Skip to main content Skip to footer site map
S36 Ep15

Natural Born Rebels | Episode 3 | The Mating Game

Premiere: 5/9/2018 | 00:00:35 | Closed Captioning Icon

Getting ahead in the mating game requires some astonishing behavior –from promiscuous prairie dogs to manakin pick-up artists, kidnapping macaques and hyenas with a bad case of sibling rivalry.

Play Icon WATCH PREVIEW

Play Icon WATCH FULL EPISODE

About the Episode

Getting ahead in the mating game requires some astonishing behavior –from promiscuous prairie dogs to manakin pick-up artists, kidnapping macaques and hyenas with a bad case of sibling rivalry.

Noteworthy Facts:

  • Female Gunnison’s prairie dogs are only receptive to mating for about six hours a year. If they don’t successfully mate during this window, they lose their chance until next year. In order to maximize this time and ensure pregnancy, two-thirds of female prairie dogs take more than one partner.
  • In Uganda, Banded mongoose packs are so tight-knit that the females tend to mate with their male relatives, resulting in a high proportion of inbred pups. When males and females from different groups wish to get together, they must incite a riot between the clans as a distraction.
  • Spotted hyenas are often born as twins, and shortly after birth the siblings fight to establish a hierarchy in their clan, which can include more than 100 hyenas. If food is in short supply, the dominant pup will push the subordinate pup away from their mother’s milk. In nearly 10 percent of hyena litters in the Serengeti, the subordinate dies of starvation.

Buzzworthy Moments:

  • Female burrowing bees wait out the winter underground, and early in the mating season, the waiting males outnumber the females hundreds to one. In an intense sequence, multiple male bees descend on a female as soon as she pops out from the burrow, wrestling their rivals for dominance. This results in a colony littered with dead bees, and occasionally the female becomes an unwitting victim as well.
  • Male long-tailed manakins attract a mate by partnering up with another male for a complex dance number. Some duos may dance together for up to 10 years, but only the alpha male gets to score with the female they attract.
  • A female praying mantis lures a mate by pulsating her abdomen in order to release pheromones. A successful mating session ends in death for her partner – eating him improves her fertility by up to 40 percent.
SHARE
PRODUCTION CREDITS: EPISODE 3

NATURAL BORN REBELS
EPISODE 3: THE MATING GAME

NARRATED BY
ALLAN PECK

DIRECTED BY
JOANNE ASHMAN
HANNAH GIBSON

EDIT PRODUCER
EMILY TAYLOR

PHOTOGRAPHY
STUART DUNN
KEVIN FLAY
PETE HAYNS
MICHAEL MALE

SOUND
PARKER BROWN
ZUBIN SAROSH
GARY STADDEN

EDITORS
PAUL KIFF
SAM ROGERS

EDIT ASSISTANT
SINEAD COOPER

COLORIST
TONY OSBORNE

ONLINE EDITOR
ALEX MOFFATT

DUBBING MIXER
BRIAN MOSELEY

DUBBING EDITOR
DAVID YAPP

GRAPHICS
KISS MY PIXEL
ORIGINAL MUSIC
WILL HYDE
SIMON PITT

PRODUCTION MANAGER
JANELLE BACKES

PRODUCTION COORDINATORS
AMANDA MCFALL
LESLEY BISHOP

ASSISTANT PRODUCER
EMMA BRENNAND

RESEARCHERS
ESTELLE CHEUK
JOLYON SUTCLIFFE

ARCHIVE RESEARCHER
DAVE COX

SPECIAL THANKS
DR KATHERINE LOUISE BARRY
PROFESSOR MICHAEL CANT
DR FAYE THOMPSON
DR ROSLYN DAKIN
KATHY KERRAN
PROFESSOR DAVID B. MCDONALD
MARIANA RIVERA RODRIGUEZ
BANDED MONGOOSE RESEARCH PROJECT
HELPING HAND TRUST

ARCHIVE
MEDIAWORKS NEWS ARCHIVE
POND5
SHUTTERSTOCK

COMMISSIONING EDITORS
ABIGAIL PRIDDLE
LUCINDA AXELSSON

EXECUTIVE PRODUCER
JO SHINNER

UNIT MANAGER
MARIA NORMAN

SERIES PRODUCER
HOLLY SPEARING

FOR NATURE

SERIES EDITOR
JANET HESS

SENIOR PRODUCER
LAURA METZGER LYNCH

COORDINATING PRODUCER
JAYNE JUN

ASSOCIATE PRODUCER
JAMES BURKE

LEGAL COUNSEL
BLANCHE ROBERTSON

SOCIAL MEDIA EDITOR
WHITNEY MCGOWAN

AUDIENCE ENGAGEMENT
CHELSEY SAATKAMP

BUDGET CONTROLLER
JAYNE LISI

ONLINE EDITOR
STACEY DOUGLASS MOVERLEY

RE-RECORDING MIXER
ED CAMPBELL

ORIGINAL FUNDING PROVIDED IN PART BY
THE ARNHOLD FAMILY IN MEMORY OF CLARISSE ARNHOLD
THE HALMI FAMILY IN MEMORY OF ROBERT HALMI, SR.
SUE AND EDGAR WACHENHEIM III
KATE W. CASSIDY FOUNDATION
LILLIAN GOLDMAN CHARITABLE TRUST
FILOMEN M. D’AGOSTINO FOUNDATION
ROSALIND P. WALTER
SANDRA ATLAS BASS
CORPORATION FOR PUBLIC BROADCASTING

SERIES PRODUCER
BILL MURPHY

EXECUTIVE PRODUCER
FRED KAUFMAN

A CO-PRODUCTION OF THIRTEEN PRODUCTIONS LLC AND BBC STUDIOS IN ASSOCIATION WITH WNET

THIS PROGRAM WAS PRODUCED BY THIRTEEN PRODUCTIONS LLC, WHICH IS SOLELY RESPONSIBLE FOR ITS CONTENT

© 2018 BBC
ALL RIGHTS RESERVED

TRANSCRIPT

♪ ♪ NARRATOR: All animals face the same challenge.

They need to find a mate and raise a family.

And in a tough world, that's never easy.

So to get what they want, some animals will break all the rules.

♪ A female's path in the mating game can be a devious and deadly one.

But is the conduct of the males any better?

Meet the planet's greatest rebels.

[ Animals chittering ] They'll fight... deceive... and even kidnap.

The key to success, it seems, is to make love and war.

We'll reveal new discoveries and astonishing science as our rebels strive to raise the next generation and get ahead in the mating game.

[ Bird warbles ] ♪ ♪ ♪ ♪♪ NARRATOR: Playing the mating game is never easy.

The search for the perfect partner can bring out the worst in both sexes and lead to some highly underhanded tactics.

♪♪ On the prairie, winter is drawing to an end.

Spring is in the air.

This is the Gunnison's prairie dog.

These sociable animals live in colonies called towns.

And in this one, the prairie dogs' every move is monitored.

♪♪ Researchers mark each one with hair dye to tell them apart.

[ Prairie dogs chittering ] And they've revealed a scandalous side to the females here.

♪♪ This is Risby.

As the morning snows melt away, she's preparing for one of the most important days of her life.

She's looking for a mate.

But Risby has a problem.

HOOGLAND: Each female is sexually receptive for only several hours on a single day.

If she doesn't mate on that day, she loses the entire year -- she can't mate again until the following March.

NARRATOR: Risby has just 6 hours a year to get pregnant.

Getting her way is going to require an audacious hustle.

[ Prairie dogs chittering ] Risby's 6-hour mating clock is ticking.

♪♪ And this male -- Patch -- is already giving her the eye.

Changes in her scent indicate that she's ready to mate.

Success!

♪♪ ♪♪ Just a couple of hours into her mating window, Risby has already mated.

♪♪ But her mission is not yet complete because she has no intention of settling for just one mate.

In fact, Risby has got designs on all the males.

The problem is jealous Patch won't let any other suitor near her.

[ Prairie dogs chittering ] This bizarre stand-off between Patch and his rivals is a prairie dog dispute.

It's like arm wrestling, but with your face.

It's often the prelude to an outright fight.

[ Chittering continues ] ♪♪ Risby is at the eye of the storm.

But it's all of her own making, and it serves her perfectly.

While Patch is preoccupied, Risby grabs an opportunity and sneaks away with lucky number 29.

And after giving both of these guys the run around, there's just enough time to entice number 31 into her burrow.

♪♪ Risby has made the most of her 6 fertile hours, going out of her way to mate with three different males.

[ Chittering ] But the interesting thing is not all female prairie dogs behave like this.

A third are entirely faithful to their partners... while two thirds mate with multiple males, sometimes as many as 6.

So what's behind this promiscuous behavior?

John Hoogland has spent over 40 years observing Gunnison's Prairie dogs.

He's discovered several advantages to playing the field.

The first is simple.

HOOGLAND: She increases the probability that she'll get pregnant.

Females that copulate with 3 or more males have 100% chance of conceiving.

That is huge because they only have one day a year.

If something goes wrong and they miss, then they lose a whole year.

NARRATOR: But conception is just the start of this fascinating story.

Mating with more than one male is called polyandry.

To understand its long-term benefits, we have to fast-forward 9 weeks from mating day... ...to early summer when the pups emerge.

♪♪ ♪♪ It's time for their first health check.

[ Chittering ] HOOGLAND: Here we go.

You are a cute, little woofer.

NARRATOR: Like their parents, these 5 week old pups need markings.

HOOGLAND: It's okay, little tiger.

NARRATOR: The next job is to work out who the father is... HOOGLAND: Okay.

NARRATOR: ...by taking a DNA sample from the pup's ear.

And it's these DNA results that explain the main reason why prairie dogs can be so promiscuous.

HOOGLAND: If the female mates with Tom, Dick, and Harry, most commonly, each male will sire some babies, and there is multiple paternity, so she has more genetic diversity among her litter.

NARRATOR: A litter of pups with different genes means if disease hits or the environment changes, it's more likely that one or two pups will survive.

John's research has also shown that polyandry leads to bigger litters -- up to 6 pups rather than 2 or 3.

HOOGLAND: So it's a win, win, win.

She's more likely to conceive, she has a larger litter, her babies survive better, so why not?

NARRATOR: But if there are so many advantages to being polyandrous, why do some female prairie dogs remain faithful to their partners?

John's research has found the answer to this, too.

HOOGLAND: Females that are polyandrous are less likely to survive until the following year.

I mean, mating is costly.

I can assure you when a female is copulating, she can't run very fast, so if a predator comes, she's vulnerable.

It also increases the probability that she'll pick up a nasty disease or a parasite.

NARRATOR: If a female prairie dog like Risby chooses to be promiscuous, there are no benefits to her at all.

[ Chittering ] But her devious behavior does significantly benefit her pups.

And in the game of life, that really is what it's all about.

[ Wind blowing ] [ Birds chirping ] When it comes to mating, most females share the same top priority.

[ Elephant grunts ] To have fit, healthy babies.

[ Bird caws ] And to achieve that goal, one rebel is as ruthless as they come.

♪♪ Queensland's tropical rainforests -- [ Animals chittering ] ...home to some truly impressive predators... ♪♪ ...including one of the most notorious.

♪♪ Her unmistakable stance gives her a holy name.

But this praying mantis is no saint.

♪♪ Her lightning-fast reflexes can take down prey in a tenth of a second -- faster than a human blink.

She's fattening up for the breeding season.

Producing hundreds of eggs takes a lot of energy.

So to have healthy offspring, she needs 2 things -- food and a mate.

♪♪ This rebel has a trick that could bring her both.

♪♪ She pulsates her abdomen... ...releasing alluring pheromones.

♪♪ These chemical signals drift through the forest, announcing that she is ready to mate.

♪♪ Sensors on a male's antennae pick up her scent and home in on her location.

♪♪ A suitor has arrived.

♪♪ ♪♪ His walking speed doesn't match his reflexes.

And even mating takes a while... ♪♪ ...sometimes up to 40 hours... ♪♪ It all seems to be going well.

♪♪ But little does the male know that for him, mantis mating often ends... like this... with losing your head.

♪♪ The female of this species really is more deadly than the male.

♪♪ Her mate is more nutritious than her usual diet.

♪♪ In fact, eating him will improve her fertility by up to 40 percent.

So snacking on her suitor will provide the energy she needs to produce the best quality eggs.

[ Insects chirping ] Scientists have found that the hungrier the female mantis, the more pheromones she releases.

♪♪ This led them to discover the true rebel of the mantis world.

Introducing the female false garden mantis.

She's under-nourished, not yet fit enough to produce eggs.

Despite this, she releases her pheromones to lure in a male.

♪♪ But instead of mating with him... ...she just eats him.

This sexual deception helps starving females to fatten up so they're ready to mate with the next male that comes their way.

[ Birds chirping ] Femme fatale or just a great mom?

A female mantis' rogue behavior is all for a good cause, ensuring a healthy and strong next generation.

[ Animals chittering ] As the mantis shows, the drive to be a mother can have unfortunate consequences for those around her.

And one female is so intent on getting her way that innocent bystanders get caught in the crossfire.

Meet Mungos mungo.

[ Chittering ] Otherwise known as the banded mongoose.

♪♪ These catlike carnivores live in packs, big, extended families up to 30 strong.

For a female in this group, life seems good.

She has plenty of food, prime territory, and great neighbors.

♪♪ Her clan does everything together... which leads to one big problem.

[ Chittering ] Mongoose groups are so tight knit that a female has to breed with many of her male relatives.

♪♪ The result is a high proportion of inbred pups, born of closely related parents.

They're often smaller, weaker, and don't survive as long as genetically healthy ones, which jeopardizes the future of the troop.

[ Chittering ] The solution to this problem seems simple.

A female just needs to mate with a male from outside her group.

The trouble is when different mongoose gangs meet... this happens.

[ Chittering ] ♪♪ Banded Mongooses are so violent that some scientists categorize them alongside chimps and humans as one of the few mammals prepared to wage war.

Quality territory, with good food and shelter, is worth a fight.

Studies show that nearly a sixth of a troop can die from their injuries... pups included.

[ Animals chittering ] Our female's ideal mate is her sworn worst enemy.

To get access to him, she needs to use some pretty treacherous behavior.

[ Device beeping ] Over 20 years of scientific study have led to a fascinating discovery.

[ Chittering ] During the chaos of battle, scientists filmed females from one group sleeping with the enemy.

♪♪ It's easy to miss the crucial moment in the confusion, and that is the point.

Just watch this.

Romeo and Juliet here are using the battle action as a smokescreen.

While the rest of the tribe is busy, the star-crossed lovers slink off into the bushes unnoticed.

Now, as sneaky tactics go, that's impressive.

But there's a whole other level to this rebel's strategy.

Scientists believe that when a female is ready to mate... she may start a battle... [ Chittering ] ...to get to her Romeo.

♪♪ Members of her own family could die.

But these mobsters need to be reckless to have strong, healthy pups.

The key to success for a female mongoose, it seems, is to make love war.

♪♪ [ Birds chirping ] A female's path to success in the mating game can be a devious and deadly one.

But is the conduct of the males any better?

To succeed, a male must do just one thing -- beat the other players and win the prize.

♪♪ [ Moose lows ] Millions of years of sexual selection of the strongest, fittest traits has led to a world where size does matter.

♪♪ ♪♪ Fights are often bloody... ...and can cost losers more than just a mate.

[ Birds chirping ] [ Buzzing ] This male Dawson's burrowing bee is waiting for a mate.

♪♪ And he's impatient.

♪♪ Beneath this baked earth, thousands of females have been dormant for nearly a year.

But winter has arrived, and now they are stirring.

The male's wait is nearly over.

The problem is, he's not the only one here.

♪♪ Male burrowing bees feverishly patrol 10,000 entrances to this colony.

Early in the mating season, they outnumber an emerging female hundreds to one.

♪♪ ♪♪ The white face of an unsuspecting female.

She will mate once, then never again.

To get this precious prize, the males have to fight it out.

♪♪ A ball forms around her as they wrestle for the chance to mate.

♪♪ Males attack rivals with their powerful jaws and spiny legs.

♪♪ Broken wings spell death.

♪♪ The colony is littered with the bodies of battle-scarred bees.

And another is about to join them.

♪♪ ♪♪ In their frenzy, these males have accidentally killed the object of their desire.

[ Bees buzzing ] ♪♪ But for other combatants, victory is in sight.

One male has fought his way out with the female.

But he's not safe yet.

To mate, they must make it to the safety of the scrubland.

♪♪ ♪♪ His fight was worth it not just for him, but for the next generation, too.

The violence is a form of quality control.

Only the fittest, strongest males will get to pass on their genes.

♪♪ But males don't always resort to violence to eliminate their competition.

[ Birds chirping ] Good looks can work just as well.

[ Birds squawking ] Fans, feathers, and flamboyance.

♪♪ In the bird world, sexual selection in males has favored not just brawn, but beauty, too.

♪♪ ♪♪ The peacock.

He's got to be the most glamorous player in all of nature.

[ Peacocks crying ] ♪♪ [ Peacocks crying ] A magnificent 5 foot train signals that the male is healthy and strong.

This dazzling display is all for one thing... to impress her -- the peahen.

She's looking for the most iridescent and colorful eyespots.

[ Crying continues ] So the male shakes his tail feathers to show them off.

The problem is... the peahen has a bevy of other males to choose from.

[ Crying continues ] There are over 30 male peacocks here.

Playing by the rules isn't always enough to get you noticed.

It's an issue that this peacock, named Sam, can appreciate all too well.

♪♪ He's having a bad day.

♪♪ ♪♪ He's been strutting his stuff all morning, trying to impress anyone in sight... [ Peacock squawks ] ♪♪ ...with no success.

And his day is about to get worse.

One of his competitors is closing in on a peahen.

This rival lothario proclaims his victory with a distinctive hoot.

[ Peacock hoots ] It's the sound a peacock makes when he's successfully wooed a lady.

[ Peacock hoots ] Sam, on the other hand, seems rather deflated.

♪♪ And worse still, his opponent's trademark mating hoot appears to have drawn in other peahens that want to check out this stud.

♪♪ For Sam, it's time for some dirty tactics.

♪♪ [ Peacock hoots ] Another victorious mating hoot.

[ Peacock hoots ] And the lucky male is... ♪♪ ...Sam.

[ Peacock hoots ] Except he still doesn't have a mate.

He's faking it.

But the lure of a Casanova is apparently too much for this female to resist.

She seems to have fallen for his fraud.

[ Peacock cries ] Pretending to be popular is a clever con that can get a plucky peacock valuable extra attention and give him the edge when it comes to mating.

[ Animals chittering ] Cheating on your courtship competitors is one thing.

But what if your biggest rival is also your life-long friend?

♪♪ Somewhere down there, love is in the air.

[ Insects chirping ] This branch is the setting for a mating ritual that involves a devious double-cross.

[ Leaves rustling ] A male long-tailed manakin woos a female through the medium of dance.

And for that, he needs 2 things.

First, the perfect branch.

He's a stickler for detail.

His female audience needs a clear view of his stage.

Next he needs his trusty dance partner.

[ Manakins chirping ] This may just be nature's ultimate bromance.

[ Manakins warbling ] ♪♪ Their complex routines take practice.

♪♪ The performers are not related, but this is a long-term relationship.

[ Warbling continues ] A duo will dance together for up to 10 years.

[ Manakins whistle ] They're so close, they even finish each other's songs.

[ Manakin chirps ] [ Manakins whistle ] A female has answered their call.

But it's April, peak display season.

She may visit several dance sites to judge and choose the slickest routine.

So this pair really needs to impress.

[ Manakins warbling ] ♪♪ The key to her heart is to be in sync with their signature manakin dance moves, like the popcorn... ♪♪ ...and the cartwheel.

As the routine reaches its rousing climax, it's clear she's interested.

But there's an obvious issue.

The numbers don't add up.

Only one lucky male flies off to mate.

For the other, this is surely the ultimate double cross.

The faithful wingman is left in the wings.

[ Manakin chirps ] ♪♪ Why on earth would he go to all that effort if he doesn't get the chance to breed?

Well this partnership is not as equal as it looks.

The pair is in fact made up of an alpha and a beta bird.

Once the elaborate dance attracts an interested female, only the dominant alpha gets to mate.

But the beta has a strategy of his own.

He's playing the long game.

[ Warbling ] Long-tailed manakins can live for 18 years.

For nearly half his life, a beta will help the alpha get the girl, building the reputation of their dance site, drawing the same females in year after year.

When the alpha dies, the beta will inherit this dance floor and all its visiting females.

♪♪ With a bit of patience, it will eventually be the beta's turn to benefit from a dance partner of his own and steal the prize.

[ Manakin chirps ] ♪♪ [ Wind whistling ] So our males and our females, using every trick in the book, have managed to mate.

[ Penguin warbles ] The result is lots of babies.

♪♪ [ Penguin chick chirps ] ♪♪ [ Screeching ] [ Elephant grunts ] ♪♪ ♪♪ [ Elephant trumpets ] ♪♪ ♪♪ [ Chirping ] ♪♪ [ Cub hisses ] Now, all that's left is to raise them.

Kids are notorious for acting up, and the little darlings of the animal kingdom are no exception.

Being born in a challenging environment can have a big impact on just how horribly they behave.

[ Animals chattering ] On the plains of Africa, young animals must come to grips with their new world.

It's a tough place to grow up.

Competition is fierce.

To survive in the Serengeti, some rebels are shockingly ruthless.

♪♪ Spotted hyenas are often born as twins.

[ Hyena whimpers ] ♪♪ They're raised in clans that can number over 100 -- a lot of mouths to feed.

♪♪ Right now, the cubs are thriving.

But as the seasons change, the life of one of these twins could hang in the balance.

Finding enough food for them can be a battle.

In the rainy season, over one and a half million wildebeest roam this savannah.

Contrary to their reputation, spotted hyenas aren't just scavengers.

They're also skilled hunters.

But as the dry season sets in, the wildebeest all but vanish on their annual migration.

So there's trouble ahead, and the cubs are ready for it.

From birth, spotted hyena twins are at each other's throats... literally.

[ Hyenas grunting ] Play fighting like this has a serious undertone.

Scientists have captured it spilling over into outright aggression.

Dr. Marion East has spent 30 years studying the social interactions of these hyenas and their unsettling sibling rivalry.

DR. EAST: The minute the first animal is born, it is born with its eyes open and its teeth erupted, and it's waiting for its sibling to be born so they can start to fight to establish their hierarchy.

♪♪ NARRATOR: With incessant sparring during the first few weeks of life, one twin will establish its dominance.

And there's one very good reason to fight for that position -- food.

DR. EAST: The benefit that dominant cubs acquire from being aggressive is that they do, even when things aren't too bad, skew the amount of milk they consume in their favor.

NARRATOR: When times are good, there's enough food for both cubs.

But when milk is in short supply, things become dire for the subordinate twin.

DR. EAST: The outcome of aggression, if it carries on and is very extreme for a couple of months, it can be that the subordinate cub starts to basically wither away.

And in the end, it will starve to death.

NARRATOR: Footage captured by Marion's research team shows dominant cubs push their subordinates away from their mother's precious milk.

Actions like this mean that in nearly 10 percent of hyena litters here in the Serengeti, the subordinate will die of starvation.

This killing of a brother or sister is known as siblicide.

So what determines which twin wins?

♪♪ The answer might just play out on a soccer field.

In sports, winning produces a surge of hormones that gives a player added confidence.

This self-assurance could mean they're more likely to score again.

[ Cheers and applause ] It's called the Winner-Loser theory.

♪♪ And it could also affect the dynamic between hyena twins.

In those early days, when one twin wins a fight over its sibling, it remembers that.

They both learn where they stand in life.

For a mother, this ruthless behavior is a harsh reality, but it does have a silver lining.

DR. EAST: If there wasn't siblicide, she'd lose both cubs because she just simply doesn't have enough milk to feed both.

So it's better for one cub to survive than for two to die.

NARRATOR: The natural world is unforgiving.

When times get really hard, having one rebel cub survive means the whole family gets a future.

Hyena cubs are in good company when it comes to questionable conduct.

Newborn babies of these underground amphibians -- caecilians -- eat their mother's skin.

Black lace-weaver spiderlings eat their mother.

♪♪ So what is the secret to a happy family?

Well, in Europe, a species not so far from our own has come up with a very unusual answer.

And it lies, of course, in a pretty despicable deed.

♪♪ These, are the Barbary macaques of Gibraltar.

♪♪ [ Chittering ] ♪♪ Europe's only wild primates live in large social groups of up to 80 males and females.

As far as macaque species go, the matriarchal Barbaries are relatively peaceful.

In this big, happy family, social tactics are often more effective than aggression.

Several hours of grooming a day keeps stress levels down.

♪♪ This is the perfect environment to bring up babies.

♪♪ ♪♪ But there's trouble in paradise.

[ Sea gulls crying ] Meet Vincent.

He's on the lookout for a precious commodity.

And he's got one thing in mind.

♪♪ ♪♪ ♪♪ Kidnapping!

[ Macaques squeaking ] Vincent has stolen a helpless baby.

Mom is left empty handed.

But why has he done this?

♪♪ Dr. Eric Shaw has been observing these macaques for over 18 years.

He's caught countless males in the act of baby stealing.

[ Macaque squeals ] DR. SHAW: It may look to most people somewhat aggressive when it's taken from the mother, but it's what transpired beforehand that's brought about what looks aggressive to the human observer.

NARRATOR: To understand what's going on, we need to backtrack to before the kidnapping.

♪♪ Though Barbaries are mostly harmonious, like human families, they sometimes erupt in conflict.

[ Macaques squealing ] ♪♪ DR. SHAW: Basically what happens is the males have arguments a little bit like we have arguments with one another.

But they can't be enemies forever.

And what they do once they've fallen out is they realize there has to be reconciliation.

They all live in the same group.

There has to be peace.

NARRATOR: They make peace in the most remarkable way -- by stealing a baby.

DR. SHAW: The loser, so to speak, will go and borrow a baby off one of the females.

NARRATOR: In our case, the loser is Vincent -- a relative nobody in the troop's pecking order.

DR. SHAW: He will take that baby and go back to his protagonist, the one that he lost against, and present it.

NARRATOR: Our winner is Aristotle on the left -- the alpha male, the boss.

Vincent needs him on his side.

Keeping good with the alpha could improve Vincent's position in the troop, and a higher rank means better access to food and females.

But what do these two males do with the baby?

DR. SHAW: You've got a little, tiny baby that gets turned upside down, his bottom gets smelled by both of them, they have a close look.

♪♪ They'll both lip smack and chatter over the baby.

NARRATOR: This is the macaque equivalent of a smile.

DR. SHAW: Showing my teeth -- harmless, nice, wide-open, friendly, 'I love you, really.'

NARRATOR: So peace reigns once more.

Aristotle has accepted Vincent's olive branch, and they are friends again.

Which is all very well for them.

But the olive branch is hungry and seems a bit distressed by his new babysitters.

DR. SHAW: It's not quite sure what's happening, but it's shouting to mummy all the time.

The mothers don't react badly because the baby's not taken.

The mother's lent it.

She knows exactly what's happening.

But they keep that watching eye.

♪♪ NARRATOR: Now that the baby has served Vincent's purpose, he doesn't seem so smitten.

It might be time to give it back to its mother.

The beauty of this bizarre apology is that Vincent isn't the only one to benefit.

The whole troop does.

Baby borrowing resolves conflict.

It reduces tension in the group.

♪♪ Instead of being a high crime, this remarkable behavior actually helps foster a happy clan.

♪♪ [ Sea gulls crying ] ♪♪ Getting ahead in the mating game often requires cheating... playing the field... cannibalism... or plain, brute force.

But being a rebel serves an important purpose.

The challenges these animals face are immense.

Thinking on your feet and outside the box can be just what it takes for an animal to succeed.

[ Chittering ] ♪♪ ♪♪ ♪♪ ♪♪

© 2021 WNET. ALL RIGHTS RESERVED.

PBS is a 501(c)(3) not-for-profit organization.