Super Powered Eagles

High flying,

sharp-eyed,

and fierce.

From mountain tops

to river valleys,

eagles rule the skies.

Tenacious and strong.

They are the ultimate bird of prey.

Now, for the first time...

..we'll follow the dramatic story of a wild bald eagle family...

..witness eagles in action...

..and join one man and his feathered friend

to put these icons of the air to the test.

Woohoo! What a girl!

We'll reveal what it takes...

..and even what it feels like...

Wow! We're flying with a golden eagle!

..to be the most powerful bird in the sky.

This is Iowa in the American Midwest...

..and in the midst of a late winter snowfall...

CHIRPING

..a bald eagle is trying to look after her most precious possessions.

These two eggs must be kept at around 37 degrees Celsius

if they are to hatch.

At night, temperatures plummet to minus 25.

By day, it's still cold enough to freeze her eyelashes.

But she'll do whatever it takes to keep these eggs safe.

Over the next few months, we'll follow them around the clock

and see what it takes to become a superpowered eagle.

Bald eagles are just one of 70 different species.

They can look very different...

..but they all share a mesmerising blend of power...

..and beauty.

They've mastered habitats across the planet.

From harpy eagles in the rainforests of South America

to Steller's sea eagles in the icy North Pacific.

And fish eagles in the Great Lakes of Africa.

They live at the top of the food chain...

..but to dominate their world, they must overcome

some significant challenges.

They have to cover hundreds of miles on the wing,

spot their food at vast distances,

and tackle the largest prey of any bird species.

BIRDS CALLING

To find out how eagles achieve this...

..we need to meet a remarkable bird.

This is Tilly.

A golden eagle with a wingspan of almost two metres.

But what makes her unique is the relationship

she has with her lifelong partner.

Bird specialist Lloyd Buck.

Hello!

Hello, my love!

Are you enjoying yourself, eh?

You're the best, ain't ya?

You're a once-in-a-lifetime bird, you are. Eh?

I'll never have another bird like you ever, will I?

Since he was a child,

Lloyd has been obsessed with birds.

Over the years, he's kept and trained many different species.

But one stands out.

Tilly.

They've been together for 20 years,

and have forged an exceptionally close bond.

As far as Tilly is concerned,

Lloyd is her mate for life.

Go on! Go and enjoy yourself, my love.

I wish I was you.

I wish I was you!

Thanks to Lloyd's dedicated work with Tilly,

she acts just like a wild eagle,

but is also comfortable around scientific equipment and cameras.

So this is an extraordinary opportunity to learn

more about these iconic animals.

Eagles are such inspirational birds.

There's so much I think that we don't understand about them,

and that's what I'm hoping to learn here.

A little window into her world, into the world of eagles.

Together, Lloyd and Tilly will take on a series of tests

that will unlock the eagle's remarkable powers.

On the other side of the world, in Iowa,

the adult female seems restless.

One of the eggs is starting to hatch.

From its first moments, the chick must show its strength.

It uses a tiny egg tooth on top of its beak to crack the shell.

CHICKS CHEEPING

Three days later,

it's joined by its sibling.

At this age, they need to eat

almost half their body weight in meat every day.

Thankfully, help is on hand,

and he's bringing fresh supplies.

As with all bald eagles, the male is about 20% smaller than his mate.

It's thought she might be bigger to help produce

and incubate the young.

Bald eagles normally pair for life,

but this female's previous partner disappeared,

so this male is new.

The breeding season can last around ten months,

so rearing these chicks will be a test of their new relationship.

The chicks' weight needs to increase

by a staggering 500% in the first week,

so the adults spend much of the time out hunting.

Bald eagles specialise in catching fish.

They can make up to 90% of their diet.

They're able to pluck them from the water

with remarkable precision.

CHEEPING

But rabbits and squirrels are also delivered to the nest.

For now at least,

this partnership is providing all the food the chicks could need.

Eagles around the world catch a wide variety of prey,

so they have a range of hunting techniques...

..and one species has come up with an extraordinary strategy.

The mountains of Oman.

In this desert realm, food is hard to come by.

But this Verreaux's eagle has a family to feed.

Other birds dive-bomb the predator,

hoping to chase it away.

But this eagle is focused on a terrestrial target.

Rock hyrax.

These small mammals are equipped with special vision.

A shield on their iris cuts out glare,

helping them spot predators,

even in bright sunlight.

But one eagle is just a decoy.

Verreaux's eagles hunt in pairs.

The first flies in plain sight,

distracting the hyrax...

..while the second eagle hugs the contours of the land,

staying hidden...

..until the last moment.

Using teamwork is devastatingly effective.

But catching their quarry is a dangerous task.

There's no room for error.

When eagles hunt airborne prey, if something goes wrong

they usually have space and time to get out of trouble.

They can even escape a glancing blow with the water surface.

But when the prey is on hard ground...

..one wrong move could result in a deadly collision.

Especially when hunting a large, heavy animal.

There's simply no scope to make a mistake.

So how do eagles target and safely catch terrestrial prey?

To find out, Lloyd has come to Scotland

to put his golden eagle Tilly to the test.

But first,

he needs something for her to hunt.

This is Robohare.

Designed and created by tech wizard Chris Watts.

With a fake fur coat

and high-speed motors, it can blend into the undergrowth

or flash across the open.

It's also fitted with an onboard 360 camera to capture all of the action.

OK. She's going to rouse. Get ready.

OK. Go! Go! Go! Fire! Fire!

In a matter of seconds, Tilly locks on to her target.

She's got him. She's done it.

Thank you very much, Tilly.

Good girl!

To challenge Tilly's hunting ability,

they repeat the test

in different conditions.

Go!

From strong winds and overcast skies

to bright sunlight.

But the outcome is the same.

To reveal the secret to her success,

we need to go through the footage frame by frame.

First, Tilly keeps a constant lock on Robohare's position.

Next, she uses her wings to adjust her trajectory

as the wind changes

or the target moves.

She keeps her legs tucked in to stay aerodynamic.

Then, just a quarter of a second before impact,

she swings her feet forwards

so both eyes can see Robohare

AND her talons.

She makes perfect contact.

But in a demonstration of sheer power...

OK, get ready, Chris.

..Tilly's hunting skill is about to reach the next level.

Robohare weighs 5.8 kilos -

one and a half times more than Tilly.

But not only can she catch Robohare...

..she can lift it high into the air.

She even has the strength to carry it with one foot.

A remarkable achievement for a load weighing 150%

of her own body weight.

Yes! Woohoo-hoo!

What a girl!

Good bird! There's a good eagle!

She's able to do this because, like all eagles,

she's armed with highly specialised weapons - talons.

and inflict fatal damage upon their victim...

..while the beak is used to cut up the meal.

The harpy eagle has some of the largest talons in the world,

measuring up to 12 centimetres - twice as long as a golden eagle's.

These weapons can suffocate their quarry

or create puncture wounds and blood loss.

To achieve this, eagles must grip with enormous force