Islands of Wonder

Narrator: In the heart of South East Asia lies the tropical island of Borneo... ...the third-largest island on Earth.

This is a lost world, home to the beautiful and the bizarre... ...where lizards fly... ...plants have become carnivores... ...and people hunt underwater.

It may seem like paradise... ...but from it's sun-drenched shores... through ancient jungles... to its mountainous heart... ...it's a struggle just to survive... but this struggle has led to extraordinary adaptations... and given rise to possibly the greatest diversity of life found on any island.

Isolated in vast tropical seas... ...they are home to remarkable animal castaways... and extraordinary human cultures.

These islands of wonder harbor precious life found nowhere else on planet Earth.

Narrator: Off the coast of Asia, 330 miles east of Singapore and a thousand miles north of Australia lies the island of Borneo.

Its shores are fringed by a tangle of mangroves and flooded forests... criss-crossed by a network of rivers.

[ Birds calling ] This waterlogged world is the last stronghold for a primate found no where else on Earth... The proboscis monkey... This male's enlarged nose serves one key purpose... to attract a mate.

And his super-sized snout has secured him a harem of adoring females... ...and their offspring.

It will take this baby 7 long years to grow a nose to rival his father's.

But for these monkeys, their pot-bellies are the key to their survival.

There is precious little nutrition to be found in the bitter leaves of these flooded forests.

Proboscis have evolved an enlarged gut to extract any goodness there is.

Still, only the youngest leaves have enough nutrition to be worth eating.

So the male must lead his troop up to a mile a day in search of fresh growth.

But their route is often blocked... by one of the many rivers that cut through the forest... ...patrolled by giant predators... ...like the saltwater crocodile, which grows to more than 16 feet long and can weigh up to a ton.

To reach the young, juicy leaves on the other side, the group will have to cross.

But the male is hesitant.

Instead, it's the alpha female who takes the lead.

[ Splash ] [ Splash ] The rest of the troop quickly follow.

[ Screeching ] [ Splashing ] Sounds of their splashes carry 700 feet through the water and can draw unwanted attention.

But unlike most other monkeys, proboscis are excellent swimmers.

To survive here, they have evolved webbed feet.

Finally, the reluctant male makes his move.

But a mother and baby have been left behind.

The baby must hang on for dear life.

[ Monkeys screeching ] This time the whole family has made it... ...even the most vulnerable.

At last they can feed on the succulent fresh leaves.

The challenge of living in this beautiful but difficult environment forces these monkeys to risk their lives in search of food, changing their behavior and their bodies.

It is this way all across Borneo, where over 6,000 unique species have adapted to face these challenges over thousands of years... evolving from ancestors that were isolated here long ago.

Borneo was once joined to Thailand and mainland Malaysia... Part of a vast landmass, home to one of the oldest forests on Earth.

But when the last ice age ended 10,000 years ago, sea levels rose, leaving Borneo and its ancient forests stranded.

The surrounding shallows are now home to some of the richest coral reefs in the world.

A single reef can support more species of coral than the entire Caribbean Sea.

For the people that live on Borneo's coast, accessing these submerged riches has led to an extraordinary adaptation.

The Bajau Laut -- People of the Sea.

Over generations of diving, their bodies have transformed.

Their spleens are 50% larger than average.

It's believed this provides their blood with more oxygen for diving.

They can hold their breath for over 3 minutes and spend 60% of their day hunting underwater, longer than almost any other human being.

The Bajau Laut settled on Borneo's coasts around a thousand years ago.

Villages like Tatagan may only be 20 miles from the nearest town... but the 200 or so people who live here still rely on the sea for nearly all their needs.

Rajamil Wali and his son Fidel are traditional fishermen.

But they're having to adapt to the modern world.

[ Rajamil speaking native language ] Narrator: Plastic is the scourge of today's oceans, but for Rajamil and Fidel, it provides an opportunity.

Rajamil is teaching his son how to turn this plastic into something useful.

[ Rajamil speaking native language ] Narrator: The lure will have to be convincing to trick the reef's most intelligent resident... ...the reef octopus.

With his new fishing technique, Rajamil can catch enough octopus to support his whole family.

[ Rajamil speaking native language ] Narrator: Adapting to change, the Bajau continue to live off one of richest coral reefs in our seas.

But as you head inland, conditions get tougher, pushing life to extremes.

[ Birds calling ] Just 10 miles from the coast lies a steamy jungle world, one of the last surviving fragments of an ancient lowland rainforest.

Covering an area larger than California, less than a square mile can hold thousands of species of trees.

But one group of giants dominate... the Dipterocarps.

Towering up to 330 feet high, they are the tallest rainforest trees in the world.

Their branches form a unique canopy world... ...that is home to the world's largest tree-dwelling animal... ...the Bornean orangutan.

[ Creatures calling ] In orangutans, the bond between mother and baby is very strong, and this youngster will stay with his mother for up to 8 years.

[ Baby orangutan squeaking ] He has a lot to learn.

Many of the forest leaves here are poisonous... but his mother can identify around 500 species that are safe to eat.

Remarkably, though, we now know their knowledge goes much further.

Twentinolosa is part of a group that has been studying the orangs here for over 20 years... ...one of the longest-running studies of its kind anywhere in the world.

[ Twentinolosa speaking native language ] Narrator: One particular orangutan has led researchers to a breakthrough discovery.

[ Twentinolosa speaking native language ] Narrator: Years of carrying a heavy baby have taken their toll.

It appears Indah is suffering from aching joints.

The medicinal paste she creates contains powerful anti-inflammatories thought to ease her pain.

Indah's vast knowledge of these ancient forests includes a treatment for arthritis.

This is the first time an animal has been found to medicate with anti-inflammatories.

Imagine what else is left to be discovered in this rich canopy?

[ Birds calling ] 90% of Borneo's jungle life is found up here.

A single tree can hold 1,000 different species.

This leads to intense competition for food and space.

To survive in these crowded canopies... life has evolved in wondrous ways.

Borneo has over twenty species of gliding reptile... ...more than any other island on Earth.

[ Bird calling ] At night, a whole new cast emerges... ...including one creature that has the key to a food source unavailable to most... ...the exquisitely decorated lantern bug.

It feeds directly from the giant trees, using a specialized proboscis, like a drinking straw, to suck out the sugary sap.

Any excess is expertly fired away with a spring-loaded spatula in its abdomen.

But nothing on Borneo is wasted.

One shrewd species of gecko has learned its way to a free meal... All it has to do is wait... ...its nose carefully positioned in the firing line.

The astonishing lives of the animals here are shaped by the competition for food, but the contest to find a mate is just as strong.

In these forests, the night air is dominated by the sound of 180 species of frog... [ Frogs chirping, honking ] ...singing for a mate.

[ Frogs chirping, honking ] The bigger the frog, the louder the call.

But this male tree-hole frog is barely bigger than a fingernail.

He'll need to do something special if he wants to be heard by any nearby females.

She may only be yards away... ...but the chorus from the other frogs is deafening.

This tiny male, however, has a trick.

He searches for a tree hole.

The size and shape of the hole are critical.

He then does something remarkable.

[ Frog chirps ] It begins with a sound check.

[ Frog chirps ] Too low.

[ Frog chirps ] He changes pitch.

[ Frog squeaks ] Too high.

[ Frog chirps ] [ Frog chirps strongly ] That's it!

At this specific frequency, the tree hole resonates, amplifying the sound and broadcasting the call more than 160 feet across the forest.

For a female, it's music to her ears.

[ Frog chirps ] With superb directional hearing, she can home in on his calls.

Finally the tiny couple meet.

Hidden from predators, the tree hole will go on to make an ideal nursery for their tadpoles.

Compared to the abundance of life in the treetops... ...on the forest floor, it's an impoverished world.

In these lowland forests, 30 miles or so from the coast, the giant tree roots suck up most of the nutrients... leaving the soil depleted.

Since Borneo was cut off 10,000 years ago, it's thought that many of the large mammals died off.

With little to eat down here, many that did persist have shrunk.

Confined to her protected forest sanctuary... ...the exceedingly rare Bornean sun bear.

Weighing just 130 pounds, it's the smallest bear in the world.

This fallen branch is a prized treat.

Filled with wood grubs and beetles.

Nothing is wasted... even a noxious millipede.

But it's not enough to sustain even this little bear.

The real prize sits high above.

Guided by her exceptional sense of smell... ...the sweet scent of honey.

[ Bees buzzing ] For larger bears, this beehive may be out of reach.

But being small helps defy gravity.

With sharp claws and rough pads on her feet, she can ascend 130 feet, higher than any other bear.

[ Bees buzzing ] To make it in Borneo's jungle treetops, this miniature acrobat has become more monkey than bear.

For those confined to the depleted forest floor, survival requires innovative solutions.

Deep into the jungle, mysterious signs line the forest paths, left by indigenous hunters that have inhabited this island's jungle for over 4,000 years.

Etat Nyato and Geran Jengan are Penan, native Borneans, and still reliant on their intimate knowledge of the forest to find food.

[ Speaking native language ] Narrator: The cut bark oozes a deadly poison.

Once concentrated, it's so potent it can stop a human heart in seconds.

The thickened mixture makes for lethal poison darts.

[ Speaking native language ] Narrator: Geran and Etat can now target prey hiding high up in the forest canopy.

[ Speaking native language ] Narrator: A common fairy bluebird.

It's a meager kill, not enough to feed themselves, let alone their families.

But the Penan have an ingenious way of reaching out to others.

Along the path, they plant sticks on which they leave messages.

A single feather signifies they have caught a small bird.

And a folded, empty leaf shows that they are hungry and in need of food.

It's an ancient sign language known as "Oroo."

[ Speaking native language ] Narrator: With more than 50 different symbols, the Penan can communicate across 100 square miles of lowland forest.

Geran and Etat have found a welcome note left by fellow hunters.

[ Sizzling ] [ Speaking native language ] Narrator: With their unique sign language and communal bonds, the Penan have overcome the challenge of finding enough food on Borneo's forest floor.

With every step inland, Borneo changes.

Fifty miles from the coast, the elevation begins to rise, and the lowland jungle gives way to enormous caves... and Deer cave is one of the largest subterranean chambers in the world.

Almost 700 feet wide in places, it's big enough to fly a jumbo jet through.

And it holds a secret as to why these lowland forests are so poor in nutrients.

[ Bats screeching ] As the sun sets, a great exodus begins.

Emerging from caves across the island, millions of bats spread out over the forest.

Bat hawks have been waiting for just this moment.

They gorge themselves on this easy meal.

But it will have little effect on the bats' numbers.

Bats are the most numerous mammal on the island... and their impact is immense.

The bats from Deer Cave alone are thought to catch up to 33 tons of forest insect every night.

At dawn they return to the caves to roost... where their excrement falls like rain... ...building, over centuries, mountains of guano more than 50-feet high.

Feeding on it is one of the largest concentrations of cockroaches in the world.

As well as a wealth of other creatures... ...foot-long centipedes... giant cave spiders... ...even a cave crab.

This horde is Borneo's lost treasure.

Almost half of the jungle's precious nutrients end up hidden inside these caves... stripped from the impoverished forests outside by the bats.

A hundred miles in, running through the center of the island, is the toughest world of all, one that has driven even greater diversity.

Mountains that are home to even more extraordinary creatures found nowhere else on earth.

Their range runs over 500 miles through the center of the island.

At over 13,000 feet, Mount Kinabalu is one of the highest peaks in South East Asia.

Moist air from below cools and condenses into a thick veil of cloud.

Here it rains almost every day... ...the water washing away any goodness in the soil.

Sheltering in ravines lie dwarf forests... the trees stunted from the lack of nutrients.

These extreme conditions have pushed one group of plants to extraordinary lengths to survive.

Pitcher plants.

They have become carnivores.

With the promise of nectar, the plant lures in its victims... ...onto its slippery edge.

Below lies a pool of deadly digestive enzymes... from which there is no escape.

The captives' bodies slowly dissolve in the pitcher's stomach-like vessel... providing the plant with the nutrients so lacking in the soil.

[ Insects buzzing ] Borneo holds over forty species of pitcher plant, the greatest collection in the world, including the Hemsleyana pitcher.

It's after something much bigger than insects... [ Bat chirping ] ...a woolly bat.

Rather than using nectar as bait... the pitcher's flat lid is perfectly shaped to reflect the bat's sonar.

...drawing it in.

But the woolly bat is safe.

After a night's hunting, this bat needs a place to shelter.

Rather than fall into its lethal pool, the bat fits snuggly into the pitcher's tapered cup.

In the heat of the day, the pitcher's waxy walls even keep its guest cool.

How the plant benefits only becomes apparent at dusk.

The nocturnal guest awakens... ...leaving behind its payment.

Once again, it's nutrient-rich bat droppings, and this plant has ensured its very own supply... delivered daily.

Living in its impoverished home, this extraordinary plant, like all life on Borneo, has been shaped by its struggle to survive.

[ Chain saws buzzing ] But with the arrival of industrial logging and farming in the last 50 years, all this has changed.

Today, over half its ancient rainforests have been cleared.

Felled for timber, much of the land has been turned into vast plantations for crops such as palm oil.

With the destruction of the forests, researchers like Twentinolosa are increasingly concerned about the future of Borneo's most iconic resident... ...the orangutan.

[ Twentinolosa speaking native language ] Despite the challenges of this island, orangutans, like so much life on Borneo, have survived in these forests for thousands of years.

But they may not withstand the impact of the modern world.

From its bustling coral reefs... ...ancient forests... ...and remote mountain peaks... ...Borneo may appear a paradise.

But to survive here, life has had to adapt in extreme ways... leading to almost unparalleled diversity... ...and making Borneo a unique, but fragile, Island of Wonder.

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