Masters of the Sky

MEET THE WHOOPER SWAN... ONE OF THE LARGEST AND HEAVIEST OF ALL FLYING CREATURES.

[SQUAWK] EVERY YEAR, FAMILIES LIKE THIS FLY ENORMOUS DISTANCES, MIGRATING BETWEEN VITAL FEEDING AND BREEDING AREAS.

BUT WEIGHING A WHOPPING 31 POUNDS, 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 2 POUNDS 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 IMPOSSIBLE AND REQUIRES SOME VERY CLEVER TECHNIQUES.

SO JUST HOW DOES HE DO IT?

WELL, 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 THEN FORWARD.

NOW HIS GIGANTIC, METER-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 THAT FIGHTS THE DOWNWARD PULL OF GRAVITY.

SO HOW IS LIFT CREATED?

WELL THE SPECIAL SHAPE OF HIS WING, KNOWN AS AN AIRFOIL, 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... UNTIL HE REACHES 13 MILES 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.

[SQUAWK] NOW HE'S REALLY FLYING, BUT THE SAME AIR THAT HELPED HIM GET UP HERE GIVES HIM A NEW CHALLENGE.

AS HE POWERS FORWARD, 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, DRAG BECOMES AN EVEN BIGGER PROBLEM.

SO WHAT IF YOU'RE ONE OF THE FASTEST ANIMALS ON THE PLANET... AND YOU'RE MOVING AT MORE THAN 200 MILES AN HOUR?

THE PEREGRINE FALCON IS ONE OF THE WORLD'S FASTEST ANIMALS.

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.

[SQUEAKING LOUDLY] AT 4 WEEKS OLD, EACH RAVENOUS CHICK EATS MORE THAN AN ADULT.

SO MOM AND DAD NEED TO RELY ON THEIR SPEED...TO KEEP UP WITH DEMAND.

[SEA GULL CRYING] AND IT'S A FULL-TIME JOB.

SO WHAT IS IT ABOUT PEREGRINES THAT MAKE 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 TO STOP THEIR EYES FROM 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 THE AIR AND THE LANDSCAPE TO ITS ADVANTAGE.

FIRST, IT USES UPDRAFTS FROM THE CLIFF FACE TO GAIN HEIGHT.

THIS EXTRA HEIGHT HELPS SPOT PREY AND GAIN SPEED FOR A SURPRISE ATTACK.

NOW IT USES GRAVITY TO ITS ADVANTAGE IN A SPECIALIZED DIVE, KNOWN AS A STOOP.

A FEW DEEP WING STROKES HELP IT ACCELERATE TOWARDS 120 MILES AN HOUR.

BUT SCREAMING THROUGH THE AIR AT THIS SPEED, DRAG FROM THE SURROUNDING AIR SLOWS IT DOWN.

SO IT TURNS ITSELF IN TO A BULLET.

BY STREAMLINING ITS BODY, THE FALCON REDUCES DRAG SO NOW IT CAN ACCELERATE FURTHER.

WITH WINGS TUCKED IN, 150 MILES PER 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 AS 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 MINIMIZED, PEREGRINES CAN TOP 200 MILES PER HOUR.

AT THIS SPEED, THEY CAN COVER THE LENGTH OF A FOOTBALL FIELD 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.

[SQUEAKING LOUDLY] THEY REALLY DON'T LIKE INTRUDERS.

AT THE SLIGHTEST HINT OF A THREAT, THE FALCONS WILL SCRAMBLE... [SQUEAKING LOUDLY] AND INTERCEPT IN SECONDS.

[SQUAWKING LOUDLY] 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.

[BARKING] PELICANS ARE 10 TIMES HER SIZE AND HERE IS 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?

[BIRDS CHIRPING] WHAT IF YOU LIVED IN AN ENGLISH COUNTRY GARDEN...

FLYING FAST, CLOSE TO THE GROUND, AND AROUND A VERITABLE OBSTACLE COURSE?

THERE'S A SKILLFUL 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.

THIS IS HOW IT WORKS.

THE TARGETS ARE RIGHT IN THE MIDDLE OF A GARDEN OVER 50 METERS 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 MAXIMIZE 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.

9 OUT OF 10 SPARROW HAWK HUNTS FAIL BECAUSE OF THIS, SO HE'S GOT TO BE FAST AND AGILE AND STRIKE IN JUST 4 SECONDS.

[BIRD SEED RUSTLING] 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 THE AIR, DRIVING HIS LIGHTWEIGHT BODY FORWARDS... TO HIT ATTACK SPEED IN UNDER 2 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... KEEPING HIM AIRBORNE AND SAVING VALUABLE ENERGY.

BUT HURTLING ALONG AT 30 MILES AN HOUR GIVES HIM JUST HUNDREDTHS OF A SECOND TO AVOID A COLLISION.

SHORT WINGS ARE PULLED IN TO PASS THROUGH THE TIGHTEST 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.

HE FLIES AS CLOSE AS POSSIBLE TO THE HEDGE TOP.

AS HE GETS CLOSER, PRECISION FLYING BECOMES CRITICAL.

HE NEEDS TO STAY HIDDEN 'TIL 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?

WELL, THERE IS A CREATURE 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 ARMOR.

IN THE WORLD OF BEETLES, HE'S A COLOSSUS, WEIGHING A HEFTY 1/3 OF AN OUNCE.

HE IS ON A MISSION TO FIND FOOD AND MORE IMPORTANTLY, A MATE, AND SHE COULD BE A MILE AWAY.

HE DOESN'T HAVE MUCH TIME, IT'S TOO FAR TO WALK.

SO HE HAS TO FLY.

BUT ATTEMPTING TO FLY WHILE CARRYING ALL THAT HEAVY BODY ARMOR, HE'S GONNA NEED SOME SERIOUS POWER.

SO HOW DOES A RHINOCEROS BEETLE KEEP ITS HUGE BODY AIRBORNE?

IT HAS A SPECIAL TECHNIQUE, FLYING VERY DIFFERENTLY TO 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 AND THRUST TO PUSH HIM FORWARD.

SO FAR, THAT'S MUCH LIKE A BIRD.

BUT BY TWISTING HIS WINGS AT THE BASE, HE CAN ALSO PUSH AIR BACKWARDS ON THE UPSTROKE.

AND THERE'S THE PROOF.

THIS GIVES HIM A LITTLE BIT OF EXTRA THRUST, AND THAT'S SOMETHING THAT MOST BIRDS CAN'T DO.

BUT HE DOESN'T LEAVE IT THERE.

EVEN HIS ARMORED WING CASES ARE WORKING IN HIS FAVOR, 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 WINGS GIVE HIM THE EXTRA LIFT AND THRUST THAT HE NEEDS TO CRUISE IN 9 MILES AN HOUR.

HE'S HARDLY SPEEDY, NOR IS A HE A LONG-DISTANCE FLYER, BUT HE CAN COVER HALF A MILE 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'VE 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.

[CHIRPING] HUMMINGBIRDS, EACH THE SIZE OF YOUR LITTLE FINGER.

TO THE HUMAN EYE, THEIR FLIGHT IS LITTLE MORE THAN A BLUR.

IT'S ONLY WHEN SLOWED DOWN 50 TIMES CAN YOU APPRECIATE THEIR INCREDIBLE CONTROL.

SO WHY ARE THE HUMMINGBIRDS SO SPECIAL?

THIS IS ONE OF THE WORLD'S MOST SPECTACULAR FLYERS: A BOOTED RACKET-TAILED HUMMINGBIRD.

ON THE SURFACE, HE'S GOT IT MADE.

HERE IN ECUADOR, HIS FOREST HOME IS FULL OF FLOWERS, EACH WITH SUGAR-RICH NECTAR HIDDEN INSIDE.

HE HAS A PROBLEM.

THESE FLOWERS DON'T PROVIDE PERCHES, NEITHER DO THEY MAKE THE NECTAR EASY TO GET AT.

NOW THE HUMMINGBIRD'S EXTRAORDINARY FLIGHT STARTS TO MAKE 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 A 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 CLOSER INSPECTION, THE WINGTIPS MOVE IN A FIGURE 8, LIKE A BEETLE.

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 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 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 A 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 MILES 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 2 MONTHS OLD, HER CHICK WILL EAT OVER A POUND 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 3-METER WINGS AND THE CLIFF TOP WIND PROVIDES THE LIFT.

UNGAINLY ON LAND, SHE'S NOW IN HER ELEMENT.

OUT HERE, FINDING FISH AND SQUID IS LIKE LOOKING FOR NEEDLES IN A HAYSTACK.

SO A MOTHER ALBATROSS WILL SCOUR THE OCEAN FOR UP TO 600 MILES A DAY.

DURING HER LIFETIME, SHE'LL TRAVEL 1.5 MILLION MILES.

THAT'S TO THE MOON AND BACK 3 TIMES, AND, REMARKABLY, SHE CAN DO THIS WITH BARELY A WING BEAT.

SHE'S ONE OF THE WORLD'S MOST EFFICIENT FLYERS, 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 10 METERS 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 10 METERS 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 AT UP TO 75 MILES 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 TO PASS UP.

NOW FULL OF FOOD, AN ALBATROSS' NEXT CHALLENGE IS GETTING 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.

AN ALBATROSS USES A SPECIAL ORGAN HIDDEN INSIDE HER NOSTRILS TO CONSTANTLY MEASURE TINY CHANGES IN AIR SPEED.

THIS GUIDES HER TO POCKETS OF STILL AIR AWAY FROM THE WIND BEHIND EACH WAVE.

FLYING IS MUCH EASIER HERE.

AND WHEN SHE NEEDS EXTRA LIFT, SHE CAN EVEN SEEK OUT UPWARD-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.

SOON, IT WILL BE DOING THE SAME.

THE ALBATROSS' ABILITY TO FLY FAR IN SEARCH OF FOOD ALLOWS IT TO LIVE WHERE FEW OTHERS CAN.

BUT THEY AREN'T THE ONLY CREATURE THAT SURVIVE BY TRAVELING HUGE DISTANCES.

OTHERS MOVE WITH THE SEASONS, FLYING BETWEEN WINTER AND SUMMER HOMES, IN THE BIGGEST JOURNEY OF THEIR LIVES.

[BIRDS CALLING] MIGRATION... OVER MANY THOUSANDS OF MILES, ACROSS COUNTRIES, SOMETIMES 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-- EXHAUSTION IS THE BIGGEST KILLER.

SO ANY WAY THAT YOU CAN SAVE ENERGY MIGHT SAVE YOUR LIFE.

THERE'S ONE ANIMAL THAT FLIES WITH INCREDIBLE EFFICIENCY NOT ON ITS OWN BUT AS A TEAM.

EUROPEAN CRANES MIGRATE NEARLY 1,700 MILES 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 ALL OF THEM A CRUCIAL ADVANTAGE ON THEIR LONG AND ARDUOUS JOURNEY.

[CALLING] ADULT PAIRS MATE FOR LIFE AND THEY DANCE TOGETHER EVERY YEAR TO STRENGTHEN FAMILY BONDS.

[CALLING LOUDLY] 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, AND THIS USES LOTS OF ENERGY.

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 PERFECTLY POSITIONED IF THE TEAMWORK IS GOING TO PAY OFF.

TO UNDERSTAND WHY, WE NEED TO SEE HOW THE AIR MOVES AROUND A CRANE'S WING IN FLIGHT.

EACH BIRD LEAVES A WAKE IN THE AIR BEHIND IT.

A TUBE OF SPIRALING AIR TRAILING BEHIND A WINGTIP 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 THEREBY 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... [SQUAWKS] WITH NO ENERGY TO INHERIT FROM BIRDS IN FRONT OF IT.

SO THE CRANES TAKE IT IN TURN TO LEAD, AND SHARE THE WORK AROUND THE TEAM.

AND 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-DISTANCE FLYING JUST A 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 QUITE AS GOOD AT OTHERS.

WHEN YOU'RE BUILT FOR SPEED, IT'S DIFFICULT TO BE ACROBATIC.

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 MANEUVERABLE BECOMES MORE OF A CHALLENGE.

IT CAN WORK TO BE A SPECIALIST, BUT WHAT IF YOU NEED TO BE A JACK OF ALL TRADES?

WHAT IF YOU NEED TO COMBINE MANY DIFFERENT FLYING SKILLS INTO THE ULTIMATE FLYING MACHINE?

WELL, 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 MEXICAN 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 HEADED TO THE SAFETY OF A CAVE.

THEIR CHALLENGE IS TO COMPLETELY CHANGE THE WAY THEY FLY MORE THAN ONCE.

FIRST, FLY FAST, TOPPING 60 MILES PER HOUR.

NEXT, HIT THE BRAKES AS THEY FLY INTO THE PITCH BLACK.

FINALLY, FLY ALONGSIDE THE HALF A MILLION OTHER BATS IN THE DARK CAVE.

NOW IT'S ABOUT BEING MANEUVERABLE AND TRYING TO AVOID COLLISION.

WITHIN A FEW SECONDS, THE BATS HAVE HAD TO PERFORM A RANGE OF COMPLETELY DIFFERENT FLIGHT TECHNIQUES.

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 THE ULTIMATE IN FLIGHT ENGINEERING, COMPLETE WITH THUMB AND 4 FINGERS AND SELF-TENSIONING SKIN IN-BETWEEN.

ITS SHAPE CAN SHIFT IN ALL 3 DIMENSIONS AND FAR MORE THAN ANY BIRD OR INSECT.

NO OTHER WING IS THIS VERSATILE.

INNOVATIVE WING DESIGN ALLOWS THE BATS TO COVER HUGE DISTANCES TO FEED...

FLY FAST TO EVADE PREDATORS... AND MANEUVER TIGHTLY IN THEIR CROWDED CAVE.

THIS EXPERT FLYING ABILITY ALLOWS THE BATS TO USE THE CAVES AS GIANT UNDERGROUND NURSERIES.

[BATS CHIRPING] HUNDREDS OF THOUSANDS OF BABY BATS HUDDLE TOGETHER FOR WARMTH.

IN HERE, ALL THE BATS ARE 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.

THEY CAN'T SEE IN THE DARK, SO EVERY SECOND THE BATS CAN STAY UNDERGROUND GIVES THEM AN ADVANTAGE.

[WATER DRIPPING] BUT SOONER OR LATER, EACH BAT IS GOING TO HAVE TO TEST ITS FLYING SKILLS TO THE MAX ONCE MORE.

THEIR STRATEGY IS TO EMERGE TOGETHER, GIVING THEM SAFETY IN NUMBERS.

SO TO SQUEEZE MANY BATS INTO THE CAVE ENTRANCE, THEY PERFORM AN INCREDIBLE FEAT OF SYNCHRONIZED 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.

NOW SAFELY AWAY FROM THE CAVE, THEY'RE FREE TO FLY AS FAR AS THEY NEED TO THEIR NIGHTTIME FEEDING GROUNDS.

A RADICAL INNOVATION IN WING DESIGN, FLYING WITH THEIR HANDS HAS MADE BATS THE ULTIMATE FLYING MACHINES.

THEY'RE THE ONLY MAMMAL TO HAVE TRULY MASTERED A 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 NEEDS ITS OWN STRATEGY TO GIVE IT AN EDGE... TO MASTER THE SKIES.

IN "SUPERNATURE: WILD FLYERS," 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 NEIGHBORS.

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 BEHAVIOR...

IMPOSSIBLE TO ACHIEVE IN ANY OTHER WAY.

TO FILM THE PLANET'S MOST ACCOMPLISHED FLYERS, THE TEAM NEEDED TO BECOME PART OF THE FLOCK.

KEY TO THEIR SUCCESS WAS A UNIQUE RELATIONSHIP BETWEEN THE ANIMAL SUPERSTARS AND THE PEOPLE WHO WORKED WITH THEM.

THE MORE AMBITIOUS THE SHOOT, THE MORE IMPORTANT THIS RELATIONSHIP BECOMES.

AND NONE PRESENTED A BIGGER FILMING CHALLENGE THAN REVEALING THE SECRET OF FORMATION FLYING, HALF A MILE ABOVE THE FRENCH COUNTRYSIDE.

CORE TO THIS IMMENSE TECHNICAL CHALLENGE IS A SPECIALLY ADAPTED LIGHTWEIGHT MICROLIGHT... A PILOT WITH A FAMILY OF FRIENDLY EUROPEAN CRANES... AS YOU TURN... AND A CAMERAMAN WITH A HEAD FOR HEIGHTS.

FRENCHMAN CHRISTIAN MOULLEC KNOWS EACH OF HIS BIRDS BY NAME.

IS THIS DENNIS?

NO, NO, NO, DENNIS.

NO.

HA HA HA!

NARRATOR: AND WHERE HE GOES, THEY FOLLOW.

[ENGINE STARTS] CHRISTIAN HAS BEEN WORKING WITH THESE PARTICULAR BIRDS FOR 2 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.

COOK: THE BIRDS MOVE AROUND SO MUCH, SO QUICKLY, AND THEN JUST TRYING TO GUESS WHERE THEY'RE GONNA 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.

COOK: CHRISTIAN.

MOULLAC: YES?

YOUR BIRDS ARE TERRIBLE!

NO, YOU ARE A TERRIBLE CAMERAMAN.

HA HA HA HA!

NARRATOR: WITH SOMETHING THIS COMPLICATED, THERE'S NO SUBSTITUTE FOR PRACTICE.

BUT THE LONGER YOU'RE IN THE AIR, THE MORE CHANCES THAT SOMETHING WILL GO WRONG.

THE ENGINE HAS CUT OUT, AND NOW WITH NO POWER, CHRISTIAN AND RICHARD HAVE TO MAKE AN EMERGENCY LANDING, FAST.

IT'S AT TIMES LIKE THIS THAT 25 YEARS OF EXPERIENCE COMES SHARPLY IN TO PLAY.

ON THE FINAL APPROACH, THEY'RE FULLY COMMITTED.

THANKFULLY, IT'S A PERFECT TOUCHDOWN.

THE CRANES DON'T SEEM TO KNOW WHAT ALL THE FUSS IS ABOUT.

COOK: 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 GONNA TAKE THE ENGINE APART THIS AFTERNOON AND SEE WHAT'S BROKEN.

NARRATOR: IN THE MIDDLE OF THE FRENCH COUNTRYSIDE ANY RESCUE, HOWEVER UNUSUAL, IS VERY WELCOME.

BACK AT THE AIRSTRIP, AND TO A TRAINED EYE THE EXTENT OF THE PROBLEM IS OBVIOUS.

COOK: JUST LOOKING AT THE TOP, THE PISTON CROWN, THE BIT AT THE TOP, IS ALL HAMMERED AND DENTED AND IT LOOKS LIKE EITHER THE EDGE OF THE PISTON OR THE RING INSIDE HAS COME APART-- ANYWAY, IT'S GIVEN UP.

NARRATOR: THE ENGINE IS BEYOND REPAIR, SO THE TEAM RESORTS 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 IS ECSTATIC.

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.