♪♪ NARRATOR: They're the ultimate predators.

♪♪ The sharpest eyes of any hunter.

[ Bird squawks ] Ears that can hear a heartbeat.

♪♪ Noses that work a mile away.

♪♪ Wherever there's prey, there's a raptor to hunt it.

♪♪ But they're even more special than we realize.

♪♪ Intelligent castaways.

[ Bird squawks ] ♪♪ Long-distance travelers.

♪♪ Resourceful parents.

♪♪ And determined survivors.

♪♪ This series reveals what makes birds of prey the most successful hunters on the planet.

♪♪ ♪♪ ♪♪ [ Wind howling ] The high Arctic.

One of the toughest places on Earth.

♪♪ But for this young snowy owl, it's home.

♪♪ Winter is biting hard.

Bringing extremes of minus 60.

♪♪ The snowy is covered in thick feathers.

The cold isn't her problem.

She can eat the human equivalent of 40 pounds of food in one day.

Searching for enough prey leads her on a never-ending journey.

♪♪ She's a nomad.

♪♪ A drifter in the frozen wastes.

♪♪ Her 5-foot wingspan carries her thousands of miles.

♪♪ At times, she ventures beyond the Arctic... ♪♪ ...appearing in unexpected places... ♪♪ ...alongside other snowy owls.

♪♪ Like her, most are youngsters.

♪♪ Drawn to the open spaces that remind them of home.

♪♪ These special visits can be years apart... [ Bird squawks ] ...though not everyone is happy to see them.

[ Birds squawking ] ♪♪ They're here because there's food.

♪♪ As long as she can hunt here, it's where she'll stay.

♪♪ Right now, there are rodents everywhere.

♪♪ So many, she can afford to miss.

♪♪ But this bounty will soon dry up.

♪♪ When it does, the snowys will vanish.

[ Mouse squeaks ] ♪♪ She may never be seen here again.

♪♪ Spending her entire life on the move.

♪♪ Snowy owls are among the most nomadic of all birds.

Their Arctic home is so unpredictable, it's the only way to survive.

♪♪ [ Mouse squeaks ] ♪♪ And while they conquer the most extreme of places, others specialize in extreme prey.

The mountains of Taiwan.

Home to a raptor with a deadly diet.

Asian giant hornets are the biggest on Earth.

Able to kill humans.

[ Buzzard screeches ] But their nests are full of larvae.

Irresistible to oriental honey buzzards.

♪♪ [ Hornets buzzing ] ♪♪ The hornets swarm in defense.

But now, with the nest open, more honey buzzards move in.

[ Buzzard screeches ] ♪♪ [ Hornets buzzing ] ♪♪ Each making off with all the larvae they can grab.

♪♪ A raptor with a death wish, maybe.

[ Buzzard screeches ] ♪♪ ♪♪ But there's more to the honey buzzard than meets the eye.

They're built to battle killer prey.

And not just hornets, but bees, too.

[ Bees buzzing ] While they feast on honeycomb, uniquely shaped feathers work like body armor... ♪♪ ...so the bees can't land a sting.

♪♪ A special membrane protects their eyes.

♪♪ And there's even evidence of chemical warfare.

A strange substance covers their feathers... ♪♪ ...which may act as a deterrent during their death-defying raids.

♪♪ Taking on killer prey needs some serious hardware.

Raptors are fine-tuned to hunt almost anything.

♪♪ There are over 500 different species, living in nearly every habitat... ♪♪ ...each with a taste for flesh... ♪♪ ...a hooked beak, and razor-sharp talons.

♪♪ But their global success lies in their differences.

♪♪ Facial disks that channel sound.

♪♪ Huge eyes that spot the slightest movement.

♪♪ Pure speed.

Unrivalled agility.

♪♪ And raw power.

Raptors rule the skies.

♪♪ But one takes physical adaptations to the extreme.

♪♪ It's so specialized, it hardly looks like a bird of prey at all.

The height of a 7-year-old child, secretary birds are raptors on stilts.

His long legs carry him up to 20 miles a day.

Holding him at the perfect height to scan the African savannah for prey.

[ Foot thudding ] Which he stamps to death.

Mostly insects, but he'll take whatever's going.

♪♪ The secret is to stay still.

♪♪ He hunts on movement.

♪♪ ♪♪ And can land a kick 10 times faster than we can blink.

♪♪ The secretary bird's long legs are perfect for hunting on the open savannah.

♪♪ And they influence every part of their lives.

♪♪ Theirs is a unique courtship.

[ Birds squawking ] ♪♪ But when it comes to raising young, being so tall causes a few problems.

♪♪ [ Lion grumbles ] ♪♪ A chick, some 9 weeks old... ...nearly fully grown.

The only nest she fits is right on top of an acacia tree.

Her big appetite means Mom and Dad spend most of their time out hunting.

This should keep her busy for a while.

But there's no time for parents to hang around.

And she's alone again.

With the day just beginning to heat up.

♪♪ On top of the tree, she's completely exposed to the African sun.

♪♪ Daytime temperatures can top 90 degrees.

♪♪ And while most bird nestlings get enough water from their food, she risks dehydrating.

♪♪ It turns out, secretary birds are one of very few who bring water back to the nest.

♪♪ ♪♪ It's extra work, but a small trade-off for being perfectly suited to hunt on the open savannah.

♪♪ Success can depend on more than killer hardware alone.

♪♪ Especially in the most hostile of all settings.

♪♪ The Falkland Islands of the South Atlantic are so remote, it takes something really special to survive here.

♪♪ It's summer, and thousands of gentoo penguins are here to breed.

Raised in the warmer months, this young, striated caracara is learning to make it on his own.

♪♪ Too small to hunt a penguin, he's here to look for scraps.

♪♪ No one wants him around.

♪♪ But he can't resist temptation.

♪♪ It's just not his day.

♪♪ ♪♪ Or is it?

♪♪ A penguin carcass.

♪♪ [ Bird squawking ] It's already taken.

♪♪ Pairs of adult caracaras hold down territories across the island.

♪♪ Lone youngsters don't stand a chance.

♪♪ But there are other young birds around.

♪♪ He sends out a call to arms.

[ Bird screeching ] And a gang assembles.

The adults respond... [ Squawking continues ] ...though there's only one way this ends.

♪♪ ♪♪ The adults work to clear the area... ♪♪ ...but are heavily outnumbered.

♪♪ It's impossible to keep up.

♪♪ And the chaos attracts even more youngsters.

♪♪ Seizing their chance, they turn on the adults.

[ Squawking continues ] ♪♪ ...who have no choice but to fall back.

♪♪ ♪♪ Most birds of prey work alone.

♪♪ But cast away on these remote islands, young caracaras stick together.

Joining gangs for the first years of their lives.

Social species are among the smartest of all animals.

Castaway on such remote islands, they need to be.

♪♪ ♪♪ When breeding season ends, food gets hard to find.

♪♪ Less than a quarter of youngsters may get through the coming months.

♪♪ Only the most resourceful and inquisitive will survive.

[ Seals bellow ] He needs to find food wherever he can.

No matter how risky.

Hanging out among 3-ton elephant seals is an accident waiting to happen.

But he needs to eat.

♪♪ And there must be something.

♪♪ Surely not.

♪♪ But elephant seal snot is on tap.

♪♪ For those brave enough.

♪♪ Raptors aren't well known for their intelligence.

But social and resourceful striated caracara are the very smartest birds of prey.

♪♪ And they're not the only ones who rely on brain power.

Others use it to conquer extreme niches.

Like the dead of night.

60 million years ago, an abundance of nocturnal mammals led some raptors into the shadows.

♪♪ ♪♪ The tawny owl is the ultimate nocturnal hunter.

♪♪ ♪♪ Feathers so silent, he could fly right by, and you wouldn't hear a thing.

♪♪ Sensitive eyes and ears.

♪♪ Razor-sharp talons to finish the job.

♪♪ [ Rodent squeaks ] ♪♪ ♪♪ That's the basic setup.

[ Owl squawks ] ♪♪ What's really special is his little-known superpower.

♪♪ ♪♪ He can fly around in total darkness.

♪♪ He can't always see where he's going.

♪♪ But he remembers his way to his favorite perches... ♪♪ ...where he can listen for prey.

♪♪ He has incredible spatial memory, helping him hunt on moonless nights and in the darkest corners of the woods.

♪♪ The only price for this power is he must hold down a strict territory... ♪♪ ...where others take a more flexible approach.

The gymnogene thrives in just about any African habitat.

Mixing up what and how he hunts.

♪♪ Gymnogene means "bald chin."

♪♪ But don't be fooled by his looks.

♪♪ If you're a starling, he's straight out of your worst nightmare.

♪♪ A hunter from whom you can run, but you cannot hide.

♪♪ He can climb vertically.

♪♪ Stiff tail feathers for grip.

♪♪ Broad wings for balance.

♪♪ [ Bird squawking ] The featherless face?

♪♪ All the better to see you with.

♪♪ And those long legs?

All the better to reach you with.

♪♪ His legs are double-jointed.

♪♪ Bending backwards and forwards for extra stretch.

♪♪ Luckily for the starlings, the chick was just out of reach.

♪♪ But he's got plenty of other options.

♪♪ Weaver bird nests are custom-made to keep predators out.

♪♪ ♪♪ But where there's prey, the gymnogene will find it.

♪♪ He searches the colony nest by nest.

♪♪ ♪♪ Unique skills and a broad diet see him make the most of any opportunity.

♪♪ For those who can catch them, there's no better opportunity than the seasonal appearance of twenty million Mexican free-tailed bats.

Spending summer at Bracken Cave, Texas, it's the greatest gathering of mammals anywhere on Earth.

And here to join them are peregrine falcons... ...red-tailed hawks... [ Bird screeches ] ...and Swainson's hawks.

Some local, others just passing through.

All waiting for the right moment.

♪♪ At sundown the bats prepare to leave for the night.

♪♪ Diving through the crowd risks injury, and inexperienced raptors move early.

♪♪ Moments later, the bats begin to stream out.

♪♪ ♪♪ In open sky, they're an easier target.

♪♪ They fly at over 60 miles an hour.

♪♪ Getting up to speed, the hunters aim for any stragglers.

♪♪ Swallowing them on the wing.

♪♪ The bats keep coming, and a feast begins.

♪♪ ♪♪ It takes hours for them all to leave the cave.

♪♪ The less experienced birds have time to hone their skills.

♪♪ While the real top guns show off... ♪♪ ...taking one bat in each foot.

♪♪ The feast lasts four months through summer... ♪♪ ...before the bats return south.

Some hunters stay the whole season.

Others move on, seeking new opportunities.

Opportunities that can see them form extraordinary relationships.

[ Wind howling ] [ Bird squawking ] Standing 3 feet tall, weighing 20 pounds, Steller's sea eagles are one of the world's biggest raptors.

In winter, they visit the remote coast of far northern Japan... ...where they're joined by white-tailed eagles, with an 8-foot wingspan.

They're all here for one thing.

In this small community, pollock fishing is big business.

♪♪ For decades, the bycatch from all these boats has offered easy pickings through the toughest months of the year.

♪♪ Known locally as the great eagles, they're a welcome sight.

♪♪ ♪♪ And on bleak winter days, they put on a spectacular show.

♪♪ Coming all the way into the harbor.

♪♪ ♪♪ Attracting another type of visitor.

Tourists.

♪♪ [ Camera shutter clicking ] ♪♪ People flock from all over the world, drawn by an awe of giant raptors.

♪♪ ♪♪ Needing boats to reach the sea ice, the tourist trade now rivals the fishing industry.

♪♪ ♪♪ For people, it's a once-in-a-lifetime shot to see a bird that spends most of its life in remote far eastern Russia.

♪♪ The eagles are simply here for an easy meal.

♪♪ But in an increasingly human world, what does the future hold for our planet's raptors?

Habitat loss, persecution, and a changing climate means 1/3 of birds of prey are under threat.

But given the space, raptors can overcome extreme challenges.

♪♪ And there are stories of hope.

♪♪ The wetlands of Central Florida.

♪♪ A patchwork of waterways.

♪♪ Home to a rare and very special bird of prey.

♪♪ The Florida snail kite.

♪♪ So called for its unusual diet.

♪♪ ♪♪ One made up mostly of aquatic snails.

♪♪ ♪♪ Snails are able to seal themselves inside their shells.

It takes a long, hooked beak to pry them open.

A unique beak with quite the tale to tell.

♪♪ In the early 2000s, an invasive snail species took over these wetlands.

♪♪ The new snails were five times bigger than their usual prey.

Most snail kites couldn't eat them.

♪♪ Many birds vanished, along with any hope for their survival in Florida.

♪♪ But 10 years later, the snail kites were back.

♪♪ Their population tripling to over 2,000 birds.

♪♪ And they were catching and eating the bigger snails.

♪♪ But with some major changes.

♪♪ Their beaks and bodies had grown up to 12% bigger in little more than a decade.

♪♪ It turns out a few big-beaked birds could handle the new supersized prey.

♪♪ And birds with bigger beaks pass those genes on to their young.

[ Birds squawking ] ♪♪ Happening in less than two snail kite generations, the speed of change is almost unbelievable.

♪♪ ♪♪ Florida's snail kites are evolving right in front of us.

♪♪ Given the chance, even top predators can adapt to extreme changes.

This tiny chick will one day be a fearsome predator.

The talons on which she'll depend are already her most distinctive feature.

But what really stands out is where she lives.

♪♪ The city of Durban, South Africa.

♪♪ Surprising, because she's an African crowned eagle, the most powerful bird of prey on the planet.

♪♪ While in the nest, Mom shows her tender side.

She is armed with talons that can crush bone.

♪♪ She takes prey weighing up to 60 pounds.

♪♪ ♪♪ Imagine a raptor whose ancestors hunted our own nesting in your backyard.

♪♪ Most people embrace the change.

And while declining elsewhere, Durban's crowned eagles are thriving.

[ Insects buzzing ] This nest on a sewer pipeline is the first ever known on an artificial structure.

♪♪ And there's now a higher density of them here than anywhere in Africa.

♪♪ In the wild, most nests are at least 3 miles apart.

In Durban, the nearest neighbors are just half a mile away.

♪♪ This is why.

♪♪ The city is full of prey.

♪♪ Vervet monkeys fall quiet in the neighborhoods where eagles nest.

♪♪ ♪♪ [ Monkeys chittering ] ♪♪ Everyone's accounted for, the alarm raised in time.

♪♪ But this rock hyrax wasn't so lucky.

♪♪ A meal like this will keep the 6-week-old chick busy for days.

But she grows quickly... ♪♪ ...looking more eagle-like every day.

♪♪ By 12 weeks, food drops are bigger.

♪♪ And she can handle them by herself.

♪♪ From now on, Mom and Dad's visits will be less frequent.

[ Eagle screeching ] ♪♪ It's confusing when parents don't answer your calls.

♪♪ But tough love encourages her to spread her wings.

♪♪ She'll still depend on them for much of the next year.

♪♪ Hunting large, smart prey will take a lot of practice.

♪♪ It's a tough time ahead.

She'll need to carve out her place, not just among her own kind but alongside the people here, too.

♪♪ A hunter's life is full of challenges.

♪♪ Intense competition.

♪♪ Other predators.

♪♪ And the uncertainties of our changing world.

♪♪ But armed with a fistful of daggers, raptors have risen to the top.

♪♪ Theirs are powers we can only dream of.

♪♪ A mastery of flight.

♪♪ Specialized adaptations.

♪♪ And mind-blowing senses.

♪♪ They've conquered nearly every habitat with inventive solutions and surprising intelligence.

♪♪ No matter how hostile the place or deadly the prey.

♪♪ Raptors are truly the greatest hunters on the planet.

♪♪ ♪♪ ♪♪ ♪♪ ♪♪ To learn more about what you've seen on this "Nature" program, visit pbs.org.

♪♪