Original subtitles

You and I belong to an extraordinary family.

A family of hundreds of bizarre

colourful

and characterful animals...

I don't think I've seen anything quite like this in my whole life.

...who lead fascinating and dramatic lives

all over the world.

We, that is monkeys

lemurs

and apes

are all primates.

And I want to introduce you to this amazing animal family

to meet some relatives you never even knew you had.

The jungles of Borneo are home to some of the most unusual primates on the planet.

Strange monkeys.

Poisonous lorises.

And our closest cousins, the great apes.

Orangutans normally spend their lives high in the treetops.

But there is one community that's unlike any other group of wild apes on Earth.

They've begun to behave in a way that's almost human.

This has got to be about one of the most bizarre things I've ever experienced.

These aren't captive animals trained to do tricks.

They're free living orangutans

who've adopted an unusual way of life.

And of all the orangutans here, Siswi is the most unusual.

Thanks, Siswi.

This has got to be the cleanest orangutan in the whole of Borneo!

Siswi and I are 2 of roughly 400 species of primate in the world

and although we all look very different

we share certain features that make us part of one of the most extraordinary families on Earth.

It's one of these shared features, our intelligence, that helps explain this curious behaviour.

Here, orangutans and humans share the same forest.

They've watched us

and begun to experiment with what they've seen.

This may look a bit bizarre but it actually shows how smart she is.

She's seen humans here every morning, washing, and she's basically doing exactly the same.

We also share a similar face.

Our eyes face forwards.

This gives us the ability to judge distances perfectly.

And there's one more similarity.

Critically we have this amazing hand with a thumb that can fold over

and that is probably the most defining characteristic of any primate.

Intelligence, binocular vision and a dexterous hand

allow these orangutans to behave so much like us.

They are the three things we all have in common.

But that certainly doesn't mean all primates look similar.

The tarsier is 400 times smaller than an orangutan.

It also has forward facing eyes, a dextrous hand, and intelligence

but it uses them in a completely different way.

This tennis ball sized gremlin is a spring loaded ambush predator.

Long back legs can propel it up to 40 times its body length.

Its huge eyes are bigger than its stomach, and gather every scrap of light.

They're too large to move in their sockets

but the tarsier can swivel its head through almost 360 degrees.

And when it can't see its prey, it uses ultrasonic hearing.

Those satellite dish ears pinpoint rustles that we humans cannot hear.

Evolution has moulded the tarsier into a ruthlessly efficient hunter.

The most carnivorous of all primates.

We humans have got some pretty bizarre cousins

but primates don't just live in jungles like the tarsier or the orangutan.

In fact we've got relatives right across the planet

and some of them have managed to scrape a living in the most unexpected of places.

Away from the tropics, life is very different indeed.

Japanese macaques live further north than any other monkey.

Right on the edge of what is possible.

Here, temperatures can hit minus 20 degrees celsius.

The secret to surviving when the temperature's this low is to have lots of layers.

Layers are really important because they trap warm air next to your skin.

With a thermal camera I can show you just how much heat you lose without those protective layers.

The first thing to go are my feet, they're feeling very, very cold now.

Only 5 minutes later, my core temperature is dangerously low.

Eventually I would enter a coma from which I would never wake up.

To live in a sub-zero world you have to be built for it.

These snow monkeys have two distinct layers of fur that trap warm air next to their skin

while their short tails and stumpy ears reduce the chance of frostbite.

Food is extremely hard to come by

and the monkeys lose almost a quarter of their body weight throughout the winter.

Snow monkeys might be built for the cold but as the temperatures plummet after dark

they have to find other ways to keep warm, and they do this in a rather remarkable way.

For a small monkey, thick fur isn't enough to stay warm in these sub-zero conditions.

For the first time ever we have a privileged insight into how these incredible monkeys stay alive.

As they climb the trees, one monkey is joined by another

then another

and another.

A single monkey would freeze to death out here

but by huddling, the macaques form a giant super-monkey

one so big that it creates a microclimate of its own.

As a baby settles down for the night

the intense glow of heat shows just how toasty it must be at the heart of the huddle.

Throughout the night the monkeys take it in turns in the hotspot.

Dawn, and the snow monkeys are snuggled up tighter than ever.

We've all been there, wrapped up in a warm duvet on a cold chilly morning.

And thanks to that huddle, these resourceful monkeys have beaten the elements.

Well, it was pretty cold last night

and if I or indeed most other primates had been out here on their own

we would have perished hours ago.

In the extremes of the primate world

it's teamwork like this that makes the difference between life and death.

The spiny forest of Madagascar is at the other extreme

one of the hottest and driest forests on earth.

The temperatures here can exceed 40 degrees, and it doesn't rain for months on end.

The few plants that grow here are protected by rapier-like thorns.

But sifakas spend their lives in this forest of spines.

These adrenaline junkies risk life and limb every day.

Their binocular vision allows them to pick landing spots with unerring accuracy.

And long back legs can catapult them 9 metres in a single leap.

Though how they avoid getting cut to pieces is still a mystery.

The prize for these hardy lemurs is lots of succulent leaves, full of precious water.

Quenching their thirst in the blistering heat.

Heat is just one problem for the most southerly monkey in the world.

Chacma baboons live in the raw exposed south African cape.

Here, there's virtually no protection from the elements.

Battered by winds, they scratch a living under the intense glare of the midday sun.

These baboons have a hard life.

By midday it's blisteringly hot and they have to spend hours roaming to find enough food

but their real problem is finding somewhere safe to sleep.

At night, leopards roam these plains

and with very few trees to hide in, the troop are exposed to the biggest danger of all

being eaten.

To avoid this, their choice of dormitory is one of the most bizarre in the primate world.

Here it is, look.

This small hole is the entrance to a cave.

It's incredibly rare for any primate to use a cave

so while the baboons are out hunting for food

I'm gonna get some kit on and go down and see what their sleeping accommodation is all about.

This is a high security location.

There are bees at the entrance and an 8-metre vertical drop.

Well, everywhere you look there's evidence of habitual use of this cave by baboons.

There's bones everywhere, remains, there's dung

some of it not so old I can tell you, some pretty fresh stuff.

I'm now a hundred metres underground

and it hasn't been easy for me but for the baboons it must be 10 times harder

because they have to do it in complete darkness.

As night falls, the baboons are clearly on edge.

With the threat of an attack a very real possibility, the cave is an inviting prospect.

An old rope left by bat researchers makes their descent easier.

In the pitch black, the baboons can't see a thing

but our cameras reveal how they cope in this secret world.

The first thing they do is call to each other to work out where everyone is.

Effectively blindfolded, they feel their way through the inky blackness.

Amazingly, like you and I know our way around our house at night

the adults appear to have a mental map of the entire hundred-metre cave system.

But when you can't see who's around you, it's easy to get spooked.

Spending your night underground might seem like an odd thing to do

but early man did exactly the same.

Putting the kids to bed is never easy.

And a cave like this provides plenty of space for some private time.

And eventually a safe and peaceful night's sleep.

Apart from the obvious security benefits

getting the right sort of sleep could have other advantages.

REM sleep, the state where you dream, allows a complex brain to repair and revitalise

and it's that much easier when you're safe underground.

It's thought that sleeping in a cave could sharpen the mind.

Which for the baboons would make life on the edge of Africa that much easier to deal with.

Over the last 55 million years, primates have branched out across the globe

but the family's roots are deep within the jungle.

It is really amazing up here.

I mean, if you think about it, it makes sense making your home up in the trees.

For one thing, all your enemies, things that would eat you, are on the forest floor, generally

30 metres below you

and there's just all kinds of things to eat up here, lots of food and fruit.

Tropical forests are home to the greatest diversity of primates on earth.

In fact over 90% of all primates live in forests.

But it's definitely not as easy up here as it looks.

I mean, this is very difficult.

For an animal my size, who shouldn't really be up trees, this is actually very alarming.

We humans may have lost our head for heights

but other primates have made the most of life in a vertical world.

There are some incredible ways to move through the forest

but the true gymnasts of the canopy have got to be the gibbons.

Their highly specialised arms allow them to fly through the treetops at breakneck speed.

But in Thailand, not all gibbons have had the chance to do that.

Six month old Sherpa has never set foot outside a cage.

But today, he and his family are being released into the wild.

They're pioneers, returning to a forest where gibbons were hunted to extinction 30 years ago.

And on a day like this, the big wide world is tantalisingly close.

Sherpa's dad is the first out, and his mum follows.

But for Sherpa it's a bit more daunting.

A little bit of reassurance, and it's time to make a huge leap of faith.

A quick hug, and after a lifetime in captivity, our young explorer is free.

Unlike a wild gibbon, Sherpa has no experience, and a bit too much enthusiasm.

These thorny branches are rattan.

Sherpa is learning a painful, but very valuable, lesson.

When you're a young gibbon, practice makes perfect.

By watching his parents, he'll soon pick up all the skills he needs.

In terms of sheer acrobatics, there's nothing to touch a wild gibbon.

That powerful brain makes hundreds of life-saving decisions in the blink of an eye.

And a ball and socket joint in their wrists gives them flexibility to slingshot through the canopy.

The huge range of environments that primates live in have shaped how they look and behave.

But their diversity is also driven by what they eat.

The Simian mountains of Ethiopia are home to one of the world's most vegetarian primates.

Geladas.

After a cold night in the mountains, dawn is a welcome relief.

I love this row here, at the edge of the cliff, who are just warming up in the sun

they're really putting their heads back and exposing their chests.

Once they've warmed up, geladas need a hearty breakfast.

But as far as the eye can see, there's only one thing to eat for every single meal.

Grass.

Grass is extremely low in calories, so these hardy mountaineers have to eat huge amounts.

Your average monkey feeds for about 4 hours a day

whereas your average gelada has to feed for up to 10 hours a day.

If I was to suddenly adopt the grass-only gelada diet

I'd have to chew down 17 kilograms of grass every day.

Geladas are built to make the most of their vegetarian diet.

Of all the primates, geladas have one of the most useful thumbs

and they use it in a pincer-like movement to pick only the most nutritious shoots and seeds.

Abrasive teeth grind up the coarse leaves just like a cow.

And built-in cushions make the long hours sitting a bit more bearable.

Geladas need to eat all day long simply to survive.

But for the smallest monkey in the world

it's less about the quantity of food, and more about its quality.

Pygmy marmosets weigh no more than an apple.

Here in Ecuador, catching dinner can be hard work

but luckily marmosets have a reliable back up.

And to make the most of it, they have a unique set of tools.

Claws rather than fingernails give them extra grip.

And their chisel-like teeth cut neat holes in the tough tree bark.

But it's not the bark they're after.

It's the sugar rich sap underneath.

Packed with energy and essential minerals, sap makes up 75% of their diet.

What's really incredible is the scale of their ambition.

A tree like this may have several hundred holes.

Food production on an industrial scale.

Marmosets harvest their crop wisely, they never take too much

and only allow the holes to close up when the yield drops.

10,000 years ago, farming was the basis of our civilization.

But deep in the Amazon

these industrious little monkeys were already enjoying a civilized way of life.

The more specialised your diet, the stranger you can look.

And in a leafy corner of the United States

science is unravelling the feeding habits of the strangest primate of all.

Well, it's a little after sunrise, but behind this door it's about sunset

and the animal in here is just waking up.

Look at this!

This is about the strangest animal I've ever seen.

If you didn't know what it was and had to describe it

you'd say it had the ears of a bat, the teeth of a rodent, the hands of an alien.

It's got a bushy squirrel-like tail and yet it's in the same group of animals as you and I.

It's almost hard to believe.

This almost mythical creature is from Madagascar.

She's an aye-aye called Ardrey.

That is so cute.

I hate to use the word cute, but they are cute.

I think I'm in love with this animal.

Aye-ayes spend the night hunting for grubs that live deep inside decaying branches.

To work out where the grubs are hidden, they use that strange-looking hand

tapping the wood at up to 10 times a second.

There she goes, she's tapping now.

I can hear it.

That's the most specialised primate hand in the whole world.

Like sonar, the sound penetrates the depths of the branch

and a coded message is echoed back to those super sensitive ears.

When she finds a hollow spot, she starts to dig.

These incredibly sharp front teeth, the incisors

which unusually for primates continue to grow

and they rip the wood apart to get access to the cavity

which might contain an insect larva.

The hearing is very acute so they can hear the larva inside.

But it's her probe-like middle finger that has to find the grub.

And the latest science is now revealing just how incredible this unique digit is.

This camera is so sensitive, it picks up on tiny changes in temperature

like the breath on my moustache.

And it highlights something rather unexpected.

Unlike her other fingers, Ardrey's feeding finger is stone cold.

It has virtually no blood flow to it at all.

But as she starts foraging, blood rushes to thousands of nerve endings in her fingertip

making it incredibly sensitive.

And in a specially constructed log, we can get a look at that ET-like finger at work.

A unique knuckle, much like our shoulder joint, means her finger can move in any direction.

And it's now so sensitive that like a blind person reads Braille

she can detect the slightest movement.

That is one of the most remarkable tools in the whole animal kingdom

and it allows the aye-aye to carve out a niche so specific

that in terms of finding food, it's in a league of its own.

The aye-aye is the ultimate specialist.

But when it comes to finding food, the world is full of possibilities.

You just need to spot an opportunity

and make the most of it.

Primate ingenuity means there are no bounds to their gastronomic ambition.

For Olive baboons

the savannahs around Lake Bogoria in Kenya are a land of plenty.

Insect grubs hidden in flamingo dung provide a welcome protein boost.

Some, however, are far more ambitious.

Timing is everything.

Once one baboon has worked it out, the whole troop soon catches on.

Hunting live prey requires ambition, speed and coordination.

For a hungry primate, meat is the ultimate food of all.

Primate diversity is shaped by home and diet.

And I think, by one more thing.

They're social animals, they live in families

and as we all know, good communication skills are essential for a harmonious family life.

And this need to communicate has also influenced how they look and behave.

It's hard to believe that these chilled out monkeys are the loudest on the planet.

But there is one way to spur them into action.

Right, the whole monkey troop is right here in this tree.

There's females, there's young ones

but the one I want you to watch is the alpha male right here.

Watch what happens.

That is very impressive, that monkey can produce 90 decibels

which is enough to, well, drown me out.

The howler monkey's roar is a call to arms.

A reply to my rather poor impersonation of a rival.

The male's calls soon sets off the entire troop.

The clever thing is that by calling together

they make their group seem much bigger than it actually is

and the bigger the call, the louder the noise, the more terrifying it is.

The secret to the sheer volume of a howler's roar is in the design of its unusual throat.

When a howler monkey calls, it flares out its lips like a natural loudhailer and it drops its jaw.

The throat contains an enormous hollow bone that reverberates like a gong

giving the voice an amazing amount of extra clout.

All this noise sends a message to neighbouring troops: keep off our patch or there'll be trouble.

The pitch of their voice is as important as the volume.

Higher frequencies are easily scattered, but low roars punch through the forest for up to a mile.

It's this mosaic of sound that sets clear-cut home ranges across the entire forest.

Shouting at your neighbours may seem like a waste of energy

but by howling every day, families can avoid coming into contact with each other

and when they do, disagreements are easily settled at arm's length

and that is a great way to keep the peace.

While a howler monkey's world is shaped by sound

other primates communicate in a much more visual way.

Mandrills live in the dark and impenetrable forests of Gabon in west Africa.

And here, vision plays a key role in finding a mate.

It's thought that female mandrills spend most of the year in large all-girl groups.

But in the breeding season, their peace is shattered.

Male mandrills are a very different animal.

These huge beasts dwarf the females, three times their size.

They're the largest monkeys on the planet, and the most colourful.

Those vibrant hues are a display of strength and power.

The big brutes pitch up to fight for the girls.

When 2 males catch each other's eye, it's a stand-off.

An actual fight is a high risk strategy; it could mean injury or death.

Every single muscle twitch has a meaning.

It's all over.

A grimace is a sign of submission.

The battle has been avoided.

And the loser lives to fight another day.

The victor is one step closer to becoming king.

And after a bout like this, a surge in testosterone will make a male's colours even more vivid.

After weeks of posturing, the healthiest male becomes the most colourful.

And the object of all the females' desire.

The single most colourful male will mate with over three quarters of the group.

He'll have their undivided attention for at least a couple of months.

Proof if ever you need it that in the mandrill mating game, looks really matter.

The challenges of where we live

what we eat

and how we live together

have shaped our incredible animal family.

But the world is changing.

In the 21st century the ultimate challenge to any monkey

is living alongside the most successful primate of all, humans.

But even the urban jungle is a land of opportunity

for those who are smart enough to exploit it.

For the resident rhesus macaques, a market-side pitch like this is what life's all about.

They may not be the prettiest, or look the most remarkable

but macaques are the most successful monkeys on the planet.

They're adaptable, devious and they work together as a team.

In their search for food, hungry macaques have swapped jungle vines for power lines.

Gangs leave a trail of destruction in their wake.

They're smart enough to spot the tiniest of opportunities.

First up, the brave ones scope out the joint.

Lookouts are posted to watch for trouble

and once the coast is clear, it's a free-for-all.

These opportunistic criminals ransack a house in a matter of minutes.

And at the slightest hint of trouble, they make their escape.

Thanks to their agile bodies and adaptable minds

macaques can beat us humans at our own game.

To these incredible monkeys, the urban jungle is just one big playground.

We primates are truly remarkable.

Not only are we physically adaptable, we're also smart and can work as a team

and that's a winning combination that allows us to survive, even thrive, in an ever-changing world.

Join me next time when we delve into the sociable world of the primate family.

And it's not as harmonious as you might think.

You need to make friends

avoid your enemies...

Look at that!

...and find your place on the social ladder.