Original subtitles

The sky is one of the most challenging places to live.

But all across the world,

extraordinary animals do something we can only dream of.

Take to the air.

Some spend their whole lives up here.

Others only visit for a moment.

We'll discover how many incredible animals thrive in the sky...

..and what clever tricks they use to get airborne.

With the help of some specially trained animals,

the latest technology

and special effects techniques,

we'll reveal brand-new discoveries

that explain how animals take to the skies.

This is Life In The Air.

So, how do animals take to the air in the first place?

In this episode, we'll meet incredible creatures,

each with their own special techniques.

But they must all overcome one of our planet's

most powerful and universal forces.

Gravity.

It takes a very special animal to defy gravity.

But in Namibia, Southern Africa,

there's one that's mastered it like no other.

The caracal.

A cat with a unique ability to leave the earth.

It does something remarkable.

It catches birds in flight.

What looks like a misplaced haystack

is the largest nest in the natural world.

Home to 100 sociable weavers.

An irresistible target for a hungry cat.

CARACAL GROWLS

You could forgive a bird for believing it was safely out of reach.

But the caracal is perfectly designed to catch it.

Its front is smaller and lightweight

But its back legs are built as a booster rocket -

30% longer and with twice the muscle mass.

This design maximises the caracal's speed on takeoff.

And the faster it's travelling when it leaves the earth,

the higher it will get.

Caracals are built for a vertical launch.

DRAMATIC MUSIC PLAYS

But what goes up must come down.

And come down in the right way.

We know that cats always land on their feet,

but how?

This mystery kept scientists arguing for over a century.

It needs to turn around,

but to do that, it has to push against something else.

But there's nothing there.

This caracal is about to do something that would seem impossible.

All cats have a remarkable design.

A flexible spine which allows them to rotate their front and back ends

in different directions at the same time.

As it falls back to earth,

the caracal creates a clockwise rotation

in the front half of its body,

but the back spins in the opposite direction.

By spinning in two different directions at the same time,

the caracal is effectively pushing against itself.

But it does even more.

Like a spinning ice-skater,

it pulls its front legs close

which makes the front half of its body spin faster.

This creates a twist in its spine

allowing it to swing the back legs round...

..and prepare for landing.

NEIL ARMSTRONG: Houston, The Eagle has landed.

This cat not only defies gravity

but lands again safely,

and it all happens...

..in under a second,

something all cats can do.

Catching food is just one of the many reasons

why animals leap into the sky.

Gazelles leap to show predators that they are too difficult to catch.

Tree-living lemurs leap to move quickly

across dangerous open ground.

The perfect way to make a rapid escape.

But while all leaping animals must overcome gravity,

there's one that uses the power of gravity itself to take to the skies.

The Australian outback is one of the toughest places to live.

Temperatures can reach 50 degrees centigrade.

A kangaroo can only survive by wetting its body to stay cool.

An extravagant use of water in one of the driest continents on the planet.

They need a constant supply of water to replace what they lose.

In a desert over a million kilometres square...

..how does a kangaroo travel huge distances

without breaking a sweat?

They've developed the most efficient form of travel found on land.

And it all relies on the unique design of those enormous legs.

FAST-TEMPO MUSIC PLAYS

The secret lies in the tendons at the base of the ankle

which connect muscle to bone.

Normally tendons are tough and strong.

But a kangaroo's are curiously weak and stretchy.

So when gravity brings it back to earth

their special tendons act like huge elastic bands

absorbing the energy but then releasing it again.

Almost half the power for the next leap

comes not from the muscles...

..but from the energy recycled by these tendons.

By taking to the air,

kangaroos have evolved the most efficient way

of travelling on earth.

But it only works because they take to the air.

When we run, our legs have to move faster,

and we use more energy.

But hopping, like this, is unique.

When a kangaroo speeds up

its legs don't move faster.

Simply by altering the angle of takeoff,

it can increase the distance it flies with each hop.

It means no matter how fast

a cruising kangaroo decides to travel,

its muscles do almost exactly the same amount of work.

They can fly along at the speed of an Olympic sprinter,

ten metres every second,

over 4m with every stride

and never get tired.

For mile after mile,

after mile, after mile, after mile, after mile...

..to reach this.

A sheep station oasis.

Where there's always water.

SHEEP BAA

While the sheep could never leap their fence,

the kangaroo still has enough energy to tackle it with ease.

It's only because of their energy-recycling tendons

and their ability to take off at the perfect angle

that kangaroos can not only survive

one of the most hostile environments on the planet,

but make it look easy.

But if you thought kangaroos had the ultimate launch mechanism,

you'd be wrong.

Early spring in an English field.

It looks empty, but down in the grass,

something extraordinary is about to happen.

One of the greatest acrobatic acts in nature.

Meet the planthopper.

Barely 4mm long.

This one is not yet fully grown,

but even though it has no wings,

it has an incredible ability to get airborne.

And it's going to need it soon.

This field won't be empty for long.

COWS MOO

Cows have spent the winter sheltering in barns.

For months, they wait to be out in the fields again.

MUSIC: The Blue Danube by Johann Strauss II

But in early spring,

the day finally arrives

when they are let loose once again.

They're so excited, they gambol like lambs.

COWS MOO

Not so exciting for the hoppers.

Now they have potentially lethal neighbours.

But when in danger,

this incredible little insect does something which looks impossible.

They simply...disappear.

Rewinding then slowing the action 700 times reveals the truth.

Fleas may be known as the greatest leapers,

but plant hoppers rewrite the record books

when it comes to one of the fastest takeoffs in the natural world.

Having the ultimate ejector seat

means they need something found nowhere else in nature.

Cogs.

COGS CLANK Just before takeoff,

between their legs rows of tiny teeth intermesh,

locking them together.

It's quite literally a clutch in their crotch.

These cogs ensure that when one leg moves

the other has to

within 30 millionths of a second,

accelerating the hopper to 700g.

If you were in that rocket,

you'd be pushed into your seat with a force of 56 tonnes.

But this record-breaking leap has one major flaw.

If it fires those legs on unstable ground,

that much power can spin the hopper hopelessly out of control.

Each launch is a leap of faith into the unknown.

MUSIC: The Blue Danube by Johann Strauss II

Hoppers, kangaroos and caracals defy gravity

with an incredible launch,

and they're not alone.

The animal kingdom is full of fabulous leapers.

But even the greatest leap inevitably ends

with gravity bringing you crashing back to earth.

A moment's lapse in concentration...

..and it can catch you completely unawares.

You might be the world's greatest leaper,

but you can't let it go to your head.

If you want control in the air and to manage your fall,

you need another strategy.

And in the flooded forests of North Carolina, USA,

there's an animal that does just this.

This is a world unchanged for thousands of years.

But we're here to meet the swamp's newest arrivals

who are about to be born.

Their proud-looking father is considered by some

the most attractive bird in North America.

But it still took time to win his partner's affection.

And this is the most important day since they paired up six months ago.

When they decided to start a family,

they had no choice but to make their nest high in the trees...

..to protect their 12 eggs.

Not only from alligators...

..but from deadly snakes.

The height that kept eggs safe

now creates huge problems

on day one.

Jump day.

Until now, they've kept their nest a secret.

With all 12 noisy chicks hatching at once,

they will soon be discovered by predators.

Their mother has to get them down in minutes.

But they can't fly.

There's only one thing to do.

Jump for it.

On the day they hatch, these tiny ducklings must confront

the force that all flying animals must conquer.

Gravity.

Now the clock is ticking.

Every splash could attract a predator.

If the fall doesn't injure them first.

You might think the water saves them...

..but hit that too fast and it's like falling onto concrete.

The ducklings save themselves

by altering the invisible air that surrounds us all.

A falling duckling encounters air resistance

caused by having to push invisible air molecules aside.

Even at a day old,

it's using airflow in two important ways.

First, the duckling instinctively angles its webbed feet and tiny wings

to make sure it's the right way up.

Like a free-falling parachutist.

Secondly, its fluffy body makes it hard for that air to get past.

It's known as drag and slows its fall.

Without this air resistance, after little more than 30 seconds,

a falling duckling would break the sound barrier.

By using the air around it,

the duckling ensures it can control its fall...

..hit the water upright and at a survivable speed.

In under a minute, all 11 - make that 12 - ducklings are down,

allowing the mother to lead them to safety

before they attract the attention of lurking predators.

These ducklings show that you can start to beat gravity

by controlling your body in the air

and altering the way air flows around you.

Surviving a free fall is one thing,

but what if you need more control to get yourself out of danger?

It's winter in the far north of America.

Temperatures nose dive to minus 40 degrees centigrade.

Colder than the average at the North Pole.

It brings big problems for the animals that live here.

Squirrels.

In the day, there are too many predators.

Night is the only time they dare venture out.

But in the winter, food is scarce.

And deep snow makes it impossible to move on the ground.

They need to find a short cut between the trees.

Their only option is to jump for it.

DRAMATIC MUSIC PLAYS

This is the moment that most squirrels would start to worry.

But these ones have something special tucked up their sleeves.

And that's really big sleeves.

They are flying squirrels.

When climbing trees, muscles retract their flying gear,

but once airborne, a wriggle reveals a simple wing.

Two layers of fur-lined skin stretched between wrists and ankles.

Just imagine a normal squirrel inside a furry, elastic duvet cover.

Flying squirrels have long limbs to create big wings.

A flattened tail adds more surface area

and steers the squirrel in the air.

And each hand has a second thumb, giving the wing an upturned tip.

These winglets can reduce drag by up to 20%

and are now found on most aircraft...

..a few million years after they first appeared on squirrels.

But how does this furry wing help the squirrel glide?

The squirrel's body diverts oncoming air...

..forcing the air downwards.

This generates a force in the opposite direction

known as lift,

which pushes the squirrel up.

It sounds complicated,

but if you've ever stuck your hand out of a car window,

you know how this works.

Using this simple wing,

flying squirrels can glide the length of a football field,

but rarely do.

And the reason is a major predator.

The great horned owl.

For the owl, the ice is an asset.

It freezes its kills,

then thaws out its frozen ready-meals...

..as and when it's hungry.

In the air, owls are silent killers.

Their feathers evolved to absorb every sound.

A squirrel is unlikely to hear an oncoming owl,

so its safest strategy is to always imagine one might be closing in.

Compared to the owl,

the squirrel's simple wing makes it a sitting duck.

That's why, whether an owl is there or not,

these squirrels feel a need for speed.

Flying up to 30km/h.

But high-speed flying gives them a new problem.

Hurtling fast towards solid wooden objects.

Thankfully, emergency stops are second nature.

Just before landing, the squirrel tilts backwards.

Its wing becomes a parachute.

The elastic skin billows out...

..trapping air to reduce speed.

An arched back absorbs impact like a curved suspension spring.

And all four limbs contact at once for a textbook landing.

The simple wing has enabled the squirrel

to not only control the air around it,

but reduce the impact of landing at speed.

Allowing the flying squirrel to escape predators

and feed safely,

even in the depths of winter.

But what if you need to glide like a squirrel from tree to tree

but you don't have any wings?

Your body would need to be a very special shape.

One, we'll find here.

The tropical rainforests of Borneo.

Home to the paradise tree snake.

When it comes to flying,

you've got to feel sorry for snakes.

Not a leg to stand on, let alone a wing to flap.

But its body shape can teach us a lot about how to fly.

Living high in the trees presents a huge challenge.

If you want to travel across the jungle...

..you've a long journey ahead.

All the way down one tree

before you can climb the next.

And the forest floor is no place to linger.

ANIMAL GROWLS

It's full of predators just waiting for animals passing through.

Perhaps that's why, here in Borneo,

so many things take to the air.

Frogs...

..lizards...

..even flying plants.

Well, seeds.

But how does a snake get around with so many gaps to be crossed?

This snake has an ingenious solution.

The bendy snake becomes a rigid rod.

Its body, a bridge.

By holding on with their tail,

tree snakes can cross gaps with 90% of their body unsupported.

But not even this incredible core body strength

can prepare them for gaps like this.

Jungle trees in Asia can be unusually tall.

The distance between them bigger.

There's no way a snake can bridge gaps like these.

Instead, it does something different.

There are 3,500 species of snake in the world.

But only one like this.

This is a snake that flies.

What is the secret to this unique gliding ability?

Remarkably, just after launch,

the snake throws its ribs forward,

flattening its body into a very special shape.

It's called an aerofoil.

This shape changes the way air flows around the snake.

Oncoming streams of air passing over the top

are suddenly forced to change direction

and speed up.

This faster moving air is strung out,

so the air pressure above drops.

With low pressure air above and high pressure air below,

the snake is pushed up and is now gliding.

The snake's flight path reveals another important way

the aerofoil shape works.

On takeoff, the snake plummets,

gravity takes hold

and the snake picks up speed.

But as it falls faster, it begins to fly forward.

That's because the faster

that the air flows over the aerofoil's surface,

the more lift it generates.

And the snake starts to glide.

Inevitably, all gliders come to earth

because they're using gravity to pick up speed.

They have to drop in height to fly forward,

so if you want to stay airborne for longer...

..you need to power your flight.

To discover how animals do that,

we're heading to the middle of the Atlantic.

This ocean stretches over 12,000km from pole to pole.

And is almost as deep as Everest is high.

In this vast wilderness,

even a single palm frond floating miles from tropical shores

can suddenly find itself the centre of considerable attention.

In an empty ocean, it offers shelter.

And inevitably, life begins to gather.

It's a haven, not just for these fish

but soon for their eggs.

For a handful of days each year...

..thousands of fish meet to give life to their next generation.

Quite how they choose the perfect moment is still a mystery.

But once the first fish spawns, the rest soon follow.

Each female can lay 20,000 eggs.

And before long, the sea turns milky as males rush in to fertilise them.

In the haze, it's hard to see approaching predators.

TENSE MUSIC PLAYS

Rapid escape is critical.

And this is when these amazing fish reveal their true identity.

Flying fish.

Fins become wings.

Unlike the snake, they can't use gravity to pick up speed...

..which is why their tail is unique amongst all fish.

The lower half is longer than the top.

So even with its body in the air,

the tip of the tail remains submerged.

Thrashing it side to side provides forward momentum,

and as the fish speeds up,

the aerofoil-shaped pectoral fins generate lift.

Until, eventually, the force is enough to send them flying.

Once their special tail has got them started,

flying fish can glide over 100m

at speeds of 60km/h.

Their fins, shaped for high-speed flight,

are a match for the fastest falcon.

But that's not all.

Flying fish are held up by a cushion of air

compressed between their bodies and the water's surface.

And when they lose height,

their powerful tail can accelerate them skyward once again.

This is powered flight.

By pushing themselves forward, the fish create more lift

and can spend longer in the air.

Now we're really flying.

Powered flight opens up the skies to many animals.

Most do this by flapping their wings.

But it's hard work.

Flapping requires more power than any other form of movement...

..increasing an animal's energy costs by up to 20 times.

To stay active, a hovering hummingbird needs to drink

two-thirds of its body weight in nectar every day.

But what if an animal could stay airborne for hours...

..with no effort at all?

It sounds impossible.

But in Africa there are those that can.

There is one species which needs to travel hundreds of kilometres

to find and follow their migrating food.

In this case, the wildebeest herds

travelling across the African continent.

This animal's great skill is taking advantage of the fact

that air is constantly in motion.

Meet the vulture.

A vulture's huge wings generate so much lift

that in a glide they lose height at less than a metre per second.

So, in theory, if they can find air

that's rising faster than they are falling,

they could fly forever without flapping a wing.

In the early morning, impatient birds take test flights.

They wait for the air to start moving.

And as the land warms up, that's just what happens.

Although we can't see it,

moving air flows through a landscape like water.

As the sun heats the cliff face,

warming air rises

dragging cool air up from the valley floor.

When this air collides with the cliff,

just like the sea hitting a harbour wall...

..it's driven further upward.

Across the plains,

an area of land that absorbs more heat

creates columns of warm rising air above it,

thermals.

These are the skies' elevators,

and the vultures ride them in their hundreds.

It's the need to capture rising air

that explains the shape of a vulture's wing.

They need to be huge like a sail

to catch as much rising air as possible.

But big wings can create problems.

As an animal flies,

the higher pressure air below a wing is sucked over the tip to the top,

creating spirals of unstable air that slow the vulture

and would make it lose height faster.

Broad wings generate more of this drag

as there's a wider wing tip for the air to spill over,

and that's why vultures have those long single feathers

at the end of their wings.

They effectively turn one wide wing into several thin ones,

which helps stop those negative spirals of air from forming.

This unique design makes the vulture a true record-breaker...

and when conditions are right, hundreds gather...

..using a thermal to gain height...

..and those incredible wings to effortlessly glide onward

in search of the next thermal.

Hopping across the African plains between islands of rising air,

they can fly hundreds of kilometres a day in search of food,

and reach altitudes of over 11,000m,

making them the world's highest-flying bird.

The vulture is just one of the many extraordinary animals

we've seen that take to the air to survive.

These animals have some incredible adaptations

for launching into the skies.

Some have mastered control in the air.

Others generate forces like drag to protect them from impact,

and lift to allow them to glide.

Those that go further

take advantage of a special aerofoil shape,

and by increasing the airspeed over its surface

can stay in flight for longer.

But only the very best combine all of these skills...

..to effortlessly beat gravity...

..and truly master life in the air.

In this series, the team's mission

was to reveal the incredible abilities of airborne animals

in more detail than ever before.

Weeks of patient filming

allowed the team to capture real-life events,

like the leaping ducklings, which only occur once a year.

Revealing the science behind how these animals master the skies

required additional filming tricks and some incredible individuals

who would allow the team to capture their unique behaviour -

impossible to achieve in any other way.

Of all the animals in the programme

none presented more of a challenge than the flying snake.

They glide effortlessly,

but capturing their natural behaviour would have been impossible

without the world's leading expert

and some ingenious film-making techniques.

To film them, the crew heads to Tenom Agricultural Park in Borneo -

a known hotspot for flying snakes.

Director Simon Bell is excited by the prospect.

So, we've got this site that gives us a beautiful backdrop.

We've got some lovely jungle in the background,

some mountains in the distance.

It's going to look great.

Cameraman Pete McCowen prepares.

The success of the shoot relies on a high-speed digital camera

that slows the action 60 times.

Director Simon is aware of the challenges ahead.

It's really hard to see these snakes in pristine forest.

They're not uncommon,

but you're never going to see them in the jungle

unless you work with a guy who knows them like Jake knows them.

Professor Jake Socha - the world's expert on flying snakes.

He's studied them for over 15 years,

and for him, the chance to observe them

in their native habitat is an opportunity

to record new behaviour.

He's brought more cameras than the crew.

Before his studies, flying snakes had been the stuff of legend.

The literature goes back into the late 1800s.

What's in there is foreigners talking to locals

who describe a flying snake,

and the scientists think the locals are making things up.

Some people say they're straight in the air,

some people say they're wiggling around.

I found it compelling to solve this mystery.

What is the snake doing and then how does it do it?

With his years of experience,

Jake is realistic about how the crew can film the snake's behaviour.

To put a camera in the trees

and hope that you have an animal glide on by,

that's impossible to do.

If you really want to see what they do in the air,

you have to set up an experimental situation.

The crew's best hope for filming snake flight

is to use a technique Jake pioneered

with a few modifications for the jungle.

They need three things.

A tower for the snakes to fly from, a target for them to aim at,

and of course, the snakes themselves.

This clearing is the perfect spot,

and with some help from the crew,

rope access specialists begin construction on a 50-foot tower,

carrying everything into the jungle by hand.

There's a lot that could go wrong.

You know, we've got some really good guys,

but that tower's only halfway up right now.

It's going to be twice that height.

The steel cable at the top

will help to compress the tower, giving it rigidity.

The problem with that is you then have a potential

for sort of...snaking, we call it.

So, what we then do is we put in half-height cables

to try and prevent that sort of S-shape developing within the tower.

That'll hold it nice and straight

and once they're there, it's a bomber.

While the rope team worked on Jake's safety,

Simon ensured the ground was covered in dry grass

for the softest of snake landings.

For his research, Jake needs to control

the exact height of the snake's flight,

so a tower is the only option.

Without him, the crew have little hope

of bringing snake flight to the screen.

So, we're kind of in his hands in a way.

You know, this is all his design, this whole set-up.

When that snake's gliding from that scaffold tower,

it's going to look spectacular.

Although Simon now feels more confident,

there's still one vital thing missing.

There are tens of thousands of this particular snake on Borneo,

but to tell you the truth, they're not easy to find.

I've never been in the forest and spotted one

and been able to catch it.

As day one ends, success is far from certain.

Day two, and as the crew put the finishing touches to the tower,

they get some good news.

Snakes have been found closer to home than anyone had imagined.

What do you think? Ah, they're beautiful.

But seeing them up close gives cameraman Pete new concerns.

They're beautiful little snakes, but like the one Jake's got,

it's a very small little snake,

so trying to capture that is going to be interesting.

You're going to have a hard time keeping track,

or maybe not cos you're a pro, right?

Yeah. That's the impression I try to give.

Filming worries aside, it's time to get Jake's experiment underway.

Trees in Borneo can be well over 75m high.

For a flying snake, a 15-metre tower is child's play.

If only it were the same for the scientists.

I'm generally bad with heights.

I don't like 'em.

I think that's a good place to be, right?

It's keeps you away from tall things

that you might fall off.

I'm a bit concerned about Jake.

He has revealed that he is a little bit afraid of heights.

It should be perfectly safe, but there will be a bit of a sway

when you get to the top of that thing.

I'm not utterly frightened.

I'm just frightened.

Hey, I'm almost there, right? Thank God.

It's a nice view, though.

Well done!

With over 15 years of experience,

Jake knows that hoisting snakes slowly in a soft bag

they can comfortably curl up in

is the best way to ensure they arrive relaxed and raring to fly.

Snake arrival by pulley.

At least, that's the theory.

He is not having any of it,

so I'm not going to force him to do anything.

To film natural behaviour,

you can't rush one of the world's most impressive flying stars.

All right.

The crew are ready...

Come on, baby. Thank you.

..and they must stay alert,

because when a snake decides to fly, you don't get much warning.

Going right away. Now.

Oooh! Ooh!

Phenomenal. Just phenomenal.

Just as Jake predicted,

from this height the snakes are landing safely

and reaching the target tree.

They're flying. They're absolutely flying.

It's a great relief, and all eyes turn to cameraman Pete.

Ready? Now.

HE MUMBLES

Yeah, that was really great. I couldn't even see it.

The snakes are really taking to the experimental set-up.

Dropping now.

All the pressure is now on Pete.

Pete, there are some bits where it's going this way. Yeah.

Did you get any of that? No.

But with the snakes flying so well,

Pete is learning to keep up with them.

Woo!

Well done, Pete. Well held.

That's amazing.

Whoa!

I think that's the first time I've ever seen this,

where you see a phenomenal glide

and then she landed on the tree there.

This is brand-new data and it tells us that

when the snake lands on a natural substrate

that its body is flat.

This is beautiful. I'm really excited to get this.

With the shots captured, there's only one thing left to do -

release the stars of Jake's research back to where they came from.

This is my favourite snake.

It's ready, it's looping down.

OK.

After nearly 20 years of study,

Jake is still discovering new things about the animal that he loves.

What I got out of this trip is a new appreciation for this animal.

Some people look at me and think that I'm insane.

They say, "Why would you want to do that?"

Any time you can learn something that is new to science

and new to the world, you know, that's pretty exciting.

This is fantastic.

The team had revealed the remarkable flight

of flying snakes in more detail than ever before,

capturing the beauty of an animal once thought of as only a myth.

Next time, we discover how nature

has pushed the basic flying body plan to the limit.

How do the heaviest animals take off,

the fastest use speed as a weapon

and half a million avert air traffic disaster in total darkness?

The sky is one of the most challenging places to live.

But all across the world, extraordinary animals do

something we can only dream of...

..take to the air.

Some spend their whole lives up here.

Others only visit for a moment.

We'll discover how many incredible animals thrive in the sky...

..and what clever tricks they use to get airborne.

With the help of some specially trained animals,

the latest technology and special effects techniques,

we'll reveal brand-new discoveries

that explain how animals take to the skies.

This is Life In The Air.

It's one thing to take to the air

and let gravity do the rest...

..but to stay airborne,

to master true flight,

you need to push the laws of physics right to the very edge...

..using power, speed,

agility, endurance

and acceleration.

These are the masters of the sky.

Meet the whooper swan,

one of the largest and heaviest of all flying creatures.

Every year, families fly enormous distances,

migrating between vital feeding and breeding areas.

But weighing a whopping 14 kilos,

how are swans able to fly at all...

..let alone so far?

To push the limits of what's possible in the air

they need strength - and lots of it - every day.

To fuel their huge bodies, swans need to eat

over a kilogram of vegetation a day.

They're constantly in search of enough food to survive.

And that means flying.

But when you're this size, just taking off

is nearly impossible and requires some very clever techniques.

So, how does he do it?

To get airborne, he's going to need raw power...

..and apply it in a very precise way.

First, he must break free of the water,

but it clings to his body, holding him back.

His huge webbed feet need to drive him upwards and forwards.

Now his gigantic metre-long wings can move freely.

They push air down and back, delivering yet more power

to accelerate him further.

Wings and feet work together to give him the speed he needs to take off.

Once at this speed,

the air is moving fast enough over his wings to create a huge

upward force called lift.

This fights the downward pull of gravity.

So how is lift created?

The special shape of his wing, known as an aerofoil,

causes air to flow differently above and below his wing,

and this affects its pressure.

With low pressure above and high pressure below,

the wing is pushed upwards.

The faster the swan goes, the more air flows over the wing,

and that creates more lift.

He needs to reach 21 kilometres an hour,

the critical speed where lift cancels out gravity altogether.

Then it's undercarriage up, and we have takeoff.

For such a huge bird to take to the sky,

everything must come together in one explosive moment

that lasts just a few seconds.

Once he's really flying, the same air that helped him

get up here gives him a new challenge.

As he powers forwards, the air pushes him back,

a force known as drag,

slowing him down and reducing the lift in his wings.

By beating his wings, he creates a constant source of power

to maintain air speed.

Without this thrust, he would soon slow to a standstill...

..and literally drop out of the sky.

So swans must keep flapping,

all the way to their new feeding grounds.

All flying animals have to wrestle the powerful conflicting forces

of gravity, lift and drag,

but the faster they go, the thicker the oncoming air feels,

and drag becomes an ever bigger problem.

So what if you're one of the fastest animals on the planet,

and you're moving at more than 320 kilometres an hour?

The peregrine falcon.

Its breakneck speed gives it the edge to surprise

and strike its prey with devastating force.

It's spring here in California,

and a pair of peregrines has a new family,

and with it, a new problem.

At four weeks old, each ravenous chick eats more than an adult,

so both parents need to hunt successfully every day.

Feeding their growing youngsters is a full time job.

So what is it about peregrines that makes them

so much faster than almost any other animal on the planet?

They've got flying at speed perfected,

down to the tiniest detail.

See-through eyelids stop their eyes drying out...

..and specially shaped nostrils

slow down the air to make breathing possible at high speed.

When off on a hunt,

a peregrine uses updrafts from the cliff face to gain height.

Up here, it can spot potential prey.

And when it does, it starts a specialist dive,

known as a stoop.

A few deep wing strokes help it accelerate

to 190 kilometres an hour.

At this speed, oncoming air smashes into every part

of the peregrine's body, slowing it down.

By tucking in its wings, the falcon can slip through the air

that much easier

so now 240 kilometres an hour becomes possible.

But the faster you go, the more of a problem drag becomes.

At top speeds, every bump on a bird's body will disturb the air

flowing over it,

and this turbulence slows the peregrine down.

But that same turbulence makes special feathers pop up over

the peregrine's back,

and this pulls the air back into line

so it flows smoothly over its body again.

With drag minimised, peregrines can top 320 kilometres an hour.

At this speed, they can cover the length of a football pitch

in only a second.

This sheer, unadulterated speed makes them masters of aerial attack.

Top-gun skills allow these falcon parents to keep their chicks fed.

But these same skills also allow them

to protect the chicks from anything they think might attack the nest.

They really don't like intruders.

At the slightest hint of a threat,

the falcons will scramble and intercept in seconds.

The falcon may be smaller and less powerful than many of her targets,

but pure speed gives her the edge to harass

and then escape before they can react.

Pelicans are ten times her size,

and here's a whole squadron of them.

But size is no match for precision, high-speed flying.

Each attack aims to disrupt the pelican's own flight.

Just jerking their head to one side is all it takes to send

the pelican out of control.

Meanwhile, her own high-speed, top-gun skills

keep her out of harm's way.

Speed helps a peregrine mother own the skies around her nest.

But what if you're a high-speed hunter

and you don't have big, wide open airspaces to fly in?

What if you lived in an English country garden?

Flying fast, close to the ground,

and around a veritable assault course of obstacles...

..there's a skilful hunter that does just this.

Meet the master of high-speed aerial agility - the sparrow hawk.

As his name suggests,

this pocket-sized predator hunts small birds,

using surprise as his strategy.

And this is how it works.

The targets are right in the middle of a garden over 50 metres away,

with escape routes in all directions.

He'll need to use as much cover as possible to hide his approach.

And by knowing every tree and shrub in his territory,

he can pick the perfect route -

skimming hedges

and hurtling through the undergrowth to maximise the element of surprise.

But there could be 20 pairs of eyes on the lookout.

And if any of them spot him, they'll sound the alarm.

Nine out of ten sparrow hawk hunts fail because of this,

so he's got to be fast and agile,

and strike in just four seconds.

Few flying creatures can do this.

But then few have the sparrow hawk's supreme flying abilities.

He has explosive acceleration.

Long legs fire him out of the blocks.

Short, rounded wings powerfully scoop up the air, driving

his lightweight body forwards

to hit attack speed in under two seconds.

Now at speed, he keeps a low profile, hugging the ground.

This low position gives him an extra advantage.

The air is squeezed between his wings and the ground,

giving him a high pressure air cushion to ride on.

This keeps him airborne and saves valuable energy.

But hurtling along at 50 kilometres an hour gives him

just hundredths of a second to avoid a collision.

Short wings are pulled in to pass through the tiniest gaps.

A long tail does the steering, constantly making fine adjustments.

And when he needs to turn sharply,

he slams on the brakes by fanning it out.

As he gets closer, precision flying becomes critical.

He needs to stay hidden until the very last moment.

The last thing a garden bird might see...is this.

It's all over in seconds.

The sparrow hawk masters the skies with speed and agility,

but what if you have neither speed nor agility?

There's a creature that's so slow and clumsy

many would doubt it could fly at all.

And yet, it performs the seemingly impossible.

The Japanese rhinoceros beetle is covered in protective armour.

In the world of beetles, he's a colossus,

weighing a hefty 10g.

He's on a mission to find a mate, and she could be miles away.

He doesn't have long, and it's too far to walk.

So he has to fly.

But attempting to fly whilst carrying all that heavy body armour,

he's going to need a combination of power and some extreme moves.

So how does such a huge beetle stay airborne?

He has a special flight technique,

very different to that of most birds.

Slowed down, you can see that he twists his wing at the base.

We need a special flight laboratory to see how this helps.

Now we can see just how the air moves around the beetle's wing.

Those mini tornadoes spinning off the wing show where

the beetle is pushing the air back, thrusting him forwards.

And because it's being pushed down, we know he's also producing lift.

So far, that's much like a bird.

But critically, by twisting his wings at the base,

he can also push air backwards as they move back up.

And there's the proof.

This gives him thrust on both the down stroke and the upstroke,

and that's something that most birds can't do.

But he doesn't leave it there.

Even his armoured wing cases are working in his favour,

forcing air down to create even more lift.

So he effectively has an extra pair of wings.

This magnificent beetle is a flying marvel.

His clever wings give him the extra lift

and thrust that he needs to cruise at nearly 15 kilometres an hour.

He's hardly a boy racer,

nor is a he a long-distance flyer,

but he can cover half a kilometre in a night.

And in a jungle, that's enough to find a female.

This huge beetle's flying mission may have seemed impossible,

but it's worth the effort.

Special wings that rotate at the base

allow the beetle to get more from the air around him,

keeping him airborne, albeit, rather clumsily.

But in Central America, there are other creatures who have

taken this to the next level

using this technique to fly in almost any direction

with ultimate precision.

They're not insects but tiny birds.

Hummingbirds, each the size of your little finger.

To the human eye, their flight is no more than a blur.

It's only when slowed down 50 times you can appreciate

their incredible control.

So, why are hummingbirds so special?

This is one of the world's most spectacular flyers,

a booted racket-tail hummingbird.

On the face of it, he's got it made.

Here in Ecuador, his forest home is full of flowers,

each with sugar-rich nectar hidden inside.

But he has a problem.

These flowers don't provide perches,

neither do they make nectar easy to get at.

Now the hummingbird's extraordinary flight technique starts to

makes sense.

It hovers so it can move its needle-like beak into position

with surgical precision.

Running down the inside of the beak,

a forked tongue laps up the nectar at up to 13 times a second.

But just performing a simple hover breaks all the rules

of traditional flight, so how does he do it?

It's a technique similar to the beetle's,

but impossible for other birds,

and requires a very special pair of wings.

They're short and stiff to cope with the stress of beating

at up to 80 times a second.

But it's how a hummingbird beats its wings that allows it to hover.

On close inspection, the wing tips move in a figure of eight.

A unique wrist joint means the wing can rotate through up

to 140 degrees...

..so he can thrust air down and back

not only on the down stroke but also on the upstroke.

That gets him hovering.

By having constant power, he can also make tiny adjustments

throughout the wing beat, and this gives him more control.

Added precision comes from the way he rolls his body,

instantly changing the angle he's pushing at.

With incredible wings like these, he can fly forwards, left,

right, even backwards.

This gives him the power and control he needs to get at the nectar

and move between the flowers.

But this super powered flying ability comes at a huge cost.

A thermal camera shows just how much heat is given off when hovering.

This heat is just a fraction of the energy that a hummingbird

needs to stay airborne.

Hovering burns far more calories than any other form of flight.

To provide his muscles with enough oxygen,

his heart has to beat at 20 times a second,

and he needs to drink his body weight in sugary nectar every day.

In fact, this tiny little bird has the highest metabolism

of any warm-blooded animal.

So our hummingbird might have the ultimate control in the air,

but he'll always be a slave to his uniquely manic lifestyle.

Trapped in a world where he needs to hover to feed

and needs to feed to hover.

Hummingbirds can afford a high-energy lifestyle

because food is always close by.

But what if your next meal is hundreds of kilometres away

and you have to go searching for it?

You're going to need a completely different flight technique.

Patrolling the ocean around South Island, New Zealand,

this is a royal albatross.

Albatrosses spend the vast majority of their lives out at sea.

The one time they need land is to nest.

This albatross is providing for one of the world's biggest chicks.

At two months old, her chick will eat half a kilo of fish

and squid in a single sitting,

so she'll have to travel far and push the limits of flying.

She's chosen to nest on this wind-blasted cliff

for a very good reason.

To take off, she spreads her three-metre wings,

and the cliff top wind provides the lift.

Ungainly on land, she is now in her element.

Out here, fish and squid can be extremely difficult to come by.

So a mother albatross will scour the ocean

for up to 1,000 kilometres a day.

During her lifetime,

she'll travel nearly two and a half million kilometres.

That's to the moon and back three times.

And remarkably, she can do this with barely a wing beat.

She's one of the world's most efficient fliers,

using the energy of the air just above the ocean

to save her own energy.

She's riding the air like a rollercoaster,

in a super efficient way.

But snaking from side to side like this

seems to make no sense at all

until you understand how air behaves above water.

At the water surface, the air collides with the rough waves,

slowing it down to a virtual standstill.

But ten metres above the waves, the air flows that much faster.

It's this difference in air speed that allows the clever albatross

to fly for free.

By sweeping up and down, she can use both the fast air

ten metres above the waves

and the still air at the water's surface.

And here's where the sheer efficiency of those long,

narrow wings is so important.

As she climbs into the faster wind,

she can create more and more free lift.

Then with height on her side, she turns sharply,

and a combination of gravity and wind now slingshots her downwards

up to 120 kilometres an hour.

Known as dynamic soaring,

the ability to use changes in air speed like this

means that albatrosses rarely need to flap their wings.

This energy-saving technique allows them to travel

huge distances to find food in the open ocean.

And when you're a mother,

scraps from a fishing boat are too good an opportunity to miss.

Now full of food, an albatross's next challenge is to get home again.

But unlike before, when she could wander in any direction,

she must now fly directly back to her chick,

even if that means heading straight into the wind.

Once again, she reads the air in front of her

and uses its movement to her advantage.

Albatrosses use a special organ hidden inside their nostrils

to constantly measure tiny changes in air speed.

This guides her to pockets of still air behind each wave.

Flying is much easier here.

And when she needs extra lift,

she can even seek out upwards moving air that flows over each wave crest.

This way, she can fly all the way home really efficiently,

even against the wind.

The chick gets fed because its mother can read the air

and ride it effortlessly.

In six months, it will be doing the same.

The albatross's ability to fly far in search of food allows it

to exploit the patchy resources of the Southern Ocean.

But they aren't the only creatures

that survive by travelling huge distances.

Others move with the seasons,

flying between winter and summer homes,

in the biggest journey of their lives.

Migration.

Over thousands of kilometres,

across countries, sometimes even entire continents.

Insects, bats and birds all make these journeys to find food,

and breed as the seasons change.

These are some of the toughest physical challenges

any animal undertakes.

Many die en route, and exhaustion is the biggest killer.

So any way that you can save energy might save your life.

There's one animal that that flies with incredible efficiency,

not on its own but as a team.

European cranes migrate nearly 3,000 kilometres every year

between their wintering grounds in Spain

and their summer home in Scandinavia.

These cranes travel together as a family,

with the chicks learning from their parents.

It's how they fly as a group that's going to give them

all a crucial advantage on their long and arduous journey.

Adult pairs mate for life,

and they dance together every year to strengthen family bonds.

THEY WARBLE

This is no frivolity.

How they bond and work together might make the difference

between life and death, particularly for the youngsters.

To understand how teamwork helps them,

we need to see the world from a crane's perspective.

Cranes are relatively large and heavy birds,

yet they'll fly multiple marathons in just one day.

This burns a lot of energy.

Like albatrosses, they're going to have to fly efficiently

if they're going to make the distance.

But unlike albatrosses,

cranes can't rely on saving energy by soaring all the time.

To make this journey,

they will need to flap their wings hard...

..so they make every flap count by working together,

and that means formation flying.

All crane species will fly in the same ingenious way.

Each flock member flies

slightly behind and slightly to the side of the bird in front,

creating a characteristic V shape.

But each bird must be positioned exactly

if the teamwork is going to pay off.

To understand why, we need to see how the air moves

around a crane wing in flight.

Each bird leaves a wake in the air behind it.

A tube of spiralling air trailing behind the wing tip

still contains energy from the bird's last flap.

If the bird behind gets in the right position,

it can use the upward motion of the spiral to keep itself up,

and therefore save its own energy.

So one flap can be used by more than one bird,

they're literally sharing the load.

Formation flying could save each bird in the team

over 10% of its energy.

On a long migration, this could make the difference

between success and failure.

The leader of the V formation has to work the hardest,

with no energy to inherit from the birds in front of it,

so the cranes take it in turn to lead

and share the work around the team.

They also share their knowledge.

Youngsters learn the migration route from their parents,

so eventually they'll be able to lead a family of their own.

Cranes may not be the strongest or the fastest flyers,

but their technique as a team

gets them to their breeding grounds each year.

Formation flying is used by many birds,

it's an energy-saving trick that makes long distances

that little bit easier.

Many flying creatures have one particular flying skill that

gives them an edge.

But perfecting one skill means you might not be so good at others.

When you're built for speed, it's difficult to be an acrobat.

Amazing acceleration burns energy,

but that's no good if you're a long distance flyer.

And if you need to power a large body into the air,

being manoeuvrable becomes more of a challenge.

It can work to be a specialist,

but what if you need to be good at everything?

What if you need to combine many different flying skills

into the ultimate flying machine?

There are some creatures who've done just that.

They aren't birds, they aren't bugs - they're mammals.

Dawn in Texas,

and half a million Brazilian free-tailed bats

are returning home after a night out feeding.

During the next few seconds,

their flight skills will be pushed to the limits.

For these aerial masters, the last part of their journey is

the most dangerous.

Predatory hawks are waiting.

The bats are heading to the safety of a cave.

Their challenge is to completely change the way they fly

more than once.

First fly fast,

topping a 100 kilometres an hour.

Next, hit the brakes as they fly into the pitch dark.

Finally, fly alongside the half a million other bats in the dark cave.

Now it's about being manoeuvrable and trying to avoid collision.

Within a few seconds, the bats have to perform a range of completely

different flight techniques, each of them highly specialised.

This requires incredibly versatile responsive wings.

Bats do something unique in the natural world.

They fly not with their arms but with their hands.

A bat's wing is a miracle of flight engineering,

complete with thumb and four fingers and self tensioning skin in-between.

Its shape can shift in all three dimensions

and far more than any bird or insect.

No other wing gives this level of control.

Innovative wing design allows the bats to cover huge distances

to feed,

fly fast to evade predators

and manoeuvre tightly in their crowded cave.

This expert flying ability allows the bats to use the caves

as giant underground nurseries.

Hundreds of thousands of baby bats huddle together for warmth.

In here, all bats are as safe as they're ever going to be.

But for the adults, that's about to change.

Outside, dusk is fast approaching, so soon the adult bats

must leave the cave again to feed for the night.

But the hawks are waiting.

The hawks can't see in the dark,

so every second the bats stay underground gives them an advantage.

But sooner or later, each bat is going to have to

push its flying skills to the limit once more.

Their strategy is to emerge together giving safety in numbers -

an incredible feat of synchronised flying.

More bats swirl up from deep underground

until the cave entrance is full to bursting point.

With their wings now outstretched, they can build up speed.

Tens of thousands of bats,

all waiting until the last possible moment.

With deep powerful wing beats,

the bats can accelerate through the danger zone.

The hawks are overwhelmed by their sheer numbers,

their manoeuvrability and their speed.

Now safely away from the cave,

they're free to fly as far as they need

to their night-time feeding grounds.

A radical innovation in wing design,

flying with their hands

has made bats perhaps the most versatile of all flying animals.

They're the only mammal to have truly mastered life in the air.

For all flying creatures, staying airborne is a constant challenge.

A life in the air requires special skills and remarkable techniques.

But if you can survive up here,

there are huge opportunities to be had,

so every animal has its own strategy to give it an edge...

..as it masters the sky.

In Life In The Air, the team's mission was to reveal the incredible

abilities of airborne animals in more detail than ever before.

Weeks of patient filming allowed the team to capture real-life events,

like peregrine falcons attacking their animal neighbours.

But to reveal the science behind how these animals master the skies

required additional filming tricks

and some incredible individuals who would allow the team to capture

their unique behaviour...

..impossible to achieve in any other way.

To film the planet's most accomplished flyers,

the team needed to become part of their flock.

Key to their success was a unique relationship between the animals

and the people that work with them.

The more ambitious the shoot,

the more important this relationship becomes,

and none presented a bigger filming challenge

than keeping up with four tame whooper swans in Scotland

and flying alongside a family of European cranes

high above the French countryside.

First meet Olive, Earther, Yellow and White,

and their human mum, Rose Buck.

If their mum's here...

When the swans first hatched nine years ago, the first thing

they saw was Rose, so to them, she's the leader of the flock.

Rose and her husband, Lloyd, have a close bond

with over 20 different bird species...

Oh, yes.

..all film stars in their own right.

And whilst the swans are on centre stage this time,

the whole family comes along for the ride,

including a golden eagle called Tilly.

Basically, when we go away, they all have to go with us

because they're like our extended family,

and that's when they're at their happiest.

You wouldn't leave your children behind if you went away,

so they expect to come with us.

The Buck family are heading to Loch Lomond in Scotland,

where the plan is to film alongside the swans in their natural habitat,

capturing their flight in minute detail.

At the heart of this immense technical challenge is

a state-of-the-art stabilising system,

to smooth out any bumps in the water...

..and a high-speed powerboat that can top 65 kilometres an hour.

After some final words of encouragement from Rose,

it's time to put the plan into action.

Let's go, go, go!

With Rose at the bow,

the swans are totally unfazed by the speeding boat,

which is more than can be said for the director.

It's a really difficult thing to do when

something as amazing as this

to be thinking about your job and the shots,

cos it's utterly awe-inspiring.

Without an image stabiliser, it's virtually impossible to get

a steady shot at speed.

Cameraman Rob Drewett has the advantage of the stabiliser,

but wind gusts are causing him unexpected problems.

Uh... It's gone. What's happened?

As the boat hits 65 kilometres an hour,

the stabiliser really starts to struggle.

As soon as I took it away from my body,

you...you felt the wind take it.

The elements aren't beating the stars,

but they're causing big problems for the technology.

Ah, it just died.

We've got a bit of a problem. Yeah.

When you're pushing the limits of filming technology,

sometimes you really need to think on your feet.

We're now having to go to new extremes to try and get

our equipment working well,

and we...we're going to use a dustbin!

With a rather unorthodox wind guard taking shape,

there's nothing the Buck family can do,

except indulge in some family time.

You wouldn't want to be skinny dipping!

Gor, struth, you wouldn't.

Meanwhile, the camera crew work on into the night.

It's the last day in Scotland, and the crew have their hopes

pinned on a £15 bin shielding a £50,000 camera system.

This is the 11th hour,

it always seems to boil down to the last day, but that's all we've got.

Now everything needs to come together in one perfect run.

Lovely.

So it looks like the shroud is doing the job, which is

brilliant cos it took us two hours last night to turn

a dustbin into something that can make us film swans.

Look at this! Oh, wow!

Filming flying animals at speed has proved difficult enough on water...

..but it's that much harder when you take to the air

with a flock of European cranes half a mile above the Earth.

To get a true bird's-eye view, you need a microlight,

a pilot with a family of friendly cranes

and a cameraman with a head for heights.

Like Rose is mother to her swans,

Frenchman Christian Moullec knows each of his family by name.

Is this Dennis? No, no, no. Dennis, no.

THEY LAUGH

Christian has been working with these particular birds

for two years, so when the microlight engine roars...

..they know it's time to fly.

The cranes follow the microlight in formation,

using the updraft from its wing to save energy.

They're performing perfectly,

just in completely the wrong place for cameraman Richard Cook.

Getting them away from the wing and into the right spot requires

precision teamwork, and this is extremely difficult.

The birds move around so much, so quickly,

and then just trying to guess where they're going to be.

So they drop off the wing here and they come down

and then underneath the aircraft, up the other side.

It's very frustrating, but we will get there.

Christian. Yes? Your birds are terrible!

No, you are a terrible cameraman.

RICHARD LAUGHS

With something this complicated, there's no substitute for practise.

But the longer you're in the air,

the more chance something very serious will go wrong.

The engine has cut out, and with no power,

Christian and Richard have to make an emergency landing.

It's at times like this that 25 years of experience comes

sharply into play.

On the final approach, they are fully committed.

Thankfully, it's a perfect touchdown.

And the cranes don't seem to know what all the fuss is about.

We landed safely, just glided in, but there's not a lot we can do.

As you can see, this is absolutely jammed solid.

So we're going to take the engine apart this afternoon

and see what's broken.

In the middle of the French countryside, any rescue,

however unusual, is extremely welcome.

Just looking at the top, the piston crown,

the bit at the top, is all hammered and dented.

Anyway, it's given up.

The engine isn't repairable,

so the team resort to the backup microlight.

And with it comes a new dose of luck.

With some perfect turns from Christian,

Richard finally gets eye-to-eye with a flying flock of cranes.

And after all they've been through, the team are truly delighted.

But even with the latest technology

and some resourceful individuals, we only get the briefest window

into the world of these amazing creatures.

And this only highlights just what an achievement it is

to spend your life in the skies.

Next time, we'll discover that the skies are crowded

full of creatures in a battle for survival.

There's competition for mates,

for food...

..and even for life itself.

Only the best flyers need apply.

The sky is one of the most challenging places to live.

But all across the world, extraordinary animals do

something we can only dream of...

..take to the air.

Some spend their whole lives up here.

Others only visit for a moment.

We'll discover how many incredible animals thrive in the sky...

..and what clever tricks they use to get airborne.

With the help of some specially trained animals,

the latest technology and special effects techniques,

we'll reveal brand-new discoveries

that explain how animals take to the skies.

This is Life In The Air.

Right now, there are billions of creatures

living in the three miles of air above our heads...

without us evening knowing they're up here.

They've overcome gravity,

they've mastered flight and now they live their lives up here,

making the most of the opportunities the skies have to offer.

There are over a thousand species of mammal

and over tens of thousands of species of birds up here.

The biggest numbers are the smallest players.

And the closer you look, the more of them you see.

Insects, trillions of them,

so many that 98% of everything that flies is an insect,

and most of them don't even have names.

The air above us is more crowded and more dangerous than you might think.

Predators are everywhere.

At every level, the skies are teeming with life.

There are thousands of creatures using

the skies as super-highways,

travelling huge distances

to find food or to migrate.

Butterflies.

Even ladybirds.

Over a kilometre above our heads there are moths

speeding by at 80 kilometres an hour.

But what happens when so many lives collide?

How do animals compete with each other up here?

How do they win a mate?

How do they find food?

How do they hunt, and avoid being hunted?

Up here, animals are pushed to the limits of what's possible.

Welcome to another world,

a world of intense competition,

of extreme lives in crowded skies.

The coast of South Africa is home to one of the most extreme

fliers in the natural world.

The Cape gannet has a unique way of beating the competition

when it comes to finding food.

The size of this island breeding colony

shows the richness of the seas around them,

enough to supply the tonnes of fish caught by these birds every day.

But it's how they catch fish that's so remarkable.

Here, the competition from other sea birds is intense.

Most can only catch fish when they swim close to the surface.

But there are richer pickings deeper down.

And that's what the gannets are after.

It requires an extreme form of flying that would kill most

other creatures.

Several kilometres from the gannets' colony,

a vast shoal of sardines is massing.

And 20,000 gannets are heading out after them.

But most of the sardines are several metres below the surface,

completely out of reach for the other sea birds.

So the gannets prepare to perform

one of the most dangerous flying stunts in the animal kingdom.

Climbing 30 metres above the surface,

they drop from the sky using gravity to accelerate...

Hitting the water at 100 kilometres an hour.

with the same force as a bullet fired from a handgun.

The impact should kill them.

At that speed, it's like hitting concrete.

So how can they possibly survive?

Less than a second before contact, they tuck in their wings and change

their shape, streamlining their body to slice through the water.

The gannets have air-filled pockets under the skin in their necks

and chests, thought to act like airbags to help

cushion their bodies from the impact of the water's surface.

But their technique must be precise.

If their shape isn't perfectly streamlined,

the impact of hitting the water would crush them.

The dive propels them down to where the fish are schooling

but they still have to catch them.

Exactly how they do that depends on a critical decision each bird

made the second before it dived.

In mid-air, the gannet has two choices -

to dive shallow or to dive deep.

A quick, shallow dive allows it to hit the water fast

and instantly snatch any fish near the surface.

But once under attack,

the sardines escape downwards, and the gannets must up their game.

..diving almost vertically to give them

the speed to reach 10m underwater in a few seconds.

Their extreme dive has taken them to an alien world,

far away from the competition from the other sea birds.

A world where wings become fins, feet become paddles...

Even their eyes change shape so that they can see underwater,

and special eyelids act like goggles.

They are the only birds down here, and they reap the reward.

Running out of breath, they return to their sky world

using the air trapped in their feathers

to carry them back to the surface.

Risking death to dive deep allows gannets to escape the competition

and find food for their families.

But using extreme flying to catch

food is not just a survival trick for gannets.

There's plenty of food out there

for the animals who can fly well enough to catch it.

An African skimmer goes fishing too, flying with such precision that the

lower part of its beak can feel for fish just below the surface.

If it snaps shut, it's caught a fish.

There's a fishing bat that expertly deploys its enormous clawed

talons as trawling fish hooks.

But bats had better watch out or they might become food themselves.

Falcons use quick reactions

and extreme control to catch fast flying bats in mid-air.

Food is not the only thing animals in the skies compete for.

When it comes to finding a mate, there are some creatures

who've taken this to a record-breaking extreme.

Meet the Anna's hummingbird.

One of California's finest.

He's no bigger than a ping-pong ball,

no heavier than a 20-pence coin,

but he's a record-breaking flying machine.

His wings pump at 2,500 times a minute.

His heart beats at 1,200 times a minute

and he can hover for well over an hour.

He needs to mate,

but he has to prove that he's fitter than the rest.

He has a problem.

There's another male vying for the female's attention,

and he's a record-breaking flying machine too.

Let the competition commence.

Aggression drives the intruder away.

But that in itself doesn't impress her enough.

Now he's going to have to pull off the flying stunt of his life.

First, he woos her to his performance arena with a song.

IT CHIRPS

Now he's got her attention,

the stage is set for this tiny bird to perform

the fastest courtship display ever seen in the animal world.

He climbs 30m above her...

Then for the grand finale, he dives straight at the ground.

That was it, over in a few hundredths of a second.

And again.

To see what he's doing, we need to slow things down.

This is much more than just high-speed flying.

By folding his wings in tightly, he mimics a missile,

travelling 20m and 400 times his body length every second.

At the last moment, he pulls up sharply,

pulling more Gs than a jet fighter pilot.

But it's not just the speed, the height or

the angle of his flight, it's all about serenading on the wing.

His tail is singing a sweet song with jet-fighter force.

The air screaming through his spread-out tail feathers makes them

vibrate in a very special way.

BUZZING

Slowed down, this is the sound they make.

BUZZING

BUZZING

It's far louder than any of his singing.

And the faster he dives, the better it sounds.

BUZZING

Who'd have thought that a sound like this...

BRIEF CHIRP

..or this... BRIEF CHIRP

..would make all the difference and see off the competition?

To her, it proves he's fit.

This bird boy-racer has won himself a mate by pushing

himself to the limit and proving he's got what it takes.

But he's not the only one who knows that a little showing off

can go a long way.

Aerial displays are a serious business.

The greater the effort, the more lasting the impression.

Meet the male spatuletail hummingbird.

It has to be said, with a tail like that,

he's already making quite an impression.

But to win over his female,

he'll need to hover and wave his enormous tail flags

at the same time.

It's such an endurance test,

every now and then, he needs to take a little rest.

With every leap,

this lesser florican is trying to prove he's fitter

than all the other males.

And today, just to make sure, he's going to do 500 of them.

In the dense jungles of Costa Rica,

there's little room for showing off.

So one amorous male woos a female

with an altogether more cunning tactic.

Meet the male glasswing butterfly.

He's got see-through wings precisely

because he doesn't want to stand out from the crowd.

There are just too many jungle predators around for that.

He too uses the air to show off,

but it's an aerial display like no other.

He's going to use the air to carry an irresistible message

to a female and to get her to come to him.

On his wings, he has little bunches of hair

loaded with his own distinctive pheromone perfume.

The perfume wafts through the trees carrying a specially coded message

invisible to others.

It tells the female who he is and how many poisonous plants

he's managed to eat.

Because he stores the poisons in his body

and uses them to show how distasteful he is to predators.

So, to a female checking out the males in the jungle,

it's good to have bad taste.

The secret message wafting invisibly through the jungle says,

"I'm here, I'm male and I taste worse than all the others."

She's hooked and follows the trail of his irresistible odour.

It's a clever trick,

the male attracts a female without attracting predators.

When it comes to finding a mate,

males will try anything that works to give them an edge.

And with the skies so full of competition,

it pays to be cunning like the glasswing.

But once animals have paired up,

it's not long before offspring arrive,

and they need looking after.

This is Oregon, USA.

Home to the kingbirds.

They're an ordinary looking couple working hard to raise a family.

But don't be deceived,

these birds are remarkable.

The male has picked the perfect home,

the air is thick with insects to eat,

but he'll have to work hard to catch them for his family.

He's agile enough to take insects on the wing, and that's no mean feat.

The top prize for a kingbird is this.

A big, juicy dragonfly.

They're more manoeuvrable than him,

and they're one of the fastest insects in the world,

topping 50 kilometres an hour.

But the kingbird is faster.

This is speed versus agility.

He'll work hard like this to feed his chicks

for nearly for nearly two months.

His commitment is total.

But his true colours are about to be revealed.

He's spotted danger in his neighbourhood.

CROWING

Ravens.

They'd kill his whole family in minutes given the chance.

He's going to have to defend his offspring.

Ravens are clever, and they're four times bigger than him.

But no-one is going to hurt his family.

As formidable as the ravens are,

the kingbird has an unexpected side to his character.

Sheer. Obsessive. Belligerence.

What he's about to do seems almost suicidal.

He manoeuvres into the raven's blind spot.

He hassles it, landing on its back, even stabs at its neck.

The raven could kill him.

But as long as he holds this position, he's in control.

Those superb acrobatic skills that helped him

chase down dragonflies are now being used to help keep his family safe.

Kingbirds will take on anything,

including large birds of prey.

They've even been seen having a go at low-flying aircraft.

A combination of spectacular flying agility and an almost

psychopathic attitude makes the skies above a kingbird nest

a little less crowded than they might be,

and the chicks, a little safer.

That's dedication.

The kingbird takes huge risks to give his young a flying start

in this competitive world.

But there's a tiny animal from Texas that takes parenthood

to an even greater extreme.

The phorid fly.

Smaller than a pin's head, she's a mother.

And right now, she needs to lay her eggs and secure a safe future

for her offspring.

But to do this,

she must face one of the most feared animals in Texas.

Fire ants.

In their thousands.

They have a vicious bite and a venomous sting.

They'll kill any insect that crosses their path.

But incredibly, these vicious predators aren't going to eat

the phorid fly's young,

the young phorid flies are going to eat them.

First, the mother must pull off one of the greatest daredevil

flying missions in the natural world -

she's going to lay her eggs on living fire ants.

She's going to have to do some serious precision flying,

or she'll be killed herself.

How she does it can only be fully understood

by watching in slow motion.

First, she hovers as close as possible to her victim

but just out of reach of the ants' jaws.

The risk is finely balanced, just a breath of wind and she's dinner.

Now she's ready to quickly deposit an egg in a chink

in the ant's armour, at a leg joint.

From start to finish, it takes just one sixtieth of a second.

Once attacked, the ants send out a chemical alarm to warn the others.

They hide, crowding under any available cover,

making it much harder for the phorid fly to get at them.

But she has over 100 eggs still to lay.

She's going to have to up her game and test her hovering skills

to the max if she's going to deliver her cargo successfully.

Her daredevil mission is accomplished.

But the story isn't over for the ants.

Inside each ant,

the fly larva has taken over the ant's mind,

reprogramming it to walk off like a zombie.

The ant finally dies safely away from its colony

where the fly larva can grow up in peace.

The ant's zombie body now becomes perfect phorid fly baby food.

For two weeks, the fly larva eats the ant from the inside.

A tiny new phorid fly stretches her wings for the first time.

Soon, like her mother, she'll fly her own mission impossible,

a hair's breadth from a fire ant's jaws.

At every stage of their lives, animals are doing what it

takes to stay ahead of the rest

to survive and raise a family.

But in our crowded skies,

they face competition from others at every turn.

With so many lives interacting, colliding and competing

and so much pressure to succeed,

animals have had to push their flying abilities to the extreme,

taking huge risks with their own lives.

Up here, it can be tough to find food...

..win a mate...

or secure a future for your offspring.

Life in the air is a life of intense competition.

And where there's competition,

there are animals who choose not to play by the rules.

Few are sneakier than an inhabitant of tropical seas

and islands around the world -

the frigate bird.

This pterodactyl-shaped bird has a curious problem.

Remarkably for a sea bird, its feathers aren't waterproof.

If it gets too wet, it'll sink and drown.

That's obviously not good for a bird that needs to catch fish.

So the frigate bird uses its unique flying speed

and agility to catch fish another, less honest, way.

It steals fish from others.

It's a flying pirate.

This time, its victim is a red-billed tropic bird.

The frigate bird is going to force it to give up its last meal,

and that means putting it under serious pressure.

The tropic bird is a superb flier,

but the frigate bird pirate is better.

His wings are unusually large, but his body remains light.

These two things combined deliver the most extraordinary

agility in the air.

The frigate bird can, in theory,

out manoeuvre any other sea bird in the world.

Perfect skills for a pirate of the skies.

But the tropic bird isn't going to give up its hard-earned meal easily.

When the tropic bird finally gives up its dinner,

the frigate bird is in precisely the right spot for the catch.

When it comes to aerial combat,

it takes a lot to beat this thieving pirate.

Our crowded skies are a competitive battle zone,

with tussles between species going on all the time,

as they've done for millions of years.

But just occasionally, the underdog fights back

and outsmarts its attacker.

Take this moth.

It can seem pretty incompetent in the air,

with weak and fluttery flight and a bad sense of direction.

It can blame that on its ancestors.

100 million years ago, insects had the night sky to themselves.

They didn't need to be strong fliers

because there wasn't much out there to get them.

But then along came new, intelligent,

highly-equipped creatures that could hunt them down easily.

They are the only mammals that have ever learnt to fly,

and many could see in the dark.

Bats were onto something.

There was a great feast to be had in the night.

To a moth, this is a sophisticated, highly dangerous enemy.

A bat finds its prey using echolocation.

Literally, it locates using echoes.

You could say it sees using sound.

It sends out clicks into the air, as many as 200 a second.

If the clicks hit anything, they bounce back as echoes.

It's by listening to those echoes in the darkness a bat can pick

out its surroundings, even a moth.

As the bat approaches its victim, the clicks get faster,

creating a buzz of sound that helps it home in on its target.

These sounds all happen beyond our human hearing.

But we can see them as sound waves.

First searching.

Then approaching.

And then finally, the attack.

So a bat is a super flyer with added superpowers,

and that's hard to beat.

If they were going to survive, moths had to raise their own game.

Some of them began to hear the bats coming.

When they hear the buzz of an attacking bat,

these moths take evasive action.

They drop out of the sky.

Simple, but effective.

An arms race had begun between bats and moths,

each trying to out compete each other in the night sky.

Eventually, a race of super moths emerged.

Super moths like this tiger moth.

Its superpowers have only recently been explained.

The tiger moth can vibrate a tiny membrane under its wing.

This produces a special high-frequency sound

to confuse bats.

When a bat attacks,

the secret weapon is deployed.

The moth's special sound jams

the bat's echolocation system,

so it can't see with sound properly.

It's enough of a smokescreen

to allow the moth to escape,

leaving the confused bat to try and find another.

Every night, around the world, hi-tech aerial battles like this

take place with sophisticated weaponry,

changing the odds, as predator is pitched against prey.

Bat versus moth,

aerial competition that's been played out over millions

of years between billions of rivals,

where the tiniest advantage may make

all the difference in the fierce battles that rage in the skies.

If you're caught in a one-on-one life or death battle in the sky

and you don't have a secret weapon up your sleeve,

you'd better be able to out-fly your assailant.

As a lone flyer, you have few other options.

But there is one way to beat even the best aerial hunter.

And that's teamwork.

A group is almost impossible to sneak up on without being noticed.

But there are other reasons that animals move together like this.

Predators can only chase one of you at a time.

The way they see has evolved to focus on just one animal.

Faced with a swirling flock, they struggle to focus.

It's information overload.

Flocking is a really effective strategy,

and many birds do this all over the world.

But how can they fly so fast

and so close to each other without colliding?

And who is deciding where to go?

Take starlings.

Their flocking behaviour is world-famous,

it even has a special name - a murmuration.

Confusing to a predator,

it's one of the most breathtaking sights in nature.

Hundreds of thousands of individual birds are moving as one,

and amazingly, there's no single bird in charge of the plan.

Just how these complex aerial displays work has baffled us

for centuries and has only just recently been explained.

Remarkably, the truth about their complexity is rather simple.

To understand how it works, imagine you could fly

into a giant flock alongside one single starling.

How she flies is all to do

with what her seven closest neighbours are up to.

As the flock moves,

those seven might change,

but the principle stays the same.

Every starling in the flock is following three simple rules.

Firstly, as you fly, steer towards each other.

Secondly, if any of your seven neighbours turn, then you turn.

Finally, don't crowd each other.

Amazingly, that's all there is to it.

Inside a flock, individual birds are making these simple decisions

in hundredths of a second, again and again.

It's enough to confuse a predator.

And when half a million birds do it altogether,

the results are spectacular.

So how do we know precisely that this incredible spectacle is

the result of just three simple rules and seven near neighbours?

The answer lies in what you see here.

This swirling mass of birds doesn't actually exist in the natural

world, it exists inside a computer.

It's a computer simulation, with virtual birds

created by scientists trying to work out how flocks work.

Incredibly, this computer-generated flock looks

and behaves exactly like the real thing.

Each bird is following its seven neighbours

and using the same three rules.

Watch a real flock anywhere on earth...

..and it will be working in exactly the same way.

In our crowded and competitive skies,

this surely is the ultimate defence against an airborne predator

and one of nature's greatest flying stunts.

Our skies are teeming with life,

every creature trying to find its way and to survive.

If you can overcome the challenges of life in the air,

there are great opportunities to be had.

It's all about finding your place in the sky

and picking a winning strategy.

For some, it's enough just to beat gravity for a few seconds.

For others, it means taking a leap of faith.

Extraordinary specialist techniques might just give you an edge.

All these animals have skills we humans can only wonder at.

Every time an animal takes to the air,

it seems to be performing its own personal miracle.

Defying gravity to live in a world

that we are only just beginning to understand.

In Life In The Air, the team's mission was to reveal the incredible

abilities of airborne animals in more detail than ever before.

To do it required some extreme perseverance

and a range of approaches.

Some animal stars could be filmed in controlled conditions,

allowing the team to move their cameras alongside them.

Others could only be filmed on their own terms out in the wild.

Blimey!

The most challenging filming in the wild involved the smallest

and fastest of flyers - the Anna's hummingbird.

To film their record-breaking dive,

the team needed a secret weapon - cameraman Barrie Britton.

Filming birds requires keeping them in shot

and in focus from great distances.

Few people on the planet can do it, and Barrie is one of the best.

But this was the first time he'd attempted to film

the legendary Anna's hummingbird.

On the edge of a university campus in California,

he has his first view of the male's display.

The hummingbird has gone really high in the sky,

and it's coming in. Whoa!

He's so small and he's just moving so quickly.

I think it's going to be a real challenge to film it.

Hummingbird scientist Christopher Clark

knows a trick that might help.

He uses a stand-in female bird to attract the males.

The birds are going at the speed of freeway traffic.

Barrie is able to piggyback on Chris's studies

to give him a chance.

And as backup, the team have brought their own range

of stand-in models.

First up, a slightly moth-eaten stuffed bird.

According to the scientists,

this female, the way her tail is,

means that she's a bit...

she looks a bit more up for it than the others.

The model is so enticing, the male skips courtship altogether.

Onto model number two.

A more modest embroidered female.

Playing hard to get,

she's perfect for encouraging the males to perform

their courtship display.

In fact, they're so keen to show off to her, the crew need to cover

her up while Barrie prepares.

I'm ready.

With the set-up sorted, it's now down to Barrie versus the birds.

Oh, here he is.

Whoa! HE LAUGHS

That's really quick.

You think you're so clever!

Blimey!

I'm not sure this is going to work, I'm just trying.

Things are starting to come together.

That's got to be good, it's got to be good.

Meanwhile, thousands of miles away in the cloud forests of Ecuador,

another team are also challenged with filming a small,

fast-moving animal.

Their mission is to fly alongside wild bats

hunting in complete darkness.

Scientist Nick Dowdy is taking the crew to his study site within

the forest, where he carries out research on how wild bats

hunt tiger moths.

Huge amounts of specialist equipment are required.

And unable to get this deep into the jungle,

the team's first task is to bring the jungle to them.

A studio within the forest will be a temporary new home for the bats.

It'll replicate the jungle

but will also be rigged with kit by cameraman Rob Drewett.

It takes five days to get everything just right before switching

to night shifts, entering the world of the bats.

Challenged with flying his camera alongside them,

Rob has a stabilising pulley system.

And his state-of-the-art infrared camera

is able to slow down the images over 40 times.

Rob's also relying on some rather less technical equipment.

I'm having to go around and just make sure there's no

holes for them to get out of the enclosure.

Fingers crossed we've got it sorted.

I think we have, it looks pretty good.

So even like that, they're going to get out, aren't they?

While Rob double checks, there's also time for final kit tests

before everything is bat-ready.

You're flapping! HE LAUGHS

Nick is trained to safely capture

and release wild bats for use in his studies.

This expertise ensures the welfare of the animals during filming.

It's also an opportunity for Nick to gain insights into their behaviour.

CLICKING

Echolocation clicks from a bat detector show

the occupants are getting to know their new home.

Now filming can finally begin.

Night after night, Rob starts to get the shots he needs.

And the controlled conditions of the forest studio come into their own.

Oh, here we go. Here we go.

Yes, it's pretty good. Yeah.

But Rob's greatest challenge is yet to come - filming the bats hunting.

Back in California, the hummingbird crew have hit a problem.

The star model has lost its appeal

and instead of diving, the males are now attacking.

There's no option but to turn to the real deal,

a female Anna's hummingbird.

For these shy creatures,

Barrie has to rely on more traditional techniques.

We just need everything to kind of line up.

We need the females to come, land on the perch

and the male has to be looking the right way.

It's going to be a test of patience,

filming all day, every day, in a hide in the Californian heat.

The shoot is in its last few days,

and finally, everything is falling into place.

Barrie's able to capture interactions between the male

and a real female, and reveal the world's fastest courtship

display in incredible detail.

That's really nice, really good.

Back in Ecuador, Rob also faces a waiting game.

He's truly immersed in the bat's world,

becoming nocturnal himself

as he strives to capture their hunting behaviour.

There's no way of knowing exactly when the bats will strike.

And once triggered, the camera needs

at least seven seconds to save the shot.

Oh, that was close.

It's frustrating for Rob

if the action happens before the camera re-arms.

And then...

Ah, no. Not now, though.

..catastrophe. No, armed?

Armed.

Ah!

Look at this.

Ah! Oh, my God.

This is disastrous.

I'm a bit nervous about using this camera -

it crashed and we lost a whole night's footage.

So fingers crossed it doesn't do that again.

Having worked through the night for over two whole weeks, Rob's spirits

are low, and he only has a few days left.

But he's not one for quitting.

Am I armed?

Yep.

Oh, that was in frame!

OK, let's have a look at that one.

I think we might have got that. Yes!

Ah, that's nice.

Great, we got one.

Yes! Well done, good work.

After many sleepless nights, Rob's perseverance pays off,

helped by a successful partnership with science, a little

technology and a great performance from the masters of the night sky.

In total, crews have worked over 300 days on location

to film incredible animals in action in the skies.

Life in the air has been captured

in greater detail than ever before.

Seeing how animals survive

and thrive up here has revealed just what it takes to master the skies.