Original subtitles

Rulers of the sky.

Symbols of freedom.

Unrivaled hunters.

We think of birds of prey

as ruthless killers.

But there's another side to their story.

Unexpectedly smart.

Surprisingly adaptable.

And more caring

than you ever imagined.

Deep winter.

This female bald eagle is having contractions.

Her eggs take 35 days to hatch.

To be ready for spring…

…she has to lay now.

But at this time of year,

the weather can quickly turn.

Exposed, her eggs would freeze in minutes.

But bald eagles are tough.

She'll do whatever it takes

to protect them.

And it's not just Mom.

Her lifelong mate.

A pair devoted to raising the next generation of aerial hunters.

Around the planet,

there are over 300 kinds of birds of prey.

From the biggest in the world, with a nine-foot wingspan,

to the smallest,

no bigger than a butterfly.

Wherever they live, they control the skies.

From dense jungles

to the frozen Arctic.

Arid deserts…

to towering mountains.

All of them are meat eaters

equipped with the same weaponry.

It's what and how they hunt

that's created such an amazing cast

of aerial assassins.

No open flight lines

and too many places to hide

make hunting almost impossible for a raptor.

Unless it's the woodland master.

The goshawk.

Armed with all the tools of the trade.

Acute binocular vision,

a sharp, hooked beak for ripping into flesh,

and large, curved talons

for grasping prey.

That's standard issue.

What makes her exceptional

is how she chases down her prey.

In a few wingbeats,

she hits 32 miles per hour…

the fastest acceleration of almost any raptor.

Using her tail as an air brake,

she turns on a dime.

Shortened wings

contort to the smallest gap.

She needs to hit her target before it reaches cover.

Hugging the terrain conceals her approach.

And if it doesn't work the first time…

goshawks are not just agile.

They're patient too.

Found in woodlands across the northern hemisphere,

the goshawk's success is down to its amazing agility.

But when it comes to pure speed…

another raptor

is unbeatable.

The fastest animal on Earth.

The peregrine falcon.

Top speed over 240 miles an hour

in a stoop.

Peregrines are so successful,

they're found all around the world.

Cliffs are their favorite habitat.

They provide a vantage point to scope for food.

And create updrafts

that peregrines use to gain height

before they strike from above.

The success of most birds of prey

depends on a mastery of flight.

But there's always one that bucks the trend.

Meet the secretary bird.

Not your typical bird of prey.

She's a raptor

on stilts.

About the height of a seven-year-old child.

And while she can fly,

she'd rather go by foot.

Up to 18 miles a day.

Those long legs aren't just for walking.

They help see into the tall grass.

They look a little ungainly…

but don't be fooled.

That kick is lethal…

unleashing 44 pounds of force

faster than a blink of an eye.

And she needs to move fast.

This living velociraptor

is also a mom.

Two chicks, almost fully grown.

Always hungry.

Parenting duties are also stepping up a gear

at the bald eagle nest.

As soon as the snow's melted,

the magical moment arrives.

Two chicks, freshly hatched.

In any weather…

…at any time…

Mom protects them the best she can.

But with those talons,

she must tread carefully.

Both adults take turns brooding

and fetching food.

Tag-team parenting gives their young the best possible start.

Four days later,

the last egg hatches.

The oldest chick is already twice its weight.

Unless the parents can provide an exceptional amount of food,

the smallest sibling won't last long.

Birds of prey are most vulnerable in the nest.

Chicks would soon perish in this baking desert…

unless they have shelter from the sun.

Sociable weavers

build huge communal nests.

Inside, it's up to nine degrees cooler.

The weavers aren't the only ones who benefit.

Their nest has attracted a pair of pygmy falcons.

Among the smallest raptors on Earth,

these unlikely squatters

take advantage of the weavers' hard work.

Sometimes,

they even eat them.

But when it comes to neighbors from hell,

weaver birds have even bigger problems.

This hive of life

attracts all sorts of predators.

The weavers appear defenseless,

but they have a security force…

…ready to fend off any attack.

Only the size of your fist,

but the falcons pack a punch.

And thankfully,

these fierce little fighters show some restraint.

They only take a few weavers each season.

Most of the time, there's plenty of other prey around.

For the weavers, it's a case of "better the devil you know."

And for the little falcons,

it's a one-stop solution

to finding food and shelter in the barren desert.

In this remote corner of South America…

life is so abundant,

every creature needs its niche.

Perching at the top of the food chain, the 15-pound harpy eagle.

But another bird of prey here

does things a little differently.

The red-throated caracara.

When caracaras sense a threat,

they let everybody know.

It's enough to put the top predator

off its game.

Caracaras are considered the world's most social and most intelligent raptors.

A winning combination that means they can tackle prey

even a harpy wouldn't touch.

Wasps.

Usually best left alone.

But working together,

the caracaras figure out a plan.

First, the direct approach.

But once the nest is stirred…

…those little stingers get everywhere.

Next, a smash-and-grab.

It takes guts to pull it off.

But a little courage

gets the job done.

If one caracara can take the pain,

eventually the wasps abandon the nest.

These paper-like constructions are as nutritious as cardboard…

but hidden away in the combs

are plump, juicy grubs.

One caracara's bravery benefits the whole team.

Once she's taken her fill, the rest share the spoils.

Served up just in time.

Life in the rain forest is tough.

But caracaras keep ahead of the game

thanks to tenacity and teamwork.

Most birds of prey aren't so cooperative.

Even in the nest, competition is fierce.

New bald eagle chicks can grow 20% bigger each day.

But the youngest is struggling to keep up.

Every feeding time,

he's at the back of the line.

In a little over two months,

these chicks need to be ten times larger

and ready to fly.

But if there's not enough food,

older eaglets will turn on their smaller siblings.

It's rare for three chicks to survive.

The parents are working hard

to keep all of their young alive.

Finding enough food is a constant struggle for all birds of prey.

Though some make it seem effortless.

Vultures use thermals,

columns of rising warm air,

to gain altitude.

Once high enough, some soar over 100 miles

without a single beat of their wings.

Along the way,

they use their telescopic vision to scan for food.

Vultures are scavengers.

Feasting on the dead has given them a bad name,

but they're the only birds of prey

that never kill.

And they do essential work as nature's cleanup crew.

It may look chaotic,

but there's a pecking order.

Nine different species of vulture live in Southern Africa alone,

and each has its own role.

First, the middleweights.

White-backed vultures.

In large numbers, they devour the bulk of the carcass,

the internal organs, and flesh.

Next, the heavyweights.

At over 15 pounds,

lappet-faced vultures are one of the biggest in Africa.

When they move in,

everyone steps aside.

Their powerful beaks rip through ligaments and hide,

opening up new parts of the carcass

for the last in line.

The lightweights.

Hooded vultures stick to the sidelines,

stealing scraps where they can,

patiently waiting their turn.

Once everyone else is done,

their small beaks pick the bones bare.

Vultures do the dirty work in keeping our planet clean.

Stomachs as acidic as car batteries

destroy any bacteria and viruses they eat.

And they deny disease-spreading insects

a place to breed.

We need vultures,

but their numbers are plummeting.

In just 15 years,

97% of India's vultures were killed,

poisoned by feeding on the carcasses of cattle

treated with a drug called Diclofenac.

When feral dogs took their place as scavengers,

it led to a rise in rabies,

TB, and anthrax.

Other raptors have suffered a similar fate.

In the 1950s,

DDT was a freely used insecticide.

But it had a devastating effect on bald eagles' eggs

and nearly wiped out this iconic species.

Once people realized its impact, DDT was banned.

Within 50 years,

bald eagle numbers increased sevenfold.

Many birds of prey are still under pressure.

Seen as a threat to livestock and game,

they are persecuted.

And when habitat is destroyed,

they lose food and shelter.

But not all are faring so badly in the modern world.

This might look like the last place a raptor would thrive…

…but for those that can adapt,

it's a world of opportunity.

In the heart of the city,

Battersea Power Station's iconic chimneys stand over 300 feet high.

They're home to a pair of peregrine falcons.

They use the concrete walls like cliffs.

City life has its advantages.

There's so much light here,

the peregrines can hunt at night.

The pair splits up to cover more ground.

The female falcon is the bigger,

more experienced nocturnal hunter.

Her vision is more than twice as sharp as ours,

thanks to eyes so large

they touch inside her skull.

By bobbing her head, she triangulates her target.

But pursuing pigeons in the city

has risks.

This many buildings make it dangerous to stoop.

It forces urban peregrines to hunt the hard way.

The level chase…

where predator and prey are more evenly matched.

But even without stooping,

even at night…

nature's top gun is rarely outmaneuvered.

Peregrine falcons have spread to cities around the world,

from New York to Sydney.

And with every breeding season, their numbers continue to rise.

At the bald eagle nest,

the chicks have come a long way.

All three of them.

All growing strong.

And finally developing their flight feathers.

The chicks' survival is a testament to Mom and Dad.

They've worked tirelessly for six months.

But now they're bringing in less food…

hinting to the eaglets

it's time to fly the nest.

The art of flying takes practice.

And conditions have to be right.

Once the weather clears, they're more determined than ever.

But the outside world is new and confusing.

Other birds are hostile towards predators.

It's scary to venture far from family.

And it takes time

to find your feet.

This is just the beginning of the long journey to adulthood.

Thankfully,

Mom and Dad will watch over them for a while.

Birds of prey aren't natural-born killers.

They need time to perfect their skills.

For three months, the secretary bird chicks

have had everything provided by their parents.

Now they must start fending for themselves.

One chick leads the charge.

When its sibling follows,

the hunt is on.

Finding prey takes a keen eye,

and a lot of walking.

Catching it doesn't come easily.

Success at last.

But one small lizard is barely a snack.

Luckily, Mom's on the case.

She'll keep feeding her young for another two months…

…as the awkward youngsters

learn to be deadly assassins,

just like Mom.

Few other birds make such devoted parents.

Raptors spend much of their lives rearing their young.

Providing protection

and hard-won meals

to ensure that one day

their chicks will be able

to survive on their own.

Late fall.

Hundreds of bald eagles have traveled from far and wide…

to hunt migrating waterfowl.

Young eagles need to build their strength.

They won't get any more handouts from Mom and Dad…

so they need to watch and learn.

Gliding into the wind,

an adult chooses its moment to strike.

Coots are quick to get out of the way…

…but can't stay under for long.

Catching prey is hard.

Keeping hold of it is even harder.

Better to give it up than risk a fight.

It's time to put what he's seen into practice.

The trick is to catch one off guard.

Easier said than done.

With every failed grab…

with every one that gets away,

he refines his timing

and angle of attack.

At last.

But he's so focused on getting away,

he drops the ball.

And now,

he's got competition.

The youngster is determined to reclaim his prize.

But this just isn't his day.

And days are running short.

As temperatures drop, eagles need more energy to keep warm.

But still no kill.

Less than half of all young eagles survive their first winter.

It's now or never.

And this time…

he doesn't let go.

Just months ago,

these new eagles entered the world as helpless chicks.

Thanks to their killer instinct and their parents' incredible devotion,

they've become fully-fledged birds of prey.

They won't develop their white head until they're five years old.

Only then will they be ready to raise a family of their own…

and pass on their skills…

to the next generation.