colorful shallows,
and far-flung exotic islands,
all revealing hidden natural treasures.
But in paradise,
the stakes are high...
in deadly battles.
Temperatures are searingly hot,
and nature's fury
is never far away.
How can island castaways
unlock the riches
of this sun-drenched world?
.
The Caribbean spans more than a million square miles.
It's fringed to the east by a chain of volcanic islands.
To the north...
by Cuba and the Bahamas.
And to the west...
by Central America.
But our journey begins...
...on the high seas.
It's a world of dazzling sapphire blue.
In these crystal-clear waters,
life must be on its guard.
A shoal of Spanish sardines
feeding on microscopic plankton.
An irresistible opportunity
for a sailfish.
A pirate of the Caribbean.
With a streamlined body
and a bill like a rapier,
sailfish are perfectly honed
for hunting in these open waters.
Time for the sardines to swim for their lives.
Sailfish have speed and endurance,
but the sardines are more nimble.
With the tightly-packed shoal moving as one,
it's near impossible to pick out a victim.
When some make a break for the safety of the depths...
...the sailfish drive them back to the surface
into a trap.
Blockers pin them from beneath.
While flankers raise their sails,
cutting off any escape route.
None of the hunters want to risk being skewered,
so they use a surprising tactic.
A sailfish can change colors.
This flash of stripes along the flank
is a sign to others to hold back
when he charges in.
Eventually, the relentless attack splinters the shoal.
The moment the sailfish have been waiting for.
In the final charge,
his bill becomes a weapon,
slashing through the shoal,
inflicting injury.
Or picking out a single victim
with lethal precision.
The sailfish may have claimed their prize,
but the Caribbean Sea holds fortunes
these fish never reach.
Its deepest waters
are the hunting ground for the planet's largest predators...
sperm whales.
Exactly how they hunt
has long been one of the great wildlife mysteries.
Until now.
The volcanic island of Dominica lies to the far east of the Caribbean.
It's shrouded in rainforest.
And surrounded by mile-deep seas.
They're the perfect home...
...for one of the world's biggest babies,
a sperm whale calf.
This young male is barely six months old,
but he already weighs two tons.
Below...
sleeping giants.
Mom and the rest of the family
are taking a nap.
Their huge heads act like corks,
keeping them upright.
But Mom always keeps
half an eye on her calf.
Baby sperm whales need to drink a bathful of milk a day.
But before he can suckle,
Mom must have a meal herself.
Sperm whales hunt their prey
in the great depths of the Caribbean Sea,
but exactly how
has long been a mystery.
To investigate,
our team spent two years developing
a groundbreaking camera system.
The camera is harmlessly attached using suction
by scientists.
Now, we can get a whale's eye view
as they dive
into the abyss.
A calf can't hold its breath for long enough to reach the depths,
so it must wait at the surface.
In a world first,
the camera follows these adults
as they begin their dive together.
And as they descend,
it also eavesdrops on their secret conversations.
A thousand feet down
in the twilight zone,
the whales separate to hunt alone.
Her destination is the seabed,
2,500 feet down.
A place no natural light can reach.
She's here to hunt squid.
And uses sound to find them in the darkness.
Each click she makes is louder than a gunshot.
It echoes off any prey within half a mile.
She's locked on.
Got it.
A cloud of squid ink is all that's left of her prey.
A sperm whale can devour a hundred pounds of squid
on a single dive.
On the surface, her hungry calf has been waiting for nearly an hour.
When you're this young, time can really drag.
Finally, the adults are on their way back to the surface.
A calf can hear his mom's clicks below him.
His calls and tail slaps help her home in.
And now, it's time to suckle.
Sperm whale milk is over 30 percent fat,
so it doesn't dissolve in water.
Calves feed like this a handful of times a day.
Blissfully unaware of the lengths and depths
their moms have gone to.
The sperm whales' open ocean world makes up 95 percent of the Caribbean.
But it's in the sunlit shallows where most life is found.
A world of colorful coral cities
and secret underwater nurseries.
And this is a destination
for a lemon shark,
one that's about to face
the most important moment of her life.
The shallow waters of the Caribbean are perhaps the most beautiful.
Coral reefs
are like a bustling underwater city.
They are home to thousands of species.
Though today, it's only a handful of protected reefs
that still truly thrive.
Surprisingly, the Caribbean's richest reefs
are found alongside a mysterious world.
And it's here that many of the reef's inhabitants
begin life.
These are the mangrove forests.
A quarter of the Caribbean's mangroves are found on its northern fringes...
In the Bahamas.
This female lemon shark is making a special journey,
back to the very same bay in which she was born.
She's heavily pregnant.
And now, as close as possible to the edge of the mangroves,
it's time to give birth.
Two perfectly formed
tiny sharks.
This pup will never see Mom again,
because where he's going,
no adult can follow.
His new home will be deep amongst the mangroves.
The mesh of underwater roots
keeps larger predators out.
So it's the safest place in the whole Caribbean
for a young lemon shark to grow up.
As he picks his way through this twisted maze...
...he's heading to a secret lagoon at its heart.
Although it's full of fish,
newborn sharks
aren't very good at catching them.
You might not think it,
but young sharks
have to practice.
And practice.
He's definitely going to need help.
And for that, lemon shark pups do something remarkable.
They make friends.
Scientists have discovered that a young pup learns quicker
by hanging out with more experienced sharks.
It's a kind of shark school,
where he can hone his technique as he grows up.
The older sharks have learned it's best to hunt
amongst the mangrove roots.
And over time,
the young pup eventually catches on.
Got one.
He's graduated.
There are over 7,000 islands in the Caribbean.
Each a slice of paradise.
And every one...
different.
Where life plays out
in its own way.
Away from the crowds,
every island also has its own unique
and extraordinary wildlife.
From tiny...
to giant.
And the Caribbean island with the most spectacular wildlife...
is Cuba.
Eight hundred miles long and a hundred wide.
Deep in the forest,
life is on the move.
The start of the strangest animal migration
anywhere in the Americas.
The lowland forest of Cuba...
...is the land
of the red...
crab.
For most of the year,
these land crabs
live underground.
But it's now the mating season.
The females
need to find a male,
head to the sea,
and lay their eggs.
And to do that,
they must start an epic,
six-mile journey.
Around ten million crabs
are on the march.
Only one thing stops them.
The intense heat of the midday sun
can bake a crab...
...to death.
So every traveler needs to find shade...
fast.
In Cuba,
siestas...
save lives.
But as the day cools off,
a female crab's mind
turns to more romantic matters.
And here,
at the edge of the forest,
males have been waiting for this very moment.
In a tight embrace, they mate.
Now, she retreats into his burrow
to let her brood develop.
Fourteen days later, she resumes her journey.
Now with 80,000 eggs cradled under her shell.
She's only a few hundred feet from the sea,
but the biggest danger is still to come.
The coastal highway.
Out here, a crab must be on her toes.
Giants.
And nowadays,
they're frighteningly quick.
Look out!
A crab can see danger coming,
but for many...
That's just not enough.
It takes split-second timing...
...and a bit of luck.
That was close.
After all that, the warm Caribbean Sea awaits.
It is a little crowded on this beach.
But she's found a good spot.
And with a little shimmy, finally,
she releases her precious cargo of eggs
into the sea.
And with her job done,
now she can return to the safety of her forest home.
But in the Caribbean, safety can never be guaranteed.
At the end of summer,
when sea temperatures are at their highest,
storm clouds are born.
They feed on warm, moist air from the ocean.
Growing and growing...
...until they tower six miles into the sky.
The larger a storm cloud,
the more powerful the winds.
And as they approach 80 miles an hour,
a storm...
becomes a hurricane.
Up to 500 miles across,
these colossal weather systems track west
with the trade winds.
The Caribbean's islands are right in the firing line.
Of all the natural forces in the Americas,
a hurricane is the most devastating.
Two-hundred-mile-an-hour winds destroy almost everything in their path.
In some years,
the Caribbean's islands are hit by as many as four deadly hurricanes.
The most powerful strip the land bare.
But all is not lost.
Caribbean plants have evolved
to bounce back after the destruction.
In a warm, moist climate,
new shoots can grow up to seven inches a day.
In just a few months, entire forests start to green up.
But what about the wildlife
on these islands?
When Hurricane Maria hit Dominica,
three-quarters of all purple-throated carib hummingbirds died.
In the aftermath,
their food, nectar-rich flowers, were scarce.
So the survivors had their work cut out.
This male must patrol an area the size
of five football fields
trying to find enough.
A tiring commute
until, at last,
one miracle plant comes into flower.
The heliconia gives a hungry hummingbird
all the nectar he needs.
But there's one thing still missing.
A mate.
Luckily,
these blooms are a magnet to female caribs.
The trouble is,
it's the same for less-welcome visitors.
Nectar thieves...
like bananaquits.
And even worse, a real heavyweight,
an Antillean bullfinch.
To get to the nectar,
this vandal rips out the heart of the flower.
And a flower without nectar
will never attract him a mate.
So he must fight off these feathered felons...
...with everything he's got.
For a lonely male,
finding love on this island
might take time.
After the hurricane,
there were very few of his kind left.
Could it be?
Yes, a female...
...inspecting his heliconias.
She likes the flowers.
She likes the nectar.
But what about him?
Now, he's got to shine.
Don't blow it, big fella.
She likes his moves.
Success.
But he's not done yet.
To mate with as many females as possible,
he's gonna have to defend
his flowers...
...day after day.
From dawn...
till dusk.
Life on Caribbean islands isn't ever straightforward.
But on one of the most isolated tropical islands of the Americas,
survival relies not so much on hard work,
but on extraordinary levels of ingenuity.
Isla Jicarón,
40 miles off the western shore of Panama.
On such a small and remote island,
food is limited.
And worse, there's nowhere to go when it runs out.
And yet, somehow, life still clings on.
Castaways.
White-faced capuchins.
These two young males spend their days scouring the coast
for anything they can find.
On a desert island,
opportunity can come from unlikely places.
A sea almond.
The nut inside is full of delicious fat.
But it's protected by a sturdy shell.
And getting into it
is frustratingly hard.
To solve this puzzle,
a young monkey might need some inspiration.
For that, he must head across the forest...
to a crystal-clear stream.
An occasional hangout for older
and wiser capuchins.
The adults have worked out that the trees here
are particularly fruitful
and the nuts collect
in convenient pools.
A unique scenario
that allows a monkey
to do something ingenious.
Take one softened nut...
The correct-sized rock...
...and a series of well-aimed blows.
It was once thought that only humans
were smart enough to use stone tools.
But these capuchins
have both a hammer...
and...
an anvil.
They're one of only three types of monkey on the planet
to have mastered this complex skill.
And it's not as easy as it looks.
For an inquisitive youngster,
the nuances of nut-cracking...
...are almost hypnotic.
He learns by watching his elder's technique.
And when the anvil is free...
...trying to copy it.
Watch your toes.
It's a bit pummeled...
...but he has cracked it.
Well, sort of.
By learning to use tools...
...these remarkable monkeys
have given themselves a break
from the challenges of island life.
For now, at least.
Living in the tropical islands of the Americas
can be tougher than it looks.
But both above
and below the waves...
...life uses every trick in the book...
...to make this wondrous place...
paradise.