The Americas

Welcome to The Americas .

An extraordinary journey...

across Earth's great super continent.

From the northern reaches of Canada...

through the breathtaking landscapes of the United States.

South to the iconic Amazon rainforest...

and the very tip...

of Patagonia.

Capturing the widest variety of life on the planet.

Five years in the making,

with 180 separate expeditions.

Revealing new discoveries...

only found here.

For the first time...

experience the strength...

the heart...

the hope.

The untold story...

of our home.

Tonight on The Americas...

The Atlantic Coast.

A world of wonder.

Where enchanted seas...

meet fairy-tale forests.

And life finds a home amongst the bright lights...

of a new world.

Although over 100 million people live on America's East Coast,

this is also where you find

200,000 square miles of historic forest.

And where the Carolinas' vast coastal plains

slip beneath the waves.

Reemerging as the ever-shifting sands of the Outer Banks.

These islands are home to surprising castaways.

Wild horses.

They live a perilous life,

braving tides and strong currents.

Legend has it their ancestors were marooned here

when the ships of conquistadors were wrecked on these shores.

But one stallion is doing very well here.

He rules this part of the island,

carpeted in lush meadows.

And at its heart lies the key to his success.

A fresh water spring.

Controlling this vital supply gives him power.

For a decade, he's defended the well and his family...

from other stallions.

He bears the scars to prove it.

But at 15 years old, the stallion may be past his prime.

Losing one big fight...

could mean the end of his reign.

That fight looks to be on the cards.

Because it's breeding season.

He can smell that one of his mares is ready to mate.

To heighten his senses,

he curls his lips, in what's known as the Flehmen response.

But other stallions have noticed too.

Including...

his arch rival.

This intruder may have dainty white feet,

but he's 500 pounds

of testosterone-fueled attitude.

The aging stallion must rise to the challenge.

Like prize fighters,

they size each other up.

Stamping.

And posturing.

The intruder is younger and bigger,

but the wily old stallion has years of combat experience.

A stamp of his foot says,

"Bring it on."

The old stallion skillfully dodges flying hooves.

He takes one ferocious kick to the chest

but rears up to avoid the knockout blow.

That...

was the challenger's best shot.

And it wasn't enough.

The stallion runs the intruder off his land.

Victory for the veteran means he can stay with his family.

And his place on these unique islands is secure,

for now.

But here, danger is never far away.

Out to sea, Atlantic waters are deadly.

Both above

and below.

In the waters just off the coast of North Carolina,

this sand tiger is heading to a shark rendezvous.

Ten feet long with teeth to die for,

this female certainly looks the part.

But she is about to reveal a very different side to her nature.

Sand tiger sharks are surprisingly sociable.

Every summer, hundreds assemble here.

But the purpose of these extraordinary gatherings

is still a mystery to scientists.

They happen in a place of eerie beauty

known as "the graveyard of the Atlantic."

More than 2000 ships have met their end on this coastline,

from Spanish galleons and pirate ships

to merchant vessels sunk in World War II.

These rusting hulks create new habitats,

swiftly colonized by many creatures.

Including vast shoals of scad.

But these little fish have a big problem.

They're on the menu.

For jacks.

30-pound high-speed hunters.

And not just one of them.

The scad must seek safety.

And they find it somewhere extraordinary.

With...

the sharks.

The scad use the sand tigers as bodyguards.

Each shark finds itself cloaked in a shimmering veil of tiny scad.

It's a remarkable relationship

and one rarely filmed.

A hidden wonder

where the human world and the natural world meet.

Journey 200 miles up the Atlantic Coast,

and you'll discover the largest estuary in the U.S.,

Chesapeake Bay.

Where 150 rivers meet the sea.

It's here that this true American icon

is forced to meet its greatest challenge head-on.

Winding through Maryland and Virginia,

the streams and rivers that feed Chesapeake Bay

are a haven for wildlife.

But they are also among North America's busiest waterways.

To thrive here takes a particular kind of attitude.

A bald eagle,

the Atlantic Coast's great success story.

In the 1970s, there were no eagles on this stretch of river.

But thanks to protection

and the banning of harmful pesticides,

and now there are more than 300 breeding pairs.

Their numbers are soaring.

With a seven-foot wingspan

and eyesight five times better than ours,

this female looks the perfect predator.

But for a bird that likes to hunt fish,

she has one major flaw.

She's not built to take off from water.

For all her power, fishing is not easy.

Missed again.

For most of the year, she can do well enough.

But in the spring, everything changes.

Ospreys arrive.

Birds of prey supremely adapted to just one thing...

fishing.

In March each year, 20,000 ospreys migrate here from the south.

They stay for the summer to raise their chicks.

Now they're in the eagle's territory.

Ospreys can hit the water...

at 70 miles an hour.

Their long legs stretch down to grab fish

three feet below the surface.

Equipped with waterproof feathers, take-off is no problem for them.

They're taking...

a lot of her fish.

Outclassed on home turf.

It's time to impose a fish tax.

Bald eagles have some powers that ospreys can't match.

Audacity.

Persistence.

And sheer strength.

Daylight robbery.

A quick barrel roll.

And it's time for her to collect.

North America's

comeback queen.

Flourishing on this most crowded coast.

Almost a third of Americans make the Atlantic Coast home.

The towns and cities we build

have been the biggest force of change here.

Where animals can sometimes find themselves in an alien world.

But here in the suburbs...

there are aliens living among us.

This peaceful corner of Maryland

is about to be invaded.

On a sleepy Maryland street,

something is stirring.

And it is not alone.

This male and thousands of others

have spent 17 years

deep underground.

They're called periodical cicadas,

and each is on a critical mission

to secure the next generation.

But things here have changed.

Seventeen years earlier, George W Bush was in the White House.

No one had heard of a smart phone,

and many suburban developments

were still plots of woodland.

Instinct drives the swarm to climb.

Many fall at the first hurdle.

But this male has found a good spot.