SANJAYAN: 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?

[CHIRPING] 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.

[SNORTS] LAST TIME AT THE HOTTEST TIME OF YEAR... [HYENAS CHATTERING] HYENAS RAN WILD.

[HYENA BARKS] OH, WOW!

LOOK, LOOK, LOOK.

SO THE WHOLE CLAN OF HYENAS COME IN, AND, WHAT, THEY'RE JUST PICKING ON HIM?

[THUNDER] SANJAYAN: NOW, THE FIRST RAINS HAVE HIT, AND THE WATERHOLE IS FACING ITS BIGGEST CHANGE YET.

THERE'S SO MUCH ACTION GOING ON RIGHT NOW.

[SCREECHING] SANJAYAN: AN EXPLOSION OF LIFE BRINGS NEW SPECIES TO THE SAVANNA.

FROM THIS ALTITUDE, I CAN SEE THE ENORMITY OF THIS, THE SCALE OF THIS.

IT'S MIND-BOGGLING.

THESE DRAMATIC CHANGES HAVE A BIG IMPACT ON A HYENA CLAN.

YOU'VE GOT TO BE CAREFUL PUTTING YOUR HEAD INTO A HYENA DEN.

THIS IS THE STORY OF LIFE... [TRUMPETS] AND DEATH AT THE WATERHOLE.

♪ WE BUILT OUR WATERHOLE IN TANZANIA... 300 MILES FROM THE EAST COAST OF AFRICA...

IN THE MWIBA WILDLIFE RESERVE.

[THUNDER] AFTER 5 TOUGH MONTHS OF DROUGHT, THE RAINS ARE FINALLY HERE.

MORE RAIN WILL FALL OVER THIS SEASON THAN IN 6 MONTHS IN NEW YORK.

WELL, WE'RE BACK, AND IT'S THE HEIGHT OF THE RAINY SEASON.

I'VE GOT AN UMBRELLA FOR A REASON.

IT'S PELTING DOWN WITH RAIN, AND WHEN IT RAINS, I MEAN, REAL RAIN.

THIS STUFF IS FAST AND HARD, IT COMES SUDDENLY, AND IT'S COLD RAIN, SO IT MUST BE COMING FROM WAY UP THERE, AND IT JUST PELTS THE LANDSCAPE, AND IT'S COMPLETELY TRANSFORMED EVERYTHING HERE.

I MEAN, MWIBA WAS THIS DRY, DUSTY PLACE THE LAST TIME I WAS HERE.

NOW WATER'S EVERYWHERE, LOADS OF GRASS, AND IT RAINS EVERY DAY.

[HONKING] SANJAYAN, VOICE-OVER: FOR 4 HOURS A DAY, IT BUCKETS DOWN.

THESE FREQUENT SHOWERS SUPERCHARGE PLANT LIFE, AND OVER 200 SPECIES OF SAVANNA GRASS SPRING UP...

TURNING THE 130,000-ACRE RESERVE INTO A LUSH, ALL-YOU-CAN-EAT BUFFET FOR HERBIVORES.

IN THIS TIME OF PLENTY, MANY ANIMALS NOW HAVE THEIR YOUNG.

OVER HALF A MILLION MAMMAL BABIES AND COUNTLESS INSECTS ARE BORN ACROSS THE SERENGETI ECOSYSTEM.

I WANT TO SEE HOW THIS POPULATION BOOM AFFECTS LIFE AT THE WATERHOLE... WHERE THE LOCAL ANIMALS ARE USED TO HAVING THE PLACE ALL TO THEMSELVES.

THE GUIDES AND I ARE KEEPING WATCH FOR EVERY VISITOR AND ADDING TO OUR SPECIES LIST THAT'S ALREADY AT 88.

AT NIGHT, WE HAD OUR FIRST ARRIVALS, A NEW HERD OF ELEPHANTS.

THESE ELEPHANTS CAME TO DRINK AT THE WATERHOLE.

LOOK AT THAT ONE FAR BACK, SEE?

YEAH.

SANJAYAN, VOICE-OVER: LOCAL GUIDE ZAC MAHANGA SPOTS THAT THIS HERD IS ABOUT TO GET BIGGER.

IT'S A HUGE FEMALE, RIGHT?

ALL RIGHT, DID THAT ELEPHANT LOOK PREGNANT TO YOU?

YEAH, SEE THE SIZE OF THE BELLY.

YEAH, YEAH.

DEFINITELY.

SHE'S EXPECTING TO HAVE A BABY SOON.

SO ELEPHANTS CAN HAVE BABIES ALMOST ANY TIME OF THE YEAR, RIGHT?

ANY TIME.

BUT DO THEY TEND TO HAVE MORE BABIES DURING THE RAINY SEASON?

RAIN SEASON, I CAN AGREE, WE CAN SEE MANY BABIES THIS TIME OF YEAR.

SO TELL ME A LITTLE BIT ABOUT THE DIFFERENCE IN SIZE OF THOSE HERDS BETWEEN THE WET SEASON AND THE DRY SEASON.

DRY SEASON, YOU CAN FIND VERY SMALL NUMBERS IN THESE GROUPS, BUT THE RAIN SEASON, THE NUMBER GETTING BIGGER BECAUSE OF THE AVAILABILITY OF FOOD AND WATER.

SO THE SUPER HERDS FORM IN THE RAINY SEASON BECAUSE LOTS OF FOOD, RIGHT?

DEFINITELY.

YES.

IF YOU WANT TO SEE AN ELEPHANT FOR SURE... UH-HUH.

IN THIS PART OF AFRICA COME IN THE DRY SEASON.

DRY SEASON.

THERE'S A BIG CHANCE YOU'LL FIND A GOOD NUMBERS OF ELEPHANTS.

BECAUSE YOU CAN WAIT AT THE WATERHOLE LIKE WE DID...

YES.

AND THE ELEPHANTS WILL COME.

ELEPHANT WILL COME DEFINITELY.

WE CAN GUARANTEE THAT.

RAINY SEASON IS NOT THE GREAT TIME BECAUSE THEY'VE SCATTERED THROUGHOUT THE LANDSCAPE.

YES.

SANJAYAN, VOICE-OVER: ELEPHANTS AREN'T THE ONLY ONES.

ALL HERBIVORES ARE SPREADING OUT RIGHT NOW, SO WE'VE GOT BOB POOLE, OUR WILDLIFE CAMERAMAN, OUT ON PATROL.

3 MILES AWAY, HE'S FINDING OUT WHY FOR GIRAFFES THIS IS THE SEASON FOR LOVE.

POOLE: OK. NOW WATCH THIS FEMALE.

IT'S INCREDIBLE.

SHE COMES UP TO THE MALE, AND SHE RUBS HER NECK AGAINST HIS LIKE THAT.

IT'S DEFINITELY A SIGN OF AFFECTION OR INTEREST.

SANJAYAN, VOICE-OVER: GIRAFFES HAVE BEEN DRINKING AT OUR WATERHOLE FOR THE PAST 5 MONTHS...

BUT NOW THEY'VE GOT OTHER THINGS ON THEIR MIND AS EXCITED MALES TRY TO SNIFF OUT A MATE.

POOLE: SO THE MALE GIRAFFE RIGHT NOW IS TRYING TO DETERMINE WHETHER THE FEMALE IN FRONT OF HIM IS IN THE PEAK OF ESTRUS.

SANJAYAN, VOICE-OVER: ESTRUS CYCLES OCCUR EVERY TWO WEEKS, BUT A FEMALE'S ONLY FERTILE FOR 4 DAYS OR LESS DURING THIS TIME...

SO THE MALES HAVE TO GET THEIR TIMING JUST RIGHT.

POOLE: SHE GIVES OFF PHEROMONES, WHICH HE SENSES THROUGH SENSORS THAT ARE IN THE TOP OF HIS LIP THERE.

SANJAYAN, VOICE-OVER: GIRAFFES CAN MATE YEAR-ROUND, BUT RESEARCH SHOWS THAT PASSIONS RUN HIGHEST WHEN FOOD IS MOST ABUNDANT.

[ZEBRA SNORTS] POOLE: ALL THE LEAVES ARE SO PLUMP RIGHT NOW.

I CAN SEE THE WAY THAT THEY USE THE TONGUE TO STRIP THE LEAVES OFF THE TWIG, WHICH IS OF COURSE LOADED WITH THESE BIG THORNS, AND EVERYTHING AROUND HERE HAS A THORN ON IT.

IN FACT, THIS PLACE IS CALLED MWIBA, WHICH LITERALLY MEANS "THORN" IN SWAHILI.

SANJAYAN, VOICE-OVER: ALL THIS FOOD MEANS THAT OTHER MEMBERS OF THE WATERHOLE COMMUNITY, LIKE ZEBRA, ARE GETTING VERY FRISKY, AND SOMETIMES, COMPETITION BETWEEN STALLIONS CAN GET PHYSICAL.

POOLE: LOOK AT THIS.

THERE'S SO MUCH ACTION GOING ON RIGHT NOW, THAT THE STALLION HERE IS RACING AROUND, TRYING TO ROUND UP THESE ZEBRA FEMALES, AND YOU CAN SEE HIM RACING ACROSS IN FRONT OF US RIGHT NOW.

AND NOW HE'S COMING BACK TO PROBABLY HIS HAREM RIGHT THERE.

THE YOUNG MALES HAVE TO STRUGGLE FOR DOMINANCE.

HE COULD GET KICKED OUT BY ANOTHER STALLION.

THESE ARE VERY SOCIAL ANIMALS.

THEY LIVE IN FAMILY GROUPS, AND THEY HAVE AN ORDER, A PECKING ORDER ESSENTIALLY JUST LIKE HORSES DO.

THEY'RE CONSTANTLY HAVING TO PUT EACH OTHER IN THEIR PLACE.

SO THERE'S A LOT OF FIGHTING AND TESTING AND ALL KINDS OF ACTION GOING ON ALL THE TIME TO SORT OF REALLY WORK ON WHO'S WHO IN THE FAMILY AND WHERE THEY SIT IN TERMS OF THE PECKING ORDER.

SANJAYAN, VOICE-OVER: AND SOME HAVE ALREADY HAD THEIR YOUNG.

THIS FOAL IS JUST A MONTH OLD.

POOLE: THE LITTLE FOAL TO THE RIGHT WOULD BE HIS FIRST FOAL OF THIS RAINY SEASON.

THE LITTLE ONES ARE SO CUTE.

SANJAYAN, VOICE-OVER: THE ABUNDANCE OF CALORIES AVAILABLE AT THIS MOMENT MEANS MOTHERS PRODUCE LOTS AND LOTS OF MILK, AND WHEN BABIES ARE READY, THERE'S GRASS ALL AROUND THE WATERHOLE.

WAITING TO BE GRAZED.

DURING THE DRY SEASON, THERE WAS A HYENA CLAN THAT WAS DOMINATING LIFE HERE, BUT NOW THEY SEEM TO HAVE DISAPPEARED.

IN THEIR ABSENCE, THE WATERHOLE COMMUNITY IS RECLAIMING THE SITE.

VERVET MONKEYS...

GIRAFFE... IMPALA...

ELEPHANT... [GRUNTS] [HUFFS] AND AN ANIMAL FAMILY THAT LIVES IN THE TREES NEARBY.

SO WE GOT BABOONS NOW JUST COME IN.

[BABOONS GRUNTING AND CHATTERING] THEY'LL EAT SEEDS, THEY'LL EAT SHOOTS, THEY'LL EAT INSECTS, REALLY ANYTHING THEY CAN FIND.

THEY'RE SPENDING OVER HALF THEIR DAY FEEDING AND DON'T FEED SUPER ACTIVELY.

THEY JUST SORT OF GRAZE OR NIBBLE THROUGHOUT THE DAY IS MORE LIKE HOW THEY FEED, AND THAT'S EXACTLY WHAT THEY'RE DOING HERE.

THEY'RE SORT OF WALKING ACROSS THE MEADOW AND THEN STRIPPING GRASS SEEDS OFF THE STALKS.

THE WATERHOLE WAS VITAL FOR THIS TROOP IN THE DRY SEASON.

NOW IT PROVIDES A RELIABLE SUPPLY OF FOOD... ALL ON THEIR DOORSTEP...

BUT IT'S NOT EXACTLY EASY FOR BABOONS TO MAKE A REAL MEAL OUT OF FIDDLY GRASS STALKS.

SEE?

LOOK AT THAT.

QUITE A DELICATE OPERATION.

I MEAN, EACH OF THOSE GRASS SEED HEADS MUST BE THE SIZE OF A PINHEAD, SO QUITE SMALL.

IT MUST TAKE HUNDREDS AND HUNDREDS AND HUNDREDS OF THOSE GRASS STALKS TO FILL UP A BABOON'S BELLY.

SANJAYAN: YOU MIGHT EVEN THINK, "WHY BOTHER?"

GRASS IS ALSO PACKED WITH WATER, SO THE BABOONS ARE GETTING NUTRITION AND HYDRATION WITH EACH MOUTHFUL.

THE OTHER THING THAT STRIKES YOU WHEN YOU SEE BABOONS ON A GRASS PLAIN, ON A MEADOW LIKE THIS FEEDING IS THAT, UNLIKE ALL THE OTHER ANIMALS THAT SHOW UP HERE, THEY DON'T HAVE TO PUT THEIR HEADS DOWN IN ORDER TO FEED.

THEY'VE GOT HANDS AND THUMBS, AND SO THEY CAN PICK UP FOOD, AND THEY CAN FEED WHILE KEEPING THEIR HEAD UP, AND THAT'S A DISTINCT ADVANTAGE THAT PRIMATES REALLY HAVE, AND IT ALLOWS THEM TO FEED IN THE OPEN WHILE STILL WATCHING OUT FOR PREDATORS AND STILL KEEPING TRACK OF EACH OTHER.

THEY ALSO PLAY A CRUCIAL ROLE IN THIS ECOSYSTEM BY PULLING UP THE GRASS, EATING IT, AND LETTING NATURE TAKE ITS COURSE, DISPERSING SEEDS ALL OVER THE PLACE, HELPING THE SITE STAY LUSH FOR THE NEXT GENERATION.

SANJAYAN, VOICE-OVER: THIS IS A SURPRISING TURN OF EVENTS.

LAST SEASON, VERY FEW ANIMALS WERE COMING IN BECAUSE THE AREA WAS UNDER THE CONTROL OF AN APEX PREDATOR.

MEMBERS OF A SPOTTED HYENA CLAN WERE THE DOMINANT FORCE.

[HYENAS CHATTERING AND GRUNTING] I'VE BEEN LOOKING BACK OVER OUR DATA, AND IT PAINTS A CLEAR PICTURE.

SO THE LAST TIME I WAS HERE, THERE WERE HYENAS VIRTUALLY EVERY DAY.

IN THE MONTHS OF OCTOBER, NOVEMBER, ESSENTIALLY A TWO-MONTH PERIOD, WE HAD 73 VISITS BY HYENAS TO THIS WATERHOLE, WHICH IS PRETTY ASTONISHING, AND I SHOULDN'T SAY DAY BECAUSE IT TURNS OUT THAT VIRTUALLY EVERY HYENA THAT CAME TO THIS WATERHOLE CAME AT NIGHT.

SOMETHING LIKE 96% OF ALL THOSE VISITS THAT WE RECORDED WERE AT NIGHT AND NOT REALLY DURING THE DAY, AND THAT IS A MARKED CONTRAST TO NOW.

THERE'S HYENAS AROUND, BUT THEY'RE NOT COMING TO THE WATERHOLE.

WE CAN HEAR THEM AT NIGHT.

SO THEY'RE IN THE AREA, BUT THEY'RE NOT COMING TO OUR WATERHOLE, AND IT'S VERY LIKELY BECAUSE OF ALL THIS RAIN ALL THE SCENTS ARE WASHED AWAY, THE PREY ANIMALS AREN'T CONGREGATING BY THE WATERHOLES ANYMORE, SO AS SIGNPOSTS OR GROCERY STORES FOR PREDATORS, WATERHOLES ARE NOT SO GREAT IN THE WET SEASON.

SANJAYAN, VOICE-OVER: BUT WHAT ARE THE CLAN UP TO NOW?

TO FIND OUT, I RETURNED TO THEIR DEN SITE JUST OVER A MILE AWAY.

SO A COUPLE MONTHS AGO WHEN I WAS HERE IN THE HOT SEASON, THIS IS WHERE THE HYENAS HAD DENNED UP, AND I REMEMBER SITTING RIGHT HERE WATCHING THESE HYENA PUPS COME OUT OF THAT HOLE, AND WE'VE LEFT A CAMERA BEHIND SO I CAN GO AND LOOK AT THE FOOTAGE AND SEE WHAT'S BEEN GOING ON EXACTLY HERE, BUT THE GROUND AROUND THE DEN DOESN'T LOOK VERY USED.

GOT TO BE CAREFUL PUTTING YOUR HEAD INTO A HYENA DEN.

OH, WOW.

OH, WOW.

THIS IS... LOOK AT THIS.

THIS IS ACTUALLY KIND OF COOL THAT THAT IS WHERE THOSE PUPS WERE COMING UP, AND I DON'T THINK IT'S BEING USED RIGHT NOW BECAUSE I DON'T SEE ANY CLAW MARKS.

DO YOU KNOW WHO IS USING IT?

MAYBE A PORCUPINE BECAUSE THERE'S A COUPLE OF PORCUPINE QUILLS RIGHT BY THE ENTRANCE.

OH, I CAN-- I CAN SEE THE PORCUPINE.

I CAN ACTUALLY SEE THE PORCUPINE IN THERE.

[WHISPERING] THAT'S THE EDGE.

IT'S REALLY GOOD NEWS THAT THERE'S A PORCUPINE IN THERE.

I MEAN, I'M SURE NOW THAT THE HYENAS ARE NOT IN THERE BECAUSE THEY'RE NOT GOING TO WANT TO SHARE THEIR HOME WITH SUCH A, WELL, POINTY CUSTOMER, BUT IT MEANS THAT THIS BURROW IS GOING TO REMAIN ACTIVE AND IN USE THROUGH THIS RAINY SEASON, AND I BET YOU NEXT YEAR THE HYENAS WILL BE BACK AND WILL BE DENNING IN HERE.

ALL RIGHT.

I'M GOING TO LEAVE THIS GUY TO HAVE HIS REST, BUT IT REALLY IS GREAT THAT THESE BIG TERMITE MOUNDS CONTINUE TO HAVE LIFE.

I MEAN, THAT'S JUST SO FANTASTIC BECAUSE THE TERMITES FIRST USE THEM, THEN ANIMALS USE THEM, HYENAS ARE USING THEM, AND NOW AT LEAST ONE PORCUPINE, MAYBE MORE, ARE IN THERE, AND THEY'LL KEEP COMING BACK HERE, SO BEST TO LEAVE HIM ALONE.

♪ SO I WANT TO TAKE A LOOK AT WHAT WAS ON THE CAMERA TRAP THAT WE LEFT OVER THERE AND SEE IF I CAN PICK UP ANY OF THOSE PORCUPINES.

A GIRAFFE CAME RIGHT BY.

LOOK AT THAT.

THAT'S COOL.

OK. OH, LOOK AT THIS.

THERE'S A HYENA, AND THERE'S A HUGE PORCUPINE WITH THE QUILLS ALL ERECT.

THAT PORCUPINE LOOKS LIKE IT'S THE SIZE OF THAT HYENA PUP, AND IT JUST CHASED IT OFF, AND YOU'D THINK A HYENA WOULD MAKE GOOD WORK OF IT.

BUT, BOY, IT'S INCREDIBLE.

PORCUPINES OFTEN LIKE TO HANG AROUND HYENAS BECAUSE THEY LIKE TO NIBBLE ON BONES.

PORCUPINES DO IT FOR THE CALCIUM, AND SO PORCUPINES KNOW THAT WHEREVER THERE ARE HYENAS THERE'S GONNA BE BONES.

SANJAYAN, VOICE-OVER: IT'S UNLIKELY A FEW SMALL PORCUPINE WOULD SCARE THEM AWAY, AND A BIGGER PROBLEM FOR THE HYENA IS REVEALED.

HMM.

WOW!

A LOT OF BUFFALO.

LOT OF BUFFALO ALL OVER THE PLACE.

BIG HERD OF BUFFALO.

IT LOOKED LIKE THEY JUST TRAMPLED THROUGH THIS ENTIRE AREA.

BUFFALOES DON'T REALLY LIKE HYENAS, AND BUFFALOES GET VERY TERRITORIAL, AND IF THEY KNOW THAT THERE ARE PREDATORS IN THE AREA, THEY WILL THEY WILL DO THEIR BEST TO CHASE THEM OFF IF THEY CAN, AND THAT MIGHT HAVE BEEN-- MIGHT HAVE BEEN WHAT HAPPENED HERE, THAT THIS DEN GOT EVENTUALLY ABANDONED BECAUSE A HERD OF BUFFALOES JUST TRAMPLED IT AND TOOK IT OVER.

WHEN I WALKED AROUND THERE, YOU COULD DEFINITELY FIND FRAGMENTS OF BUFFALO BONE AROUND HERE, SO THESE HYENAS ARE DEFINITELY EATING BUFFALO, AND SO THE BUFFALOES PROBABLY DON'T WANT THEM IN THEIR MIDST, AND IT PRETTY MUCH SEEMS THAT AFTER THE BUFFALO SHOWED UP THE DEN GOES QUIET AND WE DON'T SEE A LOT MORE ACTIVITY AFTER THAT.

AND SO SHE COULD HAVE MOVED THEM.

SANJAYAN, VOICE-OVER: HYENA CLANS OFTEN HAVE NETWORKS OF DENS DOTTED AROUND THE SAVANNA.

ONLY TIME WILL TELL IF THEY WILL EVER RETURN TO THE WATERHOLE.

I'LL BET THEY'LL BE BACK NEXT DRY SEASON.

♪ WITHOUT HYENA DOMINATING THE WATERHOLE, ANOTHER SPECIES HAS TAKEN OVER.

[HONKING] THEY'RE COMMON GEESE.

THEY'RE FOUND THROUGHOUT AFRICA.

THEY'RE USUALLY IN PAIRS OR IN SMALL FLOCKS, BUT THERE'S BEEN A PAIR THAT'S REALLY TAKEN OVER THIS WATERHOLE, AND THESE GEESE LIVE HERE.

THIS IS THEIR WATERHOLE, AND I WOULDN'T BE SURPRISED IF THEY HAVE A NEST SOMEWHERE.

THEY FEED SOMETIMES IN THE WATER, BUT OFTENTIMES, YOU SEE THEM GRAZING ON GRASS HEADS AND FORBS ON THE EDGE OF MEADOWS AND PLAINS LIKE THIS.

[HONKING] SANJAYAN, VOICE-OVER: THIS ISN'T THE FIRST TIME WE'VE SEEN THIS POWER COUPLE.

[HONKING] THEY STARTED VISITING LAST SEASON AND WERE QUICK TO MAKE THEIR PRESENCE KNOWN.

SINCE THEN, THEY HAVE BEEN REGULAR VISITORS... AND THEY'VE PROVED THAT THEY'RE NOT TO BE MESSED WITH.

[SQUAWKING] WHEN ANOTHER GOOSE CAME IN TO CHECK OUT THE NEW WATERHOLE, OUR MALE MADE IT CLEAR THIS WATERHOLE WAS NOT FOR SHARING.

[SCREECHES] EVEN THE ARRIVAL OF A MARTIAL EAGLE, A PREDATOR THAT CAN TAKE PREY AS LARGE AS A BABY ANTELOPE, DIDN'T PUT THEM OFF.

[HYENA YOWLING] AND NEITHER DID THE HYENA.

[GEESE HONKING, HYENAS GRUNTING] AFTER TWO MONTHS, THESE GEESE HAVE SECURED THEIR PLACE AS THE MONARCHS OF THE WATERHOLE.

LOTS OF ANIMALS ARE COMING TO THE WATERHOLE, BUT THESE GEESE HAVE REALLY MADE THIS THEIR HOME.

THEY'RE ONE OF THE FIRST ANIMALS THAT SHOWED UP, AND THEY'VE BEEN HERE EVERY TIME I'VE BEEN HERE.

SANJAYAN, VOICE-OVER: THE DOMINANT SPECIES AT THE WATERHOLE HAVE CHANGED WITH EACH SEASON, BUT THERE'S ONE REGULAR I THOUGHT I WOULD DEFINITELY SEE THIS TIME AROUND.

A HUGE CAPE BUFFALO HERD WERE USING THEIR SHEER NUMBERS TO MUSCLE OUT THE COMPETITION.

NOW THEY'RE NOWHERE TO BE FOUND, SO I HEAD OUT WITH BOB TO LOOK FOR THEM.

YOU CAN SMELL THEM, I MEAN, REALLY SMELL THEM.

POOLE: I'M GOING-- I'M GOING TO STOP RIGHT HERE ON THIS SAND.

THERE MUST BE OVER A HUNDRED BUFFALO JUST SPREAD ACROSS HERE, AND SOME OF THEM ARE REALLY CLOSE, AND WHAT'S SO GREAT IS THAT THESE ARE THE MAIN CHARACTERS THAT WE'VE BEEN SEEING OVER AND OVER AGAIN, RIGHT, AT THE WATERHOLE.

NUMBER-ONE VISITATION HAS BEEN BUFFALO.

YEAH.

IT'S THIS AMAZING GRASS THAT'S BROUGHT THEM OUT BECAUSE OTHERWISE THEY'RE REALLY IN THE THICK BUSH.

THEY DON'T REALLY COME OUT TILL NIGHT.

THEIR HERD'S SPLIT IN TWO RIGHT NOW.

THEY BOTH WANT TO HEAD FOR THE FOREST.

THAT'S A LITTLE BIT OF A STAMPEDE THERE.

BEEN SEEING BUFFALO ALL THE TIME AT THE WATERHOLE, RIGHT?

THEY'RE THE NUMBER-ONE CHARACTER.

WE KNOW THE DATA SHOWS THAT THE NUMBER-ONE ANIMAL AT THE WATERHOLE ARE BUFFALOES, BUT EVERY TIME I'VE BEEN HERE, BUFFALOES HAVE COME TO THE WATERHOLE, BUT IT'S ALWAYS AT NIGHT, AND BOB AND I DROVE INTO THIS GLADE AND, BANG, RAN INTO WELL OVER A HUNDRED BUFFALO.

THEY'RE ACTUALLY SCATTERED ALL THROUGH HERE.

THERE'S TWO HERDS BOTH SIDES OF THIS-- THIS LITTLE FOREST GLADE, AND IT'S THIS GRASS, THE RAINY SEASON, ALL THIS GRASS, THAT'S WHAT'S MADE THE BUFFALO COME OUT DURING THE DAYLIGHT HOURS.

AND SO IT'S KIND OF A COOL THING FOR US TO SEE THIS, TO SEE HOW CHANGE IN THE WEATHER AND THE RAINS HAVE REALLY PROMPTED AN ANIMAL THAT USUALLY IS IN THE THICK BUSH TO COME OUT IN THE OPEN DURING DAYLIGHT HOURS.

YOU KNOW, THESE ARE FORMIDABLE ANIMALS.

ACTUALLY TODAY, TODAY SOMEONE ON THIS RESERVE GOT HURT BY A BUFFALO, SO YOU REALLY DON'T WANT TO RUN INTO A BUFFALO.

I MEAN, THEY'RE INCREDIBLY POWERFUL, AND THEY HANG OUT IN BIG GROUPS LIKE THIS, AND THE PREDATORS THAT GO AFTER THEM, THE HYENAS AND THE LIONS, THEY REALLY HAVE TO BE TOUGH, TOUGH ANIMALS AND IN BIG, BIG GROUP SIZES TO BE ABLE TO TAKE DOWN A BUFFALO.

POOLE: SANJAYAN, SEE THE WAY THAT THEY'RE LOOKING AT YOU NOW?

YEAH.

THIS IS THEIR BEHAVIOR, RIGHT?

YEAH.

WHEN THEY SENSE A THREAT, RATHER THAN RUN AWAY, THEY OFTEN START COMING AT IT, AND THAT'S WHY, YOU KNOW-- THEY'RE NOT FAST ANIMALS.

THEIR ONLY ALTERNATIVE IS TO FIGHT, RIGHT?

SO THEN THEY'RE GROUPED TOGETHER, AND BOTH SIDES START COMING BACK TOWARDS US NOW IF YOU WATCH, AND THAT'S KIND OF, I THINK, WHAT'S HAPPENING RIGHT NOW.

YOU SEE THEY BOTH HAVE MOVED AT LEAST 20 METERS CLOSER TO US IN THE LAST 5 MINUTES, AND THEY'RE GOING TO KEEP DOING THAT.

[INSECTS BUZZING] POOLE: HOW INCREDIBLE.

SUNSET AND TO HAVE THEM COME OUT IN THE OPEN LIKE THIS.

YEAH.

GOSH.

IT'S COCKTAIL HOUR, BOB, AND THAT'S WHEN THE BUFFALOES COME OUT.

AMAZING FOOTAGE.

SO GOOD TO BE HERE WITH YOU, MAN.

JUST STUNNING.

YEAH.

SANJAYAN, VOICE-OVER: EVERY SINGLE BIG ANIMAL SPECIES THAT WAS COMING TO OUR WATERHOLE DAILY, LIKE CAPE BUFFALO, ARE NOW ON THE MOVE... AND IT'S ALL BEING DRIVEN BY THE GREEN STUFF.

THESE GRASSES REALLY COME TO LIFE IN THE RAINY SEASON.

I'VE WALKED BY RIGHT HERE WEEKS AND WEEKS AND WEEKS AND NEVER PAID THIS BIT OF WHAT LOOKED LIKE BARE EARTH MUCH MIND, BUT NOW WITH THE RAINS, IT JUST COMES TO LIFE, AND YOU REALLY REALIZE THAT GRASSES ARE SUCH A HUGE PART OF THIS ECOSYSTEM.

I MEAN, THEY'RE THE SAVANNAS OF AFRICA.

ABOUT HALF OF AFRICA IS SAVANNAS, AND THESE SAVANNA GRASS IN AFRICA ARE REALLY SPECIAL, AND THEY JUST DRIVE THE ENTIRE ECOSYSTEM.

IN THE DRY SEASON, MOST OF THESE GRASSES ARE COMPLETELY LOST ON YOU IF YOU WALK BY HERE BECAUSE MOST OF THEIR BIOMASS IS ACTUALLY UNDERGROUND.

IT'S IN THEIR ROOTS, PROTECTING THEMSELVES, STILL ALIVE, WHEREAS ABOVE GROUND IT JUST LOOKS COMPLETELY DEAD, AND THEN IN THE WET SEASON, THEY QUICKLY CHANGE THAT, AND THEY PUT ALL OF THE LIFE ABOVE GROUND AND QUICKLY GROW.

SANJAYAN, VOICE-OVER: REMEMBER, FOR 5 MONTHS, THERE'S BEEN VERY LITTLE TO EAT, SO NOW IS THE TIME TO BINGE.

NOW AS THIS GRASS STARTS TO GROW, IT STARTS ATTRACTING HERBIVORES, AND WILDEBEEST, WHICH ARE NOW MOVING INTO THIS AREA, ARE REALLY ATTRACTED BY SHORT GRASS.

YOU KNOW, THE BIG HERDS OF MIGRATING WILDEBEEST ARE REALLY DRAWN TO THIS PART OF THE WORLD DURING THE RAINY SEASON BECAUSE OF THAT YOUNG GRASS GROWTH.

SO THIS ENDLESS CYCLE OF MIGRATION THAT YOU SEE OF THE WILDEBEESTS COMING INTO THE SOUTHERN SERENGETI AND THEN MOVING NORTH INTO KENYA AND THEN BACK AGAIN EVERY YEAR, 1.2 MILLION STRONG, THAT'S ALL DRIVEN BY THE GROWTH OF GRASS AND THE RAINS THAT COME THAT SPUR IT ON.

SANJAYAN, VOICE-OVER: AND GUESS WHAT.

THE WORLD-FAMOUS WILDEBEEST MIGRATION IS HEADING IN THIS DIRECTION, LOOKING FOR GRASS.

THEY'VE BEEN MAKING AN EPIC JOURNEY 250 MILES SOUTH FROM KENYA.

TOGETHER, THEY CAN DRINK 3 MILLION GALLONS OF WATER AND EAT UP TO 4,000 TONS OF GRASS EVERY DAY.

TO GET A SENSE OF THE IMPACT THEY'RE HAVING ON THE AREA AND OUR WATERHOLE COMMUNITY, I'M TAKING TO THE AIR.

FROM THIS ALTITUDE, I CAN SEE THE ENORMITY OF THIS, THE SCALE OF THIS.

IT'S MIND-BOGGLING.

THERE'S WILDEBEEST QUITE LITERALLY FROM THERE ALL THE WAY ACROSS THE HORIZON, ALL THE WAY BEHIND ME, AND REALLY JUST AS FAR AS THE EYE CAN SEE.

FROM HERE, I PROBABLY AM LOOKING AT MAYBE 30,000 WILDEBEEST, 40,000 WILDEBEEST, BUT THIS IS JUST A SMALL PART OF THE 1.5 MILLION WILDEBEEST THAT MAKE IT OUT HERE ON THEIR ANNUAL MIGRATION.

ALL THESE ANIMALS ARE STREAMING TOWARDS THE WATERHOLE... AND JUST THEIR SHEER PRESENCE IS ALREADY AFFECTING ANIMAL BEHAVIOR.

WE'RE NOT VERY FAR FROM OUR WATERHOLE.

AN HOUR'S DRIVE, AND I'LL HIT OUR WATERHOLE.

MAYBE WE'RE 20, 30 MILES AWAY.

THE PREDATORS THAT USED TO HANG AROUND OUR WATERHOLE MUST BE TEMPTED TO BE OUT HERE WITH THIS ENORMOUS BANQUET.

SANJAYAN, VOICE-OVER: I BET YOU THAT OUR HYENA CLAN IS NOW SOMEWHERE DOWN THERE, TRACKING THIS MIGRATION FOR AN EASY MEAL.

GETTING EYE TO EYE WITH THIS HERD REVEALS WHY THIS HUGE NUMBER OF ANIMALS HAVE TO KEEP MOVING.

WHEN YOU LOOK AT THESE WILDEBEEST, THEY'RE ALMOST CONSTANTLY EATING.

NOW GRASS TURNS OUT NOT TO BE THAT NUTRITIOUS.

YOU'VE GOT TO EAT A LOT OF GRASS IN ORDER TO EXTRACT ENERGY, AND FOR WILDEBEEST, IT'S ABOUT 6.5% OF THEIR BODY WEIGHT, QUITE A LOT OF GRASS THAT THEY HAVE TO EAT.

A 500-, 600-POUND WILDEBEEST WILL HAVE TO EAT, LIKE, 50 POUNDS OF GRASS A DAY, AND THAT MEANS THEY HAVE TO CONSTANTLY KEEP MOVING.

HEAD DOWN, EAT, MOVE, HEAD DOWN, EAT, MOVE, AND THAT'S REALLY WHAT THEY DO, AND THEY DO THAT IN HUGE NUMBERS.

SANJAYAN, VOICE-OVER: BECAUSE WILDEBEEST HAVE NO LEADER, THE MIGRATING HERD OFTEN BREAKS UP INTO SMALLER GROUPS THAT CIRCLE THE MAIN MEGA HERD.

BY SPLITTING, THEY DO HAVE SOME PROTECTION FROM PREDATORS...

BUT THERE'S NO AVOIDING THE RISK.

NOW WITH THAT ALSO COMES THE PREDATORS, THE PREDATORS THAT DOMINATED OUR LANDSCAPE, OUR WATERHOLE, WHERE THEY SAT AND WAITED FOR FOOD TO COME TO THEM, ARE NOW OUT AND ABOUT IN THIS HUGE LANDSCAPE, HUNTING LOOKING FOR THESE WILDEBEEST.

WE HAVEN'T SEEN ANY LIONS YET SO FAR, BUT WE KNOW THAT THERE ARE PREDATORS AROUND BECAUSE WHEN YOU LOOK AT THE TOP OF THE TREES, YOU CAN SEE VULTURES, AND THOSE VULTURES ARE JUST HERE BECAUSE THEY KNOW THERE'S A MEAL TO BE HAD.

WHEN YOU HAVE 1.5 MILLION WILDEBEEST, YOU KNOW THAT SOME ARE GOING TO DIE TODAY.

IT LOOKS LIKE THIS YEAR THE MIGRATION IS GOING TO SKIRT AROUND OUR WATERHOLE...

BUT THEY'VE DEFINITELY PULLED A LOT OF PREDATORS OUT OF THE AREA... AND THAT HAS TURNED OUR WATERHOLE INTO A SAFE HAVEN FOR MANY SPECIES.

[WILDEBEEST GRUNTING] THE ENDLESS BANQUET OF GRASS AND FLOWERS ISN'T JUST BRINGING IN THE BIG STUFF.

IT'S ALSO ATTRACTING AN EXCITING ARRAY OF INSECT LIFE TO THE WATERHOLE.

[BUZZING] THE WANDERING GLIDER MIGRATES A STAGGERING 11,000 MILES FROM INDIA TO AFRICA, FURTHER THAN ANY OTHER INSECT.

AND THEY'RE NOT THE ONLY NEW ARRIVALS.

BUSH CRICKETS CAN HAVE ANTENNAE THAT ARE LONGER THAN THEIR ENTIRE BODY.

THE COMMON DIADEM BUTTERFLY MALE IS BLACK WITH WHITE SPOTS...

BUT THE FEMALE IS MAINLY ORANGE, MIMICKING A TOXIC BUTTERFLY TO AVOID BEING EATEN.

OUR FILMING HIDE PERCHED IN THE MIDDLE OF THE WATER IS ALSO PROVIDING A HOME TO ONE INCREDIBLE INSECT, ALTHOUGH I AM HAPPY TO WATCH FROM AFAR.

SO ONE OF THE REASONS I HAVEN'T GONE-- SPENT A LOT OF TIME IN THERE IN THAT HIDE RIGHT NOW IS THERE'S ALSO A WASP NEST IN THERE, AND THE WASPS HAVE FOUND THE CEILING OF THE HIDE TO BE SORT OF A DRY PLACE, AND THEY BUILT A NEST THERE, AND I THINK THEY'VE GOT LARVAE INSIDE THOSE TUBES, AND THEY'RE GONNA HATCH AT SOME POINT.

OH, THAT'S--IS THAT A DIFFERENT ONE?

MAN: DIFFERENT ONE.

THERE ARE 3 IN THERE.

3 NESTS OF PAPER WASP IN THE HIDE.

THAT'S INCREDIBLE.

YOU KNOW, THESE WASPS ARE PREDATORY WASPS, SO THEY'RE FINDING THINGS LIKE INSECT LARVAE THAT THEY'RE BRINGING BACK, AND THEY'LL END UP FEEDING THE BABIES WITH THAT.

[BUZZING] I'VE MADE IT SORT OF MY LIFE TO AVOID WASPS, TO BE HONEST, AND AS A KID, I GOT STUNG BY THEM QUITE BADLY, AND I WAS SLIGHTLY FEARFUL OF THEM, SO IT'S QUITE NICE TO SIT HERE IN THE GALLERY AND WATCH THESE WASPS AT WORK IN OUR HIDE IN KIND OF EXQUISITE DETAIL.

THEY'RE ACTUALLY QUITE BEAUTIFUL.

THESE ARE FEMALE QUEENS BASICALLY TRYING TO GET THEIR BABIES, THEIR LARVAE TO HATCH AS QUICKLY AS POSSIBLE, AND SHE FEEDS THEM.

THERE'S A LOT OF PARENTAL CARE.

YOU THINK ABOUT A WASP OR AN INSECT AND YOU THINK, "WELL, HOW MUCH PARENTAL CARE COULD THEY GIVE?"

BUT IT'S REALLY AMAZING HOW MUCH ATTENTION THEY WILL PAY.

SO FIRST OF ALL, SHE'S PICKED THE PERFECT PLACE FOR THESE NESTS.

I MEAN, THEY'RE ON THE UNDERSIDE OF A HIDE, WHICH SHE HAS TO GET TO BY FLYING OVER WATER AND THEN DUCKING THROUGH, YOU KNOW, SORT OF THE WINDOW, BUT SHE ALSO HAS TO FEED THEM, AND WHAT THEY FEED ON IS INSECT PREY, WHICH SHE'LL BRING BACK IN HER MOUTH AND THEN FEED THE LARVAE, TEMPTING THEM OUT TO COME OUT OF THEIR NEST BY GENTLY SCRATCHING ON IT TO GIVE THEM A SIGNAL THAT SHE'S AROUND AND THEN GIVE THEM FOOD.

I'M TOLD THAT THIS TIME OF THE YEAR WHEN THEY'VE GOT NESTS LIKE THIS, THEY'RE ACTUALLY NOT THAT DANGEROUS BECAUSE THEY'RE JUST TRYING TO BE CALM, PROTECT THEIR BABIES, AND BASICALLY GET THEM HATCHED AS SOON AS POSSIBLE SO THAT SHE'S NO LONGER TIED TO THIS NEST.

BUT I DON'T THINK I'M GOING TO REALLY TEST THAT OUT, AND I'M QUITE HAPPY TO WATCH THESE PAPER WASPS FROM OUT HERE.

SANJAYAN, VOICE-OVER: IT'S GREAT TO SEE THIS PLACE BECOME A HOME FOR SO MANY SPECIES.

THE LONG-TERM AIM FOR THIS WATERHOLE IS TO PROVIDE WATER FOR ANIMALS BUT ALSO HELP REDUCE HUMAN WILDLIFE CONFLICT.

WHILE MWIBA IS A PROTECTED RESERVE, PEOPLE LIVE ON THE OUTSKIRTS.

THERE'S CONFLICT OVER WATER WITH ANIMALS LIKE ELEPHANTS IN THE DRY SEASON, SO I'M INTERESTED TO SEE WHAT IS HAPPENING NOW.

QUITE A PRETTY FIELD.

YEAH.

JUST 10 MILES FROM THE WATERHOLE IS A VILLAGE THAT HAS AN ONGOING ELEPHANT PROBLEM.

MAN: THIS IS OUR CHIEF.

SANJAYAN: OK. SANJAYAN, VOICE-OVER: I'VE COME AT THE INVITATION OF VILLAGE CHIEF KASOMI IFAGELO, WHO RUNS ONE OF THE BIGGEST FARMS IN THE AREA.

THIS IS OUR CHIEF OF THE VILLAGE.

SANJAYAN, VOICE-OVER: SYLVESTER, A LOCAL GUIDE, IS MY TRANSLATOR.

SANJAYAN: AND WHAT ARE THEY GROWING HERE?

[SPEAKING LOCAL LANGUAGE] AND THE VILLAGE IS VERY CLOSE TO MWIBA, RIGHT, IT'S IN THE MIDDLE OF ALL THIS CONSERVATION AREAS, ALL AROUND IT.

YES, YES, YES.

SO THEY MUST HAVE ELEPHANT OR BUFFALO COMING INTO THE CROPS.

IS THE PROBLEM WORSE IN THE DRY SEASON OR THE WET SEASON?

SO THE MORE DANGER IS WHEN THERE'S A BIG GROUP OF ELEPHANT.

BIG GROUP, YEAH.

HOW BIG CAN THE GROUPS BE IN THE WET SEASON?

80 ELEPHANTS?

YES, YES.

CAN YOU IMAGINE WHAT 80 ELEPHANTS WOULD LOOK LIKE GOING THROUGH HERE?

YEAH, SURE.

[ROOSTER CROWING] SANJAYAN, VOICE-OVER: THE HOPE IS THAT EVENTUALLY OUR WATERHOLE WILL HELP KEEP ELEPHANTS MOSTLY IN THE RESERVE... [CLUCKING] BUT IN THE MEANTIME, A CONSERVATION OFFICER HAS COME UP WITH INVENTIVE SOLUTIONS TO KEEP ELEPHANTS AWAY.

HIS NAME IS SEEJA SOLUMU.

OK.

SO WHAT DOES HE USE TO CHASE ELEPHANTS?

[SPEAKING LOCAL LANGUAGE] [HONK] JEEZ.

CHA CHA CHA!

SANJAYAN, VOICE-OVER: WHEN HORNS ARE NOT ENOUGH, SEEJA PULLS OUT THE BIG GUNS.

OUT HERE, IT'S NOT WHAT YOU MIGHT THINK.

SO THIS THEY'RE TOLD TO CARRY-- HE ACTUALLY HAS-- OH, A CONDOM.

CONDOM.

HA HA HA!

THAT'S THE FIRST IN THE SHOW.

ANOTHER USE OF CONDOM.

I GUESS SO.

SANJAYAN, VOICE-OVER: BY PUTTING A FIRECRACKER AND SOME CHILI POWDER IN A CONDOM... WOW!

SEEJA IS TRYING TO USE SOUND AND SMELL TO SCARE ELEPHANTS AWAY.

[SPEAKING LOCAL LANGUAGE] KIND OF WHAT'S INGENIOUS ABOUT THIS IS THAT THEY'RE MAKING ALL OF THIS FROM THINGS THAT THEY CAN GET LOCALLY, AND I ACTUALLY REALLY LIKE THAT.

YOU CAN BUY A CONDOM IN ANY DRUG STORE AROUND HERE.

YOU KNOW, FIRECRACKERS ARE WELL AVAILABLE, AND THEY'RE USING LOCAL CHILI AND LOCAL SAND.

SO IT'S NOT VERY HIGH-TECH, BUT IT'S AVAILABLE TO VILLAGERS.

THAT'S PROBABLY WHAT MAKES IT MOST EFFECTIVE.

LOOK AT THAT.

YOU KNOW, THERE'S A NUMBER OF JOKES RUNNING THROUGH MY HEAD RIGHT NOW, ALL OF THEM PROBABLY NOT USEFUL.

WOW!

OK.

SO THE CHILI BOMB IS READY.

[SPEAKING LOCAL LANGUAGE] THE SAND WILL SPREAD IT, AND THE CHILIES... WE'RE GONNA HAVE TO GO LIGHT IT SOMEWHERE.

NOT HERE.

NO.

WE HAVE TO.

YOU CANNOT--THAT IS IMPOSSIBLE TO NOT LIGHT THIS THING.

WE WILL ACTUALLY, UH, CHASE AWAY PEOPLE HERE.

I DON'T CARE HOW FAR WE HAVE TO GO.

THERE'S NO WAY WE'RE NOT LIGHTING THAT.

HA HA!

HA HA HA!

WITH THESE PEPPER CONDOM BOMBS, THE TRICK APPARENTLY IS THAT YOU HAVE TO HOIST IT HIGH IN THE AIR SO THAT ONCE IT GETS DOWN THERE IT BLOWS UP.

OTHERWISE, IF YOU JUST CHUCK IT STRAIGHT OUT, IT'LL JUST SIT THERE FOR A WHILE BEFORE THE FUSE BURNS DOWN.

SO THERE'S A WHOLE SCIENCE OF ARCING THIS THING OVER TO GET IT TO NEAR WHERE THE ELEPHANT IS SO JUST AS IT'S COMING DOWN IT EXPLODES.

OH!

NO BOOM.

SYLVESTER: NOTHING.

SANJAYAN: MOTHER OF GOD.

NOTHING.

SANJAYAN, VOICE-OVER: I THINK IT'S SAFE TO SAY THAT NO ELEPHANTS, OR CONDOMS FOR THAT MATTER, WERE HARMED DURING THIS FILMING.

SANJAYAN: WE'LL JUST DO IT IN POST.

[LAUGHTER] SANJAYAN, VOICE-OVER: HERE'S WHAT SHOULD HAVE HAPPENED.

[TAPE REWINDING] [FLICKING LIGHTER] [CRACK] SANJAYAN, VOICE-OVER: A BIG NOISE LOUD ENOUGH TO PUT OFF ANY ELEPHANTS IN THE AREA BUT NOT ACTUALLY HARM THEM, SAVING THEIR LIVES AND THE VILLAGERS' CROPS.

♪ BACK AT THE WATERHOLE, THERE'S A DIFFERENT EXPLOSION GOING ON... AN EXPLOSION OF INSECT LIFE.

HOVERFLIES ARE HARMLESS, BUT THEY MIMIC WASPS AND STINGING BEES TO WARD OFF PREDATORS.

LEAF ROLLER MOTHS PUPATE FROM INSIDE A ROLLED-UP LEAF SEALED SHUT WITH THE CATERPILLAR SILK.

NEW INSECT LIFE IS ATTRACTING MORE BIRD SPECIES, INCLUDING ONE THAT HAS DECIDED TO BE ROOMMATES WITH PAPER WASPS IN OUR HIDE.

WE GOT A PAIR OF SWALLOWS THAT HAVE MADE OUR HIDE BY THE WATERHOLE THEIR OWN HOME.

SANJAYAN, VOICE-OVER: EARLY IN THE DRY SEASON, OUR CAMERAS CAPTURED THE MOMENT WHEN THESE SWALLOWS WERE FIRST CHOOSING WHERE TO BUILD A NEST.

THESE SWALLOWS TYPICALLY NEST UNDER BRIDGES FOR PROTECTION, AND THE ROOF OF OUR HIDE OFFERS A GREAT ALTERNATIVE.

OUR WATERHOLE ALSO PROVIDED THE BUILDING MATERIALS.

THEY CONSTRUCT THEIR NESTS FROM MUD, AND YOU CAN SEE THIS ONE'S BEAK FULL OF MUD DECIDING WHERE TO START PLASTERING.

[CHIRPING] REALLY A BEAUTIFUL SWALLOW.

USUALLY SWIFTS AND SWALLOWS, YOU SEE THEM IN FLIGHT, THEY'RE QUITE HIGH UP, AND THEY JUST LOOK LIKE SILHOUETTES LIKE LITTLE FIGHTER JETS ZOOMING ACROSS THE SKY, BUT THESE ONES ARE PROBABLY, I THINK, THE PRETTIEST SWALLOWS THAT YOU CAN FIND AROUND HERE.

THEY HAVE REALLY DISTINCT MARKINGS.

THEY HAVE JUST WONDERFUL STRIPES UNDER THEIR BELLY AND THEIR CHIN AND THEN A REAL RED HEAD AND THEN THESE V-SHAPED TAIL.

THEY'RE CALLED THE LESSER STRIPED SWALLOW, AND THEY'RE NOT RESIDENT HERE.

THEY'RE ACTUALLY MIGRANTS HERE.

THEY LIVE IN SOUTHERN PART OF AFRICA IN, LIKE, SOUTH AFRICA, AND THEN THEY MAKE THEIR WAY FURTHER NORTH ALL THE WAY UP HERE TO TANZANIA, WHERE THEY BREED.

WE DON'T YET KNOW HOW MANY CHICKS ARE IN THE NEST, BUT THE PARENTS ARE FLAT-OUT.

WE SEE THEM BRING BACK FOOD EVERY 20 MINUTES.

ONE THING THAT WE'RE NOT SHORT OF RIGHT NOW ARE BUGS.

I MEAN, THEY'RE JUST EVERYWHERE, AND THE MOST NUISANCE BUGS THAT YOU FIND ARE REALLY FLIES THAT ARE HERE REALLY ATTRACTED BY THE MIGRATION THAT'S HAPPENING SORT OF ALL AROUND US, AND THAT'S WHAT THESE GUYS ARE AFTER.

I MEAN, THESE SWALLOWS AND SWIFTS CATCH INSECTS ON THE WING, USUALLY QUITE HIGH UP IN THE AIR, AND THERE'S SUCH A PROFUSION OF INSECT LIFE RIGHT NOW THAT IT'S NOT GOING TO BE ANY PROBLEM FOR THESE SWALLOWS TO FEED THEIR BABIES.

SANJAYAN, VOICE-OVER: EVEN BETTER, SINCE SWALLOWS RETURN TO THE SAME NEST SITE YEAR AFTER YEAR, OUR HIDE COULD WELL BE THEIR HOME LONG INTO THE FUTURE.

OUR SPECIES LIST IS NOW APPROACHING 100.

THE NUMBER AND VARIETY OF SPECIES IS IMPRESSIVE CONSIDERING THE WATERHOLE IS JUST 6 MONTHS OLD...

BUT HOW DOES IT COMPARE TO A NATURALLY OCCURRING WATER SOURCE?

MWIBA IS PART OF ONE OF THE OLDEST ECOSYSTEMS ON EARTH, THE SERENGETI, AND 4 MILES FROM OUR WATERHOLE IS ONE OF THE OLDEST WATER POINTS ON THE RESERVE.

IT'S CALLED SELE SPRINGS.

IT'S HUNDREDS OF YEARS OLD BUT ALMOST DISAPPEARED IN THE DRY SEASON.

THANKS TO THE RECENT RAINS, IT'S FULL AGAIN.

TO FIND OUT HOW THIS ANCIENT SPRING CONTRASTS TO OUR FLEDGLING WATERHOLE, WE'VE BROUGHT IN DR. MEREDITH PALMER.

SHE'S BEEN STUDYING THE SERENGETI ECOSYSTEM FOR OVER A DECADE, AND SHE'S BEEN USING CAMERA TRAPS AT SELE SPRINGS TO GATHER DATA OVER THE PAST 6 MONTHS.

PALMER: SO HERE IF WE'RE FOCUSING ON THE MAMMAL SPECIES SHOWING UP AT EACH SITE, WE CAN SEE THAT HERE AT SELE SPRINGS WE HAVE VERY SIMILAR NUMBERS OF MAMMALS SHOWING UP.

SANJAYAN, VOICE-OVER: INCREDIBLY, OUR WATERHOLE IS ALREADY SUSTAINING AS MANY SPECIES AS SELE... AND THERE ARE SOME ANIMALS THAT ARE ONLY COMING TO OUR NEW WATERHOLE.

WE'RE GETTING MORE MONGOOSE, PORCUPINE, RABBITS SPRING HARES, A LOT MORE MONKEYS HERE.

AT OUR WATERHOLE ON THE OTHER HAND, WE'RE GETTING SERVALS.

WE HAVE THINGS LIKE WATERBUCK, KUDU, BUT WE DON'T SEE THEM AT SELE SPRINGS.

SANJAYAN, VOICE-OVER: DR. PALMER'S RESEARCH IS ALSO SHOWING THAT WILDLIFE IS BEHAVING DIFFERENTLY AT EACH SITE.

DESPITE IT BEING NEW IN THE LANDSCAPE, THE ANIMALS ARE MORE COMFORTABLE DRINKING AT OUR WATERHOLE THEN AT SELE.

PALMER: SO IMPALA ARE SPENDING FAR MORE TIME THERE THAN THEY ARE AT SELE.

WE CAN SEE THE SAME WITH GIRAFFE.

SANJAYAN, VOICE-OVER: AT OUR WATERHOLE, IMPALA STAY FOR AROUND HALF AN HOUR... TWICE THE LENGTH OF TIME THEY SPEND AT THE NATURAL SPRINGS.

THAT'S THE SAME FOR ZEBRA AND GIRAFFE.

WHY DO YOU THINK THAT IS?

COULD BE A SAFETY ISSUE.

OUR WATERHOLE IS A LITTLE BIT MORE OPEN.

YOU CAN SEE THE PREDATORS COMING, AND THEY MIGHT FEEL SAFER TO STAY LONGER.

SANJAYAN: BY WORKING WITH MWIBA AND THE LOCAL COMMUNITY TO BUILD OUR WATERHOLE IN AN OPEN AREA, WE'VE MADE IT A SAFER PLACE FOR MANY ANIMALS TO VISIT.

PREDATORS HAVE FEWER CHANCES TO HIDE, AND AS A RESULT, A LOT OF SPECIES SEEM TO BE TAKING THEIR TIME AT THIS BRAND-NEW WATER SOURCE.

WHAT IS SURPRISING, I MEAN, IT REALLY IS KIND OF STUNNING TO ME THAT, YOU KNOW, WE COULD PUT A WATERHOLE IN IN A PLACE THAT DIDN'T HAVE WATER BEFORE... MM-HMM.

AND SO QUICKLY GET THE SAME NUMBER OF SPECIES ROUGHLY, NOT NECESSARILY THE EXACT SAME SPECIES, BUT THAT ANIMALS DO FIND THEM AND START USING IT PRETTY QUICKLY, PARTICULARLY THE BIG ONES.

YEAH, I THINK IT'S AMAZING HOW QUICKLY THE COMMUNITY ASSEMBLED AT OUR WATERHOLE, HOW MANY ANIMALS WE GOT AND HOW SOON THEY SHOWED UP.

WE'RE SEEING THE SAME FORCES SHAPE ANIMAL BEHAVIOR AT OUR WATERHOLE AND AT OTHER WATERHOLES LIKE THIS, AND EVEN THOUGH IT'S STILL AN EXPERIMENT IN PROGRESS, THE COMMUNITY IS STILL JOSTLING AND ASSEMBLING AND BECOMING A WATERHOLE.

HAVING THE OPPORTUNITY TO LOOK THROUGH ALL THIS DATA AND AT SUCH A FINE SCALE HAS JUST BEEN REALLY FASCINATING.

I GUESS ONE THING IT TELLS ME THAT IN A LANDSCAPE THAT IS PATCHY WITH RESPECT TO WATER-- WATER SOURCES ARE THERE ONE DAY AND GONE THE NEXT-- ANIMALS IN THIS PART OF AFRICA ARE SUPREMELY ADAPTED.

YEAH.

CHANGING THEIR BEHAVIOR TO FIT THE LOCAL CONDITIONS AND TO TAKE ADVANTAGE OF OPPORTUNITY.

EXACTLY.

IT'S KIND OF COOL.

YEAH.

YEAH.

HEH HEH.

SANJAYAN, VOICE-OVER: IT'S OUR LAST DAY... AND WE'RE STILL ADDING NEW ANIMALS TO THE SPECIES LIST.

THE HOOPOE IS NAMED AFTER ITS DISTINCT CALL THAT SOUNDS A BIT LIKE "HOOP HOOP."

[HOOP HOOP] THE WOODLAND KINGFISHER IS ONE OF MANY KINGFISHER SPECIES THAT DON'T JUST EAT FISH.

THEY ALSO HUNT INSECTS, FROGS, AND EVEN SNAKES... AND THE RUFOUS-TAILED WEAVER.

IS A MONOGAMOUS BIRD THAT IS ONLY FOUND HERE IN EAST AFRICA AND NOWHERE ELSE IN THE WORLD.

WE'VE BEEN RECORDING A HUGE VARIETY OF WILDLIFE OVER THE LAST 6 MONTHS...

SO LET'S DRILL INTO THE DATA TO SEE HOW THIS WATERHOLE ACTUALLY FUNCTIONED OVER TIME.

YOU KNOW, WE HAD SOMETHING LIKE 1,400 HOURS OF CAMERA DATA, OF OBSERVATION THAT GAVE US ALMOST 800 MAMMAL SIGHTINGS AT THIS WATERHOLE, WHICH IS AN ASTONISHING DATA SET.

[HUFFS] SANJAYAN, VOICE-OVER: BEYOND ALL EXPECTATIONS, WE HAD NO LESS THAN 105 SPECIES VISITING OUR WATERHOLE, AND THE DATA GIVES US SOME GREAT INSIGHT.

THE BIGGEST HERD AWARD GOES TO CAPE BUFFALO.

THEY REGULARLY TOOK OVER THE WATERHOLE WITH OVER 80 INDIVIDUALS AT A TIME...

BUT THEY DIDN'T SPEND THE MOST AMOUNT OF TIME DRINKING.

CLOCKING UP AN IMPRESSIVE 19 HOURS, IMPALAS TAKE THAT CROWN.

THEY LOVED THE SAFETY PROVIDED BY THE OPEN LANDSCAPE AROUND THE WATERHOLE.

OF ALL THE ANIMALS THAT SHOWED UP, THERE WAS ONE SPECIES THAT CAME TO OUR WATERHOLE MORE THAN ANY OTHER, AND IT'S NOT WHO YOU MIGHT THINK.

[ELEPHANT TRUMPETS] THE TOP VISITOR TO THE WATERHOLE WAS... [HYENA CHATTERING] SPOTTED HYENA.

IT TURNS OUT THAT BUFFALOES AND HYENAS REALLY DOMINATED THIS WATERHOLE.

THEY CAME OVER AND OVER AGAIN.

I MIGHT HAVE GUESSED BUFFALOES.

I WOULD HAVE NEVER GUESSED HYENAS.

SANJAYAN, VOICE-OVER: I'D ALWAYS ASSUMED THAT WATER-DEPENDENT HERBIVORES WOULD VISIT THE WATERHOLE THE MOST, BUT IT'S ACTUALLY GREAT NEWS THAT HYENAS CAME SO FREQUENTLY.

SCIENTISTS KNOW THAT THEY CAN EAT ANIMALS THAT HAVE DIED FROM DISEASE, DISEASE THAT MIGHT PROVE DEADLY TO OTHER SPECIES.

THEIR STOMACH ACID AND IMMUNE SYSTEM IS SO STRONG, THEY CAN EVEN DIGEST ANTHRAX AND SURVIVE.

IF THEY RETURN, HYENAS WILL HELP KEEP THIS NEW ECOSYSTEM HEALTHY, ACTING AS THE CLEANUP CREW, EATING CARCASSES THAT COULD SPREAD DISEASE.

THIS HAS BEEN AN INCREDIBLE EXPERIMENT ON A GRAND SCALE.

WE'VE HAD A RARE CHANCE TO SEE A WHOLE COMMUNITY OF WILDLIFE TAKING SHAPE AROUND A WATERHOLE THAT JUST 6 MONTHS AGO DIDN'T EVEN EXIST.

AND THE GREAT THING IS, IT'S HERE TO STAY.

IT WILL BENEFIT FUTURE GENERATIONS OF WILDLIFE AND ALSO THE PEOPLE THAT SHARE THIS LAND.

WE BASICALLY DUG A HOLE, FILLED IT WITH WATER TO SEE WHAT WOULD HAPPEN.

IT'S FANTASTIC IS THAT A WHOLE COMMUNITY OF ANIMALS, A WHOLE ECOSYSTEM NOW HAS DEVELOPED AROUND OUR WATERHOLE, AND MANY SPECIES AROUND HERE NOW CALL THIS WATERHOLE THEIR HOME.

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