Original subtitles

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NARRATOR: WHEN YOU SEE THIS SYMBOL, YOU KNOW YOU'RE WATCHING

TELEVISION THAT IS EDUCATIONAL AND INFORMATIONAL.

THE MORE YOU KNOW ON NBC.

DYLAN: HI, EVERYBODY, I'M DYLAN DREYER, AND THIS IS "EARTH

ODYSSEY".

TODAY, JOIN US FOR A GIANT JOURNEY AROUND THE WORLD TO SEE

HOW THESE COLOSSAL CREATURES USE THEIR SIZE TO THEIR ADVANTAGE.

STARTING IN THE ARCTIC, THE LARGEST BEARS ON EARTH TRY TO

BITE OFF MORE THAN THEY CAN CHEW.

THEN, "WHALE" TAKE A TRIP TO THE OCEAN TO DISCOVER THE UNDISPUTED

LARGEST ANIMAL ON THE PLANET.

AND LATER, YOU WON'T WANT TO BE CAUGHT IN THE CURRENT WITH THESE

GIANTS OF THE AMAZON BASIN.

[MUSIC]

DYLAN: BEING ONE OF THE WORLD'S BIGGEST ANIMALS BRINGS HUGE

ADVANTAGES IN THE WILD, BUT IT CAN ALSO PRESENT ENORMOUS

CHALLENGES, FROM FINDING WAYS TO MANEUVER THEIR MASSIVE BODIES TO

FINDING ENOUGH FOOD TO KEEP THEM FULL.

THIS CAN BE ESPECIALLY TRICKY IN EXTREME ENVIRONMENTS, LIKE THE

ARCTIC, WHERE EARTH'S LARGEST SPECIES OF BEAR IS ALWAYS ON THE

HUNT FOR A BIG BITE TO EAT.

TAKE A LOOK.

THE ARCTIC, A VAST MARINE WILDERNESS COVERING MORE THAN

FIVE-AND-A-HALF MILLION SQUARE MILES, BUT THIS HOSTILE HABITAT

OF FLOATING SEA ICE AND FREEZING OCEAN WATERS IS THE HUNTING

GROUND OF THE PLANET'S LARGEST LAND CARNIVORE, THE POLAR BEAR.

IN THIS ENVIRONMENT, BEING A BIG BEAST WITH A BIG APPETITE

REQUIRES SOME SERIOUS ADAPTATIONS.

DESPITE WEIGHING IN AT MORE THAN 1,000 POUNDS, THIS ADULT MALE IS

AN EXCELLENT SWIMMER.

A THICK LAYER OF FAT USUALLY KEEPS HIM WARM IN THE FREEZING

WATERS.

BUT THIS IS LATE SUMMER.

HE'S LOST ALMOST A THIRD OF HIS BODY MASS.

NOW DESPERATE FOR FOOD, HE DECIDES TO HEAD BACK TO DRY

LAND.

HE IS A WINTER SPECIALIST, USING STEALTH AND CAMOUFLAGE TO STALK

SEALS OUT ON THE SEA ICE.

BUT IN THESE CONDITIONS, THE HUGE WHITE BEAR WILL NEED TO TRY

A DIFFERENT TACTIC.

HE'S BEEN LURED TO THIS COASTLINE BY THE SCENT OF AN

IMMENSE SUMMER BANQUET.

THESE FROZEN LANDS ARE HOME TO ANOTHER GIANT.

WALRUSES ARE THE LARGEST SEAL SPECIES IN THE ARCTIC.

THEY WEIGH MORE THAN 2,000 POUNDS AND ARE ARMED WITH TUSKS

UP TO THREE FEET LONG.

A POLAR BEAR USUALLY ONLY GOES AFTER THEIR YOUNG, BUT THE

REWARD FROM SUCH A BIG PRIZE WOULD BE WELL WORTH THE RISK.

DESPERATE TIMES CALL FOR DESPERATE MEASURES.

FACED WITH AN IMPOSING WALL OF BLUBBER, HE TRIES TO FIND A WAY

IN.

USING THEIR TUSKS AS DAGGERS, THE WALRUSES DEFEND THEMSELVES.

AS THEY RETREAT TO THE WATER, HE MUST MOVE QUICKLY.

BUT THEIR HIDE IS TOO THICK.

WOUNDED FROM THE STRUGGLE, HE GIVES UP.

THEIR VAST SIZE HAS HELPED THE WALRUS TO STAY SAFE, AND IT

APPEARS THE WORLD'S LARGEST BEAR MAY HAVE MET HIS MATCH.

DESPITE BEING THE BIGGEST CARNIVORE TO HUNT ON LAND, POLAR

BEARS ARE ACTUALLY MARINE MAMMALS, BUT THEY ARE FAR FROM

THE BIGGEST ANIMAL IN THE OCEAN.

COMING UP, WE TAKE A DEEP DIVE TO FIND OUT WHAT THIS BLUE WHALE

EATS TO STAY SO MASSIVE.

AND LATER, WE FIND OUT THE DOWNSIDES TO HAVING THE LONGEST

NECK IN THE WORLD.

PLUS, IN THE AMAZON BASIN, YOU MAY FEAR THE CAIMANS AND

ANACONDAS, BUT WHAT ANIMALS DO THEY FEAR?

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NARRATOR: WE NOW RETURN TO THE MORE YOU KNOW ON NBC.

DYLAN: THE PRIZE FOR THE LARGEST CREATURE EVER TO HAVE

LIVED GOES TO THE BLUE WHALE.

ONE HUNDRED FEET LONG AND WEIGHING 330,000 POUNDS, THIS

WHALE OUTRANKS EVEN THE BIGGEST DINOSAURS.

HIS COLOSSAL BODY MEANS HE HAS VERY FEW PREDATORS.

ONLY A LARGE POD OF KILLER WHALES WOULD ATTEMPT TO

OVERPOWER A CREATURE THIS BIG.

AND HIS SIZE BRINGS ANOTHER BENEFIT.

HE CAN MIGRATE GREAT DISTANCES WITH LITTLE EFFORT, ALLOWING HIM

TO REACH THE OCEAN'S RICHEST FEEDING GROUNDS WITH THE HIGHEST

CONCENTRATIONS OF KRILL.

BLUE WHALES EAT AS MUCH AS THEY CAN IN ONE GO.

GULPING DOWN A MASSIVE 100 TONS OF KRILL-RICH WATER IN JUST TEN

SECONDS.

IT'S THE BUOYANCY OF THE OCEAN WATER THAT SUPPORTS THIS GIANT

FRAME, ENABLING WHALES TO GROW TO A SCALE NOT POSSIBLE ON LAND,

SO THE BLUE WHALE JUST KEEPS GETTING BIGGER.

BUT MAMMALS AREN'T THE ONLY GIANTS IN THE OCEAN.

WITH 95 PERCENT OF OUR PLANET'S SEAS STILL UNEXPLORED, IT'S

THOUGHT THERE COULD BE EVEN BIGGER CREATURES LURKING DOWN IN

THE DEPTHS.

AND WE'VE ALREADY DISCOVERED SOME EXTRAORDINARY FISH.

AT MORE THAN 33 FEET LONG AND WEIGHING UP TO 20 TONS, THE

WHALE SHARK IS THE WORLD'S LARGEST FISH.

YET IT SURVIVES SOLELY ON A DIET OF PLANKTON.

IT SWIMS AT A TOP SPEED OF JUST THREE MILES AN HOUR, SUCKING IN

WATER WITH ITS HUGE MOUTH FIVE FEET ACROSS.

ITS GILL RAKERS PROCESS MORE THAN 1,000 GALLONS AN HOUR, BUT

THE REAL SECRET TO ITS SIZE IS A MORE RECENT DISCOVERY.

THIS SHARK IS NEGATIVELY BUOYANT.

IT CAN SINK TO THE BOTTOM OF THE OCEAN TO REACH ITS FOOD USING

AROUND 30 PERCENT LESS ENERGY.

THIS INCREASES ITS FEEDING TIME AND THE AMOUNT IT CAN CONSUME,

BUT IT'S NOT JUST UNDERWATER THAT THE BENEFITS OF SIZE CAN BE

REAPED.

COMING UP, HOW DO THE BIGGEST CREATURES OF THE AMAZON BASIN

COMMAND RESPECT IN A REGION ALREADY FULL OF THE FEARLESS AND

FEROCIOUS?

BUT FIRST, IT CAN BE A HIGH-PRESSURE JOB TO KEEP A

GIRAFFE ON ITS TOES.

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NARRATOR: WE NOW RETURN TO THE MORE YOU KNOW ON NBC.

DYLAN: YOU MIGHT ASSUME THAT THE BIGGEST ANIMALS ON EARTH GET

THAT WAY BY BEING CARNIVORES, ANIMALS WHO EAT MEAT.

BUT THERE'S ONE MASSIVE MAMMAL THAT NEVER EATS MEAT, AND IT

TOWERS OVER ITS CARNIVORE BROTHERS AND SISTERS.

LET'S MEET THIS VEGETARIAN CONTRARIAN, THE AFRICAN GIRAFFE.

WHEN IT COMES TO FINDING FOOD, LAND-LIVING GIANTS HAVE LEARNED

TO MAKE THE MOST OF THEIR STATURE.

STANDING UP TO 16 FEET HIGH, THIS GIRAFFE SEEMS TO HAVE IT

MADE WITH FEET THE SIZE OF DINNER PLATES AND A NECK THAT

STRETCHES TO ALMOST HALF ITS HEIGHT.

BEING HEAD AND SHOULDERS ABOVE THE REST CERTAINLY HAS ITS

PERKS.

IT MAKES GETTING THE HARDEST TO REACH LEAVES A BREEZE,

ESPECIALLY WITH AN 18-INCH TONGUE TO GO THE EXTRA DISTANCE.

JUST AS WELL, BECAUSE GIRAFFES HAVE A SUPER-SIZED APPETITE,

CONSUMING UP TO 140 POUNDS A DAY.

BUT LONG NECKS COME AT A COST.

AS IT STRETCHES UP, THE THICK MUSCLE WALLS OF ITS SURPRISINGLY

POWERFUL HEART MUST DRIVE BLOOD UP TO THE BRAIN AT A PHENOMENAL

PRESSURE.

GIRAFFES HAVE THE HIGHEST BLOOD PRESSURE OF ANY ANIMAL, WHICH

SHOULD CAUSE A PROBLEM WHEN THEY DROP THEIR HEAD DOWN TO DRINK.

BUT WHILE OTHER ANIMALS WOULD FAINT UNDER SUCH PRESSURE,

SPECIALIZED VALVES IN THE GIRAFFE'S NECK COUNTER THE

POTENTIALLY EXPLOSIVE EFFECTS OF GRAVITY, BLOCKING ALL THIS BLOOD

FROM FLOWING INTO ITS SKULL.

THIS SIMPLE SOLUTION IS NOW USED IN NASA'S SPACESUITS.

IT MAY BE ONE SMALL STEP IN EVOLUTION FOR THE GIRAFFE, BUT

IT'S LED TO A GIANT LEAP FOR MANKIND.

THE GIRAFFE'S LONG NECK AND UNIQUE ADAPTATIONS ALLOW IT TO

FEED WITH EASE, BUT MANY OF NATURE'S GIANTS HAVE TO FIGHT

FOR THEIR FOOD.

IT'S SPRING IN TURKEY'S ALPINE FORESTS, AND THE REGION'S

MIGHTIEST RESIDENT HAS RECENTLY EMERGED FROM A LONG HIBERNATION.

AFTER SIX MONTHS WITHOUT FOOD OR WATER, THE RAIN IS A WELCOME

RELIEF.

BUT HIS PRIMARY CONCERN IS FINDING SOMETHING TO EAT.

BROWN BEARS CAN LOSE UP TO 40 PERCENT OF THEIR BODY WEIGHT

DURING HIBERNATION.

WHILE ON THE MOVE, HE RUBS AGAINST TREES, LEAVING A CLEAR

MESSAGE OF HIS SIZE AND STATUS, HOPEFULLY WARDING OFF ANY

WOULD-BE INTRUDERS.

HE'S ON A COUNTDOWN TO BREEDING SEASON.

AND IF HE IS TO STAKE A CLAIM TO ANY FEMALES IN HIS HOME RANGE,

HE NEEDS TO BULK UP.

LARGER MALES HAVE BETTER MATING SUCCESS.

BUT HE'S NOT THE ONLY HUNGRY ONE IN THE FOREST.

A RIVAL.

HE'S SMALLER, BUT HE'S NOT BACKING DOWN.

[BEARS SNARLING]

SIZE MATTERS HERE, AND IT'S WON HIM THE RIGHT TO THE AREA.

HE CAN NOW GET BACK TO THE VERY IMPORTANT JOB OF FINDING FOOD.

SADLY, THE BEST PICKINGS ARE OUT OF REACH.

SURPRISINGLY, FOR A BEAST WEIGHING ALMOST 900 POUNDS,

BROWN BEARS ARE EXCELLENT CLIMBERS.

HIS GIANT CLAWS AND PAWS ALLOW HIM A SECURE GRIP, AND HE

FINALLY GETS A CHANCE TO ENJOY HIS WINNINGS.

WHILE BROWN BEARS USE THEIR SIZE TO THEIR ADVANTAGE, THERE ARE

SOME NEGATIVES TO LIVE ON THE LARGER SIDE.

CARRYING EXTRA WEIGHT REDUCES BOTH SPEED AND AGILITY, BUT HE

WON'T LET THAT STOP HIM.

COMING UP, WE'LL JUMP IN WITH THE GIANTS OF THE AMAZON BASIN,

BUT WHO'S THE MOST DANGEROUS OF THEM ALL?

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NARRATOR: WE NOW RETURN TO THE MORE YOU KNOW ON NBC.

DYLAN: THE AMAZON BASIN IN BRAZIL, A HIDDEN KINGDOM RULED

BY GIANTS.

SIXTEEN-FOOT-LONG CAIMAN PATROL THE WATERS...

...WHILE THE LARGEST CAT IN SOUTH AMERICA, THE JAGUAR,

STALKS THE RIVERBANK.

TO COMPETE WITH THIS REGION'S OVERSIZED KILLERS, A USUALLY

SMALL ANIMAL HAS GROWN TO AN EXTRAORDINARY SIZE.

THESE AMAZON BACKWATERS ARE HOME TO THE GIANT BRAZILIAN OTTER.

ADULTS CAN REACH NEARLY SIX FEET IN LENGTH.

THAT'S MORE THAN TWICE AS BIG AS A NORTH AMERICAN RIVER OTTER.

THIS FAMILY HAS YOUNG TO FEED.

AND THAT IS A FULL-TIME JOB.

LUCKILY, THEIR SIZE AND STRENGTH MAKES THEM EXCELLENT AQUATIC

HUNTERS.

THEIR DIET CONSISTS ALMOST EXCLUSIVELY OF FISH.

BUT THEY'VE BEEN KNOWN TO EAT ANACONDA AND EVEN SMALL CAIMAN.

THEY CAN CONSUME UP TO 20 PERCENT OF THEIR TOTAL BODY

WEIGHT EACH DAY.

THAT'S A LOT OF FOOD TO CATCH.

SO, FOR THIS FAMILY, IT REQUIRES TEAMWORK TO FILL EVERYONE'S

BELLIES.

EVEN THE YOUNGEST MEMBERS ARE FORCED TO JOIN IN WITH THE TASK.

DESPITE THE MURKY WATER, THEY HUNT WITH PRECISION.

IT'S NO WONDER THEY'RE KNOWN AS RIVER WOLVES.

THEIR WHISKERS DETECT THE MOVEMENT OF PREY, AND TOGETHER,

THEY HERD THE FISH TOWARDS THE BANK.

WHEN ONE LANDS A SUCCESSFUL CATCH, THEY'LL RARELY SHARE, BUT

EVERYONE WILL EVENTUALLY GET THEIR TURN.

THANKS TO THEIR SIZE AND SPEED, THE GIANT RIVER OTTERS CAN

COMPETE WITH THE LIKES OF JAGUARS AND CAIMAN FOR FOOD,

ALLOWING IT TO SURVIVE IN A COMPETITIVE ENVIRONMENT.

THANK YOU FOR JOINING US ON OUR ADVENTURE AROUND THE WORLD TO

FIND SOME OF THE GIANTS OF THE ANIMAL KINGDOM.

FROM MASSIVE MAMMALS IN THE AFRICAN SAFARI TO THE SEISMIC

SEA CREATURES OF THE OCEANS, THESE ANIMALS HAVE BEEN LARGE

AND IN CHARGE FOR THOUSANDS OF YEARS.

WE'LL SEE YOU ON OUR NEXT "EARTH ODYSSEY".

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