Narrator: HIDDEN IN THE JUNGLES OF SRI LANKA,
A VERY SPECIAL GROUP OF MONKEYS ROAMS THE TEMPLE RUINS.
WE KNOW MORE ABOUT THESE TOQUE MACAQUES
THAN ANY OTHER MONKEYS ON EARTH,
FROM PROUD ALPHA MALE DOMI...
TO LONG SUFFERING POPPIN,
A FEMALE AT THE BOTTOM OF THE HEAP.
EVERY MONKEY IN THIS FOREST HAS BEEN NAMED AND FOLLOWED
SINCE THE DAY IT WAS BORN,
THANKS TO ONE MAN,
WOLFGANG DITTUS,
WHO’S BEEN STUDYING THEM FOR ALMOST 50 YEARS...
DOCUMENTING THE INCREDIBLE SOAP OPERA
THAT IS LIFE WITHIN THE TROOP.
HIS WORK PUTS HIM IN AN ELITE GROUP OF SCIENTISTS.
Jane Goodall: HE HAD A PASSION TO FOLLOW THE LONG-TERM HISTORY.
THIS GIVES YOU STORIES THAT YOU CAN SHARE WITH PEOPLE.
Narrator: HALF A CENTURY SPENT FOLLOWING THESE MACAQUES
HAS GIVEN WOLFGANG A LIFETIME OF STORIES TO TELL.
♪
IN NORTHEAST SRI LANKA,
SWALLOWED BY THE JUNGLE,
ARE THE REMAINS OF THE ANCIENT CITY
OF POLONNARUWA.
THIS WAS ONCE SRI LANKA’S CAPITAL,
BUT A THOUSAND YEARS AGO THE HUMANS MOVED OUT...
AND MONKEYS MOVED IN.
THE ALPHA MALE IN THIS 40-STRONG TROOP
IS DOMI.
AT 14 YEARS OLD,
HE’S IN HIS PRIME--
LARGE, STRONG, AND ARMED WITH FEARSOME CANINES.
HE MIGRATED INTO THIS TROOP WITH HIS BROTHERS
SEVEN YEARS AGO
AND HAS WORKED HIS WAY UP THE RANKS.
HIS RISE TO ALPHA
REQUIRED A MIX OF PHYSICAL PROWESS
AND POLITICAL SKILL.
[CHATTERING]
MANY MALES DIE TRYING TO BECOME ALPHA,
BUT, FOR NOW, DOMI REAPS THE REWARDS--
THE RIGHT TO FATHER MOST OF THE GROUP’S YOUNG.
[CHATTERING]
DOMI’S TROOP IS A TIGHT-KNIT SOCIAL GROUP
MADE UP OF CLOSELY RELATED FEMALES AND THEIR YOUNG.
YOUNG MALES TRY TO JOIN FROM OTHER TROOPS,
LIKE DOMI ONCE DID.
SO DOMI ALWAYS HAS YOUNG PRETENDERS
EYEING HIS POSITION.
[CHATTERING AND SCREECHING]
EVERY MONKEY IS CONSTANTLY REMINDED
OF ITS PLACE IN THIS STRICT HIERARCHY.
[CHIRPING]
HIGH-RANKING FEMALES LIKE JEMUZA HAVE FIRST PICK OF ANY FOOD.
AND SHE ISN’T AFRAID TO ASSERT HER DOMINANCE.
BUT LOW-RANKING FEMALES, LIKE POPPIN,
HAVE TO SCRAPE A LIVING ON THE FRINGES OF THE GROUP.
♪
DOMI’S TROOP IS JUST ONE OF 33 IDENTIFIED TROOPS
IN POLONNARUWA.
THEIR TERRITORY IS UNDER CONSTANT THREAT
FROM DOMINANT NEIGHBORS.
♪
ESPECIALLY WHEN THE TREES ON THEIR PATCH
COME INTO FRUIT.
[CHIRPING]
THESE BIGGER, STRONGER GROUPS WILL EVICT DOMI’S TROOP
TO CLAIM THE FRUIT FOR THEMSELVES.
♪
TODAY WE HAVE A DEEP UNDERSTANDING
OF MONKEY LIFE.
WHEN A YOUNG GRAD STUDENT CALLED WOLFGANG DITTUS
ARRIVED HERE 50 YEARS AGO,
ON ASSIGNMENT WITH THE SMITHSONIAN INSTITUTION,
NO ONE GUESSED MACAQUE LIFE WAS SO COMPLICATED.
Wolfgang Dittus: WHEN WE THINK OF WILD MONKEYS
LIVING IN THEIR NATURAL HABITAT,
WE THINK, OH, WHAT A WONDERFUL PARADISE KIND OF LIFE THEY HAVE.
BUT THEY SPEND 90% OF THE DAY
LOOKING FOR SOMETHING TO EAT.
THEY PICK UP SMALL BITS AND PIECES--
AN INSECT HERE,
A SMALL LEAF HERE,
A GRUB HERE AND THERE.
IT’S NOT UNTIL YOU ACTUALLY FOLLOW THEM
AND STUDY THEM A LITTLE BIT CLOSER
THAT YOU REALIZE HOW DIFFICULT LIFE FOR THEM CAN BE.
Narrator: AND FOLLOWING THE MACAQUES
IS EXACTLY WHAT WOLFGANG HAS DONE
EVER SINCE HE ARRIVED HERE IN 1968,
MAKING THESE THE BEST-STUDIED MONKEYS IN THE WORLD.
Wolfgang: IN OUR DATA BANK
WE HAVE MORE THAN 5,000 INDIVIDUAL MONKEYS IDENTIFIED,
AND WE’VE MONITORED THEIR BEHAVIORS AND FATES.
♪
Narrator: AS THESE THOUSANDS OF LIFE STORIES
HAVE PLAYED OUT FROM START TO FINISH,
A PICTURE HAS EMERGED
OF A WORLD DOMINATED BY SOCIAL CLIMBING.
IN THIS COMPLEX SOCIETY,
JUST LIKE OUR OWN,
EVERY MOTHER WANTS THE BEST FOR HER CHILD.
BY TRACKING THE UPBRINGING AND CHARACTER
OF EVERY SINGLE MONKEY,
WOLFGANG HAS GAINED AN UNDERSTANDING
OF WHAT IT TAKES TO BE A SUCCESSFUL MACAQUE.
Wolfgang: SOME MOTHERS ARE VERY
SORT OF PROTECTIVE OF THEIR YOUNG.
THEY DON’T LIKE THEM TO GO OUT AND EXPLORE.
WHEREAS OTHER MOTHERS ARE MORE LAISSEZ FAIRE.
THEY ALLOW THEIR YOUNGSTERS TO RUN AROUND AND PLAY WITH OTHERS.
AND WHAT YOU FIND,
THAT EVENTUALLY THE ONES WHO HAVE BEEN RAISED
IN THE LAISSEZ FAIRE KIND OF APPROACH,
THEY’RE A LOT MORE CONFIDENT,
THEY’RE MORE LIKELY TO ACHIEVE HIGH RANK.
Narrator: CLUES PERHAPS TO OUR OWN SOCIAL EVOLUTION.
OVER THE YEARS, WOLFGANG’S WATCHED
THE RISE AND FALL OF THOUSANDS OF INDIVIDUALS.
HE’S WITNESSED WARS BETWEEN TROOPS...
[SCREECHING]
OBSERVED THEIR GENTLER SIDE...
DOCUMENTED THEIR STRICT HIERARCHY.
AND HE’S OVERCOME THE ODDS
TO KEEP HIS STUDY GOING FOR HALF A CENTURY.
AS A UNIVERSITY STUDENT IN THE 1960s,
WOLFGANG COULDN’T HAVE GUESSED
THAT HE WOULD CALL THIS FOREST HOME
FOR THE REST OF HIS LIFE.
Wolfgang: TAKING DIFFERENT COURSES IN BIOLOGY
AT THE UNIVERSITY LEVEL,
I REALLY GOT INTERESTED IN ANIMAL COMMUNICATION.
IF I’M GOING TO DO ANIMAL COMMUNICATION,
WHY DON’T I DO IT IN A PRIMATE,
WHICH IS, YOU KNOW,
ONE OF THE MORE SOPHISTICATED ANIMAL SPECIES ABOUT.
[CHATTERING]
AND BY SERENDIPITOUS EVENTS,
I LANDED IN SRI LANKA
WITH THE SMITHSONIAN BIOLOGICAL PROGRAM.
Narrator: IN 1968,
WOLFGANG ARRIVED IN SRI LANKA AT AN EXCITING TIME.
FOUR YEARS EARLIER,
PRIMATOLOGIST SUE RIPLEY
HAD ESTABLISHED A SMITHSONIAN RESEARCH CAMP
IN POLONNARUWA.
NOW THE RESEARCH TEAM WAS EXPANDING
TO INCLUDE SEVERAL MORE SEASONED BIOLOGISTS.
WITH THEM WAS WOLFGANG--
A COMPARATIVE ROOKIE ON AN 18-MONTH ASSIGNMENT.
Wolfgang: I WAS ACTUALLY VERY FORTUNATE
TO JOIN THE SMITHSONIAN TEAM
BECAUSE IT WAS A VERY INFORMAL KIND OF CLASSROOM
THAT I HAD THE PRIVILEGE OF LEARNING
FROM THESE MORE SENIOR SCIENTISTS.
Narrator: THE CHOICE OF POLONNARUWA
WAS AN INSPIRED ONE.
THE RUINS HAD LONG BEEN A PLACE OF PRAYER,
AND SO THE ANIMALS WERE MORE USED TO HUMAN PRESENCE.
THE MACAQUES WERE MOST VISIBLE OF ALL,
AND SEEN AS UNREMARKABLE--
A TWIST OF FATE THAT WOULD SHAPE THE REST OF WOLFGANG’S LIFE.
Wolfgang: I WAS THE LAST MEMBER TO BE RECRUITED,
AND THE SENIOR ESTABLISHED PRIMATOLOGISTS,
THEY HAD ALREADY SELECTED THEIR FAVORITE SPECIES,
OF COURSE THE PHOTOGENIC GRAY LANGUR
AND THE EQUALLY PHOTOGENIC PURPLE-FACED LANGUR,
AND NOBODY REALLY WANTED TO DO THESE UGLY-LOOKING MACAQUES.
AND SO, DITTUS WAS ASSIGNED TO DO THE MACAQUES,
AND THAT WAS MY GREAT FORTUNE
BECAUSE THE MACAQUES,
SOCIALLY THEY’RE SO MUCH MORE LIVELY,
SOPHISTICATED, AND INTERACTIVE
THAN ARE THE OTHER SPECIES.
Narrator: THROUGH LUCK,
A PARTNERSHIP FORMED THAT WOULD SEE WOLFGANG
DEVOTING HIS LIFE TO THESE MONKEYS.
BUT IT WASN’T LOVE AT FIRST SIGHT
FOR THE MACAQUES.
Wolfgang: DAY ONE,
I REALLY COULDN’T GET ALL THAT CLOSE TO THE ANIMALS.
A HUNDRED METERS FROM ME,
AND THEY WOULD, UH, THEY WOULD RUN.
♪
AND IT WASN’T ALWAYS THAT EASY TO FIND THE MONKEYS.
THE FOREST WAS FAIRLY THICK AND DENSE
ABOUT 50 YEARS AGO.
[WHISTLES]
WHEN I DID FIND THE MONKEYS,
THEY WERE NOT ALWAYS HAPPY TO SEE ME FOLLOWING THEM,
SO IT TOOK A FEW MORE WEEKS AND MONTHS
TO ACTUALLY HABITUATE THEM TO MY PRESENCE.
I WOULD DO SILLY THINGS LIKE, YOU KNOW,
INTEREST IN THIS LEAF,
LOOK AT THIS LEAF.
THAT SORT OF CALMED THEM DOWN.
I MEAN, I WASN’T INTERESTED IN THEM AT ALL.
AND IF SOMEBODY THREATENED ME, I OBVIOUSLY MOVED BACK.
I DIDN’T CHALLENGE THE THREAT.
AND IT WAS INTERESTING ALSO IN THE SENSE
THAT THE YOUNGEST ANIMALS, THE ONES WHO WERE CURIOUS,
THEY WERE THE EASIEST TO HABITUATE.
SOME OF THE ELDER FEMALES, THE OLD LADIES,
THEY DIDN’T TRUST THIS FOREIGN PERSON
WALKING WITH THEM LIKE THAT AT ALL.
Narrator: EVENTUALLY, WOLFGANG WAS ACCEPTED.
♪
OR AT LEAST HE THOUGHT HE WAS.
Wolfgang: AT THE BEGINNING, I WORE A BEARD, LIKE I DO NOW.
AND I WENT TO COLOMBO, THE BIG CITY,
AND I SHAVED, AND I CAME BACK,
AND, WOULDN’T YOU KNOW IT,
THESE ANIMALS WERE ACTUALLY MORE SHY OF ME?
♪
IT REALLY ASTOUNDED ME--
HOW, HOW FINE-GRAINED THEIR PERCEPTIONS ARE
OF THEIR ENVIRONMENT, INCLUDING ME.
Narrator: MACAQUES NEED TO BE HIGHLY TUNED
TO FACES AND APPEARANCE
BECAUSE OF THEIR EXTENDED SOCIAL NETWORK.
THEY HAVE TO KNOW WHO EVERYONE AROUND THEM IS--
FRIENDS AND ENEMIES.
Wolfgang: I REALIZED HOW THAT’S ALSO IMPORTANT FOR ME.
I NEED TO BE ABLE TO DISTINGUISH THEM AS INDIVIDUALS;
NOT JUST AS AN ADULT MALE OR AN ADULT FEMALE.
THAT’S JUST NOT GOOD ENOUGH.
Narrator: FEW SCIENTISTS AT THE TIME
HAD SURVEYED A WILD PRIMATE GROUP
IN SUCH DETAIL.
PIONEERS LIKE JANE GOODALL IN 1960
HAD IDENTIFIED INDIVIDUALS.
SHE WAS CRITICIZED FOR GIVING WILD CHIMPANZEES NAMES.
IT WAS SEEN AS UNSCIENTIFIC.
BUT IT HELPED HER TO UNDERSTAND THE INNER WORKINGS OF THE GROUP.
WOLFGANG HAD INDEPENDENTLY COME TO THE SAME CONCLUSION.
IN HIS 18-MONTH STUDY,
HE PLANNED TO CHART THE AGES, GENDER, AND RANK
OF AS MANY ANIMALS AS HE COULD--
A MASSIVE UNDERTAKING,
AND SOMETHING NO ONE HAD DONE BEFORE.
HE NEEDED A WAY TO KEEP TRACK OF THE FACES SURROUNDING HIM.
SO HE BEGAN TO DRAW PERSONALIZED CARDS,
IDENTIFYING EVERY SINGLE MACAQUE.
THIS WAS THE BIRTH OF A SYSTEM
THAT’S THE BEDROCK OF WOLFGANG’S ENTIRE STUDY.
Wolfgang: HE’S GOT THAT RED SPOT UP THERE,,
HE’S GOT THAT CUT IN THE EAR,
THAT’S A LITTLE BIT THICKER.
LUCKILY FOR ME, THE TOQUE MACAQUES
HAVE A LOT OF INDIVIDUALISTIC MARKS.
THEY HAVE DIFFERENT HAIR-DOS,
AND THEY’VE GOT LITTLE RED AND BLACK SPOTS IN THE FACE.
THERE ARE SO MANY MARKINGS ON A MONKEY
THAT HELP US TO CREATE A BARCODE, SO TO SPEAK.
♪
Narrator: NOW THAT HE RECOGNIZED EACH INDIVIDUAL,
THEIR RELATIONSHIPS AND INTERACTIONS
TOOK ON MORE MEANING.
IN THE FEMALES,
ELDERLY HONITA ALWAYS GAVE WAY TO THE JUVENILE MAYA.
YOUNG MALE FAYUM ALWAYS SUPPORTED HIS BROTHERS
IN FIGHTS BETWEEN MALES.
MOTHERS FAVORED THE YOUNGEST SIBLING.
SLOWLY, WOLFGANG WAS UNRAVELING A SOPHISTICATED GROUP STRUCTURE.
Wolfgang: I FOLLOWED THE MONKEYS FROM DAWN TO DUSK.
I WANTED TO GET A REALLY GOOD UNDERSTANDING
OF HOW A DAY IN THE LIFE OF A MONKEY PROGRESSES.
AND HOW DOES A MONKEY’S DAY IN THIS SOCIETY DIFFER
ACCORDING TO ITS AGE AND SEX AND RANK?
SO I FOLLOWED EACH AND EVERY INDIVIDUAL IN THE GROUP
FOR DAYS ON END SOMETIMES.
Narrator: AS THE MONKEYS BECAME USED TO WOLFGANG,
HE WAS ABLE TO GET TO KNOW THE WHOLE GROUP--
THEIR PERSONALITIES...
[SCREECHING]
THEIR RELATIONSHIPS...
AND THEIR HABITS.
AFTER A WHILE, HE NOTICED SOMETHING STRANGE.
Wolfgang: THE GROUP THAT I HAD BEEN STARTING WITH,
THEY DIDN’T HAVE A SUFFICIENT NUMBER
OF INFANT AND JUVENILE FEMALES.
SO I THOUGHT, OK, THIS IS NOT GOING TO GIVE ME
A BALANCED PICTURE OF WHAT SOCIETY IS ALL ABOUT,
SO I WENT TO ANOTHER GROUP,
AND I FOUND THE SAME PROBLEM THERE,
SO I WENT TO A THIRD GROUP AND A FOURTH GROUP.
HEY, WAIT A MINUTE, THIS IS A PATTERN.
THERE’S SOMETHING WEIRD GOING ON HERE.
Narrator: THE LACK OF YOUNG FEMALES IN EVERY TROOP
WAS A PUZZLE THAT GOT UNDER WOLFGANG’S SKIN.
SO HE SURVEYED ALL THE MONKEYS IN THE SACRED FOREST.
AT THAT TIME, THIS WAS 18 TROOPS.
IT TOOK HIM OVER A YEAR.
WHEN HE’D FINISHED,
WOLFGANG HAD IDENTIFIED THE AGE, RANK, AND GENDER
OF 456 INDIVIDUALS.
IT WOULD TAKE MANY YEARS BEFORE THIS DATA WOULD UNLOCK
THE MYSTERY OF THE MISSING FEMALES.
WOLFGANG WANTED TO SHARE HIS OBSERVATIONS WITH OTHERS
IN A WAY THAT WENT BEYOND THE DATA.
SO HE ASKED THE SMITHSONIAN INSTITUTION
FOR A CAMERA.
Wolfgang: BEHAVIOR IS MOVEMENT.
SO, I WANTED TO RECORD SOME OF THIS ON FILM,
AND I WAS GIVEN A HAND-WOUND BOLEX CAMERA.
Narrator: BUT CAPTURING THE FAST-MOVING MONKEYS
WASN’T GOING TO BE EASY.
Wolfgang: YOU HAVE A 20-SECOND WINDOW
TO FILM SOMETHING.
I HAD TO REWIND THE THING AGAIN.
FOR THINGS LIKE GROOMING BEHAVIOR
AND SLEEPING AND FORAGING,
THAT WAS A GOOD EXPERIENCE, ACTUALLY.
BUT, AT THE SAME TIME,
FOR SOME SOPHISTICATED BEHAVIORS...
LIKE THERE’S AN AGGRESSIVE EVENT THAT’S DEVELOPING,
AND IT’S GOING TO PLAY OUT FOR AT LEAST TWO OR THREE
IF NOT FIVE MINUTES,
AND YOU HAVE A 20-SECOND WINDOW.
IT’S A CHALLENGE THAT WAS TOO MUCH TO ACCOMPLISH
WITH THIS SIMPLE CAMERA.
Narrator: LITTLE DID HE KNOW THIS SCREEN DEBUT
WAS TO BE THE FIRST OF MANY TIMES
THE CHARISMATIC MACAQUES GRABBED THE LIMELIGHT.
EVEN AFTER 50 YEARS OF OBSERVATION,
THE SMALL EVERYDAY MYSTERIES
CONTINUE TO PROVIDE NEW REVELATIONS.
TODAY, WOLFGANG IS LOOKING FOR ONE OF THE FEMALES
FROM THE GROUP NEAR THE POND--
POINTA.
Wolfgang: A COUPLE OF DAYS AGO,
SUDDENLY SHE TURNS UP WITH THIS REALLY YOUNG INFANT,
COULDN’T HAVE BEEN MORE THAN TWO WEEKS OLD.
HOW SHE GOT THAT IS A MYSTERY.
Narrator: POINTA WAS SEEN
CARRYING AND CARING FOR THIS BABY
ROUND THE CLOCK FOR AT LEAST TWO DAYS.
BUT WOLFGANG KNOWS HER OWN BABY HAD RECENTLY DIED.
Wolfgang: THE INFANT OBVIOUSLY DID NOT BELONG TO POINTA,
ALTHOUGH POINTA BEHAVED VERY MATERNALLY TOWARDS IT.
Narrator: BUT FOR ALL HER CARE AND PROTECTION,
SHE COULDN’T PRODUCE MILK,
AND THE INFANT WAS DESPERATE.
Wolfgang: IT DID SOMETHING
THAT’S UNUSUAL FOR AN INFANT OF THAT AGE.
IT BEGAN TO FORAGE ON FOODS FOUND ON THE FOREST FLOOR.
Narrator: WOLFGANG IS ANXIOUS TO SEE
WHETHER THE BABY’S STILL ALIVE.
IT’S UNLIKELY THE INFANT COULD SURVIVE
WITHOUT ITS MOTHER’S MILK.
Wolfgang: AH, THERE’S POINTA.
AND SHE DOES NOT HAVE THE INFANT.
Narrator: FOR DAYS, POINTA HAD DONE ALL SHE COULD.
WOLFGANG HAS NEVER SEEN A MONKEY INVEST SO MUCH
IN A COMPLETELY UNRELATED INFANT.
Wolfgang: THAT DOESN’T HAVE AN EASY EXPLANATION.
I MEAN, YOU SHOULD PICK UP YOUR OWN INFANTS, YES,
INVEST A LOT AND PROMOTE THEIR SURVIVAL,
PASS YOUR GENES ON TO THE FUTURE GENERATIONS.
WHY ARE THEY DOING THIS FOR SOMEBODY ELSE’S INFANT
THAT THEY DON’T EVEN KNOW?
[CHATTER]
THAT MUST BE RECIPROCAL ALTRUISM, YOU KNOW.
THEY DO THAT SORT OF THING
BECAUSE AT SOME POINT IN TIME WITHIN SOCIETY,
THAT KIND OF BEHAVIOR WILL BE RECIPROCATED,
SO BY PARTICIPATING IN THIS SORT OF ALTRUISTIC ACT,
THE GENES FOR IT STAY IN THE POPULATION
BECAUSE EVENTUALLY IT WILL BENEFIT YOU OR YOUR CHILDREN.
Narrator: IN HUMAN SOCIETY,
RECIPROCAL ALTRUISM MEANS AN UNRELATED PERSON
BENEFITS GREATLY FROM ANOTHER’S UNSELFISH ACT OF KINDNESS.
IT’S A SOPHISTICATED EVOLUTIONARY STRATEGY
THAT MEANS SOCIETY BENEFITS OVERALL.
WE HAVE STARTED TO RECOGNIZE IT IN HIGHER ANIMALS LIKE CHIMPS.
BUT POINTA’S CARE OF THE UNRELATED INFANT
SUGGESTS THIS BEHAVIOR
MAY GO BACK FURTHER THAN WE THINK.
[SNARLING]
BY 1972,
WOLFGANG HAD BECOME DEEPLY ENGROSSED IN HIS RESEARCH.
HE’D STAYED MUCH LONGER THAN THE PLANNED 18 MONTHS.
BUT THE SMITHSONIAN MONEY WAS RUNNING OUT.
RELUCTANTLY, HE LEFT THE MONKEYS TO GO BACK TO AMERICA.
HE COULDN’T STOP THINKING
ABOUT THE MYSTERY OF THE MISSING YOUNG FEMALES.
HE BEGAN TO FORMULATE A THEORY.
COULD THIS DEARTH OF FEMALE INFANTS
BE CAUSED BY AN INTENTIONAL STRATEGY
TO FAVOR MALES IN EARLY INFANCY?
MALES GROW UP TO TWICE THE SIZE OF FEMALES.
THEY NEED TO BE BIG AND STRONG
BY THE TIME THEY BECOME YOUNG ADULTS,
WHEN THEY HAVE TO LEAVE THEIR MOTHER’S GROUP
TO FIND MATES IN A NEW TROOP.
THE RESIDENT MALES IN THE NEW GROUP
JEALOUSLY GUARD THEIR FEMALES.
INCOMING MALES RISK BEING KILLED.
ONLY STRONG MALES, LIKE DOMI,
WILL SUCCEED IN JOINING A NEW TROOP
AND SIRING OFFSPRING.
SO THE TIME TO INVEST IN A SON
IS IN INFANCY,
HELPING HIM TO GROW QUICKLY
AND INCREASE HIS ODDS OF SUCCESS.
A DAUGHTER STAYS WITH HER MOTHER’S TROOP HER WHOLE LIFE,
REPRODUCING AT A SLOW, STEADY PACE.
SHE BENEFITS FROM HER MOTHER’S INVESTMENT
THROUGHOUT HER LIFE.
♪
BUT, AS INFANTS,
DAUGHTERS ARE SOMEWHAT NEGLECTED.
AS A RESULT, MORE OF THEM DIE YOUNG.
IT WAS A THEORY,
BUT WOULD THE NUMBERS BACK UP WOLFGANG’S HUNCH?
AFTER THREE AND A HALF YEARS GATHERING DATA
ON NEARLY 500 MONKEYS,
HE WAS CLOSE TO UNLOCKING
THE MYSTERY OF THE MISSING INFANT FEMALES.
WOULD THE NUMBERS CONFIRM THAT ENTIRE POPULATIONS
TREAT MALE AND FEMALE INFANTS DIFFERENTLY?
Wolfgang: RIGHT THERE, IN BLACK AND WHITE,
THERE WAS THE DATA, UNDENIABLY.
Narrator: MALES AND FEMALES WERE BORN IN EQUAL NUMBERS.
BUT MORE THAN HALF OF DAUGHTERS DIED IN THEIR FIRST YEAR;
WHEREAS TWO THIRDS OF SONS WERE SURVIVING.
Wolfgang: I HADN’T MADE A MISTAKE
WITH MY EARLY SELECTION OF GROUPS.
IT’S A REAL PATTERN.
Narrator: MALES, THEN, HAD A MORTALITY SPIKE
AT AGE 6 OR 7,
RIGHT WHEN THEY START DISPERSING AND FIGHTING.
OVERALL, BY THE TIME THEY’RE ADULTS,
THE BALANCE OF MALES AND FEMALES IN A POPULATION
EVENS OUT.
WOLFGANG’S DATA REVEALED A KEY FACTOR
AFFECTING THE LIFE OF EVERY YOUNG MONKEY.
SO, TODAY,
WHEN WE SEE YOUNG MALES, LIKE DEXTER HERE, BEING FAVORED,
WHILE LALA IS IGNORED,
WE KNOW WHY.
MOTHERS INVEST MORE IN THEIR INFANT SONS
AND NEGLECT THEIR INFANT DAUGHTERS,
EVEN TO THE EXTENT OF PRODUCING RICHER MILK FOR MALES--
SOMETHING WE NOW KNOW TO ALSO BE TRUE IN HUMANS.
Wolfgang: IT’S LIKE HAVING A HUGE MOSAIC PICTURE
AND THE PIECES STARTED FITTING TOGETHER.
♪
Narrator: THANKS IN PART TO HIS MOTHER’S HELP,
IMOTEL IS WELL ON HIS WAY TO BEING A SUCCESSFUL MALE.
HE’S 8 YEARS OLD.
HE WAS BORN INTO A HIGH-RANKING FAMILY
IN ANOTHER TROOP,
BUT HAS LEFT TO JOIN THIS GROUP BY THE POND.
THIS DISPERSAL OF YOUNG MALES
IS THE MACAQUE’S WAY OF MIXING THE GENE POOL
AND PREVENTING INBREEDING.
AFTER EIGHT MONTHS OF FIGHTING WITH THE RESIDENT MALES,
IMOTEL HAS FINALLY BEEN ACCEPTED
AND IS NOW ALLOWED TO GROOM THE FEMALES.
♪
SUDDENLY, IMOTEL’S FORMER GROUP
APPEARS ON THE EDGE OF THEIR TERRITORY.
AMONG THEM, SOME OF IMOTEL’S BROTHERS.
[CHATTERING]
THE MOTHERS AND JUVENILES RETREAT.
IMOTEL’S YOUNGER BROTHERS ADVANCE.
BUT THE RESIDENT MALES
PUSH THEM BACK INTO THE UNDERGROWTH.
♪
IMOTEL SEEMS HESITANT, AS IF HIS LOYALTY IS DIVIDED.
♪
THE REST OF HIS NEW GROUP BACK UP THE LEADING MALES.
IMOTEL NEEDS TO PICK A SIDE.
♪
HE’S MADE HIS CHOICE.
HIS DISPLAY OF SHAKING BRANCHES
TELLS HIS OLD GROUP NOT TO COME BACK,
AND CLEARLY SIGNALS HIS ALLEGIANCE
TO HIS NEW TROOP.
WOLFGANG HAS SEEN IT ALL BEFORE.
A JUVENILE PRETENDER LIKE IMOTEL COULD ONE DAY RISE TO GREATNESS.
Wolfgang: HE STILL GETS CHASED OUT BY THE ADULT MALES,
HE GIVES THEM A WIDE BERTH,
BUT SLOWLY HE’S BECOMING INTEGRATED,
AND, AS HE GROWS LARGER,
GETS MORE PHYSICAL STRENGTH,
HE WILL BE IN THE POSITION
TO CHALLENGE THE CURRENT MALE LEADERSHIP,
AND EVENTUALLY HE MIGHT ACTUALLY TAKE OVER THE GROUP.
Narrator: BUT DOES PHYSICAL STRENGTH
DETERMINE POLITICAL SUCCESS?
OR IS IT THE OTHER WAY AROUND?
♪
WITH HIS UNDERSTANDING OF THE HIERARCHY DEEPENING,
WOLFGANG WONDERED WHETHER A MONKEY’S RANK
AFFECTED ITS GROWTH AND CONDITION.
♪
Wolfgang: I JUST WANTED TO FOLLOW SOME OF THE GROWTH CURVES
OF SOME OF THE ANIMALS THAT WE HAD IDENTIFIED EARLIER,
SEE WHAT THEIR WEIGHTS WERE AT DIFFERENT AGES.
WE DEVISED A METHOD OF WEIGHING MACAQUES
WITHOUT REALLY DISTURBING THEM.
WE HUNG A SCALE FROM A TREE,
PUT A BIT OF BAIT INTO THE PAN.
THE MONKEY WOULD GO IN FOR THE BAIT,
AND THEN WE WOULD READ ITS WEIGHT.
Narrator: AMONG HIS FINDINGS,
HE DISCOVERED THAT MALES WHO FALL IN RANK
RAPIDLY LOSE WEIGHT.
AND THE INFANTS OF HIGH-RANKING FEMALES
GROW QUICKEST--
TWO CLEAR EXAMPLES OF HOW SOCIAL STATUS
DICTATES PHYSICAL HEALTH.
SOMETHING NOT UNFAMILIAR TO HUMANS.
BY 1977,
WOLFGANG HAD SECURED A NEW SOURCE OF FUNDING
THAT WOULD MAKE HIS RESEARCH CAMP PERMANENT.
ONE OF HIS TEAM’S FIRST STUDIES
ADDRESSED A LONG-STANDING QUESTION AMONG PRIMATOLOGISTS.
WHEN DID INFANTS ACTUALLY WEAN?
IT WAS THOUGHT THAT MOTHERS HAD MILK FOR SIX MONTHS.
AFTER THAT, NURSING WAS FOR COMFORT.
Wolfgang: WE SHOWED,
AS LONG AS AN INFANT HAS A NIPPLE IN THEIR MOUTH,
IT’S NOT FOR COMFORT;
IT IS ACTUALLY FOR MILK.
MOST CAPTIVE STUDIES,
THEY SAY AN INFANT IS WEANED BY SIX MONTHS.
NO WAY!
IN THE WILD POPULATIONS,
THEY GET MILK UP TO 2.2 YEARS OLD,
WHICH IS AN ASTOUNDINGLY LONG PERIOD OF TIME.
SO THAT SORT OF SOLVES A LONG-STANDING QUESTION
IN THE PRIMATE LITERATURE.
Narrator: BY THE LATE ’70s,
WOLFGANG’S WORK WAS STARTING TO ATTRACT ATTENTION.
♪
Wolfgang: I REMEMBER IN 1978,
I HAD MY VERY FIRST VISIT OF A FILM CREW TO OUR SITE.
THEY WERE GOING TO DO A DOCUMENTARY ABOUT OUR STUDY,
THE SOCIAL BEHAVIOR OF THE MONKEYS.
IT WAS SPONSORED BY MUTUAL OF OMAHA,
A "WILD KINGDOM" SHOW.
AND I REMEMBER MARLIN PERKINS AND I
STANDING NEAR TO THIS VERY SPOT AT THE BEGINNING OF THAT SHOW.
Marlin Perkins: THIS PARTICULAR AREA
IS THE ARCHAEOLOGICAL AND NATURE SANCTUARY
AT POLONNARUWA.
THIS IS ALSO WHERE, FOR OVER 10 YEARS,
A CLOSE STUDY OF THE MACAQUE MONKEYS
HAS BEEN MADE BY DR. WOLFGANG DITTUS.
Wolfgang: ONE OF OUR MAIN RESEARCH AREAS IS CLOSE BY.
LET’S WALK OVER THERE,
AND PERHAPS WE CAN OBSERVE
SOME OTHER INDIGENOUS WILDLIFE EN ROUTE.
Perkins: OK.
Narrator: WITH HIS EXTENSIVE KNOWLEDGE OF THE GROUPS,
WOLFGANG WAS ABLE TO TAKE THE VIEWERS
INSIDE THE COMPLEX WORLD OF THE MACAQUES.
[SCREECHING]
Wolfgang: A SUDDEN SCREECHING INDICATES THIS MACAQUE
IS BEING THREATENED BY A MORE DOMINANT ONE ABOVE.
[SCREECHING]
A MOVIE IS MUCH BETTER AT DEPICTING
THESE DIFFERENT POSTURES AND GESTURES THAT MONKEYS MAKE
THAN A STILL PHOTOGRAPH OR A DESCRIPTION,
SO I’M PARTICULARLY GRATEFUL TO THE "WILD KINGDOM" SHOW
FOR PUTTING US ON THE MAP.
♪
Perkins: THE WORK BEING DONE BY WOLFGANG DITTUS
HERE IN THIS TROPICAL ISLAND WORLD
WITH THE SRI LANKAN MACAQUES
IS GREATLY INCREASING OUR KNOWLEDGE
OF ONE OF THE MORE INTERESTING SPECIES OF PRIMATES.
IT IS, AT THE SAME TIME,
CONTRIBUTING TO SCIENCE INFORMATION
THAT WILL ENABLE MAN TO ENSURE THAT THESE MACAQUES
WILL NOT BE EXTERMINATED IN SRI LANKA,
EITHER THROUGH IGNORANCE OR INTENTION.
♪
Narrator: THE MACAQUES’ RICH RANGE OF CALLS,
WHICH FEATURED IN THE TV SHOW,
CONTINUE TO INTRIGUE WOLFGANG.
[COOING]
Wolfgang: THE MONKEYS ARE ACTUALLY RIGHT HERE.
I JUST HEARD A COO CALL. HERE WE ARE, HERE WE GO.
[COOING]
HEAR THAT CALL? THAT’S A LOST CALL.
Narrator: TODAY, HE’S AN EXPERT IN THEIR COMPLEX VOCALIZATIONS.
[SCREECHING]
HERE, LADI IS SCREAMING THREATS UP AT JEMU.
[CHATTERING]
THEN SOLICITING SUPPORT FROM HIS ALLIES.
[CHATTERING AND SCREECHING]
WOLFGANG BECAME FASCINATED
WITH A CALL HE VERY RARELY HEARD.
[SQUEALING]
Wolfgang: THERE’S THIS ONE PARTICULAR VOCALIZATION
THAT THEY GIVE WHENEVER THERE IS A BONANZA OF FOOD.
THESE ARE VERY PECULIAR SOUNDS, THE HIGH-PITCHED SQUEALY SOUNDS.
[SQUEALING]
THE FIG TREE THAT’S FULLY FRUITED
ELICITS THIS CALL.
A PILE OF MUSHROOMS ELICITS THIS KIND OF CALL.
[SQUEALING]
Narrator: WOLFGANG WAS CONVINCED THESE CALLS WERE LIKE LANGUAGE,
GIVING PRECISE INFORMATION ABOUT FOOD.
Wolfgang: THEY COMMUNICATE ABOUT THE QUALITY AND QUANTITY
OF FOOD IN THE ENVIRONMENT,
AND COMMUNICATION EXPERTS REFER TO THAT
AS SEMANTIC SIGNALING.
Narrator: IN THE 1980s,
ATTACHING SPECIFIC MEANINGS TO A SOUND
WAS CONSIDERED A UNIQUELY HUMAN TALENT.
WOLFGANG WAS STRONGLY ARGUING OTHERWISE,
PUTTING HIMSELF OUTSIDE THE SCIENTIFIC MAINSTREAM.
Wolfgang: THE CALLER DOESN’T GIVE IT
UNLESS THERE IS A BONANZA OF FOOD.
THE SAME TREE WITH GREEN FRUIT WOULD NOT ELICIT A FOOD CALL,
AND HERE WE HAD CLEAR EVIDENCE
THAT, YEAH, THESE MONKEYS WERE COMMUNICATING
ABOUT THE QUALITY AND QUANTITY OF FOOD IN THEIR ENVIRONMENT.
THAT WAS SORT OF THOUGHT TO BE RARE OR NON-EXISTENT IN ANIMALS.
Narrator: ONCE AGAIN, THE SHEER VOLUME OF HIS DATA,
THOUSANDS OF HOURS SPENT OBSERVING THE MONKEYS,
HAD ENABLED HIM TO UNCOVER A HIDDEN BEHAVIOR.
BUT HIS NEXT BREAKTHROUGH WOULD RELY ON A NATURAL DISASTER.
IN 1978, A CYCLONE DEVASTATED POLONNARUWA.
50% OF THE FOREST CANOPY WAS LOST.
♪
Wolfgang: THE EFFECT OF THE CYCLONE
WAS TO INTENSIFY FOOD COMPETITION
WITHIN THE GROUPS AND AMONG THE GROUPS,
AND IT HAPPENED ALMOST SIMULTANEOUSLY
IN THREE DIFFERENT GROUPS.
BOOM, BOOM, BOOM, RIGHT AFTER THE OTHER,
THEY FISSIONED, THEY SPLIT.
[SCREECHING]
Narrator: GROUP SPLITS ARE EXCEPTIONALLY RARE.
NO ONE REALLY UNDERSTOOD HOW OR WHY THEY HAPPENED.
[CHATTERING]
Wolfgang: IT USED TO BE THOUGHT
THAT GROUP DIVISION IS INSTIGATED
AND SORT OF CAUSED BY MALES.
[SCREECHING AND CHATTERING]
THE IDEA IS THAT THIS DISPUTE AMONGST THE MALES
THEN PULLS THE FEMALE FAMILIES APART,
AND GROUP DIVISION OCCURS.
Narrator: BUT WOLFGANG DISCOVERED,
SURPRISINGLY,
THAT IT WASN’T THE MALES WHO INSTIGATED THE SPLITS.
THE LACK OF TREES AFTER THE CYCLONE
MEANT LESS FOOD.
SO THE OSTRACIZED LOW-RANK FEMALES
WERE GETTING EVEN LESS TO EAT.
[HORN HONKING]
SO THEY FORMED SMALL GANGS
AND MOVED AWAY FROM THE MAIN GROUP.
OTHER SUBORDINATE FEMALES FOLLOWED,
AND A NEW GROUP OF UNDERDOGS BEGAN TO FORM.
IT WAS ONLY THEN, AFTER A FEW MINOR SCUFFLES,
THAT THE MALES EITHER STAYED WITH THE HIGH-RANKING FEMALES
OR JOINED THE LOW-RANKING SPLINTER GROUP.
THE ROLE OF FEMALES HAD PREVIOUSLY BEEN IGNORED
BY SCIENTISTS.
BUT WOLFGANG’S DATA REVEALED THEIR TRUE SIGNIFICANCE.
Wolfgang: IT IS ACTUALLY THE FEMALES
THAT INSTIGATE GROUP DIVISION
AND THAT CARRY IT THROUGH.
THE MALES ARE SORT OF PASSIVE FOLLOWERS.
[CHIRPING]
Narrator: ONCE AGAIN,
WOLFGANG WAS TURNING ACCEPTED SCIENCE ON ITS HEAD,
SHEDDING NEW LIGHT ON SOCIAL EVOLUTION,
REVEALING A FAR MORE COMPLEX SOCIETY
THAN ANYONE HAD THOUGHT.
THE MACAQUES INHABITED A WORLD
THAT WAS PERHAPS NOT SO DIFFERENT FROM OURS.
FOR FILMMAKERS, THIS WAS AN IRRESISTIBLE OPPORTUNITY.
AND IN 1997, THE BBC CAME CALLING.
[CHATTERING]
WHEN THE CREW ARRIVED TO FILM "TEMPLE TROOP,"
TECHNIQUES HAD ADVANCED CONSIDERABLY
SINCE THE VISIT OF MARLIN PERKINS DECADES BEFORE.
AND SO TOO HAD WOLFGANG’S KNOWLEDGE OF THE MONKEYS.
♪
WORKING WITH WOLFGANG’S TEAM OF RESEARCHERS,
THE BBC CAPTURED SOME REMARKABLE BEHAVIOR.
THE MACAQUES’ INGENUITY...
FISHING FOR CATERPILLARS...
[SCREECHING]
THE BRUTALITY OF THE CLASHES BETWEEN RIVAL GROUPS...
[SCREECHING]
AND AN INCREDIBLE EXAMPLE OF THEIR STRICT HIERARCHY.
HERE, A DOMINANT FEMALE NAMED IMELDA
IS EXPLOITING A LOW-RANKING FEMALE CALLED POPPIN.
Wolfgang: THE TOQUE MACAQUES HAVE THESE CHEEK POUCHES
WHERE THEY STORE FOOD.
MOST OF THE TIME THAT’S OK,
BUT IT ALSO PUTS THEM AT RISK
OF HAVING THE FOOD ROBBED DIRECTLY FROM THEIR MOUTH.
Narrator: AS IMELDA ABUSES POPPIN,
THE LOW-RANKING FEMALE DARES NOT RESIST.
FOR IMELDA, IT’S AN EASY MEAL
AND CLEAR ILLUSTRATION OF THE PRIVILEGE OF RANK.
FOR POPPIN,
IT’S A HUMILIATING AND COSTLY LOSS OF FOOD.
BUT SOMEHOW, POPPIN MANAGED TO ENDURE.
♪
TWENTY YEARS AFTER SHE WAS FILMED BY THE BBC,
POPPIN’S STILL HERE, AN OLD LADY.
HER FACE BEARS THE MARKS OF A LIFETIME
OF HAVING HER CHEEK POUCHES PLUNDERED.
BUT THERE’S MORE THAN ONE WAY TO WIN IN LIFE
WHEN YOU’RE A MACAQUE.
Wolfgang: SO, POPPIN HAS FOUND A WAY TO BE SUCCESSFUL
DESPITE HER LOW RANK.
POPPIN HAS ADOPTED THIS VERY CASUAL STRATEGY
OF KEEPING OUT OF CONFLICT.
WHEN OTHERS ARE FEEDING AND SHE’S SUPPLANTED,
SHE GOES TO THE PERIPHERY AND SHE FINDS SOMETHING TO EAT.
Narrator: WOLFGANG HAS BEEN FOLLOWING POPPIN AND IMELDA
FOR DECADES.
Wolfgang: WE HAVE MORE THAN 25 YEARS OF RECORDS
ON THESE ANIMALS NOW,
AND, LO AND BEHOLD, LOW-RANKING POPPIN,
SHE’S GOT MORE GRANDCHILDREN
THAN SOME OF THESE HIGH-RANKING ANIMALS.
♪
Narrator: THE BBC SOON RETURNED WITH SIR DAVID ATTENBOROUGH
TO FEATURE THE MACAQUES
IN THE LANDMARK SERIES "LIFE OF MAMMALS."
David Attenborough: THIS IS ONE OF THE MOST STUDIED
MONKEY GROUPS OF ALL TIME.
FOR THE PAST 30 YEARS,
THEIR TRIALS AND TRIBULATIONS HAVE BEEN RECORDED IN DETAIL,
AND THAT HAS GIVEN US REMARKABLE INSIGHT
INTO THEIR PRIVATE LIVES.
Narrator: WORKING WITH EXPERT FILM CREWS
INSPIRED WOLFGANG TO MAKE A FILM
TAILOR-MADE FOR THE LOCAL POPULATION.
Wolfgang: ONE OF OUR STUDY SUBJECTS
IS THE FOREST GROUP.
♪
Narrator: ONCE AGAIN,
HE USED HIS RELATIONSHIP WITH THE MACAQUES
TO SHOW THEIR REMARKABLY COMPLEX SOCIAL STRUCTURE.
Wolfgang: FOR THOSE WHO MISSED A DRINK AT THE PUDDLE,
A TREE HOLE HOLDS SOME PROMISE OF WATER.
BUT TYPICALLY IN MACAQUE SOCIETY,
PRIVILEGES LIKE EATING AND DRINKING
ARE NOT EQUAL RIGHTS.
THE PUSHY MALE DRINKS FIRST.
Narrator: BUT WOLFGANG ALSO WANTED TO SHOW PEOPLE
HOW MUCH THINGS WERE CHANGING FOR THE MONKEYS.
Wolfgang: MACAQUES LOOK ON HELPLESSLY
AS THEIR FOREST HOME IS BEING DESTROYED.
WHAT CAN THIS MALE BE THINKING?
Narrator: OVER THE YEARS,
AS WOLFGANG’S APPRECIATION FOR THE MACAQUES HAS GROWN,
HE’S SEEN THE CREEPING EROSION OF THEIR FOREST.
SINCE HE ARRIVED,
THE AREA HAS LOST OVER 50% OF ITS NATURAL HABITAT.
TODAY, THE SACRED CITY IS AN ISLAND OF FOREST
SURROUNDED BY VILLAGES.
♪
AS HOUSES WERE BUILT IN THE MACAQUES’ TERRITORY,
THE RESOURCEFUL MONKEYS SAW THEM AS FAIR GAME.
THESE RAIDS NATURALLY UPSET THE HUMAN RESIDENTS.
[ROOSTER CROWING]
WOLFGANG’S ADVICE
WAS TO KEEP FOOD AND WATER OUT OF THEIR REACH.
IT’S A MESSAGE HE IS STILL REPEATING TODAY
AS NEW PEOPLE MOVE IN
AND FIND MACAQUES DRAWN TO THEIR HOUSES.
Wolfgang: PEOPLE CONSTANTLY COMPLAIN TO US
ABOUT THE MONKEYS RAIDING,
AND WE’VE GIVEN INSTRUCTIONS FOR THE LAST 40 YEARS,
IF YOU DON’T PUT YOUR GARBAGE OUT IN THE BACK,
THE MONKEYS WON’T COME.
THEY HAVE NO INTEREST IN YOUR TILES
OR IN YOUR BELONGINGS.
THEY JUST COME FOR THE FOOD AND THE WATER.
AND IF YOU ELIMINATE THOSE SOURCES
YOU WON’T HAVE A MONKEY PROBLEM.
VERY, VERY DIFFICULT
TO GET THAT VERY SIMPLE CONCEPT
TO BE UNDERSTOOD AND IMPLEMENTED.
♪
Narrator: CONTACT BETWEEN HUMANS AND MACAQUES
IS CONSTANTLY INCREASING.
THERE IS CONCERN THAT THEY MAY HAVE DISEASES WE COULD CATCH.
[MOTORCYCLE HUMMING]
Wolfgang: ONE OF THE THINGS THAT WE STARTED TO DO
IS WE SEE WHAT KINDS OF DISEASES ARE OUT THERE,
WHAT ARE THEY SUSCEPTIBLE TO?
WHAT IS THEIR PARASITE LOAD?
Narrator: WOLFGANG HAS FOUND SOME WORRYING CROSSOVER
BETWEEN HUMANS AND MACAQUES.
Wolfgang: ONE OFTEN THINKS,
WE HUMANS, WE ARE SO SUSCEPTIBLE TO CATCHING DISEASES
FROM, YOU KNOW, THESE WILD MONKEYS.
WELL, OUR EVIDENCE SHOWS THAT IT’S THE OTHER WAY AROUND.
♪
THE MONKEYS ARE CATCHING DISEASES
FROM HUMANS AND THEIR DOMESTIC ANIMALS.
WE DON’T FIND TOXOPLASMOSIS IN WILD MONKEYS.
YOU DO FIND IT IN THOSE MONKEYS, HOWEVER,
THAT OVERLAP WITH HUMAN HABITATION
WHERE THERE ARE CATS.
THEY CATCH IT FROM THE CATS.
CRYPTOSPORIDIUM IS ANOTHER
NASTY SORT OF BACTERIAL KIND OF DISEASE
THAT THE NATURAL POPULATION
OF MACAQUES AND OTHER PRIMATES DON’T HAVE.
BUT WHERE THEY OVERLAP WITH CATTLE,
THAT’S WHERE THEY PICK IT UP.
Narrator: SO WOLFGANG CAN CONFIDENTLY SAY
THE MACAQUES POSE NO THREAT TO US.
IN FACT, WE POSE A THREAT TO THEM.
WOLFGANG’S FIRST SURVEYS OF THE MACAQUES
IN THE LATE 1960s
FOUND A STABLE POPULATION,
WITH BIRTH AND DEATH RATES IN PERFECT BALANCE.
Wolfgang: I STARTED OFF STUDYING ABOUT 500 ANIMALS.
Narrator: NOW, DESPITE BEING CONFINED
TO A RAPIDLY SHRINKING FOREST,
THE POPULATION HAS ACTUALLY DOUBLED.
Wolfgang: TODAY, AT ANY ONE POINT IN TIME,
IT’S OVER A THOUSAND ANIMALS.
Narrator: ONCE AGAIN,
THE MACAQUES HAVE DEFIED CONVENTIONAL WISDOM.
A CLUE TO THIS SUCCESS
LIES IN ANOTHER SURPRISING DEVELOPMENT.
ALL THE INFANT FEMALES IN DOMI’S GROUP
SURVIVED THIS YEAR.
IN ONE WAY, THIS IS GOOD NEWS.
BUT IT’S A SIGN THAT THE DELICATE BALANCE
BETWEEN AVAILABLE FOOD AND POPULATION DYNAMICS
THAT TOOK THOUSANDS OF YEARS TO EVOLVE
IS SHIFTING.
[MOTORCYCLE HUMMING]
DESPITE SHRINKING HABITAT,
THE FOOD PROVIDED BY HUMANS
HAS MORE THAN COMPENSATED FOR THE LOSS OF THE FOREST.
[CHATTERING]
WOLFGANG’S EARLY RECORDS HAVE BECOME A VALUABLE SNAPSHOT
OF HOW MACAQUE LIFE ONCE WAS
BEFORE HUMANS CHANGED THEIR WORLD.
BUT THERE ARE OTHER PRIMATES IN THIS FOREST
THAT HAVE ALMOST NO CONTACT WITH HUMANS.
THESE ARE THE PURPLE-FACED LANGURS.
♪
THEY ARE SECRETIVE,
LIVING HIGH IN THE CANOPY IN SMALL GROUPS
LED BY A SINGLE ADULT MALE.
IN THE MORE REMOTE PARTS OF THE FOREST,
WOLFGANG’S TEAM HAVE OBSERVED WHAT SEEM TO BE HYBRIDS...
[CAMERA SHUTTER CLICKS]
WITH A MIX OF FEATURES FROM BOTH SPECIES...
[CAMERA SHUTTER CLICKS]
LIKE A PURPLE BODY
WITH THE DISTINCTIVE MANE OF A GRAY LANGUR.
[CAMERA SHUTTER CLICKS]
OR COMPLETELY GRAY
WITH JUST THE FACE OF A PURPLE LEAF MONKEY.
WOLFGANG BELIEVES THE GRAYS
ARE FORCING THE MALE PURPLE-FACED LANGURS OUT
AND BREEDING WITH THE FEMALES.
BUT WHY THEY ARE DOING THIS IS UNCLEAR.
[CAMERA SHUTTER CLICKS]
HYBRIDIZATION CAN BE EVOLUTION IN ACTION.
[CAMERA SHUTTER CLICKS]
IS THAT WHAT’S HAPPENING HERE?
♪
THE MACAQUES ALSO INTERACT WITH THE GRAY LANGURS.
THEY OFTEN GROOM THEIR DISTANT COUSINS.
BUT IT SEEMS A VERY ONE-SIDED RELATIONSHIP.
Wolfgang: IT’S ALWAYS BEEN A MYSTERY TO US.
THE LANGURS NEVER RECIPROCATE.
IT’S ALWAYS JUST THE MACAQUES GROOMING THE LANGURS.
Narrator: GROOMING IS A CRUCIAL PART OF LIFE FOR ALL PRIMATES.
NOT DOES ONLY DOES IT CEMENT RELATIONSHIPS,
BUT ALSO RELEASES CALMING ENDORPHINS IN THE BRAIN.
THIS IS WHY WE SOMETIMES SEE MONKEYS GROOMING OTHER SPECIES,
AND WHY WE HUMANS LOVE TO STROKE OUR PETS.
BUT THE MACAQUES GROOM THE LANGURS SO FREQUENTLY,
IT MAKES WOLFGANG WONDER IF THERE’S SOMETHING ELSE GOING ON.
Wolfgang: THE LANGURS HAVE
THESE SPECIALIZED BACTERIA IN THE FOREGUT
THAT SERVE TO BREAK DOWN CELLULOSE IN THE LEAVES.
AND I THINK THE MACAQUES
ARE PICKING UP SOME OF THESE BACTERIA
FOR THEIR OWN DIGESTIVE SYSTEM,
BECAUSE EVERY NOW AND THEN, THEY ALSO EAT LEAVES,
AND I SUSPECT THAT’S SORT OF, THAT’S WHAT IT’S ALL ABOUT.
OF COURSE, THIS IS NOT A CONSCIOUS BEHAVIOR.
THE MACAQUES HAVE NO IDEA THAT THAT’S WHAT THEY’RE DOING.
BUT IT DOESN’T HAVE TO BE CONSCIOUS,
AS LONG AS IT WORKS SOMEHOW.
Narrator: IF WOLFGANG’S HUNCH IS RIGHT,
THE MACAQUES WHO GROOM THE LANGURS
ARE BETTER AT DIGESTING LEAVES.
FOR A BENEFICIAL BEHAVIOR LIKE THIS
TO EMERGE IN A POPULATION THROUGH NATURAL SELECTION
TAKES MANY GENERATIONS,
MAKING THE RELATIONSHIP BETWEEN THE MACAQUES AND THE LANGURS
AN ANCIENT ONE.
♪
AS WOLFGANG’S LIST OF SCIENTIFIC PAPERS HAS GROWN,
SO HAS HIS REPUTATION AMONGST WILDLIFE FILM CREWS.
Wolfgang: WHO’S THE OTHER MALE WITH DOMI UP THERE?
Narrator: THE ACCESS WOLFGANG AND HIS TEAM
CAN GIVE TO THE COMPLEX WORLD OF THE MACAQUES
IS A FANTASTIC OPPORTUNITY.
♪
SO FANTASTIC THAT IN 2015,
THE MONKEYS LANDED A STARRING ROLE
IN THE DISNEYNATURE HIT FEATURE FILM,
"MONKEY KINGDOM."
♪
THANKS TO WOLFGANG,
THE UGLY MACAQUES THAT NO ONE WANTED TO STUDY
ARE NOW CELEBRITIES.
AND WHEN DISNEYNATURE BROUGHT OVER THEIR AMBASSADORS,
WOLFGANG GOT TO MEET ONE OF THE FEW PEOPLE ON EARTH
WHO CAN REALLY UNDERSTAND WHAT IT’S LIKE
TO DEVOTE YOUR ENTIRE LIFE TO A SINGLE SPECIES.
JANE GOODALL EMBARKED ON HER STUDY OF CHIMPANZEES
IN 1960--
EIGHT YEARS BEFORE WOLFGANG BEGAN HIS RESEARCH.
Goodall: FOR ME IT WAS A REAL PRIVILEGE
TO BE ABLE TO MEET WOLFGANG,
AND TO SIT AND TALK WITH SOMEONE ABOUT HIS STUDY ANIMALS
AND THEIR PERSONALITIES
AND ALL THE THINGS HE’D LEARNED.
HE HAD A PASSION TO FOLLOW THE LONG-TERM HISTORY,
AND OF COURSE THIS GIVES YOU STORIES
THAT YOU CAN SHARE WITH PEOPLE.
AND IT’S THESE KIND OF STORIES
THAT ENCOURAGE PEOPLE TO PROTECT ANIMALS
AND TO PROTECT THE ENVIRONMENT.
IT ISN’T SCIENTIFIC GRAPHS AND FIGURES.
WHO CARES ABOUT THAT?
WE HAVE TO PROVIDE THEM OCCASIONALLY
TO GET DEGREES AND HAVE PAPERS PUBLISHED,
BUT THAT REALLY ISN’T THE POINT OF IT,
NOT FOR ME,
AND I THINK NOT FOR WOLFGANG EITHER.
♪
Narrator: IT HAS BEEN A REMARKABLE 50 YEARS.
♪
BUT WHAT IS NEXT FOR WOLFGANG?
[CHATTERING]
Wolfgang: LOOKING TO THE FUTURE,
I HOPE THAT OTHER PEOPLE CAN BE INSPIRED
TO FOLLOW UP ON THESE KINDS OF RESEARCHES.
THERE’S ALSO A REALLY STRONG NEED
FOR SOMEONE TO TAKE UP THE CHALLENGE OF CONSERVATION.
THAT IS A TOUGH ONE.
Narrator: INSPIRING PEOPLE
MAY TURN OUT TO BE WOLFGANG’S GREATEST LEGACY.
OVER THE YEARS,
HE HAS TRAINED MORE THAN 50 SRI LANKAN RESEARCHERS
WHO NOW WORK IN CAREERS
THEY COULDN’T HAVE IMAGINED WITHOUT WOLFGANG’S PROJECT.
HIS RESEARCH STILL GOES WHEREVER THE MONKEYS TAKE HIM--
COLLECTING DATA...
INVESTIGATING THE RICH WORLD OF POLONNARUWA
AS HE HAS DONE FOR THE PAST HALF A CENTURY.
Wolfgang: LOOKING BACK, IF I HAD TO DO IT AGAIN,
I PROBABLY WOULD DO IT AGAIN,
GIVEN WHO I AM AND WHAT I DO AND WHAT I’M INTERESTED IN.
IF I HADN’T BEEN GIVEN THE MACAQUES,
I WOULDN’T BE HERE.
I DON’T THINK THE OTHER TWO SPECIES
WOULD HAVE KEPT MY INTEREST,
BECAUSE THEY’RE JUST NOT AS ACTIVE AND SOCIALLY INTERESTING
AS THE MACAQUES ARE.
Narrator: AS THE WORLD’S LEADING AUTHORITY ON MACAQUES
QUIETLY GOES ABOUT HIS BUSINESS,
IT’S THE MONKEYS THAT GRAB THE LIMELIGHT,
WHICH IS EXACTLY WHAT WOLFGANG ALWAYS WANTED.
♪