TRANSCRIPT
Narrator: A GIANT SPERM WHALE PREPARING TO DIVE OVER A MILE INTO THE ABYSS.
ON ITS EPIC DESCENT, IT WILL HOLD ITS BREATH FOR LONGER THAN THIS PROGRAM LASTS.
Man: THEY LIVE IN A WORLD THAT'S SO FOREIGN TO US AND GIVE US JUST A GLIMPSE OF THEIR LIVES.
Narrator: IN THOSE DARK DEPTHS, THEY HAVE MASTERED A REALM NOT OF SIGHT, BUT OF SOUND.
Woman: OH, NOW.
[ IMITATES DOLPHIN CALL ] Narrator: HIDDEN BENEATH THE WAVES, DOLPHINS AND WHALES USE SOUND IN WAYS SO SOPHISTICATED, SCIENTISTS HAVE DEDICATED THEIR LIVES TO LISTENING TO THEIR STRANGE, ENIGMATIC VOICES.
SHARING THESE BREATHTAKING ENCOUNTERS, TWO OF THE WORLD'S TOP UNDERWATER CAMERAMEN, DOUG ALLAN AND DIDIER NOIROT.
Allan: WELL, HE WAS CLICKING AT ME.
Noirot: YEAH, HE WAS CLICKING.
HE WAS CALLING MUM, YOU KNOW.
CAME QUICKLY TO FETCH HIM.
SHE CAME RIGHT UP AND TOOK HIM AWAY.
YEAH. YEAH.
Narrator: WE ARE ON THE TRAIL OF SPERM WHALES, WHO HUNT USING THE LOUDEST SOUNDS MADE BY ANY ANIMAL ON THE PLANET; KILLER WHALES, USING SOUND AS A WEAPON; HUMPBACK WHALES, SINGING THEIR HEARTS OUT TO THE WORLD.
IF WE ARE EVER TO TRULY KNOW THEM, WE MUST DECIPHER THE GREAT CHORUS OF THEIR VOICES CALLING OUT ACROSS THE DEEP BLUE SEA.
AN ESTUARY IN TASMANIA, AUSTRALIA.
MIGHTY SPERM WHALES LIE STRANDED.
SOMETHING'S GONE WRONG WITH THEIR POWERS OF NAVIGATION, AND THE CONSEQUENCES ARE DEADLY.
DISORIENTED AND WITHOUT SUFFICIENT WATER TO SUPPORT ITS BULK, THIS GREAT WHALE IS SLOWLY DYING.
LUCKILY, HELP IS AT HAND.
HIS RESCUERS USE THEIR BOAT TO CREATE A WAVE, TRYING TO WASH HIM INTO DEEPER WATER.
THEY CAREFULLY COVER UP HIS SUNBURNED SKIN.
AND FINALLY, THEY USE A NET TO TOW HIM TO SAFETY.
FREE AT LAST!
ONCE CLEAR OF THE SHALLOWS, HE STARTS SENDING OUT LOUD CLICKS, USING THE ECHOES TO FORM A MENTAL PICTURE OF THE WORLD AROUND HIM.
SOON HE IS BACK IN THE SAFETY OF DEEP WATER.
BUT SPERM WHALES DON'T JUST USE SOUND TO NAVIGATE.
THEIR VOICES ARE CENTRAL TO THEIR VERY EXISTENCE.
SPERM WHALES ARE REGULAR VISITORS TO THE VERY DEEP WATERS OF THE CARIBBEAN ISLAND OF DOMINICA.
HERE, SCIENTISTS ARE TRYING TO UNDERSTAND ALL THE WAYS SPERM WHALES USE SOUND UNDERWATER.
IT'S BECOME A SOURCE OF ENDLESS FASCINATION FOR BIOLOGIST SHANE GERO.
I THINK I REALLY LIKE THE SPERM WHALES IN PARTICULAR BECAUSE THEY'RE DEEP DIVERS.
THEY LIVE IN A WORLD THAT'S SO FOREIGN TO US AND GIVE US JUST A GLIMPSE OF THEIR LIVES.
IT'S ALMOST AS IF THEY HAVE THIS BIG SECRET THAT THEY'RE NOT WILLING TO SHARE, AND I JUST HAVE TO DIG AWAY AND TRY AND FIGURE OUT WHAT THAT IS.
Narrator: THE TEAM HEADS OUT INTO DEEPER WATERS.
SPERM WHALES HAVE BEEN KNOWN TO HUNT IN WATERS MORE THAN 10,000 FEET DEEP.
FINDING THEM WON'T BE EASY.
THEY SPEND MOST OF THEIR TIME SUBMERGED, ONLY RETURNING TO THE SURFACE TO BREATHE.
ANDREW ARMOUR AND HIS CREW HAVE BEEN FOLLOWING THESE WHALES FOR MORE THAN A DECADE.
TODAY, THEY ARE JOINED BY UNDERWATER CAMERAMEN DIDIER NOIROT AND DOUG ALLAN.
RIGHT. OKAY.
READY? YEP.
Narrator: THE TRICK TO FINDING SPERM WHALES IS TO TRACK THEIR SOUNDS.
AN UNDERWATER MICROPHONE, OR HYDROPHONE, WILL CATCH THEM DOING WHAT THEY DO BEST -- MAKING NOISE.
SOUND TRAVELS FASTER AND FARTHER IN WATER THAN IN AIR, SO THE TEAM WILL BE ABLE TO HEAR ANY WHALES LONG BEFORE THEY SEE THEM.
Gero: SO WHAT YOU WANT TO HEAR IS A SERIES OF CLICKS.
THE MORE YOU HEAR, THE BETTER.
IF IT SOUNDS LIKE POPCORN OR BACON FRYING, WE'RE GOING TO HAVE A GOOD DAY.
I'M AFRAID THE FRYING PAN'S EMPTY.
[ LAUGHS ] Narrator: SPERM WHALES ARE THE LARGEST TOOTHED PREDATORS ON THE PLANET.
THERE'S THE MALE.
WOW, HE'S REALLY WELL MARKED.
Narrator: BUT EVEN THEY HAVE ENEMIES... PILOT WHALES.
Man: THEY WILL ATTACK THE SPERMS.
THEY'LL GO OUT, EAT THE BABIES.
AND WE'VE SEEN THIS INTERACTION.
THE PILOT WHALES WILL ATTACK THE SPERM WHALES?
YEAH!
Narrator: COUNTING ON THE FACT THAT PILOT WHALES DON'T USUALLY ATTACK HUMANS, DIDIER IS KEEN TO TAKE A CLOSER LOOK.
CLOSE COUSINS OF KILLER WHALES, PILOT WHALES ARE ONLY A THIRD THE SIZE OF ADULT SPERM WHALES.
BUT THEY HAVE STRENGTH IN NUMBERS.
HUNTING IN PACKS UP TO A HUNDRED STRONG, THEY, TOO, WILL BE LISTENING FOR THE SOUNDS OF SPERM WHALES.
Gero: THERE IS A CHANCE THAT IF WE KEEP FOLLOWING THESE PILOTS, THAT WE'LL END UP TRACKING THEM AS THEY TRACK THE SPERMS.
Narrator: AT LAST, THE TEAM BEGINS TO HEAR SPERM WHALES.
BUT THESE AREN'T CLICKS FOR NAVIGATION.
THESE ARE CLICKS FOR COMMUNICATION, KNOWN AS CODAS.
CODAS, CODAS, CODAS, CODAS!
[ CLICKING ] OH, YEAH, OKAY, I CAN DEFINITELY HEAR THE CLICKING, YEAH!
CAN YOU HEAR THEM, SHANE?
IT GETS HARD TO COUNT MORE THAN THREE, BECAUSE AFTER YOU GET -- IT MIGHT BE A CLICK -- OH!
Man: THERE SHE BLOWS!
THERE SHE BLOWS!
LET'S PUT OUT THE FISHING BOAT! THERE SHE BLOWS!
Narrator: THE FAMOUS, THOUGH FICTIONAL, MOBY-DICK WAS A SPERM WHALE.
NO ONE WAS EAGER TO SWIM WITH HIM.
BUT DOUG AND DIDIER ARE TAKING ON THE REAL WHALES WITH THIS RARE CHANCE TO GET CLOSE TO THEM.
[ WHALE CLICKING ] SPERM WHALE FAMILIES MAY CONTAIN SEVERAL GENERATIONS OF DAUGHTERS WITH THEIR BABIES, OVERSEEN BY A WISE OLD GRANDMOTHER.
SHANE BELIEVES THAT THEY COMMUNICATE THROUGH A COMPLEX ARRAY OF CODA CLICKS, WHICH VARY FROM FAMILY TO FAMILY.
BUT THEY CAN ALSO PUT THESE CLICKS TO FAR MORE LETHAL USE.
IT'S TIME FOR THE ADULTS TO FEED.
FOR THE LAST 15 MINUTES, THE ADULTS HAVE BEEN DEEP BREATHING TO STORE AS MUCH OXYGEN AS POSSIBLE IN THEIR HUGE MUSCLES.
THEIR LUNGS, AND EVEN THEIR RIB CAGES, COLLAPSE AT DEPTH.
IT'S THE OXYGEN CONTENT THEY STORE IN THEIR BLOODSTREAM THAT LETS THEM STAY DOWN SO LONG.
NOW IT'S TIME TO DIVE.
DOUG AND DIDIER CAN ONLY HOLD A LUNGFUL OF AIR, SO THEIR DEPTH LIMIT IS AROUND 60 FEET.
BUT WITH ADAPTATIONS TO DEPTH AND PRESSURE THAT WE STILL DON'T UNDERSTAND, SPERM WHALES CAN GO A HUNDRED TIMES DEEPER AND STAY DOWN FOR OVER AN HOUR.
NO ONE HAS EVER SEEN A SPERM WHALE HUNT IN THE ABYSS, BUT SCIENTISTS NOW BELIEVE IT HAPPENS LIKE THIS.
THOUSANDS OF FEET BELOW THE SURFACE, THE OCEAN IS RICH WITH LIFE.
AND IT'S THE HAUNT OF THE SPERM WHALE'S FAVORITE FOOD -- GIANT SQUID MORE THAN 30 FEET LONG.
A MILE DOWN, IT'S PITCH BLACK.
NO LIGHT PENETRATES THIS DEEP.
THE WHALE MUST FIND ITS PREY THROUGH ECHOLOCATION -- INTERPRETING THE ECHOES OF THE CLICKS IT MAKES.
BUT THESE ARE NO ORDINARY CLICKS.
THESE HUNTING CLICKS ARE THE LOUDEST SOUNDS MADE BY ANY LIVING THING, LOUDER THAN A THUNDERCLAP.
PRODUCED IN ITS FIVE-TON NOSE, THE WHALE'S CLICKS TRAVEL BACKWARDS, THEN ARE REFLECTED FORWARDS THROUGH A SERIES OF OIL-FILLED LENSES WHICH FOCUS THEM INTO A NARROW SOUND BEAM, LIKE A SONIC LASER.
FOR THE GIANT SQUID, THERE'S NOWHERE TO HIDE.
WHILE THE ADULTS ARE HUNTING, THEIR INFANTS ARE LEFT AT THE SURFACE UNDER THE CARE OF AN AUNT OR SISTER.
BUT EVEN THE BEST BABYSITTERS CAN LOSE TRACK OF THEIR CHARGES AT TIMES.
OUT OF THE BLUE, A BABY HEADS STRAIGHT FOR THE BOAT.
REMARKABLY, IT'S ALL ALONE.
IT TAKES REFUGE BETWEEN THE HULLS.
MAYBE THEY'RE STAND-INS FOR THE COMFORTING PRESENCE OF OTHER WHALES.
THE BABY IS INTENSELY INTERESTED IN DOUG -- AND AS HE APPROACHES, IT CALLS OUT WITH A STREAM OF LOUD CLICKS.
IT IS SAID THAT WHEN AN ADULT SPERM WHALE CLICKS AT A DIVER, IT'S LIKE BEING KICKED IN THE CHEST BY A HORSE.
WHILE THIS INFANT'S CODA CLICKS MAY JUST BE BABY-TALK, THEY WILL CARRY FOR MORE THAN A MILE, DOWN TO WHERE THE ADULTS ARE FEEDING.
UP FROM THE DEEP, THE BABY'S MOTHER APPEARS.
IGNORING DOUG AND DIDIER, SHE GENTLY SHEPHERDS HER BABY AWAY TO SAFETY.
Allan: THAT WAS GREAT!
Noirot: IT'S SO CUTE!
Allan: IT WAS JUST GREAT! FOR A FIRST TIME, IT WAS SUPER!
[ WHALE CLICKING ] Noirot: WE HEARD A LOT OF CLICKS, CALLING CLICKS.
THERE WAS A LOT OF CLICKS.
YEAH, WELL, HE WAS CLICKING AT ME.
Noirot: HE WAS CLICKING, CALLING HIS MUM, BECAUSE HE WAS UNDER THE BOAT, THE MUM CAME QUICKLY TO FETCH HIM.
SHE CAME RIGHT UP AND TOOK HIM AWAY.
Narrator: THROUGH THEIR REMARKABLE MANIPULATION OF SOUND, SPERM WHALES ARE ABLE TO COMMUNICATE, NAVIGATE, AND EVEN HUNT IN A PITCH-BLACK ABYSS THAT OUR BEST INSTRUMENTS FIND DIFFICULT TO PENETRATE.
BUT IT'S NOT JUST DARKNESS AND DEPTH THAT WHALES MUST CONQUER.
IN THE FROZEN ARCTIC OCEAN, IT'S ICE.
SOMETIMES SEVERAL FEET THICK.
AN OPEN LEAD THROUGH THE PACK ICE IS AN OPEN HIGHWAY TO THE MOST BIZARRE-LOOKING OF ALL TOOTHED WHALES.
A LEGENDARY CREATURE.
THE UNICORN OF THE SEA.
THE NARWHAL.
ITS EXTRAORDINARY HORN IS ACTUALLY A TOOTH GROWING STRAIGHT OUT OF ITS HEAD.
ITS PURPOSE IS STILL A MYSTERY.
TO REACH NEW FISHING GROUNDS, THESE WHALES MUST MIGRATE HUGE DISTANCES THROUGH CONSTANTLY SHIFTING FIELDS OF ICE.
UNABLE TO HOLD THEIR BREATH FOR MORE THAN 20 MINUTES, THEY MUST FIND REGULAR BREATHING HOLES -- OR THEY RISK BECOMING TRAPPED.
STRANDED IN THE ICE, THEY FACE STARVING OR DROWNING.
HOW DO THEY FIND THESE ESSENTIAL AIR HOLES DOTTED RANDOMLY ACROSS THE VAST SHEETS OF ICE?
LIKE SPERM WHALES, NARWHALS CAN ECHOLOCATE.
THEY FIRE OFF A SERIES OF SONIC PULSES AND USE THE ECHOES TO MAP THE WORLD AROUND THEM.
THEY KNOW A GREAT DEAL ABOUT THE ICE -- HOW THICK IT IS, HOW STABLE, AND HOW IT'S MOVING ABOVE THEM.
IN THIS WAY, THEY CAN LOCATE VITAL BREATHING HOLES FROM HUNDREDS OF FEET AWAY.
AS WINTER CLOSES IN, THE SEA AROUND THE NARWHALS BEGINS TO FREEZE OVER, LEAVING THEM WITH FEWER AND FEWER OPENINGS.
IT'S ONLY THEIR SOPHISTICATED POWERS OF ECHOLOCATION, A MASTERY OF SOUND WE CAN SCARCELY IMAGINE, THAT AFFORDS THE NARWHALS SAFE PASSAGE THROUGH THE ICE.
IT'S THE VERY KEY TO THEIR SURVIVAL.
NARWHALS ARE ADAPTED TO A WORLD THAT IS DARK AND FROZEN FOR MUCH OF THE YEAR.
BUT THEY HAVE AN INTERESTING RELATIVE USING THE SAME REMARKABLE SKILLS TO FLOURISH IN THE TROPICS.
THEY LIVE IN THE LAST PLACE YOU MIGHT EXPECT TO FIND A DOLPHIN... 3,000 MILES INLAND, IN THE HEART OF THE BRAZILIAN RAINFOREST.
FLOWING THROUGH THE RAINFOREST IS THE MIGHTY AMAZON RIVER, THE PLANET'S LARGEST FRESH WATER SYSTEM.
IN SOME WAYS, IT MAKES PERFECT SENSE FOR A DOLPHIN TO MAKE ITS HOME HERE.
THERE ARE MORE SPECIES OF FISH IN THE AMAZON THAN IN ALL OF THE ATLANTIC OCEAN.
BUT HOW CAN A DOLPHIN CATCH FISH IN WATER SO MUDDY THAT IT CAN'T SEE A THING?
500 KILOMETERS WE'VE DONE, JUST... Narrator: DOUG ALLAN AND BRAZILIAN SCIENTIST VERA DA SILVA ARE ON THEIR WAY TO INVESTIGATE.
IT'S VERY BEAUTIFUL, I'M LOOKING FORWARD TO GOING DOWN THERE.
WE'LL BE TRAVELLING EVERYWHERE BY BOAT.
da Silva: JUST RIVERS AND WATER.
AND LOTS OF DOLPHINS. LOTS OF DOLPHINS.
Narrator: THIS IS THE CREATURE THAT VERA IS STUDYING, PERHAPS THE STRANGEST DOLPHIN OF ALL -- THE BOTO, OR AMAZON RIVER DOLPHIN.
IN THE MAZE OF TRIBUTARIES AND JUNGLE, DOUG NEEDS VERA'S EXPERTISE TO FIND THE DOLPHINS.
BOTOS OFTEN FISH WHERE TWO RIVERS COME TOGETHER, LETTING THE DIFFERENCES IN THE WATERS HELP THEM CORRAL THEIR PREY.
BUT IN THE WET SEASON, ONE OF THE AMAZON'S TRIBUTARIES, THE RIO NEGRO, BREAKS ITS BANKS AND FLOODS AN AREA OF JUNGLE THE SIZE OF FRANCE.
THIS FANTASTIC WATER WORLD IS KNOWN AS THE FLOODED FOREST.
[ CALLING ] THE WATER IS CLEARER HERE THAN IN THE AMAZON, BUT IT'S CHOKED BY BRANCHES AND LEAVES WITH TANNINS THAT MAKE IT AS DARK AS WELL-BREWED TEA.
FINDING THESE STRANGE DOLPHINS IN THIS STRANGE FOREST WOULD BE IMPOSSIBLE IF IT WERE NOT FOR THEIR OWN NATURAL CURIOSITY.
Allan: COME ON, BOTOS!
NO, THEY ARE THERE.
Allan: YEAH, THEY ARE THERE.
da Silva: LOOK, LOOK, LOOK!
Allan: OH, YEAH.
da Silva: RIGHT HERE, ANOTHER ONE THERE, THEY START SHOWING UP NOW.
Narrator: THE DOLPHINS CAN'T RESIST CHECKING THEM OUT, AND VERA LOWERS A HYDROPHONE TO LISTEN TO THEIR CHATTER.
da Silva: LET'S SEE HOW MUCH NOISE THESE GUYS ARE DOING NOW.
OH, OKAY.
Allan: DO YOU WANT TO LISTEN?
YES, A LITTLE BIT, THANK YOU.
[ DOLPHINS CLICKING ] da Silva: YEAH, NOW I HEARD, YEAH, LIKE A SERIES OF OH, NOW, [ LAUGHS ]. YOU CAN HAVE IT.
OH, YEAH, YEAH.
Narrator: THEY EAVESDROP ON AN EXTRAORDINARY ARRAY OF SOUNDS.
BUT WHAT IS ALL THE NOISE ABOUT?
TO FIND OUT MORE, VERA AND DOUG ATTRACT THE DOLPHINS EVEN CLOSER TO THE BOAT.
Allan: SO, IS THERE A SECRET TO BRINGING THEM CLOSER?
da Silva: YES. SOMETIMES THEY WILL REACT TO THE NOISE OR TO SOME FISH.
IF WE GIVE THEM SOME FISH, THEY WILL COME QUICKLY.
da Silva: SEE, THREE AT THE SAME TIME.
Narrator: THE BIZARRE-LOOKING BOTO SHOWS OFF ITS SLENDER TOOTHY SNOUT.
AND THE ENORMOUS BULGE ON ITS FOREHEAD, CALLED THE MELON.
TO SEE HOW IT USES THE ODD-LOOKING ANATOMY UNDERWATER, DOUG WILL NEED TO DUNK HIMSELF IN THE TEA.
Allan: OKAY.
Narrator: THE BOTOS ARE USING TWO COMPLETELY SEPARATE SOUND SYSTEMS -- SIMULTANEOUSLY.
THE CHATTERING NOISES ARE VOCALIZATIONS, THE SOUND OF THEM TALKING TO EACH OTHER.
BUT THEY ALSO APPEAR TO BE SCANNING DOUG WITH ELECTRONIC-SOUNDING CLICKS AND BUZZES.
THIS IS THEIR ECHOLOCATION IN ACTION.
Allan: HE CAME UP, TOOK THE FISH AND HE SWAM BACKWARDS, I'VE NEVER SEEN A DOLPHIN SWIM BACKWARDS BEFORE.
Narrator: RIVER DOLPHINS MAY BE THE MOST FLEXIBLE MEMBERS OF THE FAMILY.
THEIR VERTEBRAE ARE NOT FUSED LIKE THOSE OF OCEAN-GOING DOLPHINS, ALLOWING THEM TO TURN THEIR HEADS IN EVERY DIRECTION.
THE BOTOS LEAD DOUG DEEPER INTO THEIR UNDERWATER FOREST, WHERE ECHOLOCATION ALLOWS THEM TO NAVIGATE SAFELY THROUGH THIS TANGLE OF SUBMERGED VEGETATION.
THE BOTO'S CLICKS AND BUZZES ARE FOCUSED INTO A SOUND BEAM BY ITS BULGING FOREHEAD MELON.
THE BEAM WORKS LIKE A SONIC SHAFT OF LIGHT, ALLOWING THE DOLPHIN TO BUILD UP A CLEAR PICTURE OF ITS SURROUNDINGS.
Allan: IT'S AS TANGLED AND SPINY UNDERWATER AS IT IS ON THE SURFACE.
THOSE BOTOS ARE GOING TO NEED ALL THEIR MANEUVERABILITY AND ALL THE SONAR SKILLS THEY POSSESS TO OPERATE IN THIS SORT OF UNDERWATER ENVIRONMENT.
Narrator: WHILE ALL DOLPHINS CAN ECHOLOCATE, BOTOS' CLICKS HAVE A HIGHER FREQUENCY AND BETTER RESOLUTION THAN ANY OTHER DOLPHIN'S, ALLOWING THEM TO DISTINGUISH OBJECTS AS SMALL AS A PIN.
EVEN IN ZERO VISIBILITY, CATCHING FISH IS CHILD'S PLAY.
Allan: THESE ARE THE WEIRDEST DOLPHINS THAT I'VE EVER SEEN.
THEY'RE ABSOLUTELY, THEY'RE JUST FANTASTIC!
Narrator: THE FRIENDLY BOTOS, IN THEIR UNDERWATER JUNGLE, ARE CONSTANTLY CLICKING AND BUZZING.
[ CALLING ] BUT FAR AWAY, THE LARGEST MEMBERS OF THE DOLPHIN FAMILY USE SOUND AS A SOPHISTICATED WEAPON.
INCLUDING A REMARKABLE POPULATION FOUND OFF ICELAND, IN THE NORTH ATLANTIC OCEAN.
ON THE WESTMAN ISLANDS, A TEAM OF WHALE SCIENTISTS IS JOINED BY DIDIER NOIROT.
Narrator: LARGE NUMBERS OF KILLER WHALES HAVE GATHERED TO HUNT THE VAST SCHOOLS OF HERRING THAT COME HERE TO SPAWN EACH SPRING.
BUT THE COORDINATED AND FLUID MOVEMENTS OF THE HERRING MAKE THEM EXCEPTIONALLY HARD TO CATCH.
HOW DO THESE HUGE PREDATORS MANAGE TO CAPTURE THESE FAST LITTLE FISH, AND IN SUFFICIENT NUMBERS TO MAKE IT WORTHWHILE?
SCIENTIST VOLKER DEECKE IS AN EXPERT IN KILLER WHALE ACOUSTICS.
OKAY, WHERE DO YOU THINK WE'LL FIND A KILLER WHALE?
WE'VE HAD REALLY GOOD SUCCESS RIGHT IN THIS AREA.
Narrator: RECENTLY, VOLKER HAS BEEN INVESTIGATING HOW KILLER WHALES BREAK THROUGH THE HERRINGS' DEFENSES, AND IT'S ALL TO DO WITH SOUND.
FOR DIDIER TO CAPTURE THEIR TECHNIQUE ON CAMERA, THEY'LL NEED TO GET RIGHT ALONGSIDE HUNTING KILLERS.
HAVING REACHED THE AREA WHERE THE WHALES WERE LAST SEEN, VOLKER DEPLOYS HIS HYDROPHONES.
A GATHERING OF SEABIRDS MEANS A HERRING SCHOOL MUST BE CLOSE TO THE SURFACE.
SOMETHING MUST HAVE SPOOKED THEM.
Noirot: OH!
SEVEN OR EIGHT TOGETHER CAME AT THE TOP OF THE WAVES.
Narrator: KILLER WHALES.
VOLKER IS PERFECTLY POSITIONED TO RECORD THE SOUNDS OF THE HUNTING WHALES.
Deecke: 3, 4... BE GREAT TO SEE WHAT THE WHALES ARE DOING UNDERWATER WHEN THEY'RE MAKING ALL THESE SOUNDS.
Narrator: TO FILM THEM SAFELY, DIDIER USES A POLE CAMERA.
YOU ARE THE EARS, I'M THE EYE.
Narrator: GETTING IN THE WATER WITH FEEDING KILLER WHALES IS DEEMED TOO DANGEROUS, EVEN FOR A DAREDEVIL CAMERAMAN.
YEAH, THAT'S THE CALL.
THAT WAS A KILLER WHALE. NO DOUBT ABOUT IT.
Narrator: AFTER TWO HOURS OF INTENSIVE FEEDING, THE KILLERS HAVE FALLEN SILENT.
THE ATTACK IS OVER.
BACK IN WESTMAN HARBOR, THE TEAM REVIEWS THE RECORDING, WHICH REVEALS THE WHALES' SECRET WEAPON.
YOU'RE GOING TO HEAR A LOT OF ECHOLOCATION CLICKS.
BUT THEN YOU'LL HEAR SOMETHING PRETTY SPECIAL.
HERE WE GO.
WHISTLES, ECHOLOCATION... AND NOW HAVE A GOOD LISTEN.
[ HIGH-PITCHED NOTE ] [ NOTE CONTINUES ] Narrator: THIS HIGH-PITCHED NOTE IS WHAT'S KNOWN AS THE HERDING CALL.
Deecke: THE IDEA IS THAT THE WHALES MAY BE USING THE SOUND TO ESSENTIALLY CAUSE RESONANCE IN THE HERRINGS' SWIM BLADDER THAT MAKES THE HERRINGS' GUTS VIBRATE AND THAT MAKES THE HERRING VERY UNCOMFORTABLE.
[ HERDING CALL ] Narrator: PANICKED BY THE GUT-WRENCHING NOISE, THE HERRING BUNCH SO TIGHTLY TOGETHER, THEY HAVE NO ROOM TO MANEUVER.
THEY SCHOOL TOGETHER, AND THEN BANG!
Narrator: THE KILLER WHALES THEN DELIVER DEVASTATING TAIL-SWIPES WITH THE FORCE OF AN EXPLODING GRENADE.
JOB DONE, THE WHALES CAN RELAX OVER A LEISURELY FEAST OF STUNNED FISH.
WHALES AND DOLPHINS USE THEIR VOICES TO KEEP THE FAMILY GROUP TOGETHER, BUT THERE ARE TIMES WHEN TALKING JUST ISN'T ENOUGH.
IN THE RICH WATERS OFF NEW ZEALAND, HUNDREDS OF DOLPHINS TRAVEL TOGETHER IN SUPER-PODS.
MOVING AT HIGH SPEED IN SUCH LARGE GROUPS REQUIRES CLEAR COMMUNICATION.
BUT CLICKS AND WHISTLES ONLY HAVE A LIMITED RANGE.
THE ONLY WAY TO BROADCAST MESSAGES ACROSS THE GROUP IS BY GENERATING LOUDER, MORE EXPLOSIVE SOUNDS.
DIFFERENT BODY SMACKS CONVEY DIFFERENT MEANINGS.
IT'S THOUGHT DOLPHINS MAY USE SUCH ACROBATIC LEAPS TO SIGNAL THE DISCOVERY OF LARGE SCHOOLS OF FISH.
BODY PERCUSSION IS A KEY INGREDIENT IN DOLPHIN COMMUNICATION AND THEY WILL EVEN USE IT TO SIGNAL TO ON BRAZIL'S ATLANTIC COAST, ONE REMARKABLE GROUP OF DOLPHINS IS IN CAHOOTS WITH THE LOCALS.
FISHERMEN FROM THE TOWN OF LAGUNA HAVE DISCOVERED THEY DO BETTER WHEN THEY DON'T FISH ALONE.
EACH DAWN THEY GATHER IN THE MURKY SHALLOWS OF THE ESTUARY AND WAIT FOR HELP TO ARRIVE.
THEIR FISHING PARTNERS ARE A GROUP OF BOTTLENOSE DOLPHINS.
SCIENTIST ARNALDO RUSSO EXPLAINS THAT THIS LOCAL DOLPHIN POD HAS BEEN HELPING HUMANS FISH FOR MORE THAN A CENTURY.
Russo: THE FISHERMEN KNOW WHEN THEY CAN THROW HIS NETS BECAUSE THE DOLPHIN'S MAKING SPECIAL SIGNS.
THEY CAN GIVE A HEAD-SLAP OR A TAIL-SLAP INTO THE WATER.
Allan: WHEN THE FISHERMEN SEE THOSE SPECIAL SIGNS, THEY THROW THEIR NETS.
Russo: YES. IT'S LIKE A CONVERSATION.
Narrator: IT'S A CONVERSATION INITIATED ENTIRELY BY THE DOLPHINS.
FIRST, THEY HERD THE MULLET INTO SHORE AS FAR AS THEY CAN, THEN SIGNAL TO THE MEN IN THE SHALLOWS.
Russo: GO, GO, GO.
Narrator: IT'S AS THOUGH THESE DOLPHINS HAVE DISCOVERED THAT HUMANS ARE SMART ENOUGH TO TRAIN.
THE DOLPHINS CORRAL THE FISH ON ONE SIDE AND GET THE HUMANS TO WORK THE SIDE THEY CAN'T REACH.
SINCE THEY DETECT PREY BY ECHOLOCATION, THEY HAVE NO PROBLEM FINDING FISH IN THE MURKY WATER.
BUT EVEN CLOSE TO THE SHORE, THE FISH HAVE PLENTY OF ROOM TO ESCAPE.
BY CASTING THEIR NETS ON CUE, THE FISHERMEN SEND THE PANICKED FISH THEY DON'T CATCH STRAIGHT BACK INTO THE OPEN MOUTHS OF THE DOLPHINS.
WHILE THE DOLPHINS OF LAGUNA HAVE BEEN ABLE TO REACH OUT TO US, WE HAVE YET TO DECIPHER WHAT THEY ARE SAYING TO EACH OTHER.
ONE ENDURING MYSTERY SURROUNDS THE MOST CELEBRATED MUSICAL EVENT IN NATURE -- THE SONGS OF THE HUMPBACK WHALE, PERFORMED EVERY WINTER OFF THE ISLANDS OF HAWAII, IN THE MIDDLE OF THE PACIFIC OCEAN.
BEFORE THE SINGING CAN BEGIN, THE PERFORMERS GIVE A MASTER-CLASS IN PERCUSSION.
40-TON BODIES HIT THE SEA WITH AN EAR-SPLITTING CRASH.
AND GIANT TAIL FLUKES THUNDER OUT A MESSAGE TO RIVAL MALES.
DIDIER MAKES SURE TO GET A FRONT ROW SEAT.
Crew member: NEUTRAL.
Narrator: THE OCEAN REVERBERATES WITH EXPLOSIONS OF BUBBLES... AND THEN THE OPERA BEGINS.
[ WHALES SINGING ] Noirot: THE SONG OF THE HUMPBACK, IT'S SOMETHING REALLY BEAUTIFUL.
THE MOST BEAUTIFUL SOUND YOU CAN HEAR IN THE SEA.
Noirot: YOU'RE THE SCIENTIST.
Narrator: JIM DARLING HAS SPENT THE LAST THIRTY YEARS TRYING TO WORK OUT THE MEANING OF THESE EXTRAORDINARY SONGS.
[ WHALE SINGING ] IT'S VERY CLOSE.
WOW.
THERE ARE A FEW OF THEM, YEAH?
YEAH, THERE'S A FEW.
THERE'S ONE CLOSE AND THEN 3 OR 4 IN THE BACKGROUND.
YEAH, THEY ARE A BEAUTIFUL SOUND.
Narrator: WITH HIS MOUTH SHUT TIGHT, SHUNTING AIR BACK AND FORTH THROUGH A LARYNX THE SIZE OF A VENDING MACHINE, TECHNICALLY HE'S HUMMING, NOT SINGING.
WHATEVER IT IS, IT'S A VOICE THAT CAN TRAVEL THOUSANDS OF MILES ACROSS AN ENTIRE OCEAN BASIN.
THE MALE'S RECITAL MAY INCLUDE HALF A DOZEN DISTINCT THEMES WHICH HE'S LEARNED FROM OTHER MALES.
HE MAY EVEN ADD HIS OWN PERSONAL VARIATIONS.
BUT THE ASTONISHING THING IS THAT FROM MEXICO TO JAPAN, ALL THE SINGERS ARE WORKING ON THE SAME SONG, AT THE SAME TIME.
IT'S A COMPOSITION THEY IMPROVISE TOGETHER FROM ONE YEAR TO THE NEXT.
BUT DOES IT HAVE A PURPOSE?
Darling: FOR A LONG TIME, IT WAS PRESUMED THAT THE SINGERS WERE SINGING TO ATTRACT A FEMALE, AND I THINK PEOPLE LIKE THAT IDEA BECAUSE IT'S BEEN WRITTEN ABOUT A LOT, BUT THERE'S NOT A SHRED OF EVIDENCE FOR IT.
WE'VE NEVER SEEN A FEMALE APPROACH A MALE.
Narrator: IF THEY AREN'T CALLING A MATE, THEN WHY ARE THEY SINGING?
IS IT A WAY FOR MALES TO SIZE EACH OTHER UP?
COULD THEY EVEN BE MAKING MUSIC FOR PLEASURE?
THE TRUTH IS -- NOBODY KNOWS.
THE ENIGMATIC VOICES OF WHALES AND DOLPHINS HAVE CAPTURED OUR IMAGINATION FOR CENTURIES.
SCIENTISTS MAY ONE DAY UNDERSTAND THESE EXTRAORDINARY VOICES OF THE SEA, BUT FOR NOW, THE PRIVATE LIFE OF THESE OCEAN GIANTS REMAINS WONDERFULLY MYSTERIOUS.
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