MAN: WE'RE ALL FAMILIAR WITH THE ICONIC AFRICAN WATERHOLE.

IN THE BAKING HEAT OF THE SAVANNA, THEY LITERALLY TEEM WITH LIFE.

BUT HOW DOES ONE ACTUALLY FUNCTION?

WHAT ARE THE POLITICS OF ANIMAL COEXISTENCE?

AND WHO RULES WHEN THE HEAT IS ON?

TO FIND OUT, WE BUILT OUR VERY OWN AFRICAN WATERHOLE.

THIS WATERHOLE, IT'S HUMAN-MADE.

WE'VE TEAMED UP WITH SOME GREAT SCIENTISTS AND CONSERVATIONISTS TO BRING THIS MUCH-NEEDED WATER SOURCE INTO THIS DRY, ARID LANDSCAPE.

THIS IS A WATERHOLE WITH A DIFFERENCE.

WE HAVE A NEW AND TOTALLY EXCITING WAY OF KEEPING TRACK OF WILDLIFE BIOLOGY AND DRAMA.

WE'VE GOT A HIDE, HALF-SUBMERGED, RIGHT IN THE MIDDLE OF THE WATERHOLE, AND WE'VE GOT REMOTE CAMERAS RIGGED UP AROUND THE WATERHOLE, KEEPING TRACK OF ANIMAL BEHAVIOR LIKE NEVER BEFORE.

[NICKERS] IT'S A UNIQUE CHANCE TO FOLLOW THE EVOLUTION OF A WATERHOLE... AND THE DAILY DRAMAS OF THE ANIMALS THAT DEPEND ON IT FROM THE VERY BEGINNING.

MAN: WOW!

SANJAYAN: YEAH?

THAT'S A BEAUTIFUL, BIG MALE LION.

SANJAYAN, VOICE-OVER: WE DON'T KNOW WHO'S GOING TO TURN UP AND IN WHAT NUMBER, BUT WE'LL OBSERVE AND RECORD EVERY SINGLE SPECIES OVER A PERIOD OF 6 MONTHS.

WE'RE FILMING FROM THE MIDDLE OF THE LIFE-SAPPING DRY SEASON, WHEN WATER IS SCARCE AND TEMPERS FRAY.

SANJAYAN: HE'S WALKING STRAIGHT TO THEM.

IT'S A GAME OF CHICKEN, EXCEPT WITH BUFFALO.

UNTIL THE PRESSURE FINALLY BREAKS... [THUNDER] AND THE ANNUAL RAINS CHANGE EVERYTHING.

TO SEE IT FROM UP HERE GIVES ME A TOTALLY DIFFERENT PERSPECTIVE ON THE LANDSCAPE.

WE'LL GET TO KNOW A WILD CAST OF CHARACTERS AS THEY FIGHT FOR SURVIVAL AT THE ONE PLACE THEY ALL MEET.

IF THEY LINGERED ANY LONGER, THEN THEY BECAME TARGETS FOR PREDATORS.

[ELEPHANT TRUMPETING] THIS IS THE STORY OF LIFE... MAN: WHOA, LOOK AT THAT, LOOK AT THAT.

AND DEATH AT THE WATERHOLE.

IN EAST AFRICA, TANZANIA, SOUTH OF THE SERENGETI ECOSYSTEM, IS MWIBA WILDLIFE RESERVE, A PROTECTED AREA SPANNING 130,000 ACRES.

IT PROVIDES A SANCTUARY FOR COUNTLESS ICONIC SPECIES INCLUDING ELEPHANT... HIPPO...

GIRAFFE... LEOPARD... AND LION.

BUT THERE ARE ALSO PEOPLE WHO LIVE NEAR THE RESERVE.

THEY MUST SHARE A SCARCE SUPPLY OF FRESH WATER WITH WILDLIFE.

COMPETITION REACHES ITS PEAK RIGHT NOW IN THE DRY SEASON, SO, I'M HEADED TO KAKESIO, A MAASAI VILLAGE 10 MILES AWAY.

THIS IS THE HEIGHT OF THE DRY SEASON, AND WATER IS A REALLY PRECIOUS RESOURCE FOR THE MAASAI AT THIS TIME OF THE YEAR.

WHAT I WANT TO FIND OUT IS WHAT DO THEY DO, WHERE DO THEY FIND WATER, AND DOES IT PUT THEM IN CONFLICT WITH THE ABUNDANT WILDLIFE THAT IS IN THIS AREA.

[CONVERSATION IN MAASAI] SANJAYAN: VILLAGE CHIEF TINAYAY TANGWA HAS BEEN LIVING HERE FOR OVER 30 YEARS.

THIS IS HIS PLACE.

RECENTLY, HE HAS SEEN HOW A LACK OF WATER HAS BEEN IMPACTING HIS FAMILY AND CATTLE.

IT'S QUITE SORT OF EXTRAORDINARY HAVING ALL OF THIS LIVESTOCK RIGHT NEXT TO WHERE HE AND HIS FAMILY LIVE.

[COWS MOOING] THE CHIEF HAS INVITED ME TO SEE THE DAILY ISSUES HE IS FACING WITH WATER.

IN TANZANIA, THERE ARE NO FENCES BETWEEN WILDLIFE RESERVES LIKE MWIBA AND HUMAN SETTLEMENTS.

[COW MOOS] OUT HERE, PEOPLE, LIVESTOCK, AND WILDLIFE ALL FIGHT OVER THE SAME RESOURCES.

[INSECT BUZZING] TO GET ENOUGH WATER, THE MAASAI HAVE TO DIG WELLS, AND SOMETIMES THEY'RE UP TO 20 FEET DEEP.

IT'S BONE-DRY.

THERE ARE LOADS OF WELLS THAT DOT THIS AREA.

SOME ARE OLD AND ABANDONED, OTHERS ARE VERY MUCH FUNCTIONAL...

WHICH ARE JUST DUG OUT BY HAND INTO WHAT I CAN ONLY IMAGINE IS REALLY PRETTY TOUGH SOIL.

WATER IS SO PRECIOUS, THE WELLS OFTEN ATTRACT WILDLIFE... AND THAT'S HOW THE CONFLICT STARTS.

I MEAN, YOU LOOK AT THIS FENCE.

I MEAN, THIS IS A PRETTY SOLID FENCE AND IT'S ALL HERE JUST TO KEEP WILDLIFE AWAY FROM THAT WELL.

BECAUSE IT TAKES SO MUCH WORK TO BUILD THAT WELL, THE LAST THING THIS COMMUNITY WANTS IS THAT WELL TO BE DESTROYED OR ELEPHANTS GOT IN THERE AND JUST DRANK ALL THE WATER.

[SPEAKING MAASAI] LOOK AT THIS.

SEE THAT?

THAT'S ELEPHANT DUNG.

IT'S OLD ELEPHANT DUNG, BUT IT'S ELEPHANT DUNG NONETHELESS.

SO, YOU KNOW, IT'S COMPLETE PROOF THAT ELEPHANTS COME HERE REGULARLY AND DRINK THIS WATER.

WITH THE GROWING IMPACT OF CLIMATE CHANGE, COMPETITION FOR WATER IS SET TO GET FIERCER.

TEMPERATURES IN AFRICA ARE RISING.

IN JUST 30 YEARS, IT'S PREDICTED THAT THE CONTINENT WILL ENDURE 50% MORE WARMING THAN THE REST OF THE PLANET.

THERE SIMPLY ISN'T ENOUGH WATER TO GO AROUND.

FOR THE MAASAI, WHAT IS REALLY AT THE TOP OF THEIR HIERARCHY OF NEEDS IS WATER, WATER THAT WILDLIFE NEED AND THE MAASAI NEED.

THEN THE POTENTIAL FOR CONFLICT JUST INCREASES.

TO HELP EASE TENSIONS, MWIBA RESERVE HAS DECIDED TO BUILD A WATERHOLE JUST FOR WILDLIFE ON AN OPEN PATCH OF GRASSLAND, EASILY ACCESSIBLE FROM ALL DIRECTIONS.

THE CONSTRUCTION WAS BLESSED BY THE ANCESTRAL STEWARDS OF THE LAND, THE HADZABE TRIBE.

[PEOPLE SINGING IN NATIVE LANGUAGE] THIS IS A GREAT CHANCE FOR US TO LEARN HOW DIFFERENT SPECIES FIND, USE, AND INTERACT AROUND A NEW WATERHOLE.

WE'RE INSTALLING A REMOTE CAMERA SYSTEM, ABLE TO RECORD DAY AND NIGHT.

13,000 GALLONS OF WATER FROM A SUSTAINABLE UNDERGROUND RESERVOIR FILL TWO SEPARATE POOLS, GIVING MORE ACCESS POINTS FOR WILDLIFE.

YOU MIGHT THINK IT NEEDS TO BE BIGGER, BUT THE AVERAGE WATERHOLE IS PUDDLE SIZE.

THESE TWO POOLS ARE REFILLABLE AND BIG ENOUGH TO QUENCH THE THIRST OF THOUSANDS OF ANIMALS.

SO, HERE'S THE PLAN.

WE'LL FOLLOW THE LIFE CYCLE OF THE WATERHOLE ACROSS 3 DISTINCT TIMES OF THE YEAR.

WE'LL START IN THE MIDDLE OF THE WINDY, DRY SEASON.

THEN, A COUPLE OF MONTHS LATER, IT TURNS TO THE HOTTEST TIME OF THE YEAR... AND FINALLY, AT THE HEIGHT OF THE FIRST RAINS.

WE'VE GOT 20 CAMERAS SET TO RECORD EVERY DETAIL OF LIFE AT THE WATERHOLE.

WE CONTROL THEM FROM OUR BASE CAMP 800 FEET AWAY, WHERE AN INTERNATIONAL GROUP OF BIOLOGISTS AND LOCAL EXPERTS CAN WATCH AS THE DRAMA UNFOLDS.

IT'S REALLY IMPORTANT TO STRESS THAT THIS HAS NEVER BEEN DONE BEFORE.

I HAVE NO IDEA--WE HAVE NO IDEA WHAT'S ACTUALLY GOING TO HAPPEN.

TO KEEP TRACK OF THE ACTION, WE'LL ATTEMPT TO COLLATE DATA ON EVERY VISITOR, BUILDING A SPECIES LIST TO TELL US HOW MANY ANIMALS COME TO A NEW WATERHOLE.

OUR FIRST QUESTION-- HOW LONG WILL IT TAKE FOR WILDLIFE TO FIND IT?

THE ANSWER--JUST 45 MINUTES.

[WARTHOG GRUNTING] IT'S A WHOLE FAMILY OF WARTHOGS, 4 OF THEM, JUST SHOWED UP.

TAILS WAGGING, ROOTING UP THE ENTIRE EDGE OF THIS WATERHOLE THAT WE'VE CONSTRUCTED, MAKING IT LOOK SO MUCH MORE NATURAL.

THE WARTHOG FAMILY LIVES ABOUT A THOUSAND FEET AWAY.

THEY PROBABLY DISCOVERED THE WATERHOLE WHILE OUT FORAGING FOR FOOD.

INTERESTINGLY, THEY'RE NOT HERE TO DRINK.

WHAT THEY'RE REALLY AFTER IS A MUD BATH.

IT'S A STIFLING 95 DEGREES, BUT WARTHOGS DON'T HAVE SWEAT GLANDS THAT REGULATE THEIR BODY TEMPERATURE.

OUR INFRARED CAMERA SHOWS HOW EFFECTIVE MUD BATHING IS.

THEIR BODIES TURN BLUE THE COOLER THEY GET.

MUD BATHING CAN REDUCE BODY TEMPERATURE BY A LIFESAVING 7 DEGREES FAHRENHEIT.

OUR WATERHOLE ALREADY HAS ITS FIRST HAPPY CUSTOMERS.

THEY LOOK REALLY IN GREAT CONDITION, AND THEY ARE LOVING, LOVING THIS WATER.

PROBABLY HOW COLD IT IS AND ALL THE MUD, AND THEY'RE JUST PIGS IN HEAVEN RIGHT NOW.

AS WELL AS WATCHING THE WATERHOLE, WE WANT TO UNDERSTAND HOW A BRAND-NEW WATER SOURCE AFFECTS LIFE AROUND IT.

SO, WILDLIFE CAMERAMAN BOB POOLE WILL BE PATROLLING A 6-MILE CIRCUIT, KEEPING US UPDATED ON WHAT'S GOING ON IN THE AREA.

POOLE: YEAH, SANJAYAN, DO YOU COPY?

HI, BOB.

THE ELEPHANT'S ON HIS WAY.

HE'S JUST MOVING, ACTUALLY, QUITE QUICKLY TOWARDS YOUR DIRECTION.

SANJAYAN: YEP!

WELL DONE.

HOLY COW.

THAT-- NO, HOLY ELEPHANT.

I MEAN, THAT IS INCREDIBLE.

YOU JUST SAW A LITTLE GREY MOVE, RIGHT?

POOLE: IF YOU CAN SEE HIM, MAYBE THIS IS A GOOD TIME FOR ME TO LEAVE.

SANJAYAN: OK, WE CAN SEE HIM.

IT'S FINE.

IT'S THE MIDDLE OF THE DAY, AND HE'S TUCKED IN SOME SHADE, USING THOSE BIG EARS TO FAN HIMSELF AND GENERATE SOME AIR FLOW BECAUSE THAT'S HOW ELEPHANTS TYPICALLY LOSE SOME OF THEIR HEAT, IS THROUGH THOSE BIG RADIATORS IN THEIR EARS.

THERE'S BOB.

HEY, I THOUGHT YOU WERE OUT WITH THE ELEPHANT.

YOU KNOW, IT'S AMAZING HOW IT DISAPPEARS INTO THIS ENVIRONMENT.

OH, MY GOODNESS.

I LOST HIM 3 TIMES OUT THERE.

OH, THIS IS FANTASTIC.

HE'S DEFINITELY ON THE MOVE AND COMING RIGHT OUT INTO THE OPEN.

SANJAYAN: HERE HE'S FINALLY GETTING WHAT HE WANTED ALL THIS TIME.

POOLE: YEP, STRAIGHT TO THE WATER... AND SO HE'LL-- SANJAYAN: DEEP TASTE OF IT.

YEAH, HE'S GOING TO TAKE A GOOD, LONG TASTE OF IT.

MY GUESS IS HE'LL DRINK FOR QUITE A WHILE, AND THEN HE'LL JUST COVER HIMSELF, ONCE HE TOTALLY RELAXES INTO THIS.

I THINK HE'S NOW AMAZED AT THE QUALITY OF THIS WATER.

HE'S LIKE, WOW, I HAVEN'T TASTED THIS IN A LONG TIME.

HA HA HA!

YEAH, JACKPOT, RIGHT?

THIS IS VERY, VERY EXCITING.

SANJAYAN, VOICE-OVER: AN AFRICAN ELEPHANT NEEDS TO DRINK NEARLY A BATHTUB OF WATER EACH DAY.

THEY MIGHT HAVE TO WALK OVER 100 MILES TO FIND ENOUGH, WHICH IS WHAT LEADS TO CONFLICT WITH LOCAL VILLAGES.

HOPEFULLY, THIS ELEPHANT COMING HERE MEANS HE STAYS OUT OF TROUBLE.

SANJAYAN: YEAH, THERE HE GOES, WITH SOME WATER ON HIS BODY... POOLE: NOW LET'S SEE.

SO HE CAN START TO COOL DOWN.

POOLE: NOW HE'S HAD SOMETHING TO DRINK, HE'S PROBABLY GOING TO START COVERING HIMSELF WITH CLEAN WATER AND THEN MUD, AND YOU CAN SEE, WATCH HIS TAIL, YOU KNOW, JUST ABSOLUTELY, TOTALLY LIMP AND RELAXED THERE.

YOU SEEM PRETTY LIMP AND RELAXED RIGHT NOW YOURSELF.

I'M JUST HAPPY TO BE IN OUT OF THE TSETSE FLIES.

HA HA!

OH, LOOK, HE'S GETTING A-- HE'S STARTING TO FEEL REALLY GOOD, LET'S PUT IT THAT WAY.

[LAUGHTER] THAT'S NOT A LEG.

LOOK AT THAT.

LOOK AT THE CAMERA 4.

LOOK AT THAT SHOT.

POOLE: ISN'T THAT BEAUTIFUL?

SANJAYAN: FANTASTIC, RIGHT?

I LOVE THE LOW ANGLES.

I DO, TOO.

THAT'S IT.

FANTASTIC STUFF.

REALLY FANTASTIC.

I MEAN, YOU JUST HAVE TO PUT THIS IN PERSPECTIVE, THAT THIS WATERHOLE DIDN'T EXIST, YOU KNOW, A MONTH AGO, AND, YOU KNOW, THE BIGGEST, WELL, NOT JUST THE BIGGEST MAMMAL OUT HERE BUT THE BIGGEST LAND MAMMAL ON THE PLANET IS ALREADY USING IT.

YEAH.

I MEAN, THAT'S PRETTY INCREDIBLE.

IT'S ALSO GREAT BECAUSE ELEPHANTS ARE THOUGHT TO HELP OTHER ANIMALS LOCATE WATER IN THE DRY SEASON.

AS HE FORAGES, THIS MALE INADVERTENTLY CREATES PATHWAYS THROUGH THE BUSH, LEADING BACK TO THE WATERHOLE.

AND, SURE ENOUGH, 15 MINUTES LATER, MORE THIRSTY ANIMALS ARRIVE.

SANJAYAN: WE'VE GOT AN IMPALA THAT'S SHOWN UP.

SANJAYAN, VOICE-OVER: THE IMPALA ARE FOLLOWED BY ZEBRA.

BOTH THESE ANIMALS GET A LOT OF HYDRATION FROM THE PLANTS THEY EAT.

BUT IN THE DRY SEASON, THEY MUST RELY ON WATERHOLES, AS A LOT OF THE PLANT LIFE DIES OFF.

TO ADD 4 SPECIES TO OUR LIST ON DAY ONE, WITHIN JUST A FEW HOURS OF THE WATERHOLE BEING FINISHED, SHOWS JUST HOW MUCH IT'S NEEDED.

160 FEET AWAY, THE NEAREST WATER SOURCE IN THE AREA, THE OLOIBORRISINYAI RIVER, IS COMPLETELY DRY.

AND FOR HERBIVORES, EVEN THE PLANT LIFE CAN BE HOSTILE.

I WANT TO SHOW YOU SOMETHING.

THIS IS ACTUALLY ONE OF MY FAVORITE TREES.

IT'S CALLED A WHISTLE THORN ACACIA BECAUSE APPARENTLY WHEN THE WIND BLOWS, IT MAKES A WHISTLING SOUND THROUGH THESE TREES, AND THEY'RE FOUND ON THESE EAST AFRICAN SAVANNAHS.

AND WHAT I LOVE ABOUT THEM IS THIS TREE IS-- FIRST OF ALL, IT LOOKS SO WICKED, AND YOU THINK IT'S DEAD RIGHT NOW, BUT IT ISN'T, IT'S JUST DORMANT BECAUSE IT'S IN THE MIDDLE OF THE DRY SEASON.

AS SOON AS THERE'S A LITTLE BIT OF MOISTURE, IT'S GOING TO LEAF UP.

BUT NOT ONLY DOES IT HAVE THESE GIGANTIC THORNS, AND YOU'D THINK THAT WOULD BE ENOUGH TO DETER ANYTHING FROM EVEN ATTEMPTING TO EAT IT, BUT IT HAS AN EXTRA LAYER OF DEFENSE.

IT PRODUCES THESE GALLS THAT YOU CAN SEE SCATTERED THROUGHOUT THIS WHOLE TREE.

IT HOUSES ANTS WITHIN THEM, AND THESE ANTS NOT ONLY PRODUCE A FAIRLY NASTY BITE, BUT THEY ALSO SPRAY FORMIC ACID AND THEY DETER HERBIVORES, THEY DETER THINGS LIKE KUDU AND IMPALA AND EVEN GIRAFFE, THAT ARE CONSTANTLY TRYING TO BROWSE ON THESE TREES.

NOW, HERE'S KIND OF AN AMAZING THING.

IF I WAS TO FENCE THIS TREE AND KEPT ALL THE HERBIVORES AWAY, AFTER A WHILE THIS TREE WILL THINK, NOTHING'S EATING ME ANYMORE, IT WILL STOP PRODUCING THESE GALLS, AND IT WILL KICK OUT THE ANTS.

SO, THERE IS THIS TRADE-OFF THAT THIS TREE ACTUALLY MAKES.

IT USES SOME ENERGY TO KEEP ITSELF SAFE, BUT IT ONLY DOES THAT IN PLACES WHERE IT'S REALLY BEING BROWSED QUITE HEAVILY.

THE PRESSURE ON THIS ENVIRONMENT IS SO CONSTANT AND SO UNRELENTING THAT BIG THORNS ALONE IS NOT ENOUGH.

YOU HAVE TO HAVE, IN THIS CASE, AN EXTRA LAYER OF ANT DEFENDERS TO KEEP YOU SAFE.

AT NIGHT, THERE'S SOME RELIEF FROM THE HEAT OF THE DAY, AS TEMPERATURES DROP TO 59 DEGREES.

BUT THIS IS OFTEN THE MOST DANGEROUS TIME TO BE AT A WATERHOLE.

LION, LEOPARD, AND HYENA ARE MUCH MORE ACTIVE AFTER DARK.

AND ON THE FIRST NIGHT, AROUND 8 P.M., IT HAPPENS.

ONE OF MWIBA RESERVE'S MOST NOTORIOUS HUNTERS HAS DISCOVERED THE WATERHOLE.

LEOPARDS HAVE THE LARGEST RANGES OF ALL THE AFRICAN BIG CATS.

MALE TERRITORIES CAN SPAN OVER 1,200 SQUARE MILES.

IT'S NOT CLEAR IF THIS GUY IS A MWIBA RESERVE RESIDENT OR JUST PASSING THROUGH.

TO FIND OUT, LOCAL GUIDE SAITOTI OLEKUWAI JOINS ME TO REVIEW THE SHOTS.

OLEKUWAI: OOH, LOOK AT THAT.

OH, UH-HUH.

SANJAYAN: YEAH.

BEAUTIFUL.

LOOK AT THAT.

A BIG LEOPARD JUST SHOWED UP.

YOU CAN SEE IT'S A BIG LEOPARD.

AND HAVE YOU SEEN THIS GUY BEFORE?

YES, I'VE SEEN THIS GUY BEFORE.

HIS NAME IS UJASIRI, MEANS CONFIDENCE.

A LEOPARD NAMED CONFIDENCE IS THE FIRST ONE TO COME TO THE WATERHOLE, YEAH?

SO, WHEN YOU SEE THIS GUY LIKE THIS, YOU CAN TELL WHICH LEOPARD THIS IS?

YES.

IT'S MAINLY THE WHISKER PATTERNS, THE BLACK MARKING OR THE DOTS THAT-- IT'S LIKE THE SPOTS RIGHT ON THE... ON THE MOUTH?

YEAH.

HE'S GOT TWO ON HIS, ON ITS RIGHT-HAND SIDE.

YES, AND THEN WHEN WE LOOK AT THE OTHER SIDE, THAT GIVES YOU AN IDEA OF EXACTLY WHICH LEOPARD THIS IS.

EXACTLY.

SANJAYAN, VOICE-OVER: UJASIRI'S ARRIVAL IS A SIGN THAT OUR WATERHOLE HAS ALREADY GRABBED THE ATTENTION OF THE AREA'S PREDATORS.

LEOPARDS HUNT A WIDE VARIETY OF PREY, FEEDING ON EVERYTHING FROM INSECTS TO RODENTS TO LARGE ANTELOPE.

AND THEY HAVE EVOLVED A KILLER ADAPTATION TO HUNT AT NIGHT.

SANJAYAN: SO, WHEN YOU LOOK AT THESE GUYS, WHEN THEY LOOK AT THE CAMERA, YOU CAN REALLY SEE THEIR EYES ARE LIKE ALMOST AS IF THERE'S A LIGHT INSIDE IT.

I MEAN, THE EYE SHINE IS SO STRONG.

WELL, THAT IS CALLED THE TAPETUM LUCIDUM.

ANY AMOUNT OF LIGHT THAT'S REFLECTED FROM THE STARS GOES IN THERE.

THAT ENHANCE THE EYESIGHT OF THAT CAT.

THESE CATS CAN SEE 6 TIMES BETTER THAN US AT NIGHT.

HE'S BEAUTIFUL, AND HE'S FULL-BELLIED THERE.

LOOK AT HIS ROUNDISH TUMMY.

HE'S PROBABLY JUST ATE SOMETHING.

YOU THINK SO?

YEAH, YEAH, YEAH.

HE IS FULL-BELLIED.

AND DO YOU KNOW, THESE GUYS, AFTER THEY HUNT LIKE THIS, THEY DO LIKE TO COME TO THE WATER, RIGHT?

THEY WILL, YEAH, THEY WILL LIKE TO DRINK.

ALTHOUGH IT'S NOT NECESSARILY THAT THEY NEED IMMEDIATELY TO GO TO DRINK BECAUSE THEY WILL GET THAT LIQUID FROM THE BLOOD.

IT'S A BEAUTIFUL CAT.

SANJAYAN: AFTER UJASIRI'S VISIT, THE NIGHT GROWS QUIET AT THE WATERHOLE.

BUT THE SILENCE DOESN'T LAST LONG.

OVER THE NEXT FEW DAYS, WE ADD AN INCREDIBLE 15 NEW SPECIES TO OUR LIST...

INCLUDING CAPE BUFFALO.

THEY HAVE A SYMBIOTIC RELATIONSHIP WITH OXPECKERS IN THE DRY SEASON.

THE BIRDS PICK OFF PARASITES FROM THE BUFFALO'S SKIN AND IN RETURN GET A FREE RIDE TO WATER.

ALONG WITH OXPECKERS, 4 NEW SPECIES OF BIRDS COME TO THE WATERHOLE.

YELLOW-BILLED STORKS OFTEN HUNT IN SHALLOW WATER.

BLACK-FACED SANDGROUSE ARE SPECIALISTS AT TRAVELING LONG DISTANCES TO WATERHOLES, NOT ONLY TO DRINK, BUT TO WET THEIR BREAST FEATHERS TO CARRY WATER BACK TO THEIR CHICKS.

CAPE TURTLE DOVES, WHICH ARE FOUND ACROSS EAST AFRICA.

BARE-FACED GO-AWAY BIRDS, WHICH GET THEIR NAME FROM THEIR DISTINCTIVE CALL, WHICH SOUNDS LIKE "GO AWAY."

[BIRD CALLS] AFTER DARK, AFRICAN HARE HOP IN.

WATER HELPS THEM DIGEST VEGETATION.

AS WE WATCH, THE SPECIES LIST GROWS.

ON NIGHT 3, A LONE WATERBUCK, WHICH NEEDS WATER DAILY TO SURVIVE, COMES IN FOR A DRINK.

TWO SPECIES OF PRIMATES ALSO FIND THE WATERHOLE-- OLIVE BABOONS AND VERVET MONKEYS.

THEY LOVE TO SOCIALIZE AROUND WATER SOURCES, MUCH TO THE ANNOYANCE OF EVERYONE ELSE.

ON DAY 5, THE PARTY REALLY GETS STARTED.

20 SPECIES HAVE FOUND AND ARE SHARING THE WATERHOLE.

THE SAME ANIMALS ARE RETURNING EVERY DAY AND THERE'S MORE TO THEIR VISITS THAN MEETS THE EYE.

NOW, OBVIOUSLY, WE'VE BEEN HAVING THESE CAMERAS RUN 24/7, AND THAT'S COLLECTING DATA-- REALLY INTERESTING DATA!

AND I'VE BEEN PARTICULARLY KEEN TO FIND OUT WHAT ANIMALS SHOW UP WHEN.

FOR SOME OF OUR SPECIES THAT COME TO THIS WATERHOLE, IT'S LIKE CLOCKWORK.

THERE'S ALREADY A SCHEDULE TO LIFE AT THE WATERHOLE.

FROM AROUND 8 A.M., A STEADY STREAM OF IMPALA COME IN FOR A DRINK.

11:00 IS THE MOST FREQUENT TIME FOR ZEBRA.

[NICKERS] AT 1 P.M., THE VERY PUNCTUAL WARTHOG FAMILY COMES FOR A MUD BATH.

3:00 IS WHEN ELEPHANTS OFTEN TURN UP.

[ELEPHANTS TRUMPETING] AND THE HERD OF BUFFALO, WELL, THEY'RE COMING IN FIRST THING IN THE MORNING AND AT DUSK.

[BUFFALO GRUNTING] I HAVE A THEORY AS TO WHY THIS ROUTINE HAS BEEN SET SO EARLY ON.

YOU KNOW, LOOKING AT THIS DATA, THERE ARE CERTAIN PATTERNS THAT, YOU KNOW, IMMEDIATELY JUMP OUT AT YOU, AND ONE OF THE THINGS THAT'S BEEN MOST SURPRISING TO ME IS THAT IN THE MIDDLE OF THE DAY, IN THE HEAT OF THE DAY, WHEN YOU'D THINK THE WATERHOLE WOULD BE COMPLETELY DESERTED, SOME ANIMALS, IT TURNS OUT TO BE A SURVIVAL STRATEGY.

THEY ARE WILLING TO DEAL WITH THE HEAT BECAUSE THEY KNOW IT'S A TIME WHEN THEY'RE SAFE FROM PREDATION.

IF THEY COME TOO LATE IN THE DAY, THAT'S WHEN THE PREDATORS ARE ABOUT AND THEY'RE VULNERABLE.

AN UNDERSTANDABLE FEAR OF PREDATORS IS AFFECTING WHEN ANIMALS SHOW UP.

BUT THE CAMERAS ARE PICKING UP SOMETHING DEEPER.

AFTER 8 DAYS, A HIERARCHY IS DEVELOPING WITHIN THE WATERHOLE COMMUNITY... AND BY ANALYZING FOOTAGE, IT'S CLEAR THAT TWO AFRICAN GIANTS ARE BATTLING TO CONTROL THIS PRECIOUS RESOURCE.

SO, RIGHT NOW YOU HAVE THE BUFFALO, AND THEY'VE KIND OF FORMED A SEMI-CIRCLE AROUND THE WATERHOLES.

SO, THIS IS A GREAT BIT OF BEHAVIOR, AND THIS IS REALLY TYPICAL.

SO, ONE YOUNG-- RELATIVELY YOUNG ELEPHANT, A TEENAGER.

NOW, HE'S APPROACHING THE BUFFALO DEAD ON.

HE'S WALKING STRAIGHT TO THEM.

IT'S A GAME OF CHICKEN EXCEPT WITH BUFFALO.

EARS WIDE... TRUNK RAISED... [ELEPHANT TRUMPETS] HEAD HELD HIGH, TRYING TO MAKE ITSELF LOOK MUCH BIGGER THAN IT REALLY IS.

IT'S A TEENAGE BOY, TESTOSTERONE-FUELED.

HE'S GOT TO PROVE TO SOMEONE THAT HE'S THE BIGGEST ELEPHANT ON THE BLOCK, EVEN THOUGH HE REALLY ISN'T.

I DON'T ACTUALLY THINK HE'S THAT THIRSTY.

I THINK HE JUST WANTED TO SHOW OFF TO THE BUFFALO THAT HE'S AN ELEPHANT.

THE BUFFALO HAVE STRENGTH IN NUMBERS, BUT AN ELEPHANT CAN WEIGH OVER A TON, AND THE BUFFALO ARE SIMPLY NOT WILLING TO PUT UP MUCH OF A FIGHT, FOR NOW.

IN 24 HOURS, WE MEASURE THAT BETWEEN THEM, BUFFALO AND ELEPHANT ARE DRINKING OVER 1,500 GALLONS OF WATER.

A NATURAL WATERHOLE MIGHT DRY UP WITH THIS HUGE AMOUNT OF CONSUMPTION.

BUT THIS ONE HAS A PLUMBED-IN FRESH WATER SUPPLY.

THERE'S SOME ZEBRA OVER THERE.

SO, THIS IS NOT LIKE ANY OTHER WATERHOLE I'VE EVER SAT AT, BECAUSE IT'S GOT THOSE TWO TAPS, AND THESE TAPS BASICALLY CONTROL HOW MUCH WATER GOES INTO THAT WATERHOLE AND THAT WATERHOLE.

WE ARE KEEPING TRACK OF WATER USAGE.

HALF AN INCH DROP IN BOTH POOLS IS 500 GALLONS OF WATER.

IT COMES FROM A NATURALLY OCCURRING RESERVOIR ABOUT 150 FEET UNDERGROUND.

THIS IS A SUSTAINABLE WATER SOURCE THAT IS REPLENISHED EVERY RAINY SEASON.

WIND TURBINES POWER THE PUMP, WHICH CAN DELIVER UP TO 2,600 GALLONS PER HOUR, SHOULD WE NEED IT.

OVER THE NEXT COUPLE OF DAYS, THE IMPORTANT ROLE OUR WATERHOLE IS STARTING TO PLAY IN THE REGION IS UNDERLINED BY A STAGGERING 20 NEW SPECIES THAT COME FOR A DRINK...

INCLUDING THE HADADA IBIS, WHICH ARE NATIVE TO SUB-SAHARAN AFRICA.

THE WHITE-TAILED MONGOOSE, WHICH IS THE LARGEST OF MONGOOSE SPECIES, REACHING 3 FEET IN LENGTH.

KIRK'S DIK-DIK, ONE OF THE WORLD'S SMALLEST ANTELOPES, STANDING AT JUST A FOOT TALL.

AND A BLACK-BACKED JACKAL THAT WASTES NO TIME MARKING THIS TERRITORY AS HIS OWN.

SO FAR, 40 SPECIES HAVE VISITED THE WATERHOLE.

POOLE: THERE WE ARE.

THAT'S PERFECT.

WOW!

ALL RIGHT.

LET'S SEE WHAT WE GOT.

TO BE AT THIS LEVEL IS SO NICE.

SANJAYAN: ON DAY 10, BOB AND I ARE LUCKY ENOUGH TO BE FILMING IN THE BLIND WHEN THE TALLEST ANIMALS ON EARTH COME FOR A DRINK.

[SPEAKING SOFTLY] THERE'S 8 GIRAFFES, EIGHT OF THEM, AND THEY'RE ALL WATCHING US, AND THESE GIRAFFE KNOW SOMETHING IS UP BECAUSE THEY ARE LOOKING AT US LIKE--LIKE A COP WITH A RADAR GUN ON THE HIGHWAY.

THIS IS THE FIRST TIME THESE GIRAFFE ARE DRINKING FROM THIS WATERHOLE WHILE WE'RE IN THIS HIDE, BUT THIS IS THE FIRST THAT WE'VE SEEN... AND IT'S LIKE MY HEART IS RACING RIGHT NOW, KNOWING THAT AT ANY MOMENT, THEY MIGHT JUST BOLT.

WE'RE SURROUNDED BY GIRAFFE AND ZEBRA.

WHEN A GIRAFFE DOES THAT, GETS HIS NECK DOWN, IT BASICALLY HAS TO SURRENDER ITSELF TO WHATEVER MIGHT ATTACK IT.

SO, IT'S A VERY VULNERABLE, UNCOMFORTABLE, CONTORTED POSITION.

THAT'S WHY THEY'RE SO NERVOUS WHEN THEY'RE DRINKING.

10 GIRAFFE ALL DRINKING RIGHT IN FRONT OF US.

IT'S ONLY TAKEN 10 DAYS FOR THE WATERHOLE TO LOOK LIKE AN ESTABLISHED OASIS IN MWIBA RESERVE.

BUT ON THE 12TH DAY, THINGS GO REALLY QUIET.

IT'S OUR FIRST BIG MYSTERY.

WHERE DID EVERYONE GO?

BOB HAS A THEORY, AND HE HEADS OUT TO INVESTIGATE.

LESS THAN 300 FEET FROM THE WATERHOLE, HIS HUNCH PAYS OFF.

RIGHT THERE.

THAT'S A PRETTY BIG ANIMAL, YOU SEE.

1, 2, 3, 4, AND THE PAD GOING TO HERE.

LOOK AT THE--LOOK AT THE DISTANCE IN THAT.

IT'S DEFINITELY A BIG CAT, WHETHER IT'S A LION OR A BIG LEOPARD.

LOOK AT THE SIZE OF THIS HERE.

YOU SEE?

SO, YOU CAN TELL THIS IS A VERY FRESH TRACK BECAUSE YOU'VE GOT A VEHICLE TRACK HERE, AND RIGHT ON TOP OF THAT, BOOM, IS A BIG CAT.

SANJAYAN: JUST THE SMELL OF A BIG CAT IN THE AREA IS ENOUGH TO MAKE ANIMALS WARY.

BOB WILL TRY TO TRACK DOWN THE OWNER OF THESE TRACKS.

WE WERE A BIT WORRIED THAT THE DAYS OF THIS OASIS WERE NUMBERED, BUT IT TAKES MORE THAN A PREDATOR IN THE AREA TO KEEP THE BIG DRINKERS AWAY.

IN TANZANIA, ELEPHANTS ARE RARELY PREDATED ON BY LIONS, AND THIS HERD HAS ALSO STRENGTH IN NUMBERS.

[ELEPHANTS TRUMPETING] OLEKUWAI: THAT'S A BREEDING HERD.

SANJAYAN: OH, THAT'S, WOW.

LOOK, THEY'VE GOT YOUNGSTERS.

YOU SEE, ALL, THEY'RE LIFTING UP THEIR TRUNKS.

LOOK AT THE BABIES.

THEY LIFT UP THEIR TRUNK, THEY'RE LIKE, "NO WE CANNOT BELIEVE IT.

IS THAT WATER?

OR WHAT'S, WHAT'S IN THERE?"

SANJAYAN: HA HA!

LOOK AT THEM.

LOOK AT THEM.

IT'S LIKE THIS DISMAL NEIGHBORHOOD... OLEKUWAI: YEAH.

THAT HAD NO GOOD RESTAURANTS OR, YOU KNOW, BARS AROUND, AND ALL OF A SUDDEN YOU'VE GOT, LIKE, YOU KNOW, THE MOTHER OF ALL BARS THAT JUST OPENED UP.

THEY COME UP WITH THE TRUNK UP, THEY'RE LIKE, "OOH, THAT SMELLS VERY NICE," YOU KNOW, IT'S, YEAH, TIME TO DRINK.

OH, THIS IS SO INCREDIBLE.

LOOK AT THAT.

BEAUTIFUL.

YEAH.

REALLY INCREDIBLE, ISN'T IT?

THEY'RE SO BEAUTIFUL.

SO PRETTY.

SANJAYAN: A HERD OF 12 MAKES THIS THE BIGGEST NUMBER OF ELEPHANTS AT THE WATERHOLE SO FAR.

[ELEPHANTS GRUNTING] ELEPHANT HERDS ARE LED BY A MATRIARCH, WHO IS IDENTIFIABLE BY BEING BIGGER AND OLDER THAN THE OTHERS.

THIS ONE IS ABOUT 30 YEARS OLD...

THE YOUNGEST CALF, JUST OVER A YEAR.

THE DRY SEASON, LIKE IT IS NOW, FOR THOSE YOUNG BABIES, IS IT DIFFICULT FOR THEM TO GO FOR A LONG WAY FROM WATER, OR CAN THEY GET MILK FROM THE MOTHER?

I MEAN, HOW, HOW DO THEY SURVIVE IN THIS INCREDIBLY DRY ENVIRONMENT?

THEY SURVIVE BY DEPENDING ON THE SUPPLEMENT OF THE MILK THEY'RE GETTING FROM THEIR MOTHER.

[ELEPHANTS TRUMPETING] SANJAYAN, VOICE-OVER: THE YEARLING IN THIS FAMILY IS JUST GETTING TO GRIP WITH TRUNK CONTROL.

THERE ARE OVER 40,000 MUSCLES IN AN ELEPHANT TRUNK, AND IT CAN TAKE CALVES OVER A YEAR TO MASTER.

IT'S A VITAL SKILL, ESPECIALLY DURING THE DRY SEASON WHEN WATER IS SCARCE AND EVERY DROP COUNTS.

SANJAYAN: AT THIS TIME OF YEAR, ARE THESE ELEPHANTS REQUIRED TO DRINK EVERY DAY?

SOMEWHERE.

IT'S HIGHLY PREDICTABLE.

THEY WILL DRINK EVERY DAY, SO, THEY WILL GO INTO ANY WATERING HOLE WHICH IS AROUND.

ONCE THEY'VE DONE THIS, LIKE, ONCE THEY'VE DRUNK AT THIS NEW WATERHOLE... YEAH?

IT'S IN THEIR MEMORY, RIGHT?

I MEAN IT, THAT-- THAT'S THE GREAT THING ABOUT ELEPHANTS, THEY REALLY DO HAVE GREAT MENTAL MAPS.

EXACTLY.

AND THESE MOTHERS WILL KNOW TO COME BACK HERE WHEN THEY NEED WATER.

YES, IT WILL GET IMPRINTED INTO THAT BIG COW, AND THAT ALSO WILL BE TRANSFERRED INTO THE YOUNGSTERS AS WELL.

SO, WITH TIME, THESE WATERHOLES JUST GET BETTER AND BETTER AND BETTER.

YES.

[CALLS] SANJAYAN: SADLY, AFTER THE ELEPHANT FAMILY LEAVES, THE WATERHOLE GOES MYSTERIOUSLY QUIET AGAIN.

BOB IS STILL TRACKING THE BIG CAT PRINTS, BUT THE TRAIL HAS NOW GONE COLD.

[BIRDS CALLING] POOLE: GUINEA FOWLS ARE ALARM CALLING OVER THERE.

IT SOUNDS LIKE KA GE-GE GE-GE GE-GE GE-GE GE-GE.

AND THEY GIVE AWAY PREDATORS ALL THE TIME.

PERHAPS THERE'S A LION OR A LEOPARD RIGHT IN THIS BUSH.

THAT NOISE RIGHT THERE: KA GE-GE GE-GE GE-GE GE-GE GE.

IT'S AN ALARM CALL.

HMM.

I'M GONNA GO UP THERE AND SEE WHAT THEY'RE KA-KING AT.

THERE'S A LION RIGHT THERE.

THERE'S A BIG LION RIGHT THERE.

DO YOU SEE IT?

AT THE BASE OF THE TREE, RIGHT THERE?

WOW.

WE FOUND IT.

HE'S JUST WAKING UP FROM A LONG DAY'S SLEEP.

HE'S HUGE!

HE'S WEARING A COLLAR, SO HE'S OBVIOUSLY BEING STUDIED.

BUT HE'S A SERIOUSLY BIG LION.

SANJAYAN: MALES ARE NOT ALWAYS PART OF A PRIDE, SO, THIS LARGE LION COULD BE TRAVELING ALONE.

IT'S LIKELY THAT HE'S NOTICED THE INCREASED PREY ACTIVITY AT THE NEW WATERHOLE.

POOLE: IN THE DRY SEASON LIKE THIS, WILDLIFE GETS CONCENTRATED AROUND WATER POINTS, AND THAT MAKES IT EASIER FOR LIONS BECAUSE THEY CAN AMBUSH THOSE WATER POINTS, AND SO THAT GIVES LIONS AN ADVANTAGE.

IT'S A GOOD CHANCE THAT THIS GUY HAS SHOWN UP OVER HERE BECAUSE THERE'S WATER NEARBY.

HERE HE COMES.

WOW.

THAT IS A BIG LION, AND HE'S HEADED IN THE DIRECTION OF THE WATERHOLE.

SANJAYAN, VOICE-OVER: TO TRY TO KEEP TRACK OF THE LION, I HEAD OUT WITH BOB ON A GOOD OLD-FASHIONED STAKEOUT.

YOU SHOULD PICK UP A COUPLE OF DIK-DIK IN HERE.

WE'LL SCAN A 3-MILE CIRCUIT AROUND THE WATERHOLE, AND WE HAVE A MILITARY-GRADE THERMAL CAMERA TO SPOT THIS ELUSIVE BIG CAT.

POOLE: WHAT IS THAT?

SANJAYAN: HEY, WHAT'S THAT?

IT'S NOT MOVING.

POOLE: DIK-DIK.

TWO OF THEM.

WHAT'S BEHIND THEM?

OH, THAT'S SOMETHING.

SANJAYAN: BUSHBABY.

NO, NO, NO.

POOLE: NO, IT'S GOT HORNS.

IT'S GOT HORNS, RIGHT?

YEAH.

IMPALA.

SANJAYAN: IMPALA.

YEAH, YOU'RE RIGHT.

POOLE: A SPRING HARE.

A SPRING HARE?

I THINK SO.

SEE?

OH, NO, BUSHBABY.

BUSHBABY.

THAT'S WHAT IT IS.

JUMPING ACROSS THE GROUND.

THAT'S PROBABLY A PRETTY GOOD LIFE.

LIFE OF A BUSHBABY.

HMM.

YOU GOT TO PEE ON YOUR HANDS ALL THE TIME, THOUGH.

OH, THAT'S TRUE.

AND SO WHAT?

NOT THE END OF THE WORLD.

[LAUGHTER] I'VE DONE THAT A FEW TIMES BY MISTAKE.

[LAUGHTER] LISTEN--LIONS!

YOU'RE RIGHT.

LISTEN, LISTEN.

YOU HEAR?

[LIONS GRUNTING] [SPEAKING SOFTLY] YEAH.

NOT FAR.

THAT'S FAR.

NO.

YEAH.

IT IS?

YEAH.

LISTEN.

WHERE IS THAT?

I DON'T KNOW.

I'M WONDERING IF THERE ISN'T SOMETHING HERE.

OH, HE'S CLOSE.

[LOUDER GRUNTING] HE'S CLOSE.

OH, HE'S CLOSE.

HE'S RIGHT THERE.

YEAH.

I MEAN, IT SOUNDED LIKE HE WAS ALMOST PARALLEL TO US, DIDN'T HE, THEN?

IT DID.

JUST A LITTLE BIT BEHIND... LET'S GO.

LET'S GO OVER THERE.

YOU SURE?

YEAH.

WELL, YOU KNOW WHAT, LET'S TURN THE LIGHT ON, THEN.

[BLEEP].

I CAN'T SEE.

HANG ON, HANG ON.

OH, JESUS.

WHAT IS IT?

THE TEQUILA.

IT GOT TIPPED.

[BLEEP] DID YOU DROP ANY?

UH-HUH.

WE HAVE SOME STILL.

SANJAYAN, VOICE-OVER: IN OUR RUSH TO CATCH UP WITH THE LION, WE ALMOST LOSE ANOTHER PART OF OUR STAKEOUT KIT.

WHAT!

OH, FOR [BEEP].

NO WAY.

YEAH, IT WAS WRAPPED AROUND THAT CORD.

IT'S OK. DON'T WORRY.

NO WAY.

IT'S OK, IT'S OK, IT'S OK. OH, MY GOD.

SANJAYAN, VOICE-OVER: THANKFULLY, THERE'S JUST ENOUGH TEQUILA TO KEEP US GOING.

BUT THE LION IS NOWHERE TO BE SEEN.

THE NEXT DAY, WE CHECK THE FOOTAGE FROM THE CAMERAS AROUND THE WATERHOLE.

THE LION SLIPPED RIGHT PAST US AND CAME FOR A QUICK DRINK JUST AFTER MIDNIGHT.

AS IT TURNS OUT, SAITOTI HAS SEEN THIS GUY BEFORE.

OLEKUWAI: OOH, LOOK AT THAT.

HA HA HA.

WOW.

YEAH?

IT'S A BEAUTIFUL, BIG MALE LION.

OOH.

LOOK AT THAT MANE.

EXACTLY.

THE SIZE OF THAT, UH, THAT CAT IS HUGE.

IT'S IMMENSE.

DO YOU KNOW THIS LION?

I KNOW THIS GUY.

REALLY?

YEAH, HE'S, TO ME, HE'S THE BIGGEST, OR HE'S THE LARGEST LION.

THIS LION IS ABOUT, UM, 10 YEARS OLD.

HE'S ON HIS PRIME.

WE NAME HIM FROM THE MAASAI TRIBE.

THE BOYS, WE CALL HIM KALAMAS.

MEANS "SNEAKY BOY."

SANJAYAN, VOICE-OVER: THE NAME SAYS IT ALL.

IT WASN'T JUST BECAUSE WE WERE DRINKING TEQUILA ON THE STAKEOUT.

THIS SNEAKY BOY IS AN EXPERT AT MOVING AROUND THE SAVANNAH WITHOUT BEING SEEN.

HE'S SUCH A UNIQUE INDIVIDUAL, TANZANIAN SCIENTISTS HAVE BEEN TRACKING HIS MOVEMENTS FOR THE PAST TWO YEARS.

OLEKUWAI: WHEN YOU LOOK AT HIS FACE...

HE'S GOT NO SCARS.

MEANS HE HAS TRIED TO AVOID THE FIGHTING WITH THE OTHER LIONS.

THAT'S PROBABLY KEPT HIM IN THIS BETTER, GOOD CONDITION LIKE THIS UNTIL NOW.

THESE LIONS, THEY CAME FROM NGORONGORO AND... ALL THE WAY FROM NGORONGORO CRATER?

ALL THE WAY FROM THE CRATER.

SANJAYAN, VOICE-OVER: KALAMAS' TRACKING DATA SHOWS THAT HE HAS RECENTLY BEEN IN THE NGORONGORO CRATER-- A NEIGHBORING RESERVE TEEMING WITH WILDLIFE.

BUT THIS UNUSUAL MALE LION HAS CHOSEN TO MAKE A HUGE MIGRATION TO MWIBA, WALKING OVER 50 MILES.

SANJAYAN: BUT IS HE IN SOMEONE ELSE'S TERRITORY RIGHT NOW?

OLEKUWAI: YES, HE IS IN, IS IN THE TERRITORY OF OTHER TWO MALES THAT ARE ON THIS AREA.

IF THEY FIND HIM, THEY'LL FIGHT?

THEY WILL FIGHT BUT... OR CHASE HIM.

HE DON'T LIKE FIGHTING, AND SO HE WILL JUST WALK AWAY.

HA HA HA.

THIS IS A GREAT LION STORY.

YEAH.

YEAH.

SO THIS GUY DOESN'T LIKE TO FIGHT?

YEAH, HE DOESN'T LIKE TO FIGHT, AND PROBABLY THAT, HE FIND THAT IS THE BEST WAY FOR HIM TO SURVIVE... AND THAT'S WHY HE HAS BEEN AROUND FOR A LONG TIME.

YEAH.

YEAH.

SANJAYAN, VOICE-OVER: THE TWO MALES ARE PART OF THE MWIBA PRIDE.

THEIR DEN IS JUST OVER A MILE AND A HALF FROM THE WATERHOLE... A DISTANCE THAT KALAMAS THE LION COULD HAVE COVERED IN 30 MINUTES.

BOB GOES TO SEE IF HE'S MADE IT THERE LAST NIGHT, AND, ON THE WAY, HE SPOTS LIONS IN THE BUSHES.

THERE THEY ARE.

TWO MALE LIONS.

WOW.

TOTI AND TOM ARE A COALITION OF MALES AND IT LOOKS LIKE THEY'VE HAD BETTER DAYS.

HAVE PROBABLY JUST HAD A RUN-IN WITH KALAMAS.

I THINK I SEE A LITTLE BIT OF A SCAR ON ONE OF THEIR EYES, WHICH MAKES SENSE BECAUSE THEY WOULD REALLY BE DEFENDING THEIR CUBS.

KALAMAS WOULD KILL THEM INSTANTLY.

THERE'S A FEMALE.

ONE OF THESE TWO IS PROBABLY THE DAD.

KALAMAS IS A GREAT BIG MALE, AND HE'S FORMIDABLE EVEN ON HIS OWN, BUT THESE TWO GUYS CERTAINLY WOULD OVERPOWER HIM, BUT IT COULD HAVE BEEN QUITE A FIGHT, AND THEY LOOK LIKE THEY'VE HAD A ROUGH NIGHT.

SANJAYAN: JUST LIKE SAITOTI SAID, KALAMAS AVOIDED A BIG FIGHT AND HAS SNEAKED OFF AGAIN...

BUT HIS PRESENCE SEEMS TO HAVE ALTERED THE ROUTINE OF THE COMMUNITY AT THE WATERHOLE.

SO EVERYTHING CHANGES ONCE THIS LION SHOWS UP.

IT SEEMS THAT THE WHOLE SPECIES COMPOSITION-- YOU KNOW, WHO SHOWS UP WITH WHOM-- SEEMS TO CHANGE AFTER A PREDATOR APPEARS AT THE WATERHOLE.

SO A COMMON GROUPING AT OUR WATERHOLE, FOR EXAMPLE, IS GIRAFFES, ZEBRA, AND IMPALA, AND THAT KIND OF MAKES SENSE.

GIRAFFES CAN SEE LONG DISTANCES; THEY CAN SPOT THINGS FAR, FAR AWAY.

ZEBRAS HAVE GREAT EARS AND GREAT NOSES; THEY CAN PICK UP SCENT AND SOUND.

AND IMPALA, BEING KIND OF LOW TO THE GROUND, ARE ABLE TO SPOT THINGS THAT MIGHT BE CROUCHING, HIDDEN IN THE UNDERBRUSH.

SO, EACH OF THESE ANIMALS IS REALLY COMPENSATING, OR ADDING THEIR POWER TO, UM, TO THE GROUP, AND SO, YOU HAVE SAFETY IN NUMBERS FOR SURE, BUT YOU ALSO HAVE SAFETY IN DIVERSITY.

NOW THAT PREY ARE TEAMING UP TO WATCH OUT FOR PREDATORS, THE WATERHOLE IS GETTING BUSY AGAIN... [BIRDS SQUAWKING] AND WE'RE SEEING MORE NEW BIRD SPECIES, INCLUDING... FISCHER'S LOVEBIRDS.

THEY'RE ONLY FOUND IN TANZANIA.

MARABOU STORKS, WHICH ARE THE WORLD'S LARGEST STORK SPECIES, REACHING UP TO 5 FEET TALL.

COLORFUL LILAC-BREASTED ROLLERS--THEY SYMBOLIZE PEACE FOR MANY AFRICAN COMMUNITIES.

WE ALSO GET OUR FIRST BIRD OF PREY: AN AUGUR BUZZARD.

THEY SCOPE OUT WATERHOLES AND PREDATE ON RODENTS AND SMALL BIRDS THAT COME TO DRINK.

ADDING THE AUGUR BUZZARD BRINGS OUR SPECIES LIST TO 61.

ON AVERAGE, WE'VE HAD 4 NEW SPECIES A DAY COME FOR A DRINK DURING THE DRY SEASON.

AND DESPITE PREDATORS BEING A CONSTANT THREAT, THERE HASN'T BEEN ANY SIGN OF HUNTING AT THE WATERHOLE.

BUT JUST A MILE AND A HALF AWAY, BOB MAKES A DISCOVERY.

I'VE JUST FOUND THIS MALE KUDU CARCASS IN THE DRAINAGE RIGHT HERE.

SANJAYAN: IT LOOKS LIKE PREDATORS AREN'T HUNTING AT THE WATERHOLE BECAUSE THEY'RE PICKING OFF PREY AS THEY TRAVEL TO AND FROM IT.

POOLE: IT'S SO INTERESTING BECAUSE IT'S JUST BEEN KILLED.

YOU CAN SEE THE STOMACH HAS BEEN OPENED.

SANJAYAN: WHATEVER KILLED THIS KUDU IS PROBABLY GOING TO BE BACK.

SO, BOB IS GOING TO STAKE OUT THIS CARCASS.

AFTER A FEW HOURS OF WAITING, HE SPOTS SOMETHING MOVING IN THE BUSHES.

MY GOODNESS.

THAT'S INCREDIBLE.

WOW.

WHAT A POWERFUL ANIMAL.

SANJAYAN: IT'S THE MWIBA PRIDE LIONESS LERIAH, AND SHE'S MADE THE KILL.

THE MALES TOTI AND TOM ARE NOWHERE TO BE SEEN, BUT THIS MEAL ISN'T JUST FOR HER.

WHOA.

LOOK AT THAT.

LOOK AT THAT RIGHT ON THERE, ON THE LEFT SIDE OF THE SCREEN, CUBS COMING DOWN THE BANK.

WHOA!

THAT'S INCREDIBLE.

LOOK AT THAT!

I HAVEN'T SEEN ANY OTHER LIONESSES, SO, IT MEANS SHE'S ALL ALONE, AT LEAST AS FAR AS I CAN TELL.

SANJAYAN: LION PRIDES VARY IN SIZE, BUT THEY USUALLY HAVE UP TO A DOZEN FEMALES.

A LONE MOTHER LIKE THIS IS A HIGHLY UNUSUAL SIGHT, ESPECIALLY WITH TWO CUBS THAT ARE JUST 6 WEEKS OLD.

THAT'S A REALLY TOUGH THING FOR A LIONESS TO BE ALL ALONE LIKE THAT WITH TWO CUBS.

VERY DIFFICULT FOR HER MOVING FORWARD.

ONLY ABOUT 50% OF THE CUBS MAKE IT WHEN THEIR MOTHER'S ALONE LIKE THIS.

SANJAYAN: THE WATERHOLE COULD BECOME AN IMPORTANT FOCAL POINT FOR LERIAH, AS IT PROVIDES A RELIABLE SOURCE OF FOOD AND WATER.

IT'S BEEN JUST 14 DAYS SINCE THE WATERHOLE WAS BUILT, AND THERE'S ALREADY BEEN SO MUCH MORE ACTION THAN WE EVER EXPECTED.

I WAS LOOKING AT ALL THE ANIMALS THAT THIS WATERHOLE HAS ATTRACTED, AND IT'S WELL OVER 70 SPECIES OF VERTEBRATES THAT HAVE COME TO THIS WATERHOLE IN JUST THE FIRST MONTH OF-- OF THE OPENING.

I HONESTLY CAN SAY IT'S BEEN MORE THAN I EXPECTED.

EVER EXPECTED.

NUMBERS AT THIS WATERHOLE HAVE GONE WILD-- A FULLY FUNCTIONING ECOSYSTEM HAS SPRUNG UP... FROM BUTTERFLIES TO BUFFALOS AND LAPWINGS TO LIONS.

WE HAVE SEEN A WILD COMMUNITY BUILD FROM NOTHING, BUT THEIR LIVES ARE GOING TO GET TOUGHER.

IN A COUPLE OF MONTHS, THE DRY SEASON DRAWS TO A CLOSE AND MWIBA RESERVE ENTERS THE HOTTEST TIME OF YEAR.

WE'LL BE BACK TO FOLLOW OUR WATERHOLE ANIMALS WHEN THE HEAT IS REALLY TURNED ON.

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