Original subtitles

♪♪

Narrator: ANIMALS...

DO THE MOST INCREDIBLE THINGS.

[ GOAT BLEATS ]

LIKE THIS...

AND THIS.

I BET YOU'RE WONDERING, "HOW DO THEY DO THAT?"

WE'RE REVEALING ANIMALS' BIGGEST SECRETS, LIKE...

HOW DO SEA TURTLES FIND

THE EXACT SAME BEACH WHERE THEY HATCHED

AFTER 20 YEARS AT SEA?

WHAT'S THE SECRET BEHIND A DOG'S BARK?

AND HOW AND WHY DO SLOTHS TURN GREEN?

THESE WONDERS AND MORE ON...

--Captions by VITAC-- www.vitac.com

CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS

THEY'RE OUR BEST FRIENDS IN THE ANIMAL KINGDOM,

BUT EVEN BEST FRIENDS CAN HAVE SOME ANNOYING HABITS.

[ DOGS BARKING ]

SOME HABITS ALSO ANNOY THE NEIGHBORS

BUT NOT ALWAYS THE OWNER.

BECAUSE FOR THOUSANDS OF YEARS,

DOGS HAVE BEEN BARKING THEIR WAY INTO THEIR OWNERS' HEARTS.

WHAT'S THE SECRET BEHIND A DOG'S BARK?

THE DOG'S BARK ORIGINATES

FROM THEIR COMMON ANCESTORS, THE WOLF.

COME ON. [ CHUCKLES ]

IN NEW MEXICO, LEYTON COUGAR RUNS A SANCTUARY

THAT RESCUES CAPTIVE-BRED WOLVES AND WOLF DOGS.

FOR 20 YEARS, LEYTON HAS STUDIED

BARKING, HOWLING, AND OTHER SOUNDS

COMING FROM WOLVES.

AND TO TRY TO FIGURE OUT WHY DOGS BARK,

HE'S INVESTIGATED THE DIFFERENT WAYS WOLVES COMMUNICATE.

OKAY.

FLURRY IS THE ALPHA MALE OF THE WOLF PACK.

SO RIGHT NOW, AS FLURRY LEAVES THE COMPOUND,

THE WOLVES ARE SINGING ABOUT IT.

THEY'RE COMMUNICATING THAT FLURRY IS LEAVING THE PACK.

[ HOWLING ]

Narrator: WHEN FLURRY GETS MORE THAN 100 YARDS AWAY,

IT BECOMES A TWO-WAY CONVERSATION...

[ HOWLING CONTINUES ]

...USING THAT INFAMOUS WOLF HOWL.

WOLVES, WHEN THEY'RE VOCALIZING, WHEN THEY'RE HOWLING --

THEY'RE COMMUNICATING TO OTHER PACK MEMBERS.

[ HOWLING CONTINUES ]

Narrator: THE HOWL IS LIKE A LONG-DISTANCE PHONE CALL SAYING...

"HEY, GUYS, GUESS WHERE I AM."

THEY'RE STILL SINGING FOR YOU,

SO LET'S GET YOU BACK TO YOUR HOUSE.

COME ON. LET'S WALK.

Narrator: WHEN FLURRY GETS BACK, THE HOWLING STOPS.

BUT ANOTHER TYPE OF WOLF COMMUNICATION CAN START --

THE BARK.

SCIENTISTS THINK THE WOLF'S BARK

MAY BE WHAT STARTED THE UNIQUE RELATIONSHIP

THAT WE HAVE WITH OUR DOGS.

AROUND 40,000 YEARS AGO,

HUMANS HAD TO WORRY ABOUT BEING ATTACKED --

BY BOTH OTHER HUMANS AND WILD BEASTS.

THEY NEEDED AN EARLY-WARNING SYSTEM,

AND THEY GOT IT BY ADOPTING ORPHANED WOLF CUBS.

A WOLF WILL INSTINCTIVELY BARK TO WARN THE PACK OF DANGER.

THAT WARNING BARK IS REALLY SOMETHING THAT HUMANS WANTED

BECAUSE YOU WANT TO PROTECT YOUR CAMP,

AND WHEN THERE'S A CANINE

WHO CAN HEAR AND SEE WAY BETTER THAN WE CAN,

HAVING THAT WARNING BARK IS REALLY ESSENTIAL FOR HUMANS.

Narrator: OVER TIME,

GUARD WOLVES WERE BRED INTO DOMESTICATED GUARD DOGS,

AND AS THEIR RELATIONSHIP WITH HUMANS CHANGED,

THE MEANINGS OF THE DOGS' BARKS CHANGED.

DOGS HAVE LEARNED TO ADAPT THEIR BARKS

FOR DIFFERENT SITUATIONS AND DIFFERENT SCENARIOS.

Narrator: AS THE HOWL BECAME A LESSER PART OF DOG LANGUAGE,

DOMESTICATED DOG BARKS HAVE EVOLVED TO HELP THEM COMMUNICATE

WITH DELIVERY PEOPLE,

INATTENTIVE OWNERS,

AND NEIGHBORS' CATS.

AND DOGS HAVE LEARNED TO BE EVEN MORE COMMUNICATIVE WITH US.

BY CHANGING THE PITCH OF ITS BARK,

A DOG CAN SAY MANY DIFFERENT THINGS.

EVERY GOOD DOG OWNER KNOWS

EXACTLY WHAT THEIR DOG'S BARKS MEAN.

Narrator: SCIENTISTS HAVE PUT THIS TO THE TEST.

RESEARCHERS RECORDED DIFFERENT BARKS MADE BY DOGS

IN A VARIETY OF SITUATIONS.

AND IT TURNS OUT WE'RE SURPRISINGLY GOOD

AT UNDERSTANDING WHAT DOGS ARE SAYING.

FROM "I WOULD REALLY, REALLY, REALLY LIKE

TO HAVE THAT BALL YOU'RE HOLDING,"

TO THIS HIGH-PITCHED LONGER BARK WITH SHORT PAUSES THAT SAYS,

"I'M LONELY. WHERE ARE YOU?"

SOME SCIENTISTS NOW THINK

THAT IT WAS OUR ADOPTION OF WOLVES 40,000 YEARS AGO

THAT LED TO THE SUPREMACY OF HOMO SAPIENS OVER NEANDERTHALS.

WE DO KNOW THAT NEANDERTHAL MAN AND MODERN MAN

WALKED ON PLANET EARTH AT THE SAME EXACT TIME,

BUT THE DIFFERENCE BETWEEN THEM IS THE DOG.

Narrator: BY ADOPTING WOLVES

AND BREEDING THEM INTO DOMESTICATED DOGS,

HUMANS FOUND A FURRY FRIEND THAT WOULD WARN THEM OF DANGERS,

FIGHT OFF ENEMIES, AND HUNT FOR FOOD.

SUDDENLY, HUMANS COULD FIND AND KILL THEIR DINNER

A LOT QUICKER THAN THEIR NEANDERTHAL RIVALS.

SO EVEN IF THE BARKING DOES GET IRRITATING,

IF IT WASN'T FOR FIDO, WE'D ALL LOOK LIKE NEANDERTHALS.

♪♪

SLOW-MOVING SLOTHS ARE BORN BROWN,

BUT IN THE WILD OVER TIME THEY TURNED GREEN,

WHICH IS SUPER STRANGE BECAUSE

NATURE DOESN'T MAKE GREEN MAMMALS.

NO GREEN DOGS.

NO GREEN CATS.

NO GREEN POLAR BEARS.

SO HOW AND WHY DID SLOTHS TURN GREEN?

LOTS OF ANIMALS LIKE TO MAKE THEMSELVES AT HOME

ON OTHER ANIMALS.

BARNACLES CLING TO WHALES.

TICKS LOVE SHAGGY DOGS.

AND REMORAS LOVE A SHARK.

LIVING IN THE EMERALD GREEN FUR OF A WILD SLOTH

IS NOT ONE CRITTER,

BUT A BUSTLING, GIANT COLONY

OF MITES, TICKS, BEETLES, AND MOTHS.

IT'S LIKE THE SLOTH IS A MINIATURE SLOW-MOVING FOREST,

AND THERE'S A REASON FOR THAT.

THE SLOTH'S GREEN COAT

IS THE RESULT OF AN AMAZING PROCESS.

FIRST, ITS UNIQUE INDIVIDUAL HAIRS

HAVE TINY GROOVES THAT COLLECT RAINWATER.

THE NATURAL SALTS AND MINERALS IN BOTH HAIR AND RAINWATER

MEAN ALGAE CAN GROW IN THOSE RIDGES

WITHOUT NEEDING NUTRIENTS FROM SOIL.

ESSENTIALLY, OVER TIME,

THE SLOW-MOVING SLOTH'S THICK, COARSE FUR

TURNS INTO A LUSCIOUS, GREEN ALGAE GARDEN.

SO, INSECTS ARRIVE TO EAT THE ALGAE

AND DECIDE THEY LIKE THE NEIGHBORHOOD SO MUCH

THAT THEY MOVE IN AND SETTLE DOWN.

WORD GETS AROUND, AND BEFORE YOU KNOW IT,

THE SLOTH BECOMES INSECT CENTRAL.

THEN WHEN THE OLDER INSECT RESIDENTS DIE OFF,

THEIR DECOMPOSING BODIES BECOME FOOD FOR THE GREEN ALGAE,

AND SO THE WHOLE GREEN CYCLE CONTINUES.

IT MAY LOOK LIKE AN ITCHY MESS,

BUT THIS LIVING ARRANGEMENT IS ACTUALLY GOOD FOR THE SLOTH.

IF THERE'S ONE THING THE HARPY EAGLE LOVES EATING FOR LUNCH,

IT'S SLOTH.

THIS APEX PREDATOR STANDS NEARLY FOUR FEET TALL,

AND THERE'S NO WAY A SLOW-MOVING SLOTH

CAN OUTRUN THE 50-MILE-AN-HOUR RAPTOR.

THE SOLUTION --

IMITATE A BUSH OR TREE.

SO THE SLOTH, THE ALGAE, AND THE INSECTS

HAVE ENTERED INTO A CONVENIENT MUTUAL ARRANGEMENT.

IN FACT, ALGAE ARE SO IMPORTANT TO THE SLOTH,

A MOTHER WILL HOLD HER YOUNGSTER CLOSE

TO ENCOURAGE THE ALGAE TO COVER THE BABY,

AND THAT KEEPS THEM BOTH SAFE FROM PREDATORS.

COMING UP,

ANIMALS THAT CAN JUMP MORE THAN 20 TIMES THEIR OWN HEIGHT

AND HOW SEA TURTLES REMEMBER EXACTLY WHERE THEY WERE BORN.

NARRATOR: THE ANIMAL KINGDOM IS FULL OF CREATURES

WHO LEAP INTO ACTION WHEN LIFE DEMANDS IT.

FROM TIGERS WHO JUMP 12 FEET FOR THEIR DINNER...

TWO GAZELLES WHO VAULT TO AVOID BECOMING PREY.

ANIMALS GO AIRBORNE FOR A WHOLE HOST OF REASONS,

BUT WHO IS NATURE'S GREATEST JUMPER?

WHEN IT COMES TO JUMPING THE LONGEST,

THERE IS ONE ANIMAL THAT SPRINGS TO MIND --

THE KANGAROO.

KANGAROOS CAN COVER AN IMPRESSIVE 25 FEET

IN A SINGLE BOUND.

BUT THERE'S AN ANIMAL THAT CAN JUMP FARTHER THAN A KANGAROO --

US.

OLYMPIC LONG JUMPERS CAN HURL THEMSELVES MORE THAN 29 FEET.

THAT MAKES HUMANS ONE OF THE LONGEST LEAPERS ON LAND.

BUT WHAT ANIMAL JUMPS THE HIGHEST?

THE FOUR-OUNCE KANGAROO RAT JUMPS

BECAUSE ITS LIFE DEPENDS ON IT.

WHEN A RATTLESNAKE STRIKES,

SPRINGY TENDONS IN THE RAT'S PROPORTIONALLY HUGE BACK LEGS

REACT IN JUST 40 MILLISECONDS --

10 TIMES FASTER THAN THE BLINK OF AN EYE,

THROWING THEM AWAY FROM DANGER.

THEY CAN REACH HEIGHTS OF NINE FEET.

THAT'S 20 TIMES THEIR OWN LENGTH.

BUT, SURPRISINGLY, THE GREATEST JUMPER OF THEM ALL

IS ONE OF THE TINIEST CREATURES --

THE HUMBLE FLEA.

THESE MINI BLOODSUCKERS ARE NO BIGGER THAN A GRAIN OF RICE,

AND THEIR FOOD, INCLUDING OUR PETS,

TOWERS ABOVE THEM.

TO REACH SUCH LOFTY HEIGHTS,

THE FLEA NEEDS MORE FIREPOWER

THAN THEIR LEG MUSCLES ALONE CAN PROVIDE.

SO THEY HAVE A SECRET SUPERPOWER --

AN EXTRA STORE OF ELASTIC ENERGY AND A PROTEIN CALLED RESILIN.

UNLEASHING THIS ENERGY STORE

FORCES THE FLEA'S BENT LEGS TO STRAIGHTEN SUDDENLY,

LAUNCHING IT INTO THE AIR.

THIS KING OF SPRING CAN LEAP

UP TO 200 TIMES ITS OWN BODY LENGTH.

THAT'S LIKE A HUMAN JUMPING TO THE TOP OF THE EIFFEL TOWER.

OF COURSE, WE'D NEED AN ELEVATOR TO GET BACK DOWN AGAIN.

COMING UP, HOW CAN SEA TURTLES

LOCATE THE EXACT SPOT THEY HATCHED

AFTER MORE THAN 20 YEARS AT SEA?

AND THE SECRET OF THE BEETLES THAT CAN BREATHE UNDERWATER.

Narrator: SEA TURTLES TRAVEL THOUSANDS OF MILES ACROSS OCEANS,

RETURNING AFTER 20 YEARS TO THE EXACT SPOT WHERE THEY WERE BORN

IN TIME TO LAY THEIR OWN EGGS THERE.

THAT'S LIKE A PERSON GOING BACK TO THE CITY OF HER BIRTH

AND TRYING TO FIND THE HOSPITAL SHE WAS BORN IN

WITH NO ONE TO ASK AND NO SMART PHONE TO HELP.

SO HOW DO THESE GUYS DO IT?

HOW DO THE SEA TURTLES FIND THEIR WAY HOME?

SEA TURTLES SPEND PRETTY MUCH THEIR ENTIRE LIVES --

80 YEARS OR MORE -- AT SEA,

AND SATELLITE TAGGING OF ATLANTIC SEA TURTLES

HAS REVEALED WHERE THEY'VE BEEN GOING.

THEY SWIM IN A GIANT LOOP FROM FLORIDA TO WEST AFRICA

THEN WEST TOWARD SOUTH AMERICA

BEFORE HEADING BACK TO THE WATERS OF THE SUNSHINE STATE

TO MATE AND LAY EGGS.

THEY CONTINUOUSLY SWIM THIS 12,000 MILE ROUND TRIP.

WHEN IT'S TIME TO NEST THE FEMALES SOMEHOW KNOW

THE PRECISE LOCATION OF THE EXACT SPOT WHERE THEY WERE BORN

EVEN THOUGH IT COULD HAVE BEEN 20 YEARS

SINCE SHE WAS LAST THERE.

THEY MAKE THIS INCREDIBLE JOURNEY

TO PASS ON TO THEIR HATCHLINGS

THEIR INHERITED IMMUNITY FROM THE PARASITES AND DISEASES

ON THAT PARTICULAR BEACH.

BIOLOGIST KEN LOHMANN HAS BEEN TRYING TO DISCOVER

THE SECRET OF THE SEA TURTLES' NAVIGATIONAL POWERS.

SEA TURTLES, IN EFFECT, HAVE AN IN-BUILT GPS SYSTEM.

Narrator: SCIENTISTS BELIEVE THAT SEA TURTLES

ARE SOMEHOW READING THE EARTH'S MAGNETIC FIELD,

THE SAME FORCE THAT DIRECTS A COMPASS.

TO FIND OUT HOW,

KEN'S CREATED A MINIATURE OCEAN IN HIS LAB

AND ENLISTED THE HELP OF OSCAR,

A THREE-MONTH-OLD HATCHLING BORN ON A BEACH IN FLORIDA.

I'M PLACING THE TURTLE INTO A SOFT CLOTH HARNESS.

THIS WILL ALLOW IT TO SWIM IN PLACE

INSIDE THE MAGNETIC COIL SYSTEM.

Narrator: OSCAR'S SWIMSUIT IS TIED TO A ROD

WHICH IS SUSPENDED ABOVE THE TINY OCEAN.

THE WATER, REPRESENTING THE ATLANTIC OCEAN,

IS SURROUNDED BY

A COMPUTER-CONTROLLED MAGNETIC-COIL SYSTEM,

WHICH IS RECREATING THE EARTH'S MAGNETIC FIELDS.

BY VARYING THE STRENGTH AND DIRECTION OF THE CURRENTS,

KEN CAN SIMULATE THE ELECTROMAGNETIC SIGNATURE

OF DIFFERENT LOCATIONS AROUND THE PLANET.

Lohmann: THE FLAGS INSIDE THE COIL

REPRESENT DIFFERENT PARTS OF THE WORLD.

WE'RE GOING TO TRY TO TRICK THE TURTLES INTO THINKING

THAT THEY'RE AT THOSE LOCATIONS BY EXPOSING THEM

TO THE MAGNETIC FIELDS THAT EXIST THERE.

Narrator: FIRST KEN TYPES IN THE ELECTROMAGNETIC SIGNATURE

FOR THE FLORIDA BEACH

WHERE OSCAR THE HATCHLING WAS BORN.

AND INCREDIBLY, JUST AS IF HE WERE OUT IN THE ATLANTIC,

OSCAR RESPONDS BY TURNING HIS BACK ON FLORIDA

AND HEADS TOWARD WHAT HE THINKS IS AFRICA.

Lohmann: WE'RE NOW GOING TO TRY TO TRICK THE TURTLE

INTO THINKING THAT IT'S IN SENEGAL

BY EXPOSING IT TO THE MAGNETIC FIELD

THAT EXISTS AT THAT LOCATION.

Narrator: OSCAR NOW BELIEVES HE'S IN SENEGAL.

SO HE ADJUSTS HIS DIRECTION TO THE SOUTHWEST

AS IF HE'S CONTINUING HIS MIGRATION TOWARD BRAZIL.

IN THE WILD, IT WOULD TAKE A YEAR FOR A TURTLE

TO REACH SOUTH AMERICA.

OSCAR GETS THERE IN 45 SECONDS.

KEN RESETS THE ELECTROMAGNETIC FIELD,

AND OSCAR NOW BELIEVES HE'S OFF THE COAST OF BRAZIL.

HE IMMEDIATELY CHANGES DIRECTION AND SWIMS NORTHWEST

AS IF HEADING BACK UP TOWARD FLORIDA.

Lohmann: THESE ARE TRULY ASTONISHING RESULTS.

THESE ARE TURTLES THAT HAVE NEVER BEFORE BEEN IN THE OCEAN.

BUT DESPITE THAT,

THE FIRST TIME THEY ENCOUNTER THESE MAGNETIC FIELDS

FROM DISTANT LOCATIONS, THEY KNOW WHAT DIRECTION TO GO.

Narrator: KEN TESTED OVER 100 BABY TURTLES

ALL WITH THE SAME RESULTS.

HIS EXPERIMENT REVEALED SEA TURTLES ARE BORN

WITH A PRE-PROGRAMMED BLUEPRINT OF THE DIFFERENT LOCATIONS

ON THEIR EPIC MIGRATORY ROUTE.

AND EACH LOCATION IS RECOGNIZED BY A DIFFERENT STRENGTH

AND DIRECTION OF ELECTROMAGNETIC FIELD LIKE A MAGNETIC MARKER,

BUT HOW DO TURTLES READ AND INTERPRET THESE INVISIBLE SIGNS?

RECENTLY, SCIENTISTS HAVE DISCOVERED THAT SEA TURTLES

HAVE TINY PARTICLES IN THEIR BRAINS CALLED MAGNETITE.

THESE MAGNETIC PARTICLES DETECT THE SMALLEST VARIATIONS

IN MAGNETIC FIELD STRENGTH,

ALLOWING THE TURTLE TO PHYSICALLY FEEL

WHETHER THEY'RE HEADING NORTH, SOUTH, EAST, OR WEST.

Lohmann: IN EFFECT, THE TURTLES ARE USING THESE REGIONAL MAGNETIC FIELDS

AS A KIND OF SYSTEM OF NAVIGATIONAL MARKERS

OUT IN THE OPEN OCEAN,

AND A TURTLE, THEREFORE, IS NEVER LOST.

Narrator: OVER THOUSANDS OF YEARS,

THE LOCATIONS OF DESIRABLE PLACES

HAVE BEEN HARDWIRED INTO TURTLES.

WHICH IS WHY THEY'RE ABLE TO RETURN

TO THEIR EXACT BIRTHPLACE 20 YEARS AFTER LEAVING IT.

♪♪

COMING UP,

HOW AIR-BREATHING BEETLES CONQUER THE DEPTHS.

Narrator: THEY'RE FOUND ON THE HIGHEST, COLDEST PEAKS...

THE MOST PARCHED, SCORCHED DESERTS...

AND EVERYWHERE IN BETWEEN.

IN FACT, ONE IN EVERY FOUR ANIMAL SPECIES

ON THE SURFACE OF THE EARTH IS A BEETLE.

AND DESPITE BEING A LAND INSECT,

THIS SUPER SUCCESSFUL CRITTER

HAS MANAGED TO CONQUER THE DEPTHS, TOO.

BUT HOW DO BEETLES BREATHE UNDERWATER?

THE ONE-INCH LONG GREAT DIVING BEETLE'S

FAVORITE FOOD OF TADPOLES, NEWTS, AND OTHER WATER INSECTS

LURKS AT THE BOTTOM OF THIS POND.

SO THE AIR-BREATHING BEETLE HAS TO FIGURE OUT A WAY

TO STAY ALIVE WHILE HUNTING UNDERWATER.

ON LAND, HOLLOW TUBES HIDDEN UNDERNEATH THE WINGS

CALLED SPIRACLES CARRY AIR INSIDE THE BUG'S BODY,

BUT DIVING COULD CAUSE THESE TUBES TO FILL WITH WATER

DROWNING THE BEETLE.

SO THE BEETLE PROTECTS THE OPENINGS OF THE SPIRACLES

WITH A BIG OXYGEN-RICH BUBBLE OF AIR

TRAPPED BENEATH ITS PROTECTIVE WING CASING.

UNFORTUNATELY, THE BUBBLE MAKES THE BEETLE FLOAT LIKE A BALLOON,

SO THE DIVING BEETLE

HAS TO FIGHT AGAINST THE BUBBLE'S BUOYANCY

WHENEVER IT DIVES.

AND THAT MAKES DIVING TRICKY.

THE EFFORT NEEDED TO REACH THE BOTTOM OF THE POND

USES UP MOST OF THE OXYGEN

IN THE BUG'S AIR-BUBBLE AIR TANK.

TO REFUEL, THE GREAT DIVING BEETLE

DOES SOMETHING THAT APPEARS TO BE SUICIDAL.

PRESSING UP WITH THE ABDOMEN,

THE BEETLE PUSHES OUT MOST OF THE AIR BUBBLE.

THIS IS A CRITICAL OPERATION.

IF THE BEETLE LOSES ITS AIR TANK,

THE BUG RUSHES BACK TO THE SAFETY OF THE SURFACE.

BUT THE BEETLES THAT CAN CONTROL THE BUBBLE

CAN STAY SUBMERGED FOR HOURS.

BECAUSE OUT IN THE OPEN, THE BUBBLE ABSORBS OXYGEN

DISSOLVED IN THE POND WATER,

NATURALLY REFUELING ITSELF.

AFTER REFUELING FOR LESS THAN A MINUTE.

THE GREAT DIVING BEETLE SUCKS THE BUBBLE BACK IN.

NOW THE BUG CAN GET ON WITH WHAT IT CAME DOWN HERE FOR --

FEASTING ON THE POND'S UNDERWATER BOUNTY.

YUM.