NARRATOR: THE ANDES.

THE WORLD'S LONGEST MOUNTAIN RANGE... STRETCHING 5,000 MILES ALONG SOUTH AMERICA'S SPINE.

HIDDEN AWAY IN THESE MOUNTAINS ARE AN ASTONISHING NUMBER OF DIFFERENT WORLDS-- CLOUD FORESTS LOCKED IN MIST, THE LARGEST SALT FLATS ON EARTH, ICE FIELDS 200 MILES ACROSS.

THE ANDES HAVE A THOUSAND DIFFERENT FACES, SO FOR THOSE WHO CALL THESE MOUNTAINS HOME, ADAPTATION IS EVERYTHING.

OPPORTUNISTS FIND RICHES IN THE DESERT... [INSECTS BUZZING] WHILE BOLD MOUNTAINEERS TRAVERSE VERTICAL LANDSCAPES.

BIG CATS HUNT IN DESOLATE WILDERNESS... AND BRAVE PARENTS DARE TO RAISE THEIR FAMILIES DEEP IN AN ICE WORLD.

BUT EVEN WITH THESE SKILLS, SURVIVAL IN THE ANDES IS NO SURE THING.

IT'S A BATTLE FOR SURVIVAL THAT RAGES ACROSS THE WORLD IN GREAT MOUNTAIN RANGES THAT TOUCH THE SKIES.

HOSTILE, UNFORGIVING WORLDS THAT PUSH LIFE TO ITS LIMITS, WHERE AGAINST ALL ODDS, A FEW EXTRAORDINARY ANIMALS AND REMARKABLE PEOPLE DARE TO LIVE IN THE HIGHEST PLACES ON EARTH.

NARRATOR: THE ANDES SPAN SOUTH AMERICA FROM BOTTOM TO TOP, STRETCHING 3 TIMES THE LENGTH OF THE HIMALAYA.

WITHIN THESE MOUNTAINS LIE WORLDS BOTH REMARKABLE AND UNIQUE, AND ONE OF THEM LIES ON THE EQUATOR, WHERE THE ANDES CROSS THROUGH ECUADOR.

THE CLOUD FOREST.

[ANIMALS CHATTERING] EVEN 6,500 FEET UP, IT'S 60 DEGREES, WITH LOTS OF SUNSHINE... AND MORE RAIN THAN ANYWHERE ELSE IN THE ANDES, 20 FEET A YEAR.

[THUNDER] IT'S THE PERFECT RECIPE FOR LIFE.

TENS OF THOUSANDS OF SPECIES VIE FOR SPACE... NEARLY A THOUSAND TYPES OF BIRD, 1/6 OF ALL PLANT SPECIES.

BUT INTENSE COMPETITION MAKES LIVING HERE TOUGH.

IT SEEMS EVERYTHING WANTS TO EAT EVERYTHING ELSE.

THE WAY TO SURVIVE IS TO ADAPT.

STICK INSECTS MIMIC THORNY PLANTS.

GLASS FROGS GO A STEP FURTHER.

WITH TRANSLUCENT SKIN... TO SOFTEN THEIR SILHOUETTE...

BUT THERE'S ONE FROG HERE THAT TAKES ADAPTATION TO A WHOLE NEW LEVEL... A NEWLY DISCOVERED RAIN FROG, LESS THAN AN INCH LONG.

ON THE FACE OF IT, HE LOOKS QUITE ORDINARY, BUT HE HAS A TRICK UP HIS SLEEVE THAT BAFFLES BIOLOGISTS, A TRICK THAT ALLOWS HIM TO VANISH FROM HIS PREDATORS... LIKE THIS EYELASH VIPER.

LARGE EYES LOCK ONTO THE PREY.

HE LEAPS FOR COVER... AND NOW, HE PERFORMS A BIT OF MAGIC.

HE GROWS 3-DIMENSIONAL CAMOUFLAGE.

HIS NEW SHAPE, COLOR, AND TEXTURE BLEND SEAMLESSLY WITH THE MOSS.

IT'S THE PERFECT ADAPTATION TO THE CLOUD FOREST.

THIS IS THE STORY ALL THROUGH THE ANDES.

IT'S ADAPTATION THAT MAKES THE DIFFERENT WORLDS OF THIS MOUNTAIN RANGE SURVIVABLE.

EACH WORLD DEMANDS SPECIAL ABILITIES FROM ITS INHABITANTS... AND NOWHERE IS MORE CHALLENGING THAN THE FAR SOUTH.

THE ANDES START AT CHILE'S SOUTHERNMOST TIP, CAPE HORN.

SOME CALL IT THE END OF THE EARTH.

[WIND BLOWING] DOWN HERE, FEROCIOUS WINDS BLOW AT OVER 100 MILES AN HOUR.

THE WEATHER CHANGES FASTER THAN ANYWHERE IN SOUTH AMERICA.

[THUNDER] ONE MOMENT, A STORM'S BREWING... [THUNDER] THE NEXT... TOTAL CALM.

TO LIVE IN THE SOUTHERN ANDES, ANIMALS MUST ADAPT TO THE CONSTANTLY CHANGING ENVIRONMENT.

[GROWLS] A PUMA.

THE BIGGEST CAT IN THE ANDES.

[HIGH-PITCHED GROWLING] SHE HAS 3 CUBS AND MUST RAISE THEM ON HER OWN.

JUST 4 MONTHS OLD, THEY'RE ALWAYS HUNGRY.

[CUBS GROWLING] SHE MUST MAKE A KILL EVERY 4 DAYS, WHATEVER THE WEATHER...

BUT TODAY, CLEAR SKIES AND COLD WINDS HAVE BLANKETED THE LANDSCAPE IN FROST.

THE PUMAS HAVE LOST THEIR NATURAL CAMOUFLAGE IN THIS WHITE WORLD.

HUNTING WILL HAVE TO WAIT.

THE CUBS USE THE TIME TO PLAY, PRACTICE FOR WHEN THEY'LL HAVE TO HUNT FOR REAL IN JUST A FEW MONTHS' TIME.

BUT THE WINTER SUN SOON BURNS OFF THE FROST... AND THAT CHANGES EVERYTHING.

[ANIMAL SNORTING] A GUANACO, A RELATIVE OF THE LLAMA, AND AT 6 FEET TALL, THE ANDES' LARGEST ANIMAL.

NOW CAMOUFLAGED AGAIN, THE PUMAS GO UNNOTICED, AND THERE'S NO WIND TO CARRY THEIR SCENT...

BUT WHEN IT'S THIS CALM, THE SLIGHTEST RUSTLE COULD GIVE HER AWAY.

THE PUMA'S WEAPON IS STEALTH, NOT SPEED.

SHE MUST REMAIN UNDETECTED AS LONG AS POSSIBLE.

[GUANACO BLEATING] ONCE A GUANACO GETS GOING, THERE'S NO CATCHING IT.

[WIND BLOWING] A WIND FROM THE COAST BRINGS YET ANOTHER CHANGE IN THE WEATHER.

FOG BLOWS IN AND IS TRAPPED BY THE MOUNTAINS.

VISIBILITY DROPS TO A FEW FEET.

SOUND HAS BECOME MUFFLED.

FOR AN AMBUSH HUNTER LIKE THE PUMA, IT'S PERFECT.

[PUMA SNARLS, GROWLS] AND WHEN THE FOG LIFTS, IT REVEALS MOTHER PUMA'S SUCCESSFUL KILL.

THE FAMILY CAN EAT 30 POUNDS OF MEAT IN A SINGLE SITTING.

THEIR LIVES DEPEND ON MAKING THE MOST OF EVERY OPPORTUNITY THAT COMES THEIR WAY... AND THERE'S ONE FINAL WEATHER CHANGE FOR THE DAY.

A BURST OF MOUNTAIN SUNSHINE IS A WELCOME WARMER AND THE PERFECT EXCUSE FOR ANOTHER PLAY SESSION.

THIS CALM SPELL MIGHT ONLY LAST A MATTER OF MINUTES.

IN THE SOUTHERN ANDES, CHANGE IS THE ONLY CERTAINTY, BUT WHATEVER THE CONDITIONS, THEY WILL BE READY.

THIS LANDSCAPE STRETCHES FOR OVER A THOUSAND MILES UP THROUGH CHILE AND ARGENTINA.

BUT FURTHER NORTH ARE DIFFERENT MOUNTAIN WORLDS, EACH WITH ITS OWN CHALLENGES.

AND AT THE VERY TOP OF CHILE IS THE STRANGEST PLACE IN THE ENTIRE ANDES.

SURROUNDED BY A WALL OF HIGH MOUNTAINS, RAIN CLOUDS CAN'T REACH THE ATACAMA DESERT.

40,000 SQUARE MILES, THE DRIEST PLACE ON EARTH.

SOME WEATHER STATIONS HERE HAVE NEVER RECORDED A SINGLE DROP OF RAIN, YET ONE REMARKABLE CREATURE IS SO WELL SUITED TO LIFE HERE, IT'S FOUND NOWHERE ELSE ON THE PLANET.

THE SALT FLAT LIZARD.

HIS WHOLE LIFE REVOLVES AROUND WATER AND TRYING TO FIND IT.

IN THIS SUN-WARPED WORLD, LAKES SEEM TO APPEAR OUT OF THIN AIR AND VANISH JUST AS QUICKLY.

[SPLASH] BUT THIS TIME, THE WATER IS FOR REAL.

[SQUAWKING] MELT WATER FROM DISTANT MOUNTAINTOPS FLOWS UNDERGROUND UNTIL IT WELLS UP HERE.

IT SEEMS LIKE AN OASIS, BUT APPEARANCES CAN BE DECEIVING.

THIS WATER IS SATURATED WITH SALT, LEACHED FROM THE ROCKS.

BUT THERE'S A SECRET TO SURVIVING IN THIS WORLD.

[INSECT BUZZING] AND IT'S RIGHT IN FRONT OF HIM.

[BUZZING] BRINE FLIES.

SALT SPECIALISTS.

THE FLIES DRINK THE WATER, THEN FILTER OUT THE SALT... LEAVING THEM SWEET AND JUICY AND FILLED WITH FRESH WATER.

ALL THE LIZARD NEEDS TO DO... IS CATCH THEM.

TO GET THE EQUIVALENT OF A TEASPOON OF FRESH WATER, HE HAS TO EAT 400 FLIES.

THIS FLY-RIDDEN SHORELINE IS A PARADISE... AND THAT'S THE PROBLEM.

THERE'S A NEW GUY IN TOWN, AND THIS TERRITORY ISN'T BIG ENOUGH FOR THE BOTH OF THEM.

THE DEFENDER PUFFS HIMSELF UP.

MAYBE THE INTRUDER WILL BACK DOWN.

OWNING A STAKE IN THIS SHORELINE CAN BE THE DIFFERENCE BETWEEN LIFE AND DEATH.

BAD NEWS FOR THE INTRUDER.

THE VICTOR HAS HELD HIS GROUND, SO THE FLIES ARE ALL HIS AT THE ONLY SPRING IN HUNDREDS OF SQUARE MILES OF ANDES DESERT.

200 MILES TO THE NORTH, THE REMNANT OF A VAST PREHISTORIC LAKE SCARS THE BARREN LANDSCAPE.

TRAPPED BY THE ANDES, THE LAKE SLOWLY EVAPORATED, LEAVING BEHIND AN EXTRAORDINARY LEGACY.

INCREDIBLY, THE WORLD'S FLATTEST PLACE LIES HIDDEN AT 12,000 FEET AMONGST THE PEAKS OF THE BOLIVIAN ANDES.

THE SALAR DE UYUNI, THE WORLD'S BIGGEST SALT FLAT... 4,000 SQUARE MILES OF NOTHING...

EXCEPT FOR 50 BILLION TONS OF SALT.

THE SALT FLAT IS THE MOST HOSTILE ANDEAN WORLD.

NOTHING GROWS HERE.

THE SALT IS 16 FEET THICK, STUDDED WITH COUNTLESS POLYGONS, FORMED AS THE SALAR DRIED OUT.

THE SCENERY SEEMS UNCHANGING, BUT SOMETIMES IN LATE SUMMER, A MIRACULOUS TRANSFORMATION TAKES PLACE.

[THUNDER] SUDDEN RAINS LEAVE A LAYER OF DEAD-CALM WATER JUST AN INCH DEEP...

TURNING THE SALT FLAT INTO A NATURAL WONDER...

THE WORLD'S LARGEST MIRROR, 80 MILES ACROSS.

AT NIGHT, THE LANDSCAPE IS TRANSFORMED AGAIN...

INTO A 360-DEGREE STARSCAPE.

THIS DAZZLING SHOW IS ONLY POSSIBLE BECAUSE THE SALAR DE UYUNI IS PERFECTLY FLAT.

YET ONLY 200 MILES TO THE NORTH, THE ANDES ARE STAGGERINGLY VERTICAL.

HERE, 160 PEAKS RISE TO OVER 18,000 FEET.

THIS IS THE CENTRAL ANDES, A SERIES OF RUGGED WORLDS... AND ONCE THE HEART OF THE LARGEST CIVILIZATION THE ANDES HAS EVER KNOWN...

THE INCA EMPIRE.

ONLY 500 YEARS AGO, IT WAS THE GREATEST EMPIRE ON EARTH... AND MACHU PICCHU WAS ITS FINEST ROYAL ESTATE.

THE INCAS RULED 10 MILLION PEOPLE SCATTERED ACROSS THE ANDES.

THEY WERE MASTERS OF ENGINEERING.

THEIR GRANITE BLOCKS FIT TOGETHER PERFECTLY.

SOME WEIGH 14 TONS, EACH HEWN BY HAND AND HAULED INTO POSITION.

TODAY, THE INCA EMPIRE IS LONG GONE, BUT ITS CHALLENGING, RUGGED WORLD REMAINS.

THE APURIMAC RIVER CARVES A 600-FOOT GORGE THROUGH THE PERUVIAN HIGHLANDS.

AT QUEHUE, IT SPLITS COMMUNITIES IN HALF.

BUT THE LOCALS ARE DIRECT DESCENDANTS OF THE INCAS.

THEY'VE INHERITED THE SAME LANGUAGE, THE SAME AMAZING ENGINEERING SKILLS.

IN JUNE EVERY YEAR, THEY COME TOGETHER TO HARVEST A HARDY MOUNTAIN PLANT... COYAICHU GRASS.

IT'S STRONG AND FLEXIBLE TO COPE WITH THE HARSH MOUNTAIN WINDS.

PERFECT TO MAKE A SPECIAL ROPE.

AQUILINA RUIZ IS 77.

[RUIZ SPEAKING QUECHUA] RIGHT NOW, EVERY LOCAL HOUSEHOLD IS BUSY MAKING 200 FEET OF ROPE.

IT'S A REAL COMMUNITY EFFORT.

[LAUGHTER] SOON, ENTIRE VILLAGES WILL GATHER ON BOTH SIDES OF THE GORGE.

THEIR GRASS IS ABOUT TO PLAY CENTER STAGE IN A MOUNTAIN RITUAL PASSED DOWN SINCE INCA TIMES.

[MAN SHOUTING IN QUECHUA] [CHATTERING IN QUECHUA] ALL THIS WORK HAS ONE PURPOSE.

A BRIDGE HAS STOOD HERE SINCE INCA TIMES, A LINK BETWEEN COMMUNITIES.

BUT THIS IS NO ORDINARY BRIDGE.

IT'S MADE OF HUNDREDS OF THESE HANDMADE ROPES, WOVEN OUT OF TENS OF THOUSANDS OF FEET OF COYAICHU GRASS.

AQUILINA HAS BEEN USING IT SINCE CHILDHOOD.

BUT IN THE MOUNTAINS, THE BRIDGE WEARS OUT FAST AND MUST BE REPLACED EVERY YEAR.

AND NOW, THIS BRIDGE'S TIME HAS COME.

[MEN SHOUTING] BUT IN ORDER TO CREATE A NEW CROSSING, THEY MUST FIRST SEVER THEIR PRECIOUS CONNECTION.

PRIESTS MAKE OFFERINGS TO THE MOUNTAIN SPIRITS JUST AS THEIR ANCESTORS DID.

ONLY NOW CAN A NEW BRIDGE TAKE SHAPE.

[MEN SHOUTING] [CHEERING] AFTER 3 DAYS OF HAULING AND WEAVING, IT'S READY, THE COMBINED WORK OF 4 ENTIRE VILLAGES.

NOW AQUILINA CAN VISIT THE OTHER SIDE IN SAFETY... ALL THANKS TO A BRIDGE MADE OF SIMPLE MOUNTAIN GRASS... AND ORIGINAL INCA INGENUITY.

THE CENTRAL ANDES AREN'T JUST AN OBSTACLE FOR PEOPLE.

700 MILES TO THE NORTH IN WESTERN PERU, THE MOUNTAINS ARE SO LARGE, THEY LITERALLY STOP THE CLOUDS.

CREATING A SCORCHED WORLD OF DRY FOREST... WHERE RAIN RARELY FALLS.

IT'S OVER 100 DEGREES, EVEN IN THE SHADE.

THIS PARCHED LANDSCAPE IS HOME TO THE ANDES' MOST ELUSIVE ANIMAL...

THE SPECTACLED BEAR.

HE CAN GO 5 MONTHS WITHOUT A REAL DRINK, JUST SURVIVING ON SUCCULENT PLANTS.

STRONG, LONG LEGS AND CURVED CLAWS ARE PERFECT FOR CLIMBING.

HE KNOWS THE SECRET TO MASTERING THIS DESERT.

HE KNOWS THE SIGNS.

ON A FAR HILLSIDE, HE SPOTS IT, A SINGLE FIG TREE, AND THAT MEANS WATER.

[WATER BUBBLING] [BIRDS CHIRPING] A SPRING WELLS UP HERE.

IT'S CREATED A REFUGE WHERE MOUNTAIN ANIMALS FIND SHADE... AND LIFE-SAVING WATER.

[BEAR GROWLING] BUT LITTLE BEARS, LIKE THIS ONE, HAVE TO BE WARY.

THIS SANCTUARY IS A MAGNET FOR OTHER BEARS.

[DIFFERENT BEAR GROWLING] BEST TO NOT RISK A FIGHT WITH A BIG MALE LIKE THIS ONE.

[BEAR HUFFING] YOUNG BEARS MOVE BETWEEN OASES, SEEKING A PLACE TO CALL THEIR OWN.

THERE'S ONLY A HANDFUL OF SPRINGS IN 200 SQUARE MILES OF HIGH-ALTITUDE DESERT.

IN TIME, BEARS MAKE A MENTAL MAP OF EVERY SPRING IN THEIR TERRITORY.

[BIRD CHATTERING] SOME ARE NOTHING MORE THAN A COOLING MUD SLIDE.

OTHERS HAVE MAGNIFICENT BATHING FACILITIES.

[BEAR GROWLING] THANKS TO HIS AMAZING MEMORY, THIS BEAR CAN EVEN ENJOY A SWIM IN A DESERT.

THE REMOTE WORLDS OF THE SPECTACLED BEAR MAY NOT BE ISOLATED FOR MUCH LONGER.

ROADS ARE GRADUALLY CONNECTING THE CENTRAL ANDES...

BUT THESE ROADS ARE LIKE NO OTHERS IN THE WORLD.

NORTHERN PERU IS A DANGEROUS MAZE OF STEEP SLOPES, DEEP CANYONS... AND ROUGH ROADS.

THEY'RE ONLY FOR THE BOLD.

IN HUANCABAMBA, VILLAGERS RELY ON ONE MAN.

SOME HERE CALL HIM A HERO.

GLORIOSO ALBANEIDA HAS ONE OF THE WORLD'S MOST DANGEROUS JOBS.

HE'S THE BUS DRIVER, AND THIS IS THE 12:58 TO LIMA.

GLORIOSO HAS BEEN BEHIND THE WHEEL FOR OVER 50 YEARS.

HE STARTED AT AGE 14, DRIVING TRUCKS ACROSS THE ANDES.

[SPEAKING SPANISH] IT STARTS OFF EASY ENOUGH, DROPPING OVER 3,000 FEET ON A SERIES OF SWITCHBACKS CALLED "THE HORSE KILLER."

EVERY YEAR, OVER A THOUSAND LIVES ARE LOST ON PERU'S MOUNTAIN ROADS.

FOR GLORIOSO, IT'S JUST A NORMAL DAY.

HE'S BEEN DRIVING THIS ROUTE FOR 12 YEARS.

THE MOUNTAIN ROADS ARE SO ROUGH, HIS TIRES ONLY LAST 10 WEEKS.

BUT THE HARD PART IS FURTHER DOWN THE VALLEY.

THE ROAD IS BARELY A FOOT WIDER THAN THE BUS... SANDWICHED BETWEEN A 100-FOOT DROP ON ONE SIDE AND A TOWERING CLIFF ON THE OTHER.

NOT A PLACE TO MEET ONCOMING TRAFFIC.

[HONKS HORN] FOR THE PASSENGERS, IT'S JUST THE USUAL COMMUTE.

NOBODY'S IN A RUSH.

AS THE LOCAL SAYING GOES, IT'S BETTER TO ARRIVE A LITTLE LATE IN THIS WORLD... [HORN HONKING] THAN EARLY IN THE NEXT.

AND THAT'S THE SECRET TO A LONG CAREER AS A PERUVIAN BUS DRIVER, TAKING THE MOUNTAINS AT THEIR OWN PACE.

ROADS LIKE THIS WIND THEIR WAY THROUGH THE REMOTEST CORNERS OF THE CENTRAL ANDES, BUT SOME PEAKS WILL ALWAYS BE OFF-LIMITS.

AT 40 MILLION YEARS OLD, THE ANDES ARE THE YOUNGEST OF THE GREAT MOUNTAIN RANGES.

EVEN NOW, DEEP UNDERGROUND, TWO COLOSSAL TECTONIC PLATES ARE COLLIDING.

AS THE LAND BUCKLES, THE ANDES CONTINUE TO BE FORMED.

MUD BOILS WHERE IT OVERLIES VAST UNDERGROUND MAGMA CHAMBERS.

AS THE CHAMBERS SWELL, THE LAND ABOVE RISES FURTHER.

IN SOME PLACES, BY OVER 6 FEET A DECADE.

SOMETIMES, MAGMA PUSHES ALL THE WAY TO THE SURFACE.

THERE ARE OVER 200 ACTIVE VOLCANOES SPREAD ACROSS THE ANDES, MORE THAN ANYWHERE ELSE ON EARTH.

AN ERUPTION CAN BLAST A BILLION TONS OF ASH 13 MILES INTO THE ATMOSPHERE.

TECTONIC ACTIVITY HAS LEFT A REMARKABLE LEGACY ACROSS THE CENTRAL ANDES.

THE SOLIDIFIED REMAINS OF ONE ANCIENT MAGMA CHAMBER DOMINATES PERU'S PARON VALLEY.

A GRANITE TOWER IS A RARITY IN THE ANDES.

IT DRAWS PILGRIMS FROM ALL OVER.

MAN: WHEN I CAME TO THE MOUNTAIN, IT'S LIKE WHEN OTHER PEOPLE GO TO THE CHURCH AND PRAY.

I FEEL THE SAME CONNECTION WITH GOD.

NARRATOR: ALL HIS LIFE, IVAN CALDERON'S PASSION HAS BEEN FOR CLIMBING IN THE ANDES...

BUT TODAY, IT'S HIS FIRST ATTEMPT AT SCALING THIS TOWER... LA ESFINGE, OVER 3,000 FEET TALL, NEARLY VERTICAL.

WHEN THIS ROUTE WAS FIRST CLIMBED 30 YEARS AGO, IT TOOK 10 DAYS.

IVAN AND HIS PARTNER FUCO ARE ATTEMPTING IT IN JUST ONE.

THIS IS BIG WALL CLIMBING IN THE EXTREME.

FALLING FROM THE TOP, IT WOULD TAKE 22 LONG SECONDS TO HIT THE GROUND.

BECAUSE THIS GRANITE SOLIDIFIED SO SLOWLY OVER TENS OF THOUSANDS OF YEARS, IT'S PACKED WITH LARGE QUARTZ CRYSTALS, AND THAT'S THE KEY TO THE CLIMBERS' SUCCESS.

AS COARSE AS SANDPAPER, QUARTZ IS GOOD FOR GRIP BUT HARD ON THE SKIN.

3 HOURS IN AND 15,000 FEET UP, THERE'S ONLY HALF THE OXYGEN AS AT SEA LEVEL.

IVAN'S MUSCLES ARE SCREAMING.

[IVAN GRUNTING] AND NOW, HE FACES THE TOUGHEST PART OF THE CLIMB.

[IVAN BREATHING HEAVILY] NEXT, A SHEER FACE... [IVAN GROANS] POLISHED SMOOTH BY ICE AND WIND.

[IVAN GROANING] I'M EXHAUSTED.

THE AIR IS SO THIN, AND IT'S HARD TO BREATHE AT THIS ALTITUDE.

NARRATOR: 6 RELENTLESS HOURS INTO THE CLIMB, FUCO TAKES HIS TURN IN FRONT.

AFTER 10 HOURS, THE SUMMIT.

HEH HEH HEH.

HEH HEH HEH!

YEAH.

IVAN: ALL DAY FOR-- IT'S JUST FOR THIS MOMENT.

YOU KNOW, JUST TO ENJOY THIS VIEW.

WOW!

AMAZING.

NARRATOR: IVAN AND FUCO HAVE CLIMBED ABOVE THE CLOUDS TO 17,400 FEET.

BEYOND THEM STRETCHES A WHOLE NEW WORLD OF EXTREME HIGH ALTITUDE... PERU'S CORDILLERA BLANCA, THE "WHITE RANGE."

CLOUDS BLOW IN FROM THE AMAZON BASIN 200 MILES TO THE EAST.

BECAUSE THEY ARE SO LADEN WITH RAIN-FOREST MOISTURE, THEY GENERATE WET, DENSE SNOW, CREATING AN ICE WORLD FULL OF HUGE SNOW SCULPTURES... CORNICES MADE BY SNOW BLOWN OVER MOUNTAIN CRESTS, THOUSANDS OF TONS, TEETERING ON THE RIDGELINE.

THE SNOW CLINGS TO NEAR VERTICAL CLIFFS.

FLUTINGS FORM WHERE AVALANCHES HAVE GOUGED CHANNELS.

AND MOST MYSTERIOUS OF ALL, PENITENTES, BLADES OF ICE, EACH UP TO 20 FEET TALL, FORMED BY THE SUN CARVING TROUGHS IN THE SNOW.

ONE OF THE GREAT NATURAL WONDERS OF OUR PLANET, 4 MILES UP AND ALMOST NEVER SEEN.

ONE CREATURE, THOUGH, MAKES A HOME IN THE CENTRAL ANDES' ULTIMATE ICE WORLD.

PERU'S QUELCCAYA GLACIER COVERS 15 SQUARE MILES.

IT'S THE LARGEST EXPANSE OF ICE IN THE TROPICS.

ENORMOUS TONGUES OF ICE FLOW DOWN FROM QUELCCAYA'S SUMMIT UNTIL THEY BREAK UP AT ITS LOWERMOST REACHES.

AMAZINGLY, THE WHITE WINGED DIUCA FINCHES THRIVE HERE, 18,000 FEET UP.

[CHIRPING] ALSO KNOWN AS GLACIER BIRDS, THEY COME TO QUELCCAYA TO AVOID PREDATORS... AND THEY'VE DISCOVERED THE PERFECT PLACE TO RAISE A FAMILY...

THE GLACIER ITSELF.

[CHIRPING] TWO CHICKS ARE HIDDEN SAFELY INSIDE, THE WORLD'S ONLY GLACIER-NESTING BIRDS.

THIS IS ONE OF THE ULTIMATE ADAPTATIONS FOUND ANYWHERE IN THE ANDES.

AT NIGHT, THE TEMPERATURE DROPS TO 14 DEGREES... [WIND BLOWING] BUT INSULATED IN THEIR NEST, IT'S NOT THE COLD THAT THREATENS THEM UP HERE.

IT'S THE SUN.

THE CHICKS DON'T HAVE LONG.

IN LESS THAN A MONTH, THEIR HOME WILL MELT OUT OF THE ICE CLIFF.

IT'S A RACE AGAINST TIME.

IN PLACES, QUELCCAYA IS RECEDING OVER 30 FEET A YEAR.

OTHER NESTS HAVE ALREADY FALLEN.

FINALLY, ONE CHICK IS BOLD ENOUGH TO FOLLOW ITS PARENTS INTO THE OUTSIDE WORLD... LEAVING ITS SIBLING ALL ALONE.

NOW, THE NEST IS BEGINNING TO COLLAPSE.

[CHIRPING] AS A LAST RESORT, THE PARENTS CUT BACK ON FEEDING.

PERHAPS A MORE HUNGRY CHICK CAN BE COAXED OUT.

SAFE AT LAST.

BUT THE FUTURE FOR ITS SPECIES IS LESS CERTAIN.

THE AIR TEMPERATURE UP HERE IS RISING, AND QUELCCAYA'S RETREAT IS ACCELERATING.

AT CURRENT RATES, QUELCCAYA WILL BE 30% SMALLER IN JUST 20 YEARS.

THE HOME OF THE GLACIER BIRD IS SLOWLY DISAPPEARING.

ALONG THE LENGTH OF THE ANDES, EXTRAORDINARY ANIMALS HAVE MADE REMARKABLE ADAPTATIONS, EACH TO THEIR OWN UNIQUE WORLDS, BUT THESE WORLDS ARE CHANGING NOW MORE THAN EVER.

CORNERS THAT WERE ONCE ISOLATED ARE NOW WITHIN REACH.

OLD TRADITIONS ARE UNDER NEW PRESSURES, AND AS THE CLIMATE CHANGES, ANCIENT WORLDS MAY DISAPPEAR.

[FINCH CHIRPING] FOR THE ANIMALS AND PEOPLE OF THE ANDES, THE GREATEST CHALLENGE IS YET TO COME.

"KINGDOMS OF THE SKY" IS AVAILABLE ON BLU-RAY AND DVD.

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