Original subtitles

In the heart of Africa, a giant moves through the mist.

These are not the great icons of the savannah,

but elusive creatures few have ever seen.

For millions of years, they have hidden away

in the second largest rainforest on the planet.

Everything about African forest elephants.

Their bodies.

Their families.

How they live.

Is shaped by their rainforest home.

The Congo Basin.

An impenetrable wilderness.

Larger than Alaska, it stretches across six Central African countries.

Criss-crossed by tens of thousands of miles of waterways.

It is home to one of the least understood animals on Earth.

It's always been my dream to see African forest elephants.

Dr. Paula Kahungu has come to Odalakokwa National Park with one aim.

To track down the elusive African forest elephant.

She's a renowned expert on the savannah elephant.

Having spent 30 years immersed in their world.

I know a lot about their behavior, their social lives, their communication.

But forest elephants are a completely different species.

They separated from savannah elephants at least three and a half million years ago.

I wonder how different they are.

How living here has shaped them and their behavior.

But first, I've got to find them.

The vegetation is so dark, it's just a wall of green.

Where are they?

I imagine that these elephants have already seen me.

They're probably peering back at me from in there.

Oh my God.

My first forest elephant.

They don't seem to know that I'm here.

So I'm keeping my distance.

Seeing them in the flesh is so clear to me they are a different species.

These ellies are the same color as savannah elephants.

But they're much smaller.

And their ears are round like Mickey Mouse.

They're very cute.

Some of them have these pale yellow eyes.

And their tusks are totally different.

They're darker and much straighter.

Probably an adaptation to allow them to push through the undergrowth.

Oh, another one is coming.

Oh, two.

Two more are coming out of the forest.

You know...

If these were savannah elephants, I'd be able to hear rumbling and trumpeting.

But these guys, they're just so quiet.

They'd be so easy to miss.

If I hadn't come up here, I wouldn't have seen any of them.

And then, like ghosts...

they're gone.

I'm so used to savannah elephants.

They are impossible to ignore.

But these elephants are almost silent.

I didn't even hear the babies crying to their mothers.

Most times, the moment they see people...

they run away.

You don't see these behaviors in savannah elephants...

except in populations that have been heavily endangered.

They're suddenly heavily poached.

Oh, it just left so suddenly.

They're clearly terrified of humans.

It feels really quite tragic.

These elephants' fear of humans is justified.

Their tusks, which can grow up to five feet long...

are denser than those of savannah elephants.

Making their ivory highly prized.

For this, forest elephants have paid a heavy price.

In just three decades, their population has plummeted...

by 85%.

Yet, there are places, like Odsalakokua National Park...

where elephant numbers are holding steady... or even beginning to rise.

Thanks, in part, to how well these animals... have adapted to their home.

Like other tropical rainforests... the Congo straddles the equator.

This means intense sunlight... and high rainfall...

and an abundance of plant life.

Which should be a good thing... for this female forest elephant.

As she has hungry mouths to feed.

Unlike her savannah cousins... who live in large families to share childcare.

She raises her two teenage daughters...

and her young son...

on her own.

The plants around them... look like tasty elephant food.

But the leaves...

contain something dangerous.

That's meant to keep them away.

Poison.

Eat too much...

and they could die.

This clever mom, however... has a solution.

Their Congo home... is unlike any other rainforest.

Broken up... by islands of marsh... and grassland.

It's a patchwork landscape...

with thousands of plants on offer.

So... mom takes her family on a tour...

of the Rainforest Buffet.

Showing them... that they must only eat... a little of this... and a little of that.

So that they never eat... a dangerous amount...

of anything.

She teaches her children... exactly as her mother taught her.

Preparing them for life... in this remarkable ecosystem.

Is her job...

and hers alone.

Life... is very different... for Bulls.

Having left his mother's care... in his early teens...

this male now leads a bachelor's life.

Spending most of his time... searching for his favorite food.

Something seasonal... that can be hard to find.

Fortunately for him...

he has twice as many smell receptors... as a dog.

So he can sniff out... calorie-rich ripe fruit...

from miles away.

Only needing... two hours of sleep each day.

He follows his nose... into the night.

While we can only follow him...

with infrared.

The fruit...

of these riverside palm trees...

hang 50 feet above ground.

Well out of his 20-foot reach.

So...

he employs... another tactic.

Making use... of his three... tons...

of body weight.

No joy at this tree...

but... he knows the odds...

so he perseveres.

Jackpot!

His trunk... is covered... in small sensory hairs...

that help him... find his reward.

Forest elephants... eat... at least 100... varieties... of fruit.

All ripening... at different times... of year.

So they keep... a mental list... to know when... and where... to find fruit...

that's ready... to eat.

Still...

there is one ingredient... missing...

from the diets... of forest elephants.

Something... that fruit... and vegetation...

can't provide.

Calves... receive all they need... from their mother's milk.

But for adults...

it is something... that must be found.

Living in the far west... of the Congo basin...

this special group...

of forest elephants...

makes an extraordinary... journey...

across land...

Some make this pilgrimage... alone.

Others... prefer company.

All...

have the same... destination.

Where the Congo basin...

meets the Atlantic Ocean.

The missing ingredient... vital for brain... nerve and muscle function...

can be found here... in abundance...

Salt.

Plants coated by sea spray provide all that the mother needs for herself and her baby.

But it turns out these elephants might be

getting something that's not strictly essential.

This is iboga.

Long valued by local people for its hallucinogenic effects.

What these elephants experience, we can only guess.

But what we know is that for generation after generation, salt-encrusted iboga

will keep drawing this group of forest elephants back to this beach.

Most of the Congo's elephants live too far

inland to travel to the beach for their salt.

Swampy forest clearings, like this one, are found throughout the Congo basin.

In the local language, they are known as bais.

Free from the shade of the canopy, smaller plants

flourish, creating vital pit stops for grazing animals.

But bais are more than just forest clearings.

They are places where salt and other minerals are hidden in the ground.

Many elephants are nervous being out in the open.

Due to poaching.

Only under the cover of darkness, does this

bull step out of the shadows and into the bai.

Filmed here for the first time using only moonlight.

He knows exactly where to go.

The salt and minerals he needs are buried in the riverbed.

And he has the perfect multi-tool to mine for them.

Blowing jets of air, he breaks up the sediments, creating a rich, salty soup.

His trunk acts as a jackhammer, cup and straw.

He barely spills a drop.

The sound of the bull mining is a beacon, signaling to the

more cautious forest residents that tonight, this bai is safe.

There is a strict hierarchy.

Who gets the best spots, and for how long.

But

not everyone follows the rules.

Mining provides these landlocked elephants with all the salt and minerals they need.

It's a vital life skill.

One that's not inherited, but learned.

Trunks move in synchrony.

A dance performed under the stars.

It's by mirroring their mothers and siblings that youngsters learn to

coordinate the 40,000 muscles in their trunks.

Only by perfecting their technique will they

be able to get the salt they need on their own.

And finally, leave their mother's care.

As

dawn breaks, the lessons end.

It's remarkable how these elephants disappear

so quickly and so quietly into the forest.

Paula wants to understand how such large animals

move through the dense forest with such ease.

But for her, getting lost is a real possibility.

So she is guided by eco-guard Prosper Ballot.

Today, this is where they passed.

Wow.

From the outside, the rainforest looks impenetrable.

And mostly it is.

Yet here, we can walk straight through it.

This path hasn't been cleared by humans.

It's made by elephants.

One elephant pushes through the forest.

The next follows the same route as it's easier.

Like walking through snow.

With each elephant that passes through, the path gets wider and wider and wider.

All these elephant footsteps trample new growth, keeping the pathways open.

The savannah elephants that I study follow in each other's footsteps too.

But here, in this dense forest, the effect is striking.

For the canopy to have opened up like this, elephants have

probably been using this pathway for hundreds of years.

You can see they've cleared it all the way out.

This seems to be the major highway through the forest.

There are all these other junctions coming from other parts of the forest.

You can see one here.

There is another trail going through there.

Huge footprints.

Once you start looking, you see these pathways everywhere.

It's like a forest transit system that takes

the elephants directly to everything they need.

So instead of having to find new sources of food and

salt, all they need is to know where each path leads.

Knowledge that helps them to survive in this forest.

To humans, the true extent of this maze of pathways may never be known.

But what we do know is that all roads ultimately lead here.

The downtown of the Congo Basin.

Isangabai.

A place not just for elephants, but for every resident of the forest.

It's a melting pot.

Where the elephants feel safe enough to be noisy.

While most come for the much needed salt, they stay for the other amenities.

But most importantly, after months alone in the forest, it's a chance to reconnect

with family and friends.

Over 200 forest elephants can gather each day at Isangabai.

It's the perfect place for introductions.

This baby was born deep in the forest.

And is only one week old.

Her mom is the only elephant she has ever seen or heard.

These calls are so loud.

She can feel the vibrations through her feet.

But it's just her grandma saying hello.

For

a 200-pound newbie, it's overwhelming.

Being social is something you have to learn.

She's taken aside by her mom for a moment of calm.

Nursing is soothing.

So when the next time group of relatives turns up,

she's more confident.

She's well on her way to mastering forest elephant social etiquette.

It's been a successful debut for the littlest elephant in the Bai.

For all the young elephants who are lucky enough to visit,

Dzanga Bai is both a playground and an elementary school.

It's important for young bulls as family life in the forest is female-led.

But at the Bai, there are plenty of older males to learn from.

Like human arm wrestling, sparring matches are how bulls test each other's strength.

And most importantly, establish their status.

It is such a critical skill to master.

Copycat matches break out all around the Bai.

The size of 20 football fields, Dzanga Bai has space and opponents for everyone.

And you're never too young to start practicing.

Especially when you've got such a long way to go.

But if there's one thing that's sure to dampen an outdoor party,

this is the rainforest after all.

In the Congo Basin, three inches of rain can fall in one day.

A challenge for the elephants, as the one thing they hate to be is clean.

And

as each storm passes, the elephant's top priority is to get dirty again.

Thanks to the weather, reapplying their mud coat can be a daily chore.

Despite their skin being an inch thick, it's sensitive.

And a well-applied mud coat protects from biting insects.

Which is especially important for newborn skin.

And at Zangabai, the mineral-rich mud means catwalk looks for everyone.

The importance of Zangabai for elephants is clear to see.

But, as Paula knows, understanding their relationship to

their forest home can take a little more detective work.

Within the forest, it's hard to observe the elephants directly.

They smell and hear you coming before you can even get close.

This is why the clues they leave behind are so important.

This is an amazing fig tree.

It's clearly very popular with the elephants.

You can see that they've been picking at it with their tusks and digging and

gouging it and chewing on the bark.

I don't think that they are eating it because the sap of these fig trees is

actually not very nice and you can see it when you damage the tree a little bit.

It's full of nasty tasting chemicals that the elephants don't like.

So maybe they're just doing it to

in doing so they've created an amazing network of holes and little nooks and

crannies where other animals live and other plants can also get purchased.

But it's not just with their tusks that

elephants create habitats for other species.

All along their pathways you find dung.

And growing from it are baby fruit trees.

Elephants eat so much fruit and walk so many miles each day that they are more

effective at dispersing seeds than any other animal.

Elephants don't just live in this forest.

They plant it.

And that is why they're known as the gardeners of the rainforest.

The impact forest elephants have on the Congo Basin is bigger than we could have

ever imagined.

In their endless quest for the fruit, vegetation and salt that they need.

Generations of elephants with stomping feet, tusks and trunks have engineered an

ecosystem unlike any in the Hundreds of bais, oases of light and life,

connected by countless miles of elephant pathways.

This isn't just a rainforest, it's an elephant metropolis that's become a

natural As elephants build this world, they thin out the undergrowth,

allowing the trees to grow taller and store even more carbon than those of the

Amazon, making the Congo Basin one of the most important lungs of the Earth.

The survival of this planet-sustaining rainforest

is intimately tied to that of the elephants.

Given space and protection, this calf could live to be 70 years old,

a

grandmother, and a true guardian of this great rainforest.