Original subtitles

\h\h\h\h\h\h\h\hNarrator: THE MIGHTY MISSISSIPPI...

AN ICON THAT FLOWS THROUGH \h\h\h\hAMERICA’S HISTORY

AND ITS LANDSCAPES...

AND SHAPES THIS NATION \hLIKE NO OTHER RIVER.

IT CHANGES CHARACTER \hAS IT HEADS SOUTH.

[SPLASH]

FIRST, ITS HEADWATERS ARE A VISION OF GRACE,

\h\hWINDING THROUGH PRISTINE WILDERNESS.

\h\h\h\hTHEN IT GROWS STRONG THROUGH AMERICA’S HEARTLAND,

A SYMBOL OF COUNTRY LIFE,

AN ENGINE OF COMMERCE,

\hAND A POWERFUL FORCE OF NATURE.

NOW, INTO THE DEEP SOUTH,

THE MISSISSIPPI BECOMES \h\h\h\hA RIVER OF SOUL,

SPICY CAJUN,

AND DELTA BLUES.

♪

FOR THE CREATURES HERE, LIFE IS A LITTLE HOT...

A LITTLE OUT THERE...

\h\h\hAND MORE THAN A LITTLE DANGEROUS.

GET READY.

THE MISSISSIPPI RIVER’S \h\h\h\h\h\h\hFINAL ACT

IS A RIDE THROUGH ITS WILD SIDE.

♪

IT BEGINS IN THE WILDS \h\h\h\hOF MINNESOTA,

\h\hFLOWS AND GROWS THROUGH THE HEART OF MIDDLE AMERICA.

NOW IN ITS HOME STRETCH,

\h\hTHE MISSISSIPPI RIVER STRIKES A DIFFERENT CHORD.

IT BECOMES A POTENTIAL THREAT.

♪

NEAR ST. LOUIS,

\h\h\hSNOWMELT AND SPRING RAINS POUR IN FROM THE MISSOURI RIVER.

SWOLLEN WITH THE EXTRA LOAD,

\hTHE MISSISSIPPI RISES AND STRESSES ITS BANKS.

♪

BARELY A HUNDRED YARDS \hFROM THE WATERLINE,

\h\h\h\h\h\h\hA RED FOX FAMILY IS CLOSE TO BEING WASHED OUT.

♪

IF THE MISSISSIPPI FLOODS,

THE VIXEN WILL HAVE TO UPROOT HER FIVE KITS.

[SQUAWKING]

[SQUEAKING]

\hFOR THE FIRST EIGHT WEEKS, THEY NEED MOM AND HER MILK,

\h\h\h\h\hSO SHE KEEPS WATCH WHILE DAD DOES THE HUNTING.

♪

USUALLY HE’S A NOCTURNAL HUNTER,

\h\hBUT THE NEED TO KILL FOR HIS FAMILY OF SEVEN

FORCES HIM INTO THE DAYLIGHT.

♪

\hHE’LL TAKE DOWN THOUSANDS OF RODENTS AND RABBITS THIS YEAR.

♪

\h\h\h\hBUT NOW FLOODS FORCE HIM TO HUNT IN UNFAMILIAR TERRITORY.

HE WIELDS A WELL-HONED ARSENAL \h\hSIMILAR TO OTHER CANINES.

WITH BINOCULAR VISION,

\h\h\h\h\hHE SCANS THE BRUSH FOR THE SLIGHTEST MOVEMENT.

♪

\h\h\hHIS SEARCH MAY COVER 20 MILES IN A SINGLE DAY.

♪

HIS SENSE OF SMELL--

100 TIMES STRONGER \hTHAN A HUMAN’S--

HELPS HIM HOME IN ON PREY.

♪

♪

\hBUT IT’S HIS HEARING THAT ALLOWS HIM TO PINPOINT FOOD.

♪

HE’S ABLE TO ISOLATE THE ORIGINS OF MOST SOUNDS TO ONE DEGREE.

♪

\h\hONCE HE’S LOCKED ON, HE PREPARES HIS STRIKE.

\h\hHIS BONES ARE 30% LIGHTER THAN A COMPARABLE SIZED DOG...

MAKING HIM QUICKER \hAND MORE AGILE.

♪

\h\h\hHE’LL KILL AS MANY AS A DOZEN TIMES A DAY:

MICE, RABBITS, SQUIRRELS...

EVEN GROUNDHOGS.

HIS KITS’ LIVES DEPEND ON IT.

♪

♪

\h\h\hTHEY WON’T BE INDEPENDENT AND ABLE TO HUNT FOR THEMSELVES

UNTIL 7 MONTHS OLD.

♪

\hUNTIL THEN, THEY WILL RELY ENTIRELY ON THEIR PARENTS...

♪

\hAND ON THE MERCY OF A MIGHTY RIVER,

\h\h\h\h\h\h\h\hEVER GROWING AS IT PUSHES ITS WAY SOUTH.

♪

\h\h\h\h\h\h\hFROM ST. LOUIS DOWN TO THE GULF OF MEXICO,

THE MISSISSIPPI BECOMES \hAN UNSTOPPABLE FORCE.

WATER CONTINUES TO POUR IN \h\hFROM ITS TRIBUTARIES.

\h\h\h\h\h\h\h\hMOST NOTABLY, JUST SOUTH OF CAIRO, ILLINOIS,

IT MEETS THE OHIO RIVER.

♪

HERE, THE TWO RIVERS CHARGE SOUTH AS ONE,

\h\h\h\h\h\h\h\hPRODUCING THE GREATEST FLOW OF WATER

IN THE UNITED STATES.

IN SPRING, TWO MILLION GALLONS \h\h\h\hPASS BY EVERY SECOND.

♪

\h\hSOME OF THE WATER SPILLS OVER THE BANKS

AND BACKFLOWS.

♪

THIS ALLIGATOR SNAPPING TURTLE

\h\hFINDS A CALM SPOT TO WAIT OUT THE SURGE.

HE HAS SEEN ALL THE MISSISSIPPI HAS TO OFFER,

\h\hHAVING LIVED IN AND AROUND THE RIVER

FOR MORE THAN 50 YEARS.

\h\h\hAND THAT’S ONLY HALF OF HIS EXPECTED LIFE SPAN.

WEIGHING IN AT SOME 150 POUNDS,

HE MAY YET REACH 220.

HE EARNS HIS CALORIES

BY BECOMING JUST ANOTHER \h\hROCK ON THE BOTTOM.

♪

HIS SPECIAL SENSE ORGANS

"TASTE" THE PRESENCE OF PREY \h\h\h\hIN THE MURKY WATER.

♪

♪

JUST SAY "AHH"...

TO SET THE TRAP.

♪

♪

THE WORM-SHAPED APPENDAGE ON THE TIP OF HIS TONGUE,

CALLED A VERMIFORM,

LURES IN A CURIOUS FISH.

♪

\h\h\hONE WRONG MOVE COULD GIVE HIM AWAY.

♪

♪

\h\h\h\h\h\hIT’S LUNCHTIME IN THE MISSISSIPPI RIVER.

♪

THE ALLIGATOR SNAPPING TURTLE’S INCREDIBLE VISE-LIKE BEAK

CAN TEAR THROUGH FLESH \h\hAND SHATTER BONE.

♪

SNAKES, OTHER TURTLES,

EVEN SMALL MAMMALS \h\hARE FAIR GAME.

♪

\h\h\h\h\hAND NOW THERE’S A NEW OPTION ON THE MENU.

CHEWY ON THE INSIDE...

VERY CRUNCHY ON THE OUTSIDE.

♪

\h\h\h\h\h\h\hTHIS HAIRY FOOTBALL-SIZED CREATURE

IS THE NINE-BANDED ARMADILLO.

\h\h\h\h\hHER ANCESTORS HAIL FROM SOUTH AMERICA,

\hBUT OVER THE LAST 70 YEARS, POPULATIONS HAVE SPREAD NORTH.

SOME HAVE EVEN REACHED ILLINOIS.

♪

SOME SPECIES SEE THE RIVERS \h\h\h\hAS NATURAL BARRIERS.

♪

\h\h\h\hBUT THE ARMADILLO IS A MASTER IN THE WATER.

♪

[SPLASH]

♪

\h\h\h\h\h\hSHE INFLATES HER INTESTINES WITH AIR,

\hTURNING THEM INTO FLOATATION DEVICES,

JUST LIKE TUBING.

ALL SHE HAS TO DO IS PADDLE.

♪

SHE CAN HOLD HER BREATH \h\h\h\hFOR SIX MINUTES.

♪

♪

THOUGH NEARLY BLIND AND DEAF,

SHE CAN SMELL FOOD BURIED 8 INCHES BELOW THE EARTH.

\h\h\h\hSHE’LL SPEND ALL DAY WITH HER NOSE TO THE GROUND,

HUNTING FOR GRUBS AND SLUGS

STIRRED UP BY THE RISING WATERS OF THE MISSISSIPPI RIVER.

♪

SHE’S NOT THE ONLY CREATURE

\h\hTHAT MUST OVERCOME THE SEASONAL FLOODING.

♪

\h\h\h\h\h\h\hGARTER SNAKES IN THE MISSISSIPPI CATCHMENT AREA

ARE OFTEN DISPLACED BY WATER.

AS THEY’RE FLUSHED OUT,

\hTHEY ALSO ATTRACT THEIR OWN PREDATORS.

♪

♪

♪

♪

THE SNAKE WILL STRIKE \hTO DEFEND ITSELF...

♪

[HISSING]

BUT IT’S ONLY MILDLY VENOMOUS.

IT’S AN EASY MEAL FOR A FOX,

BUT FIRST THE VIXEN WILL USE IT TO TEACH HER KITS.

[BARKING]

♪

[SQUAWKING]

[BARKING]

♪

\h\h\h\h\h\hTIME TO LEARN HOW TO WRANGLE A REPTILE.

[CHATTERING]

♪

TESTS LIKE THIS ARE VALUABLE TO A YOUNG FOX’S EDUCATION.

\h\h\h\hTHE NEXT SNAKE MAY BE MORE VENOMOUS.

♪

IT’S A DANGEROUS WORLD,

\h\h\h\h\h\h\h\hAND SOON THEY’LL HAVE TO FACE IT.

[CHATTERING]

\h\h\h\h\hFOR NOW, THOUGH, IT’S ALL FUN AND FROLICS.

[CHATTERING]

♪

♪

THERE’S LITTLE AGGRESSION \h\h\h\h\hIN THESE TUSSLES

\h\h\h\h\h\h\hTHAT TARGET THE OPPONENT’S SHOULDERS.

[SQUAWKING]

BUT IT’S GOOD PRACTICE \h\h\hFOR REAL FIGHTS,

\h\h\hWHEN THEY’LL GO FOR THE FACE AND NECK.

♪

\h\h\h\h\h\hAT AROUND 10 MONTHS, THE KITS WILL BE SEXUALLY MATURE

AND HAVE A DECISION TO MAKE...

[WHIMPERING]

STAY WITH THE FAMILY...

OR HEAD OUT ON THEIR OWN \h\h\h\hAND FIND A MATE.

♪

UNTIL THEN, THEY CAN PLAY...

UNAWARE OF THE LOOMING THREATS \h\h\h\hOF THE OUTSIDE WORLD.

♪

CLOSE TO THEIR DEN,

THE MISSISSIPPI’S BANKS SEEM TO BE HOLDING FIRM.

♪

NOT SO JUST DOWNSTREAM.

♪

IT’S SPRING,

AND THE RISING WATERS \h\hOF THE MISSISSIPPI

\hTHREATEN THE PEOPLE OF MEMPHIS, TENNESSEE.

♪

\h\h\hTHIS CITY IS KNOWN AS THE HOME OF THE BLUES

AND THE BIRTHPLACE OF ROCK AND ROLL.

NOW AND THEN IT GETS \h\h\h"ALL SHOOK UP"

BY DRAMATIC FLOODS.

\h\h\hIN PAST YEARS, MEMPHIS HAS SUFFERED

\h\hSOME OF THE LARGEST AND MOST DAMAGING FLOODS

IN THE RIVER’S HISTORY.

♪

THE RIVER FLOODS FARMS

AS IT CONTINUES SOUTH BETWEEN \hARKANSAS AND MISSISSIPPI...

DEPOSITING A THICK LAYER OF SILT ACROSS THE FLOODPLAIN.

♪

ALTHOUGH THE FLOODS RUIN CROPS,

\hTHIS MINERAL-RICH SEDIMENT IS WHAT MAKES THE LAND SO FERTILE.

♪

SPRING FLOODWATER

ISN’T THE ONLY SEASONAL DANGER \h\h\h\hCOMING FROM THE NORTH.

ANOTHER THREAT EMERGES ALONG THE RIVER BANKS.

DEER TICKS.

MORE AGGRESSIVE BUGS

\h\h\hARE SPREADING SOUTH FROM THE NORTHERN STATES,

\h\h\h\hAND THEIR IDEAL HABITAT IS WHERE FOREST MEETS SUBURBIA.

THAT SPELLS TROUBLE

\h\h\hFOR PEOPLE LIVING ALONG THE BANKS OF THE MISSISSIPPI.

\h\h\h\h\h\h\h\hDEER TICKS ARE THE PRIMARY SPREADERS

OF DEBILITATING LYME DISEASE.

\hIT STARTS WITH A BACTERIA THAT THEY PICK UP FROM MICE.

♪

MICE CARRY THE PATHOGEN, \h\h\h\hBUT ARE IMMUNE.

\h\hWHEN A TICK FEEDS ON AN INFECTED MOUSE,

\h\h\h\h\h\h\hTHAT TICK PICKS UP THE DISEASE...

AND THEN PASSES IT ON \h\h\h\h\hTO WHATEVER

OR WHOMEVER IT BITES NEXT.

♪

\h\hKEEPING THE MOUSE POPULATION IN CONTROL IS KEY TO PREVENTION.

NOTHING DOES THIS BETTER \h\h\h\h\h\hTHAN SNAKES.

\h\h\h\h\hTHERE ARE MORE THAN 25 DIFFERENT SPECIES OF SNAKES

LIVING IN THE SOUTHERN MISSISSIPPI WATERSHED,

INCLUDING THE TIMBER RATTLER.

[RATTLING]

BUT ONE OF THE MOST COMMON \hIS THE BLACK RAT SNAKE.

\h\hTHE JACOBSON’S ORGAN ON THE ROOF OF ITS MOUTH

\h\h\h\hENABLES THE SNAKE TO SMELL AND DETECT PREY,

EVEN IN THE DARK.

♪

THERMAL CAMERA IMAGERY

ALLOWS US TO SEE THE SNAKE’S MOVEMENT IN PITCH BLACKNESS.

♪

♪

\h\hTHE RODENT IS OBLIVIOUS TO THE SILENT TERROR NEARBY.

♪

♪

[SQUEAKING]

THE RAT SNAKE IS A CONSTRICTOR.

IT SUFFOCATES ITS VICTIM,

SQUEEZING OUT ITS LAST BREATH

\hBEFORE SWALLOWING ITS WARM BODY WHOLE.

♪

♪

\h\h\h\h\h\hLOTS OF SNAKES MEANS FEWER RODENTS AND LESS DISEASE.

♪

THE MIGHTY RIVER CONTINUES SOUTH,

\hDELIVERING A DOUBLE WHAMMY FOR VICKSBURG, MISSISSIPPI.

♪

\h\h\h\hTHIS YEAR, HIGH RAINS PRODUCED FREAK WINTER FLOODS.

♪

NOW THEY HAVE THE HIGH WATER \h\hOF SPRING TO TOP IT OFF.

♪

THE RIVER HAS ALWAYS PLAYED A MAJOR ROLE

IN VICKSBURG’S HISTORY.

♪

DURING THE CIVIL WAR,

IT WAS THE LAST MAJOR CONFEDERATE-HELD CITY

ON THE RIVER.

IN 1863,

MAJOR GENERAL ULYSSES S. GRANT \h\h\hLED 17,000 TROOPS HERE.

HE MOUNTED THE LARGEST \hAMPHIBIOUS OPERATION

IN AMERICAN MILITARY HISTORY,

UP UNTIL NORMANDY.

\h\h\hTHE UNION’S VICTORY HERE WON THEM CONTROL OF THE RIVER

AND ULTIMATELY THE WAR.

♪

\hAS THE RIVER MOVES SOUTH, TEMPERATURES BEGIN TO SOAR.

\h\h\h\hTHE PLAINS TURN TO SWAMP AND MARSHLAND.

♪

♪

THIS IS CAJUN COUNTRY.

♪

THE BAYOUS OF MISSISSIPPI \h\h\h\h\h\hAND LOUISIANA

ARE HOME TO SOME OF THE DENSEST POPULATIONS OF INSECTS

ON THE PLANET.

\h\h\h\h\hTHE PERFECT PLACE FOR A HUNGRY AMERICAN TOAD.

[CROAKING]

\h\h\hTHIS MALE CAN EAT 1,000 INSECTS IN A DAY.

[BUZZING]

BUT TODAY, HE’S MORE INTERESTED IN SINGING THAN EATING.

[CROAKING]

♪

WHEN WATER LEVELS ARE RIGHT,

MALES CONGREGATE IN SWAMPY BOGS

FOR A HIGH-STAKES TALENT SHOW.

[CROAKING]

FEMALES CHOOSE WINNERS BASED ON THEIR CROAKS.

[CROAKING]

THE DEEPEST SONG GETS THE GIRL.

[CROAKING]

\h\hBREEDING ONLY HAPPENS FOR A FEW DAYS IN SPRING,

WHEN THE BAYOUS RESONATE \h\h\hWITH THEIR CALLS,

DAY AND NIGHT.

[CROAKING]

\h\h\h\h\h\h\hWHEN A FEMALE SHOWS INTEREST IN A CROONER,

THE SMALLER MALE QUICKLY POUNCES.

[SPLASH]

♪

ONCE SHE GIVES CONSENT,

\h\hHE ATTACHES HIMSELF TO HER BACK FOR HOURS...

EVEN DAYS--

A BEHAVIOR KNOWN AS AMPLEXUS.

♪

\h\h\h\hTOO LATE NOW FOR SECOND THOUGHTS.

HE’S COMMITTED,

AND NOTHING SHE CAN DO \h\hCAN SHAKE HIM OFF.

♪

WHEN THEY’RE PROPERLY COUPLED,

\h\hTHE FEMALE RELEASES OVER 4,000 EGGS IN TWO LONG ROWS.

SHE ANCHORS THEM TO VEGETATION,

HIDING THEM FROM PREDATORS.

THE MALE SIMULTANEOUSLY \h\h\h\hRELEASES SPERM,

FERTILIZING THEM AS THEY GO.

[SPLASHING]

♪

THE SPEED WITH WHICH \h\hTHE EGGS DEVELOP

DEPENDS ON THE TEMPERATURE \h\h\h\h\h\hOF THE WATER.

♪

IN ANYWHERE FROM 3 TO 12 DAYS,

THE EGGS HATCH AS TADPOLES...

AND FORM SCHOOL-LIKE GROUPS \h\h\h\hCALLED AGGREGATIONS.

♪

\h\h\hTHEY FEED ON ALGAE AND SMALL INVERTEBRATES

AND DEVELOP RAPIDLY...

BUT DO SO AT DIFFERENT RATES \hTO AVOID A MASS EMERGENCE.

\h\hSOMEWHERE AROUND TWO TO THREE WEEKS,

\hTHE INCH-LONG TADPOLES BEGIN TO GROW HIND LEGS.

♪

A FEW WEEKS LATER,

\h\h\h\h\hWITH CLOSED GILLS AND FULLY FORMED FRONT LEGS,

A NEW GENERATION OF TOADLETS

MAKES ITS FIRST VENTURE \h\h\h\h\h\h\hONTO LAND.

♪

FOR 160 MILES, THE RIVER \h\hSERVES AS THE BORDER

BETWEEN LOUISIANA TO THE WEST \hAND MISSISSIPPI TO THE EAST.

\h\hEVERY MILE IT MOVES SOUTH, IT GETS HOTTER AND MORE HUMID.

♪

♪

THE POSSUM HAS PROVEN ITSELF

\h\h\h\h\h\h\hTO BE A MASTER OF FITTING INTO ANY CLIMATE.

\h\hIT’S EQUALLY AT HOME IN MISSISSIPPI SWAMPLAND

OR THE FORESTS OF THE NORTH.

♪

IT THRIVES IN THE BAYOU’S \hWARM AND STICKY CLIMATE.

DON’T MISTAKE IT FOR A RODENT.

IT’S MORE LIKE A KANGAROO.

♪

IT IS NORTH AMERICA’S \h\h\hONLY MARSUPIAL.

♪

\h\h\h\h\hPOSSUMS DINE ON DESTRUCTIVE GARDEN SLUGS,

ROTTING CARCASSES,

AND MANY OTHER UNPLEASANTRIES.

\h\hTHEY ARE THE MISSISSIPPI’S TRASH REMOVAL AND PEST CONTROL

ALL IN ONE.

♪

THEY’LL EVEN CLIMB FOR A MEAL.

\h\h\h\h\hSHARP CLAWS AND A PREHENSILE TAIL

GRIP BRANCHES

AND HELP THIS FEMALE NAVIGATE \hTHE TREES IN SEARCH OF FOOD.

SHE NEEDS ALL SHE CAN GET.

THIS MARSUPIAL IS ALSO A MOM.

♪

\h\hHER YOUNG WERE BORN AND RAISED IN HER POUCH.

♪

THEY’RE NOW FOUR MONTHS OLD \h\hAND WEANED OFF HER MILK.

BUT THEY WILL STAY WITH MOM \h\hFOR ANOTHER MONTH OR SO

\h\h\h\h\hAS THEY PREPARE TO HEAD OUT ON THEIR OWN.

♪

THEIR WORLD WILL BE ONE

\h\h\h\h\hWHERE WILDERNESS INTERSECTS WITH HUMANITY.

♪

\h\h\h\h\hWHERE THE RIVER LEAVES ITS NAMESAKE STATE,

\h\hENGINEERS HARNESS AND LOCK THE MISSISSIPPI AT EVERY TURN.

♪

\hSOME OF THE WATER FEEDS AQUATIC FARMS

THAT NOW APPEAR ALONG ITS BANKS.

\h\h\hTHIS SUSTAINS A CULTURE THAT STRETCHES BACK 250 YEARS.

IN 1763, GREAT BRITAIN FORCED FRENCH ACADIANS

OUT OF EASTERN CANADA.

THE EXILES SOUGHT REFUGE \h\h\h\h\hIN LOUISIANA,

\hAND EVER SINCE, CAJUNS HAVE BEEN HERE, FISHING.

♪

♪

LOUISIANA HAS APPROXIMATELY \h\h\h1,200 CRAWFISH FARMS.

♪

TOGETHER THEY PRODUCE MORE THAN 55,000 TONS A YEAR--

OVER 90% OF THE CRAWFISH \h\h\hEATEN IN THE U.S.

♪

♪

\h\h\h\h\h\h\h\hCRAWFISH IS A MISSISSIPPI STAPLE.

\hTHE CRUSTACEAN’S BODY ARMOR IS MADE FROM 19 SEPARATE SEGMENTS.

THEY BREATHE THROUGH \hFEATHERLIKE GILLS

\h\h\h\h\hAND FEED ON ALL KINDS OF BIO-MATTER AS IT BREAKS DOWN.

♪

LIKE THEIR COUSIN, THE LOBSTER, THEY HAVE CLAWS,

USED PRIMARILY FOR FEEDING... \hAND DEFENSE WHEN NECESSARY.

♪

\h\h\h\hAT THE END OF SUMMER, WHEN WATER TEMPERATURES SOAR,

THE FARMERS DRAIN THEIR FIELDS \h\hBACK INTO THE MISSISSIPPI.

WITH THEIR WATERY WORLD \h\h\h\h\hDRAINING AWAY,

MOST CRAWFISH KNOW WHAT TO DO.

♪

\hIT’S PART OF THEIR NATURAL LIFE CYCLE.

THEY MUST BURROW ALL THE WAY \h\hDOWN TO THE WATER TABLE.

BUT IT’S HARD WORK,

AND SOME AREN’T SO QUICK.

♪

A CROWD BEGINS TO FORM...

PREPARING FOR THE EVENT \h\h\h\h\hOF THE YEAR...

THE GREAT BAYOU FEEDING FRENZY.

♪

[BIRDS CALLING]

♪

THOUSANDS OF WOOD STORKS, \h\h\hEGRETS, SPOONBILLS,

AND OTHER BIRDS

\h\h\h\h\h\h\h\h\hFLOCK TO THE MISSISSIPPI WATERSHED.

\h\h\h\h\hTHEY’RE HERE FOR A CRAWFISH FEAST.

♪

\h\h\h\h\hCAJUN FOOD, FRESH FROM THE BAYOU.

♪

♪

♪

THE SURVIVORS WILL BREED IN WATER-FILLED TUNNELS.

IN A FEW MONTHS, THEY’LL RETURN TO THE SURFACE WITH YOUNG.

\h\hMEANWHILE, THE WATER THAT FILLED THEIR FIELDS

GOES BACK TO THE MISSISSIPPI.

♪

AS THE RIVER LEVEL FLUCTUATES \h\h\h\h\hTHROUGHOUT THE YEAR,

ENGINEERS DIVERT WATER \h\hFROM NEARBY RIVERS

TO ENSURE THE MISSISSIPPI STAYS DEEP ENOUGH TO CARRY CARGO.

\h\h\h\h\h\h\h\hALONG ITS BANKS, THE BOUNDARY BETWEEN WET AND DRY

BLEEDS INTO THE BAYOU.

\h\h\hPERFECT HABITAT FOR HUNGRY PREDATORS LURKING IN THE SWAMPS.

THESE COLD-BLOODED REPTILES

\h\h\h\hMUST CONTROL THEIR BODY TEMPERATURE MANUALLY.

ALLIGATORS USE THE SUN \h\h\h\h\h\hTO WARM UP

AND THE WATER TO COOL DOWN.

THE AMERICAN GATOR

\h\h\hIS AT THE TOP OF ITS FOOD CHAIN--

AN APEX PREDATOR

THAT CAN GROW TO 14 FEET

AND WEIGH HALF A TON.

THIS FEMALE’S ON HIGH ALERT,

BUT SHE’S NOT HUNTING;

SHE’S PROTECTING.

[CHIRPING]

\h\hFOR THE PAST TWO MONTHS, SHE’S BEEN GUARDING 15 EGGS,

INCUBATING BENEATH A 4-FOOT-TALL NEST

OF GRASS AND DEBRIS.

NOW IT’S LATE AUGUST--

TIME FOR HER NEWBORNS TO EMERGE.

[SQUEAKING]

♪

[SQUEAK]

♪

[SQUEAKING]

♪

ONE BY ONE,

THE HATCHLINGS SLICE THEIR WAY \h\h\hOUT OF THE EGG CASINGS.

[SQUEAK]

♪

THE TEMPERATURE OF THE NEST \h\h\h\h\hDURING INCUBATION

\hDETERMINES THE SEX OF THE BABY GATORS.

\h\h\h\h\h\h\h\h\h\hHEAT ALTERS A SPECIAL PROTEIN IN THE EMBRYO.

[SQUEAKING]

A NEST OF 86 DEGREES OR BELOW \h\hWILL PRODUCE ALL FEMALES.

BUT WARM UP TO 92 DEGREES, AND YOU’LL GET ALL MALES.

[SQUEAKING]

TEMPERATURES IN BETWEEN \h\h\hCAN PRODUCE A MIX.

♪

♪

THEY INSTINCTIVELY HEAD TO THE WATER.

♪

IN THEIR EARLY STAGES,

\hTHEY’RE VULNERABLE TO RACCOONS, BIRDS,

\hEVEN OTHER GATORS LOOKING FOR A SNACK.

♪

THEY QUICKLY FIND MOM.

♪

IF SHE SUCCESSFULLY \h\h\hPROTECTS THEM

THROUGH THEIR FIRST YEAR OR SO,

\h\h\h\hTHEY’LL GO FROM ONE OF THE MOST VULNERABLE CREATURES

TO THE TOP PREDATOR \h\h\hOF THE BAYOU.

A POSITION THEY HOLD \hFROM HERE ON DOWN.

♪

♪

♪

FROM BATON ROUGE,

\hTHE MISSISSIPPI BEGINS HER FINAL PUSH SOUTH...

150 MILES TO THE GULF.

♪

THE LOUISIANA STATE CAPITAL \h\hIS THE NORTHERNMOST STOP

FOR HUGE CARGO SHIPS DELIVERING GOODS UP THE MISSISSIPPI.

THEY HELP MAKE BATON ROUGE

THE EIGHTH LARGEST PORT \h\h\h\h\h\hIN THE U.S.

♪

LEAVING THE CITY,

\hTHE RIVER QUICKLY RETURNS TO THE WILD.

♪

AS AUTUMN SETS IN,

\h\hTHE SWAMPS GET SOME RELIEF FROM THE SOARING TEMPERATURES,

\h\h\h\h\h\h\hDRAWING OUT A NEW CAST OF CHARACTERS.

♪

RACCOONS ARE SURVIVORS.

THEY’RE AMONG THE MOST ADAPTABLE CREATURES ON THE PLANET

AND CAN LIVE ALMOST ANYWHERE.

♪

\h\h\h\hRACCOONS OFTEN HUNT UNDER THE COVER OF DARKNESS,

BUT COOLER AIR AND HUNGER

\hENTICE THIS ONE INTO THE SUNLIGHT.

♪

IN THESE PARTS,

TRAVEL ALONG THE WATER’S EDGE \h\h\h\h\h\h\hCAN BE PERILOUS.

[GROWLING]

♪

\h\h\h\h\hA 12-FOOT-LONG AMERICAN ALLIGATOR WAITS

FOR A CHANCE TO STRIKE.

♪

♪

\h\h\h\h\hTHE RACCOON WILL SUSTAIN THE GATOR

\h\hFOR THE COMING CHANGE OF SEASONS.

FALLING TEMPERATURES

WILL TRIGGER THE REPTILE \h\hTO BECOME LETHARGIC

AND ENTER A STATE CALLED BRUMATION.

IT WILL WAIT OUT THE WINTER AND NOT EAT FOR FOUR MONTHS.

♪

THE RIVER’S FINAL LEG

\h\h\h\h\h\hTAKES IT PAST THE BONNET CARRÉ SPILLWAY,

THROUGH NEW ORLEANS,

AND DOWN TO THE GULF OF MEXICO.

THIS IS THE MISSISSIPPI \h\h\h\h\h\hRIVER DELTA.

♪

♪

FOR NEARLY 3,000 MILES,

THE RIVER HAS CARRIED A LOAD--

\h\h\h\h500 MILLION TONS OF SILT, SAND, AND ROCK.

\hNOW IT FINALLY GETS TO DEPOSIT ITS BURDEN.

SEDIMENT FROM THE RIVER

\hHAS BUILT UP OVER THOUSANDS OF YEARS,

CREATING A DELTA THAT NOW COVERS 4,000 SQUARE MILES.

\hTYPICALLY, RIVER DELTAS MOVE AND CHANGE OVER TIME.

\h\hBUT NOT HERE, NEAR THE SPILLWAY.

WE’VE SPENT BILLIONS OF DOLLARS

\h\h\h\h\h\hCONSTRUCTING A VAST SYSTEM OF LEVEES

TO PROTECT OUR CITIES

FROM THE MISSISSIPPI’S NATURAL EBB AND FLOW.

\h\h\h\h\h\h\h\h\h\hTOGETHER, THE RIVER’S LEVEES ARE LONGER

THAN THE GREAT WALL OF CHINA.

♪

THE BARRIERS HAVE ALLOWED \hTHE CITY OF NEW ORLEANS

TO BECOME A GATEWAY \h\hTO THE WORLD...

♪

A CULTURAL ICON...

♪

\h\h\h\h\hWITH A HERITAGE INFLUENCED BY THE FRENCH,

THE SPANIARDS, AFRICANS, \hAND NATIVE AMERICANS.

♪

\h\h\hNEW ORLEANS ALSO MARKS THE END OF AN EPIC JOURNEY.

♪

\h\hWATER FROM NEARLY EVERY RIVER AND STREAM

IN THE HEART OF THE COUNTRY

WINDS UP HERE,

IN THE GULF OF MEXICO.

\h\hTHE ESSENCE OF 31 STATES FUNNELS TO THIS VERY POINT.

\hWITH ALL THIS WATER COMES EVERYTHING WE PUT INTO IT--

THE GOOD AND THE BAD.

NUTRIENTS, PESTICIDES, \h\h\h\hFERTILIZER...

\h\h\h\h\h\hALL FLUSHED INTO THE GULF OF MEXICO.

WITH SUMMER’S WARMTH,

ALGAE RAPIDLY BLOOM \h\h\hAND THEN DIE,

CAUSING OXYGEN LEVELS \h\h\h\h\hTO PLUMMET.

BY AUGUST,

\h\h\hIT CREATES A PHENOMENON THE SIZE OF MISSISSIPPI STATE,

CALLED A DEAD ZONE.

\h\h\h\hNEARLY ALL OF THE NORMAL RESIDENTS--

FISH, SHARKS, SHRIMP, CRABS--

EITHER LEAVE OR DIE.

♪

\hTHERE’S ONLY ONE CREATURE THAT THRIVES IN A DEAD ZONE.

JELLYFISH.

♪

\h\h\h\h\h\hMOON JELLYFISH CAN SURVIVE AND REPRODUCE

WITH VIRTUALLY NO OXYGEN.

THEY FEED MOSTLY ON PLANKTON--

MICROSCOPIC PLANTS AND ANIMALS \h\h\h\hFLOATING IN THE WATER.

♪

\h\h\hTHEIR SHEER NUMBERS SHOW AN IMBALANCE IN THE ECOSYSTEM.

♪

IT WILL TAKE A NATURAL SHOCK, \h\h\h\h\h\hLIKE A HURRICANE,

\h\h\h\hTO STIR THINGS UP AND REOXYGENATE THE WATER.

♪

UNTIL THEN, THERE’S LITTLE ELSE THAT CAN SURVIVE...

\h\h\h\h\h\hNEAR THE MOUTH OF THE MISSISSIPPI RIVER.

♪

[BIRDS CALLING]

THE RIVER DELTA IS A PLACE \h\hWHERE WORLDS COLLIDE.

♪

\hLAND AND WATER... HUMAN AND NATURE...

RIVER AND SEA.

♪

NOW THE MISSISSIPPI’S JOURNEY \h\h\h\h\h\h\hIS FINALLY DONE.

♪

FOR 2,300 MILES,

THE RIVER PROVIDES FOR LIFE \h\h\h\h\hALONG ITS SHORES.

♪

IT PLAYS DIFFERENT ROLES \h\h\h\hALONG THE WAY--

BARRIER, PROVIDER, CHALLENGER.

\h\h\h\hBUT ALWAYS WITH ITS OWN SINGULAR DRIVE--

TO REACH THE SEA.

THOUGH WE MOVE SOME OF ITS WATER TO OUR WILL,

THE RIVER IS ALWAYS \hTRULY IN CONTROL.

♪

WE ARE JUST WITNESSES \hTO THE ICONIC LEGACY

\hOF AMERICA’S OWN MISSISSIPPI RIVER.

♪