Original subtitles

Four billion years in the making.

An astonishing planet.

Home to over eight million different types of plant and animal.

And us.

Eight billion humans.

When it comes to looking after our home,

it would be fair to say that we dropped the ball.

But that's not the end of the story.

Around the world, ingenious communities, scientists and experts

are working to protect the natural world,

and fix what is broken.

Hang on, hold the phone! It might sound bonkers, OK?

Is he making this up?!

Oh, man! So good to see you, brother!

These people are surprising...

They are inventive...

We're using that biology of the elephants

to come up with new solutions.

And above all, they are determined.

We have crocodiles, in baskets, on mopeds, travelling in convoy.

Didn't ever think I would say that!

There just seems to be life everywhere.

We'll be exploring extraordinary places,

rich in nature.

Hot work!

Six pivotal locations...

I didn't for a second think this was going to work!

Six teams of heroic humans...

These are the kind of wounds that, in a human being,

it would kill you.

We'll be following their inspiring stories.

Brilliant animal, great location, fantastic scientists.

Together we hope to better understand

the future of our changing planet.

I've returned to the beautiful Laamu Atoll in the Maldives.

This chain of more than a thousand gem-like islands -

many rising no more than a metre above the sea -

is encircled by gigantic rings of protective coral.

A living shield from storm erosion and rising sea levels.

Last year I saw for myself how a thriving coral reef

can have a huge role to play in our broader ocean health.

But as sea temperatures rise,

experts are predicting that coral could cease to be reproductive.

That would mean that, eventually,

coral reefs would disappear altogether.

This would be catastrophic.

Around the world a billion people depend on reefs in some way

for their livelihoods.

But scientists have made an extraordinary new discovery...

..that will bolster the life of baby coral.

ECHOING RUMBLES AND POPS

Most coral animals release billions of eggs and sperm

on one night of the year.

This sexual soup results in millions of tiny coral larvae

drifting in the sea.

They have no brain and no central nervous system,

and yet something triggers them to drop down to the bottom...

..cling to a rock, and begin to grow.

Bioacoustics expert Professor Steve Simpson,

along with a pioneering team at Bristol University,

think they know what it is.

They're listening to reefs and piecing together

the secret world of underwater animal chatter.

This is a real protype, I was up late last night building this.

These are some wooden poles from the building site nearby.

What this is, effectively, is a human listening device

with our ears now spread a metre and a half apart...

And what we've got here are four hydrophones.

So that will mean we can start to listen to the reef

in surround sound, spreading our sensory system out

over a much larger area.

I love a Heath Robinson bit of kit

that looks like it was knocked up overnight!

Which is exactly what it was! Which is exactly what this is, yeah!

Jess Hodge, a marine ecologist

researching coral restoration at Laamu, guides us to a prime spot.

As we drag Steve's giant ears through the reef,

we're able to listen live to what Steve calls the "ocean's orchestra".

RESONANT BURBLING AND CLICKING

Those noises are the fish, the shrimp, the lobster, communicating.

Something we would never normally be able to hear.

I didn't think for a second this was going to work!

That is the first time I've ever heard a reef like that.

That is amazing.

It's the first time anyone's ever heard a reef like that, that's why!

Steve, it's quite familiar to us to dive on a coral reef

and appreciate the colours and how it appears.

It's quite different to be thinking about how it sounds.

As we explore coral reefs, we tend to look around -

we see bright, colourful fish, we see the colourful corals.

We don't really hear very much - our ears don't function underwater

particularly well.

But with recording equipment we realise that the soundscape

is absolutely full of life, full of information.

And that's information that all the animals living on the reef use

to make decisions, to be able to understand

the larger biodiversity of the habitat that they're living in.

Steve now has evidence that those eerie clicks and whistles

could also be used to communicate specifically with baby coral.

And this could be a game-changer.

This discovery came not from the wild reef,

but from a state-of-the-art laboratory 5,000 miles away,

in England.

Deep in the bowels of Bristol University

is a Nasa-grade facility designed for testing rocket parts.

But now Steve's team are using it to study baby coral.

This is precision baby-sitting like I've never seen.

Josh Pysanczyn is a coral researcher working with Steve.

He's devised an experiment that reveals for the first time

that the tiny hairs - or cilia - on the body of larval coral

vibrate in response to different frequencies of sound.

It's a discovery that could be harnessed to help

the world's reefs recover.

Josh releases 50 free-swimming baby corals into a tank.

Smaller than a pin head, but really starting to explore the tank.

At first, the larvae randomly bob about with no sense of purpose

or direction.

But obviously, it's complete silence in there. Yeah. All right?

Steve has recorded a party playlist of sounds from a healthy coral reef.

FIZZLES AND CLICKS

When the recording is played into the tank,

the once aimless corals start actively swimming,

spiralling downwards, looking for a place to set up home.

Look at that! I mean, that one's falling out of space!

It looks like a meteorite, doesn't it?

Making a beeline for the bottom!

Something in that coral reef playlist triggered the coral larvae

to begin searching for a place to settle. But what was it?

This is the first time we've ever known what a coral can hear.

It is, isn't it? Yeah.

They isolate the individual sounds of the reef to work out

which one excited the coral and got its cilia waving about.

And they discover something that could shape the future

of global reef restoration.

It's the fish.

Right?

So the coral is potentially hearing...

Do you hear that? Du-du-du-du!

Yeah. It's potentially hearing just the fish out of the whole

soundscape of the reef. The coral is listening for the fish.

Wow. Hear that? ECHOING POPS

It's just the fish, isn't it? Yeah.

POPPING AND CLICKING CONTINUES

Pwhhhh!

Not only is this mind-blowing for Steve and Josh -

it's big news for me, too.

Hang on. Hold the phone!

You're talking about teeny tiny floating larvae hearing a reef?

Absolutely. So these fuzzy tennis balls

the size of a pin head, covered in hairs,

are moving around in the water.

And those hairs are being moved by the sound.

And so as the hairs get moved, it gives the coral a way

of detecting its soundscape and selecting based on

what it's picking up in those hairs, exactly which type of habitat

it wants to settle onto.

It might sound completely bonkers, OK?

Is he making this up?!

The lab work showed Steve that corals move not towards

a noisy reef, but towards specific fish on that reef.

The fish - not the waves, or the lobsters or the shrimp -

are the trigger for coral to come in, sink to the bottom,

and set up home.

Now, he wants to know which fish on these reefs

can help guide baby corals in from the deep.

When we listen to the reef, we can start to actually

tick off different species, use it like a register.

What we're going to try and do today is two things.

The first is to go and deploy these little self-contained

recording systems, OK?

So they're programmed today just to be recording constantly.

We'll put those down on the reef and we can leave those.

They'll just be clocking the local soundscape.

But what we don't often know is which species are making

which sounds, so we're going to do a bit of an experiment

where we set four of these Hydramoths in a square

about two metres apart, and then put a 360-degree camera

in the middle of it.

And when we hear a sound, we can then turn our screen

to look at which species was making that sound.

Many of the reefs around Laamu have not recovered

from the last severe warm water spike seven years ago,

but Jess has found us one that's buzzing.

Steve only developed this setup a few weeks ago,

so we're all excited to see how it works in the field.

If we can match faces to voices,

we can ultimately work out which species of fish the coral

listens to, and use those voice recordings to the reef's advantage.

With all our equipment installed, we have no choice but to wait

as the reef whispers and whirs and sings into our recorders.

Covering a third of California

are 33 million acres of spectacular forests.

Vast, beautiful, wildernesses.

But now they're under threat more than ever before.

It's now mid-October 2022,

and a year ago when we were filming about 250 miles north

of here, the Windy Fire of 2021 was ripping its way

through this very spot in the Sequoia National Forest.

The fire was part of the second-worst fire season

that California has ever experienced,

and it burned for over two months,

and obliterated almost 100,000 acres -

including some of the largest and oldest trees on Earth.

California's iconic giant sequoias.

They've evolved to withstand fire,

relying on its heat to germinate their seeds,

but even they can no longer cope.

This is - or was - Pack Saddle Giant,

the 38th largest giant sequoia in the world.

It could have been as old as 3,000 years,

but it was completely destroyed by the Windy Fire

and there's no way it can recover from a burn like that.

Fuelled by a 20-year drought, over-managed waterways,

global warming, and over a century of fire suppression,

the intense infernos of recent years are responsible

for 20% of the world's giant sequoias going up in smoke.

The state government has spent billions of dollars

fighting wildfires.

But I'm here to find out how these out-of-control blazes

might be prevented in the first place.

Bordering the Sequoia National Forest

is the Tule River Tribe Reservation.

I know this sounds massively counterintuitive

in one of the world's worst hot spots for wildfires,

but I'm joining the Tule River Tribe who are about to set fire

to that meadow up the track.

Today we're restoring the meadow and we're restoring the watershed

and the land.

Ron Goode is an elder from the Tule's sister tribe,

the North Fork Mono.

He's an expert in a traditional fire practice called cultural burning.

Today's burn aims to clear the overgrown meadow.

We have to take care of our back yard.

When we do that, we're doing our part to take care

of climate change, but we have to lead by example.

OK, so everybody's getting organised now.

I'm going to get stuck in and make myself useful.

Low-level wildfires are a natural part of many forest ecosystems -

and, perhaps surprisingly, they are a good thing.

They remove debris from the forest floor,

establish clearings for new growth,

and help to create nutrient-rich soil.

But for more than a century, all fires across California

have been suppressed as part of a state-wide no-fire policy,

originally introduced to protect commercial timber.

Hot work! Whoooo!

The result is densely packed, overgrown forests,

with plenty of fuel just waiting to go up in flames.

A virtual tinderbox.

What you've been doing, when do you expect it to work?

What century do you expect it to work?

Because it hasn't worked for two centuries,

and I don't see where it's going to work for the next century.

Indigenous peoples in California have been mimicking nature,

using fire in a controlled way to holistically manage their lands

for many thousands of years.

If you use fire in the right way, it's good for life.

But it's the wildfires that get away, are uncontrollable,

that's bad fires. The cultural burning is a good fire

because you're using it in ways that benefit everybody.

Making use of fire and other forest-management practices

such as thinning, reduces the fuel load

and restores the health of the landscape.

The Tule River Tribe hope this will better protect

their reservation from today's megafires.

Talk me through the big fires of the last couple of years

and how they affected your reservation.

Say last year, the lightning strike on the Windy Fire,

it started on the reservation, it was small.

It moved off the reservation, it come back in.

On all the big fires, a lot of them gain speed

when they get off the reservation because you go off the reservation

and they're not allowed to do any of the work that we do.

But change is on the horizon.

This age-old indigenous practice -

which uses good fire to prevent bad fire - is finally being recognised.

The state government has pledged to undertake

nearly half a million acres of controlled burning a year

across California's forests.

What's more, for the first time in history,

the Tule River Tribe are working directly

with the National Forest Service to incorporate traditional knowledge

into forest management, and this could build even greater resilience.

It still feels really weird to be setting fire to this place,

knowing how bad the wildfires have been in this area,

but this is going to help restore this meadow.

Fire resistance, fire resilience, crucially, will also be improved.

But with wildfires here predicted by some experts to triple

by the end of the century, cultural and controlled burning

will not be enough.

I want to know if there are other nature-based solutions

that can help prevent California from the devastating blazes.

While we wait for our recorders to eavesdrop on the reef,

I'm finding out about another Maldivian resident.

Turtles.

What a treat!

Oh, so many turtles!

So far, hawksbills. They're really characteristic,

they've got a parrot-like beak, a kind of overbite

from the upper jaw, and then the back of the shell

has this almost saw-tooth look about it.

You can see them instantly.

Sea Turtles patrolled the oceans while dinosaurs roamed the Earth,

more than 200 million years ago.

They've evolved a close relationship with coral.

Hawksbill turtles are like sea sheep,

spending their days grazing and defecating.

They eat a variety of plants and sponges.

The turtles obviously need the food, but it works both ways.

Without the turtles, the plants quickly get out of control,

smothering the coral and killing it.

Their future is totally tangled up with the health of these reefs.

Protect the coral, and you protect the turtles.

With the coral situation here on a knife edge,

the Maldives cannot afford to lose its turtles.

Hawksbill turtles like these are critically endangered,

but a team of researchers are working to monitor and protect

these coral gardeners.

And they're doing it without darting or tagging -

just waiting and watching.

You're basically a paparazzi for turtles.

That is exactly it! We are going into the water

and getting photo ID shots of the face of sea turtles in the water.

And then we're uploading the photos onto our laptop

to see which individual it is -

whether it's one that we've seen before, or whether it's a new one.

We're going to find out which turtles are on gardening duty

in this reef today.

Camera was upside down!

You didn't see that, did you?!

Julian has built a comprehensive database of 750 turtles,

which will alert him to any significant changes

in the population.

OK, Sarah, have you got any sense of who any of our heroes might be?

Well, there's a turtle called Daisy who's very commonly seen

in the site you just went to.

So, I'm just going to type her name down on the database.

And, yep, that is Daisy.

What is it you're looking for in these photos for identification?

We're just looking for the distinctive patterns

on the turtles' faces.

Every turtle has a different pattern, kind of like a fingerprint.

This reef and its attendant turtles are living proof

that coral can recover unaided

after extreme sea temperature events.

But as these events become more severe and more frequent,

there will be no recovery time between the blows.

This is likely to be the case for 99% of the world's reefs.

Coral is going to need life support.

We've had our artificial eyes and ears spying on the reef

for a couple of days.

In fact, the clownfish seem very at home in the camera tripod.

So, this is totally new to science.

It's been really exciting starting to unpack these recordings.

Do we have any moments where you can link up the sound

with something we can see?

So this is the really exciting thing.

This is a really new direction that we can go in,

where we can put the recorders down next to the camera. Yeah.

To try and get a good example, of that...

WHIRRING AND CLICKING

So I'm calling it the laugh, high, low, low...

"Whurrpp, burrp, burrrp, burrrp. Whurrpp, burrp, burrrp, burrrp."

OK? So then if I go into the video, this is that moment.

OK? So if we watch the video, we're looking for a fish arriving

and producing the sound, and it's this guy here...

Whoa! So, the Regal Angelfish... An Angelfish? ..swims in.

And so I've gone through the video to find other times

that the Regal Angelfish is in the frame. Yep.

And sure enough, we hear that

"whurrpp, burrp, burrrp, burrrp, whurrpp, burrp, burrrp, burrrp".

So it's a really nice way of actually being able

to put some characters into the soundscape for the first time.

That's extraordinary!

It's like you recorded a bird song for the first time

in the 21st century.

We are a long way behind underwater, but it means we can listen

with our eyes open. It's so exciting.

This feels pretty special to me.

These are fish I don't think a human has ever heard before.

Species that have never been recorded.

So this really is a pioneering adventure into the soundscapes

of coral reefs.

These new discoveries have huge ramifications

for the coral-restoration work beginning here.

Steve plans to play these recordings,

taken from healthy reefs, back out into the ocean

using loudspeakers, essentially tricking millions of baby coral

into setting up home on dead and degraded reefs,

jump-starting them back to life.

You're talking about playing the sounds of a perfect, pristine reef

as a kind of calling card?

Absolutely.

As a "come hither" to floating coral larvae.

That's the plan.

And over probably two or three generations,

two or three seasons,

you start to then make that coral reef its own loudspeaker again.

Because, ultimately, we can call the punters to the nightclub,

but I think here we've got the chance to actually rebuild

the nightclub.

What if some cheap underwater speakers pumping out

the Greatest Fish Playlist on repeat could give coral a future?

Visibly thriving reefs rising from the dead in three years.

What we've found out so far has completely blown my mind.

I, as a naturalist, am obsessed with things like frog calls

and bird songs, and all of a sudden,

this whole new era of natural history

is opened up to me, a whole field of study I didn't even think of.

And the possibility that there is the power to use sound

to rejuvenate these reefs, kind of feels like science fiction.

But right here, it could become a reality.

I've come to the very remote north-eastern coast of Greenland.

The nearest settlement is more than 200 miles away.

There's no Wi-Fi, there's no phone signal,

the average temperature is minus nine.

And there's the very real chance that I could bump into a polar bear.

Climate scientists journey here to put their fingers

firmly on the pulse of our changing planet.

I can't think of a better place to be to pick up

from last year's experience.

In 2021, I witnessed just how fast the world's ice is slipping away

from us as our planet warms.

This year, I'm back on an Arctic expedition to understand

another pressure on life here.

Extreme weather events are threatening this ecosystem,

and one of the most ancient creatures on the planet.

So I'm meeting a scientist who's been studying them

for over 20 years, and is developing ingenious solutions

to monitor them in this inhospitable landscape.

I've just arrived at the world-famous

Zackenberg Research Station

to meet Niels Martin Schmidt. And here he is.

I recognise your photo! Niels, nice to meet you.

Nice to meet you. And who have we got here?

This is the musk ox team.

Well, we're in search of musk ox. Have we come to the right place?

You have definitely come to the right place.

This is the high Arctic. This is where you find musk ox.

And since there's only one large herbivore,

they play the key role up here.

It's thought there are up to 12,500 musk oxen

here in northeast Greenland.

Relics of the Ice Age, they're finely tuned to life here,

shaping the landscape for thousands of years.

There's a general perception that, as things warm up,

animals which have adapted to cold climates will simply move

northwards until there's no more northwards left, one presumes.

But of course, if they vacate an ecosystem, it will change.

We have realised over the years they are really

an integrated part of this ecosystem.

They graze in these more productive areas and then they go and rest

and defecate on the more drier spots

and they transport all these nutrients uphill.

And then all this grazing and the trampling they do

when they forage also changes the composition

of the plant communities.

And ultimately, they end up dying and that's also a resource,

at least for the Arctic fox that rely on dead musk oxen in winter.

Niels and his team have excluded musk oxen

from some small test sites.

These areas, devoid of this key species,

resulted in dramatic changes to the vegetation.

So you'll have a completely different ecosystem

if you take away the musk oxen.

The results have shown that in the sites without musk oxen,

the vegetation is far less effective at absorbing carbon

from the atmosphere.

Carbon capture is very much influenced by animal grazing.

So every time an animal walks into an area and starts to graze,

the plant will respond by regrowing.

So that will increase the uptake of carbon into the system.

These interactions made by the musk oxen,

they are part of the entire climate feedback system.

So, it's not just climate impacting the musk oxen -

their presence feeds back to the climate system, too.

Niels is trying to understand how musk oxen will respond

to a rapidly shifting climate.

And it's not steady warming that worries him most.

He thinks an increase in extreme weather will eventually

push them to the brink.

But the Arctic is vast, difficult to access,

and for three months of the year, Zackenberg is in darkness.

Niels hopes high-tech collars and clever gadgets

will offer a solution to gain insight into how musk oxen survive

in the depths of winter, when he can't be here.

Tomorrow, the adventure begins.

I'm going to like it here, I think.

It's my type of place. Spick and span, neat, orderly.

I'm going to be here for nearly a week with no phone signal,

no news, nothing.

I might stay here forever!

Maybe I could just - I don't know - tend to the oxen.

TEAM CALL OUT INSTRUCTIONS

Ooh! Perfect! That is good.

The scientists have done their necessary preparation and rehearsal,

so we've got to the stage now

whereby we need to spot the musk oxen.

But the musk oxen's range is vast, covering an area

of around 2,000 square miles across this hostile landscape.

Today, we're in luck.

10, 11, 12, 13, 14, 15, 16. 17 in that group.

The team spread out like a pack of wolves, surrounding the group,

and driving them to higher ground.

OK, I see you, thank you.

Currently we are trying to move the herd,

to make them stay put so we can have the vet approach.

But they're not behaving right now.

It's a process that requires guile and patience.

The musk oxen have formed a defensive group.

All I can see is a series of heads and horns facing outwards.

This group has no calves.

Most of the females would be suitable here.

So, if they've got no calf,

that means that they are likely to give birth next year? Yes, yes.

The calves are born between April and May.

I would expect that they're actually pregnant now. Yes.

Which would be great for your study. Yeah.

Niels' research focuses on females and their babies,

because understanding the next generation is vital

in protecting the future of this population.

OK. I think we should start to move a bit closer.

Now they are moving. I think they are stopping.

Wait a minute.

Nothing prepares the team for the highs and lows

of chasing musk oxen across the tundra!

Our first attempt to encircle the musk oxen and move them

to somewhere where they would be calm enough to remain

so that we could dart one or more of them has unfortunately failed.

They fled over to the other side of the hill.

It's strenuous work, walking over 12 miles a day,

laden with kit, but the scientists push on.

During this expedition, Niels is hoping to deploy 21 collars.

But in three weeks' time, this place closes down

for the Arctic winter - no-one gets in, no-one gets out.

There they are!

Our mission is to get them onto that steep hill there.

Musk oxen like to run uphill.

When they're on the top, they stand still and look down.

And then the vet can approach.

Oh, whoa, whoa! They are up in, like, five seconds.

Just follow along the ridge, guys.

The team work together to keep the herd on the brow of the hill.

So, if you are in the south position, move out of the area.

So my role at the moment is to stand here and be a human,

which is challenging at times in this temperature!

But ideally the musk oxen won't come down if they see me

standing here, and if they show any signs,

I'm going to wave my arms and go,

"Whoa, musk oxen," or something like that.

I'm very confident that I'll be able to stop a musk oxen

in its hooves, no question about it.

The vet must get to within 45 metres to dart.

I am ready to shoot, everybody.

SHOT FIRED

The dart is in the female,

so we're just going to wait for that to kick in.

The cow is down. Yeah, I have her. Super. We got her!

Once the animal is anaesthetised,

it's essential that everyone works as a team as rapidly as possible.

The animal's welfare is absolutely paramount here.

One, two, three!

She is weighed using a series of luggage scales.

And let go.

OK, Chris, your numbers?

23.47. 11.5. 11 and 14.

She comes in at a healthy 217kg.

She's measured...

Blood is taken to assess her overall health

and, crucially, to identify if she is pregnant.

This is about bigger-picture ecological changes, isn't it?

Yes.

So they're a perfect indicator, basically,

for some of the climatic changes that are taking place here.

What we basically can do is to understand the full extent

of the role the musk oxen play in an ecosystem.

And it's not just climate impacting musk oxen, it's all interlinked.

There are many impressive things about the musk ox,

I've got to say, but just look at the fur.

On the outside, you've got these really long guard hairs,

but if I try and tease it apart to reveal the underfur here,

the insulating layer,

and there you can just see that white line, that's the skin.

But look at the depth of that.

No wonder they can survive up in the Arctic.

Oh, and what about the smell?

Hmmm. It's a bit sheepy, actually.

No, not really. No, it's unique, but not musky.

Because of this incredible hair, musk oxen can survive

in temperatures between +10 and -40 degrees Celsius.

Remarkably, these hairs can also paint a picture

of what she's eaten for the past five years,

with each two millimetres of the strand representing nine days

of her diet.

This research provides clues about the surrounding environment.

Periods of starvation could indicate particularly heavy snow events

that prevented her from feeding.

Such a specialist in such a fantastic, remote,

and beautiful environment. This is a real privilege.

Limited access to the Arctic means Niels can't be here

for calving season,

so the vet has inserted a vaginal implant transmitter.

This vaginal transmitter will give a signal once she gives birth.

And the idea now is that it will be egested at the point

of giving birth, and then we'll know exactly where and when

she's given birth! Exactly. Great gadget! Very clever.

We're going to reverse the anaesthetic.

And here she goes. Good girl. Whooo!

I'm really tired.

It's because I've been tramping across an Arctic tundra all day.

These guys are like, you know,

some sort of Danish scientific athlete.

They just run up and down the tundra mountain sides like,

I don't know, chamois, mountain goat!

But I shouldn't complain -

I've got a strong feeling tomorrow is going to be even better.

Cultural burning is a powerful tool for reducing

the impact of wildfires,

but another nature-based solution can also be found in California.

The beaver.

The Tule River Tribe have always understood

the benefits of this enigmatic ecosystem engineer.

And now, this traditional knowledge

is being complemented by exciting new science.

I'm meeting ecohydrologist Dr Emily Fairfax.

So, what I study is how beavers impact fire-affected landscapes.

And in these kinds of settings,

it's really quite incredible seeing what they can do.

Oh, wow! Yeah.

This doesn't look like it belongs here.

It's pretty impressive.

Coming from all of this ash and all these dead trees.

I can't believe what I'm seeing.

It's a proper little oasis.

Mm-hm. And it is completely engineered by the beavers here.

The beavers transformed this into an absolutely thriving wetland.

This is absolutely stunning. And look! Yeah.

You've got some of their little chew marks here.

So, during the fire,

are you telling me this just didn't burn?

No, it didn't burn at all.

So these trees, they're burnt right up on the edge.

If you were a beaver during this,

you are encircled with walls of fire.

I thought it was too much for them, and then the first time

I came up here and I see this, and I'm like...

I ran down into the pond.

I was like, this is so amazing! The beavers were safe.

It was just way too wet to burn.

I am almost speechless.

I mean, this is mind-blowing, it really is.

Almost three hectares in size,

this wetland is maintained by one family of four beavers.

And it would have taken them just two years to build.

Emily uses her drone to show me the complexity of their work.

So, what we have here is this main primary beaver dam.

But "busy as a beaver" is a phrase for a real reason -

they keep building. Look at that!

They've dug a ton of canals just radiating out from their pond.

And I presume that's contributing to the ground water, as well?

What you can't actually see is that, beneath all of this,

there's about five times as much ground water storage -

we're standing on it now.

And any plant that can access all that water,

that when you have something like a wildfire come through,

are just too wet to burn.

It's this healthy plant life that Emily uses to collect her data.

Multi-spectral drones and satellites allow her to measure burn severity

by analysing the "greenness" of landscapes with and without beavers.

So far, her results have shown that beaver-dammed areas burn

three times less intensely than when beavers are absent.

Why would beavers work so hard to build such an extensive complex?

When beavers are in the water, they're very safe,

they're excellent swimmers, they hold their breath

for 15 minutes, no predators can get them there.

But, as soon as they're out on the land, easy pickings for predators.

Like, that's a big chicken nugget just walking around the landscape!

And so they want to have more water area to keep themselves safe.

So how effective, then, can one beaver family be helping

to mitigate the force of the fires that are raging through California?

Well, this family at least was able to protect this entire wetland.

Scale that up, and instead of patches,

you're looking at huge strings of fireproof landscape -

that's a firebreak.

Each one of those is like a little speedbump and so you can start

to fundamentally alter how fire is moving through the landscape. OK.

But there's a problem.

Beavers were hunted to near extinction over 100 years ago,

leaving few remaining wild populations in California.

Today, many people regard them as pests,

and when their dam building clashes with human infrastructure,

they are often killed.

If we get things right in California when it comes to beavers,

what would you like to see happen?

Let's relocate those beavers and help re-establish them

in some of these watersheds where they've been gone for so long.

Emily and the Tule River Tribe are part of a network of organisations

and communities working to bring beavers back to California.

And last year, real progress was made.

New legislation was passed, making it legal to relocate

so-called nuisance beavers in the coming years.

But I also can't help thinking,

will there come a time when what beavers do best

simply won't be enough in the face of our ever-increasing threats?

You know, beavers are incredibly resilient,

they can keep working and fixing things for a long time.

But at some point, they run out of resources, too,

then they can't make these patches.

We have to deal with the root causes of climate change.

The beavers, they cannot cut our emissions for us,

they cannot stop the trajectory of climate change.

That's on us - that's our job.

California has effective nature-based solutions at its

fingertips that can help build more resilience in its forests.

The hope now is that further legislation will lead to

their implementation so that nature can carry out these vital roles.

As for beavers, the next step is to work out how to successfully

reintroduce them into their rightful home.

Further up the coast, in Washington, biologist Molly Alves is

already making headway and is preparing to share her work.

Wow, that is a big dam.

That's a big dam.

She's spent the last eight years working with another

indigenous community - the Tulalip Tribes.

And so far, over 300 beavers have been relocated under their watch.

All right, safety is off, traps are live.

Molly and her team temporarily house persecuted beavers

waiting to be rehomed.

When a new beaver arrives,

they take the opportunity to gather vital information.

First, we are going to take a hair sample

to have a DNA sample from this beaver.

Very quick pull.

Beautiful.

Next up, an ear tag.

Nice work, Molly. That was so quick.

Finally, we need to identify if this is a male or female.

And there's only one way to find out.

Whoa.

So... So, what are you doing now?

Now I am going to access the cloaca of the beaver.

And cloaca houses all of the reproductive organs.

It's where all the excrement comes out.

And with beavers,

they have these castor glands that we need to express.

Based on the scent, colour, and viscosity of the castor,

we can tell if it's a male or female.

If it's more viscous and smells like motor oil

and is more of a brownish colour, that's a male.

And if it's more white and milky and smells like kind of bad cheese,

that's a female.

I'm almost hoping for a male, I don't know why!

There we have a gland expressed. Yeah.

You have to tell me what you think.

That's a female.

It sure is!

All right! Right, I'm never going to forget that moment.

Everything's done.

Now we transfer this adult female to her temporary home.

Beaver families form strong social bonds,

so the rest of her family

will be trapped and brought here to join her.

Meanwhile, an adult male and his four kits

are ready to be moved to their new home.

But the mother is missing.

As we were trapping this site, a wildfire broke out

at the location, so we weren't able to return to capture her.

You're kidding.

Once the fire subsides, we'll try to go get the adult female

and reunite her with her family at the release site.

Yeah? Beautiful! Well done!

Molly has identified a suitable release site

for this family of five in the Mount Baker-Snoqualmie National Forest.

She hopes they'll turn a drying river into a thriving wetland

and keep wildfires at bay.

We're done. Let's do this.

Yes, honey, I know.

One, two, three.

Dad!

Come on, Dad. Here we go, here we go.

Out with a splash.

He wants his other babies.

That is the most glorious sight.

How soon before this begins to transform into proper beaver meadow?

By next summer, I hope that where we're standing,

we would be swimming in a cool, deep pool.

There will be bears, cougars, bobcats,

all kinds of amphibians and migratory songbirds.

You name it - they thrive in beaver-ponded areas.

So we are taking our knowledge and sharing it

so that programmes like this can benefit other states, as well.

So, the sooner that folks can start to relinquish a bit of the control

and let the beavers protect us,

the better off we'll be in the future.

I am now in awe of this gorgeous little semi-aquatic rodent

who is now exploring his new home.

I have been fascinated by what I've seen in Washington and California.

The meeting of Indigenous knowledge and Western science is helping

to build solutions to the wildfire crisis in a really tangible way.

Recognising the importance of traditional ecological wisdom

is long overdue, but it is so crucial

because this profound understanding

of the natural world and how to harness nature-based solutions

is going to be one of our strongest allies against climate change.

But, of course, there's a lot more work to be done,

and that's where each of us comes in.

We all can help with this - with everything we do in life,

we can choose to support the planet

and that can lead to even bigger change.

After a night of snow, I wake up to a transformed landscape.

But a snow day in an Arctic research station

doesn't result in snowball fights and snow angels.

It's a chance to review data from retrieved collars.

To date, Niels has collared over 60 musk oxen.

Super-advanced collars determine their location,

as well as the movement of their heads and necks in three dimensions.

If you are grazing, your head will be moving like this

or if you are walking, it will be more like this.

It's a bit like my fitness device. It's very much the same.

It knows when I'm walking, when I'm resting. Yes, exactly.

So we can infer behaviour based on the data

we can extract from these collars.

So we have seen that during winter, for instance, they will rest

approximately half the time, whereas in summer they shift gear and

turn to foraging almost continuously throughout the light season.

Their data has also revealed that when not pregnant, musk oxen can

drop their body temperature 0.8 degrees Celsius to conserve energy

and save themselves about 20 kilos of body weight

over the winter.

They feed over summer and build up these huge fat depots

and then they live off these through the winter

and develop the foetus based on these resources.

But extreme snowfall events are becoming problematic.

If snow conditions are really bad - that means a lot of snow -

they can't forage and refuel over winter

and they have to rely 100% on these depots

and that means that they will skip the calf in order to survive.

In years of heavy snow, the musk oxen run out of fat reserves

and will abort their pregnancies.

It can take a year before they are strong enough to try breeding again.

If you have to adapt to such a variability,

that will sort of push the organism to the limit.

Even in the good snow years, when 70% of cows give birth,

their babies are born without their waterproof guard hairs.

Increasingly early and erratic rainfall can be fatal.

If they suffer a soaking, pneumonia sets in, and in some years,

all the calves will perish in the slushy wet spring.

But there's still a missing piece of the puzzle.

The vaginal implant transmitters tell Niels exactly

when certain females give birth, but he still knows very little

about what happens to the calves after that...

Hi, Niels. Hi, Chris.

..until now.

We have these camera collars - they have a small camera here.

Oh, wow. That's fantastic. Yes.

So it's the first time we will use these

and hopefully we will get some nice footage of the newborn.

These cameras will also shed a light on a key part of the musk oxen's

life cycle that's never been observed here,

yet is paramount to the health of their population -

they will reveal how the mother's behaviour changes when she has

a calf in tow, and whether that calf can survive a more volatile climate.

Niels has already noticed a decline in the musk ox population

by a third in less than ten years.

But with all this new tech and growing data, there's hope

these majestic mammals will be better protected in the future.

Finally, the snow subsides.

But with valuable time lost

and the end of the field season fast approaching,

the team must battle the elements to get the camera collars deployed.

RADIO: Can you give an update?

It's looking good so far.

Excellent.

Over here we have an audio logger that will, for the next six weeks,

continuously record every sound in the neighbourhood of a musk ox.

Cor, it's fantastic.

So, again, this can be used to validate their behaviours.

So it's an exciting year with technology.

You've got the audio loggers, the cameras,

but you're going to have to wait how long to get the data?

One and a half years.

And then we need to recover all the collars also. Yeah.

And they can be spread out in this area.

If you'd have told me that, when I was 61,

I'd be standing in Arctic Greenland helping a bunch of brilliant

scientists tag a musk oxen, I'd have burst.

I mean, this is just phenomenal. Look at this landscape.

Harsh, hostile, but extremely beautiful.

And these supremely well-adapted animals are living out here

throughout the course of the year.

But what I like even more

is not that I've got close to an animal, but I've got close to

an animal which is now telling us a story about our changing planet.

Because we're all too aware of the fact that we're in

a deep, deep crisis and we've got to do something about it,

and we can only do something about it if we better understand it.

So, for me, today is a double, double win.

Brilliant animal, great location, fantastic scientists,

and more knowledge that could help us all protect our planet.

Next time on Our Changing Planet...

..Gordon Buchanan is in Brazil,

catching up with the team at the forefront of jaguar science...

Healthy, healthy.

..Ella Al-Shamahi is back in Cambodia, meeting locals

and scientists saving a living fossil from the brink of extinction.

And Ade Adepitan returns to Kenya, where game-changing solutions

are protecting communities from the effects of the ongoing drought.

Four billion years in the making.

An astonishing planet.

Home to over eight million different types of plant and animal.

And us...

..eight billion humans!

When it comes to looking after our home, it would be fair to say...

..that we dropped the ball.

But that's not the end of the story.

Around the world, ingenious communities, scientists and experts

are working to protect the natural world

and fix what is broken.

Hang on, hold the phone! It might sound bonkers, OK...

Is he making this up?!

Oh, man, so good to see you, brother.

These people are surprising...

..they are inventive...

And we're using that biology of the elephant to come up with new solutions.

..and above all, they are determined.

We have crocodiles in baskets on mopeds travelling in convoy.

Didn't ever think I would say that.

There just seems to be life everywhere.

We'll be exploring extraordinary places, rich in nature.

Hot work.

Ooh!

Six pivotal locations.

I didn't think for a second this was going to work.

Six teams of heroic humans...

These are the kind of wounds that in a human being, it would kill you.

We'll be following their inspiring stories.

Brilliant animal, great location, fantastic scientists.

Together, we hope to better understand

the future of our changing planet.

I have returned to the Pantanal, the biggest wetland on the planet,

and the stronghold of the Brazilian jaguar.

Home to the world's largest population of caiman, anaconda,

rare parrots and the largest rodent on Earth...

..it's a magical ecosystem.

This place seems pristine.

It feels a lot like a paradise.

But there's trouble in paradise.

All of the animals that live here are under threat.

A vote 500 miles away is going to decide

if six new hydroelectric dams can be built,

slowing the Pantanal flood pulse.

I'm here to follow that story

and to update on a project I reported on last year

that is protecting jaguars by making them worth more alive than dead.

Bon dia. Hey, hey. How are you? How are you?

Good to see you. Good to see you, it's been a long time. I can't believe it's been a year.

For ten years, biologist Lili Rampin has been collaring wild jaguars

and habituating them to vehicles.

Last year, I saw for myself how this ecotourism project

has proved to be a game changer.

Once hunted and killed by cattle ranchers,

jaguars are now seen as money makers

and their presence on the land is celebrated.

This amount of money, it represents more money

than the "damage" that jaguars cause, you know, on these farms.

If you kill a jaguar, you are wasting your money.

So they understood, OK,

I can actually make money with this jaguar being alive.

When this project started, people grew up here never seeing a jaguar.

Now, Lili can identify 40 individuals on this one ranch.

What would happen with Brazil's jaguars

if you said, just leave them alone?

Extinction. Like, immediate extinction.

They will just disappear

because people will kill them until they're gone.

This year I'm joining Lili to find out how her team

are protecting the wider population with scientific techniques

that respond to the rapidly changing nature of this landscape.

One extremely helpful tool is collars, radio collars, actually.

During the next two weeks, we're going to be working, working, working,

trying to capture the jaguars, setting some traps

and we study them deep, deep, deep with great results for science.

Much of what we think we know about jaguars

is actually based on data collected from African leopards.

Now scientists have this large, easy to study population,

we can start to discover the truth about jaguars

and how best to protect them.

People used to believe that jaguars don't stay up on the trees.

They think that just the leopards, their cousins,

are doing this kind of behaviour for so long.

But they discovered that they not only like to stay in trees,

but they also mark the trees, you know, as their territory.

We can only see that and from close

because we are right there observing them.

Lili has teamed up with specialist wildlife vet Joares May

to understand a new threat.

We can learn a lot with this.

They're looking for connections between parasites found in livestock

and diseases in jaguars that can weaken and even kill them.

Links have been discovered between falling predator numbers

and increases in diseases that affect people.

Scientists like Joares are scrambling

to understand this better.

But to do that, they need samples.

Live ones!

I know that sounds crazy,

but this is the correct way to send to the lab,

so with the ticks alive.

Then we have more and more information about what's going on.

And to collect samples, he needs to first catch a jaguar.

Easier said than done.

Luckily, Joares has a plan...

..with a little help from me.

He's a professional!

May I? Yeah.

Joares plans to set up humane traps on these roads

to capture the jaguars.

If the jaguar moves around, nothing here can hurt it.

You can put your left hand. Really?

Yes. Really, really? Yes. So I'm going to be the guinea pig.

And I'm going to stand on this and tiny bit of pressure...

Oh, I was expecting it to be painful.

There you go.

Next we install a sensor that alerts the team at base camp,

via a radio signal, when the trap is triggered.

And it just minimises the amount of time that the jaguar's in the trap.

From years spent studying jaguar behaviour,

Joares has learnt natural ways to funnel jaguars towards the trap.

In the dead of night that would be deafening.

Any prey that is around here would hear a noise like that,

so the jaguar's going to want to stick to this surface

that doesn't make any noise - soft sand.

And it moves along here and then the next step it takes,

it'll trigger the foot loop.

And then it can contribute to science.

Because it's so hot in the day,

Joares only activates the traps after dark.

Now, there is nothing left to do but wait.

It's about 3:00am and still no sign of a jaguar.

Yeah, it could be a long night.

One of us checks the radio every 20 mins.

And then suddenly...

..it's all go.

But things are not as they should be.

What is it, Lili?

It's a giant anteater.

They're going to remove it without any drugs.

Giant anteaters are not aggressive, but they can be dangerous

and this one is understandably cross.

ANTEATER GROWLS

Stay back.

Joares wants to attempt release without sedation,

but he must be careful.

You've got to expect if you put a trap on a trail

there's going to be other creatures moving around at night-time.

Anteaters can rear up on to their hind legs

and slash out with powerful four-inch claws.

These giant insect eaters are fully capable of fighting off a jaguar,

so the team need to keep their distance as they race to free it.

Sorry, fella.

Case of mistaken identity.

As it disappears into the night, our long wait for a jaguar continues.

Hi, can I get a lift?

Thank you, thank you.

It's great to be back in the hustle and bustle of Cambodia.

This year I'm here to discover more

about Southeast Asia's greatest river system

that is being drained not just of its water, but of its sand.

Hearing that the Mekong River system

could collapse in just three to five years

and seeing for myself the devastating impact that could have,

it's truly sobering.

I'm in Phnom Penh to meet Brian Eyler.

Brian has spent the last 20 years

researching and engaging with local communities from China to Vietnam,

to protect Southeast Asia's longest river - the Mekong.

The river's a mighty system

that provides for tens of millions of people.

It's probably not something many of us have given much thought to...

..but after water, sand is the most exploited resource in the world.

So this is what we're talking about, sand mining.

This has actually got two pumps.

And actually if you look around you can see

there's some boats that are barely above water level

because they're so filled with sand.

Around the world we use 50 billion tonnes of sand and gravel a year -

enough to build a colossal wall to encircle the planet.

It's the key ingredient of cement and concrete,

so all of our cities and roads are built of it.

All of this sand comes from nature

and nature, as it turns out, needs it back.

Eight years ago, none of these tall buildings were here,

and they're all built from sand taken out of the river.

And they're being built at a very rapid pace.

We're extracting sand from the Mekong

seven times faster than it's replenishing.

So this pace can't keep up.

When a river is robbed of its sand and sediment, it gets hungry,

and if it doesn't have it, it's going to look for more

and it gets the extra new sand from banks.

River banks are collapsing, homes are falling into the river as well,

so we're paying the price for this.

The impact of sand mining is being felt hundreds of miles away.

Historically, the flood pulse of this river sends water

surging into one of the world's largest freshwater fisheries,

the Tonle Sap lake.

It's capable of providing half a million tonnes of fresh fish a year.

By taking sand out at the bottom, the river level drops.

So it's going to take much more energy and water

to cast that water up into the Tonle Sap,

which feeds the fishery, which then feeds the people of Cambodia.

Traditional fishermen, like Mr Leur who I met last year,

depend on the Tonle Sap floods.

They were having to search for alternative sources of protein,

like snake, to feed their families.

The Tonle Sap fishery provides roughly 75%

of all the protein eaten by Cambodians.

Its collapse would be devastating and dangerous.

The impact of that is so real, not on the medium term and long term, it's on the here and now.

You're coming across communities who are facing that on a daily basis.

Yes. The scale that could play out here is huge.

It's at the country level. It's at the region level.

If sand mining continues unchecked, on top of irrigation and damming,

the impact on this system could be the final straw for the Tonle Sap.

Are there solutions that will solve this?

There are ways to bring this breakdown

that's happening here under control.

Researchers from Newcastle University

have been using scanning technology

to track changes on the riverbed over time.

These dots are craters? Correct. Ten years ago.

Here you see these beautiful sand dunes, you know,

like you would see along the ocean, except they're under the river,

and now they're gone.

Where towering dunes once stood, now gigantic craters,

eight metres deep and 70 metres wide, scar the riverbed.

This is so alarming, that's just a completely different surface.

But also, this technology allows us

to measure how much sand is being removed.

So now that we can see it, it's possible to bring transparency

and accountability and in a way to make this more sustainable.

So data, which is quite depressing, you're saying,

could actually be part of the solution?

But from here, there's progress.

Standing here, the scale of this

just feels completely and utterly overwhelming.

But at the same time, you heard what Brian said.

The solutions are all there. They're there.

And so I'm also leaving this boat with a sense of surprising hope,

which I think we should all be clinging to.

Sand is not the only thing missing from Cambodia's river system.

I will be continuing my adventure with an action-packed journey

into the jungle to join a team putting something back.

While the team wait for a jaguar encounter,

I want to find out about the threats facing this magnificent animal.

In Brazil, jaguars across the Pantanal

are recorded as being vulnerable to extinction.

Now, there's a new proposal

that may cause this entire ecosystem to vanish.

And the jaguars with it.

And this man, Gustavo Figueiroa,

a biologist and director of SOS Pantanal,

has been fighting it every step of the way.

Thank you. Welcome. Are we good to go? Yes.

Welcome to the most magical place on Earth. Ah, it's amazing.

There just seems to be life everywhere -

in the trees, on the banks, in the water.

It's exactly why they say Pantanal means life.

There's life everywhere you look.

Pantanal holds the highest concentration of jaguars,

giant otters and hyacinth macaws in the world.

It's a wildlife sanctuary here. That's why it's so important.

This water world is under threat,

because 500 miles away in Cuiaba city,

politicians are voting whether or not to allow

a series of six new hydroelectric dams to be built.

These will crisscross the Cuiaba River

and block unimaginable quantities of water from reaching this ecosystem.

They are building and they are allowing more dams to be built

and this blocks the water flow.

50 years ago, the building of dams

was seen as this sort of amazing thing

and it brought prosperity, it brought jobs.

Brazil's population is set to rise to almost 230 million people,

so they're going to need a lot more power

and, for many, hydroelectricity is the answer.

This country has the perfect geography for it.

Elevation changes, mighty rivers...

..and historically heavy rainfall.

Hydroelectricity can be considered green

because no fuels are burned and no direct emissions released.

It already accounts for two-thirds of Brazil's power,

making them far less reliant on fossil fuels

than many other countries.

But we are seeing that manipulating the natural flow of water

can have a different kind of environmental impact.

To show me how vital water is in this landscape,

Gustavo takes me to an area that's dry not because of dams,

but because of reduced rainfall.

As you listen out, you can't hear any birds,

you can't hear any insects.

And if you compare that down to where the lakes and the rivers are,

there's life everywhere - on every leaf,

on every sort of patch of ground, and in the water as well.

Exactly.

You're pinning all of your hopes and dreams

on these dams not being approved.

Have you prepared yourself emotionally and mentally

for the event they may go ahead?

No. Erm... It's not an option for me to believe that.

It will get drier.

There's going to be less water entering the system

and less fish reproduction, less animals feeding on the fish

and less fish being caught by local fishermen, people who depends on it.

So basically, you're going to see this multiply all over Pantanal.

So the vote is tomorrow morning?

Tomorrow morning. OK. Call me as soon as you hear.

Gustavo is passionate in his belief

that campaigning against dam construction

is essential if we are to hang on to caiman, otters,

macaws and of course, jaguars.

If the water is lost, then all of Lili's work,

all the patchwork conservation projects taking place

across the Pantanal will mean nothing.

With time running out and still no jaguars in the trap,

the capture team are tense.

But then Joares, the vet,

sees an opportunity to use a different technique - free darting.

Just got the call that there is a jaguar that's been spotted

and we're on our way there.

We've got a bit of an unusual,

but almost perfect scenario here with this jaguar.

When it's hot, jaguars like to find shade

and this particular female has found shade in this culvert pipe.

And it's given Joares an opportunity

without any branches, any foliage in front of the jaguar.

He's going to get a clear shot of her.

The dart's in. Now the team have less than an hour to work.

Joares crawls into the pipe

to pull out what he hopes is a sleeping jaguar.

Oh, she's big.

She's huge.

The team snap into action.

Happy, happy?

There's no room for mistakes here.

Once out of the storm drain,

Joares can see that this is actually a young male.

First on is the radio collar.

In a few days' time,

the team can begin the meticulously slow habituation process.

Pulse gone down. What did she just say, two and half?

Two and a half years old. Amazing.

So it's not just about, you know, fitting the satellite collar,

that's just part of the data as far as parasite load,

the number of ticks, the weight, the measurement, the size of its paws.

It's just using these opportunities to find out

as much as possible about these animals.

Healthy, healthy. Very sharp as well.

Blood samples will be examined in the lab for blood-borne diseases.

He weighs over 110 kilos and with no handles,

it's hard to get purchase on such a massive dead weight.

He starts to stir.

The team up the pace, keeping a watchful eye at all times.

There's some fairly deep wounds on this jaguar,

so there's been flies that have been coming

and laying their eggs in those wounds.

Lili discovers they're full of maggots.

Bot fly and screwworm are parasites usually found on cattle and dogs.

But, as the wild shrinks and the world warms,

there's an increasing threat of diseases

from domestic animals spilling over into wild ones.

I'm cleaning the wound. It's full of maggots.

So I'm cleaning, first of all to collect samples

and secondly to help him.

These are the kind of wounds that in a human being, it would kill you.

It would get infected and you'd die from it.

But jaguars are amazingly resilient

and can cope with these horrific injuries.

Joares and Lili collect every blood-sucking tick

and each flesh-eating maggot from the jaguar so they can be studied.

At least Joares will be happy.

He can add them to his parasite collection.

OK, step back, people.

He's coming round fast now.

OK, everything was fine.

We could collect all the samples, we did the measurements,

we set the radio collar and for now everything is OK.

This jaguar can now tell us so much about its life -

where it goes, how it lives, what it needs to survive.

Every single jaguar is valuable,

but what we can learn from these jaguars

that are now being studied, that is... That's invaluable.

We draw back, watching from a distance

as the jaguar sleeps it off in the evening sun.

All of this work and potential insight becomes irrelevant

if the Pantanal isn't protected.

MOBILE PHONE RINGS

Right, here we go.

The outcome of the vote is all anyone can think about.

Gustavo. Hello, Gordon. How you doing?

I'm really fine, because we won it.

We needed 13 votes to put it down and we had 20.

So it was a huge victory and I'm very happy

because it's going to be a mark for our struggle

on the defence of this biome.

We made it. We made it, my friend. You must be emotionally exhausted.

Yeah.

Emotionally and physically. I haven't slept well.

I just want to go home now.

Mission accomplished.

Take care. Take care, Gordon.

So this is two years in a row that I've returned to the Pantanal,

but I think you could return here every single year of your life

and keep learning about it.

I've seen how imaginative projects

like habituation and parasite monitoring

are key to saving these jaguars and their habitat.

But more is needed to conserve this vast and complex ecosystem.

The Pantanal's long-term future is in the hands of politicians

and the people that elect them.

One sounds like they're toiling away.

Ah, man. It's so good to see you, brother.

Last year, whilst in Kenya, I met baby elephants

who had been orphaned by the bleak drought conditions

and rescued in the nick of time by the Sheldrick Trust.

The terrain is rough,

but it's worth it to be here for the first meal of the day.

Breakfast with Ade and the elephant.

I'm trying to have a conversation whilst I'm being...

Whilst I'm being almost eaten!

Talk to me about the numbers, Julius.

How do the numbers of elephants you have here now

compare to when I was here last?

The numbers have risen so fast.

Last time, I think when you were here

we had something like 18 or 17 elephants.

Now we are talking of about 30 elephants in the nursery.

So it's almost double? It's almost double.

Who knows, the number might still be going up.

And there's a curveball.

Elephants and people are now coming into violent conflict

over shrinking resources.

Physical fights over food and water between people with guns

and five tonnes of desperation.

I'm joining a community at the centre of the conflict.

On our journey to the village of Sagalla,

I learn that you don't actually need to go far

to meet someone that has experienced conflict with elephants.

Your cousin was killed by an elephant? Yeah.

He was killed by an elephant.

He died because of blood,

he was hit be an elephant and then unfortunately, we lost him.

I'm sorry, man. I'm sorry.

John is a Maasai warrior from the north of Kenya

and part of our film crew.

So you've always lived with the animals and never had any problems?

Never had any problem.

But now because of climate change, because of the drought,

it's forcing you to go into conflict.

They need to eat, we need to eat,

and now we have to fight because of that.

That took me by surprise, hearing John's story,

but I guess I feel quite naive now...

..because of course climate change

and of course the drought is going to affect everybody.

You know, this is a country which really relies on agriculture

and farmland, and climate change is affecting all of that.

Now, I've come to one of the villages,

which is right on the edge of Tsavo National Park.

I mean, this is the front line,

the line between wildlife and human life.

Jones and his family traditionally grow what they need to survive.

When I was growing up, it was very hard to see an elephant.

Yeah. We were scared of elephants because they were not common.

But nowadays, they always come.

When was the change? When did they start coming, do you think?

In 2017, that's when we started having big numbers.

There was a day I counted 200 elephants in one herd.

Coming here? Yeah. Coming here. On to your land? Yeah, on to my land.

2018...

..400 at a go.

Oh, my... Yeah, so they're just increasing in number.

With little food and water left in the neighbouring National Park,

the elephants have been coming to the village in search of food.

My family depends on what we are going to harvest.

So this for you, was literally a life and death situation.

You had to stand your ground because if you lost all your crops,

then your family would not have any food?

But, if you attack the elephant or try to chase the elephant away,

it could potentially kill you? Exactly.

Someone who is acutely aware of the need to find ingenious ways

of helping people to coexist with elephants is Dr Lucy King,

head of the Human Elephant Coexistence programme

for Save the Elephants.

Every one of these elephants needs

two or three to four hundred kilos of food

and you look around you, where are they going to get it from?

And the last serious drought we had here,

we lost 500 elephants to starvation.

It's not just about the year of the drought,

it's about the next two to three years.

And we're not sure whether the rains are going to come at the end of the year.

If they don't come, I think we're going to be in serious trouble.

That's when the rainy season is supposed to start,

but the predictions are it's not going to happen.

Just a few days before I met Dr King,

humanitarian agencies published an alert warning

that there was a genuine risk that the 2022 late rainy season

could also fail.

That actually makes me go cold, because if that's true,

I really don't know what we're going to do.

We have hundreds and hundreds of people living next to the park

who we work with, who haven't got a bean to eat right now,

and they're all planning on the rains.

So if those rains don't come, these elephants won't have anything to eat

and they're going to go into the farms

and they're going to start to find food in houses and in schools and in people's properties,

and we're going to have an escalation of human-elephant conflict like we've not seen before.

And that's the moment which we're all dreading,

is the final break point where there is no food for anyone.

This is a complex problem involving both elephants and humans.

The question is, is there a solution?

I am continuing my Cambodian adventure

by journeying deep into the Cardamom rainforest

to meet one of its rarest creatures.

For three decades the Siamese crocodile,

once a key player in the Mekong River system,

was believed extinct in the wild.

Then, a miracle population was discovered,

and great things started happening.

Pablo Sinovas and the team

at the Siamese Crocodile Conservation Breeding Facility

are about to return ten captive- reared crocodiles to the wild.

Would you like to see some of the babies? Yes, definitely. All right.

Bless.

Would you like to... How is this your job?!

Would you like to hold it? Yes. Around there.

Hold it so it doesn't snap. OK. Don't bite me, please. No biting.

I'm basically holding one of the rarest species on Earth,

and I'm holding, like, the hope for it, right?

That's absolutely right, yeah.

This species was rediscovered here in Cambodia

in a remote corner of the Cardamom mountains.

Actually local people, the indigenous people of the area

were protecting those populations

because they do consider these guys to be sacred.

That was their saving grace,

the fact that the indigenous people actually regarded them as sacred.

That's right.

What caused the decline of these animals?

The demand for their skins, for the leather trade,

and as a result they disappeared from 99% of their former range.

My God. So basically, these poor creatures

were about to become extinct because of handbags and belts.

Yeah, basically.

Thankfully, the demand for crocodile leather has reduced globally,

relieving pressure on crocodiles in Cambodia.

But Pablo is focused on just one species - Siamese.

How many crocodiles have you actually released into the wild?

We've released 140 crocodiles so far.

And how many are in the wild?

In Cambodia, there's an estimated 300 crocodiles left in the wild.

So you are responsible for half the crocodiles in the wild in Cambodia.

So every crocodile counts.

The adults are fitted with a tracking device...

..that will allow the team to monitor them from space.

These top predators were almost lost from Cambodia

before scientists really knew they were here.

We've been given a second chance to not mess it up.

Oh, my gosh.

The crocodile's mouth is taped closed to prevent accidents.

Hold its head, It can be quite strong.

OK. Doing it. Yes. Be careful. Oh, my God.

I feel like my heart's in my mouth.

The vet drills through a scale to attach the tracker.

This doesn't hurt the animal.

This is like the equivalent of putting holes in your ears, isn't it? Right. Yeah.

Once the trackers are firmly attached,

the crocodiles are secured in baskets

that protect them for the journey ahead.

The animals are wrapped tightly to prevent them from thrashing

and the baskets soaked in water to keep them comfortable

until they reach their new home.

This might seem brutal, but I guess it's a really small price to pay to get back into the wild.

Yeah, and these are very tough creatures.

Soon enough, in a few days this crocodile will be one of the happiest Siamese crocodiles

in a very pristine environment.

Three adults and seven young crocodiles are fitted with tags...

..bundled, and loaded onto the vehicle.

All right.

So it's been a really long day

and it's going to be a long night, right?

It is. Yeah, it's going to be eight hours now, driving.

Long night, but it will be worth it.

We travel through the night

to avoid the tropical sunshine as much as possible.

Where the road ends, the expedition has to continue...

..on mopeds.

So basically, we have crocodiles in baskets,

on mopeds, travelling in convoy.

Didn't ever think I would ever say that.

We are heading deep into the Cardamom Mountains rainforest.

This time much further than last year,

and the journey is not for the faint-hearted.

But the effort is well worth it.

In 2022, Pablo and his team oversaw the biggest ever release

of Siamese crocodiles back into the wild.

They successfully released 35 of these precious reptiles,

boosting the Cambodian population by over 10%.

After 24 hours travel and a very numb bottom,

we arrive at the protected release site.

There you go, babe.

Our ten crocodiles are released into a temporary pen,

where they will acclimatise to their new environment.

And it's finally time for me to "acclimatise"

in my hammock for the night.

Once released, these crocodiles will be protected

by the community that live here.

And, in return, their presence will hopefully safeguard

the wider ecosystem and the people that call it home.

Mr Chan is from the indigenous Chorng community

and has lived in this region for over 70 years.

He joined the team of wardens here 15 years ago.

How have things changed over the years with crocodile numbers?

Mr Sam Han, a researcher for Fauna and Flora,

joined Mr Chan in his crocodile conservation efforts

and The Cambodian Crocodile Conservation Project was formed.

The Cardamoms is one of the largest and oldest tracts of rainforest

in Southeast Asia.

The dense vegetation, however, makes it almost impossible

to see and monitor wildlife.

But scientists in the UK have developed an ingenious bit of kit

to get around the problem.

This technology is absolutely ground-breaking.

Using this water here, which looks completely clear to the naked eye,

we're going to be able to identify what species are in this area.

That is very impressive.

Yeah, the animals that are in the river

will shed cells from their skin, hairs etc.

We're collecting water samples and forcing them through filters,

which trap the microscopic animal flakes ready for lab analysis.

This filter is basically collecting everything that is in the water,

but what we're interested in is tiny fragments of DNA,

of genetic material, that we can then use

to detect the species that are present in the area.

So this is an incredibly efficient way of building a picture

of the diversity of species in a given area.

When we protect the crocodiles,

what we are doing is protecting the habitat,

and by protecting the habitat, we are helping ensure

that the entire array of species living here actually survives.

It's more than just about the crocodiles.

It is about, you know,

the biodiversity of this entire ecosystem in the Cardamom mountains.

We see this pattern a lot, right?

Protecting a species protects the environment around it, and that it lives in.

And I guess actually that's what Gordon is seeing

in Brazil with the jaguars -

that by protecting them, they're protecting the environment.

Exactly. It's the same thing with Siamese crocodiles.

The time has finally come for the crocodiles

to take their rightful place in the forest.

This is so cool. The crocs have been acclimatising for three days,

it's the moment we've all been waiting for.

It's the moment it was bred for and my heart is racing right now.

These are literally her very, very last few seconds

before she is released into the wild, before she is free.

It's kind of epic, right?

Good luck, guys.

Woo! Amazing! Well done!

Mr Han.

Look at his face. He's just beaming. Oh, my God.

What is your hope for this crocodile and all the other crocodiles?

My hope is that she will start producing lots of eggs

and then that will help boost the populations.

The ultimate goal would be to have a population that is viable in the long term.

We're aiming for 10,000 crocodiles in Cambodia.

It's an ambitious target, but we are... We are on our way.

She's literally never been in the wild before.

This is a completely new environment for her.

It is the first time it's swimming free in a river.

This is a six-year-old crocodile. So after six years...

Can you imagine? ..swimming free. Oh!

All the crocodiles are set free.

Recent data suggests that half the world's GDP is dependent on nature.

If an ecosystem, and ultimately the planet, is to stand a chance,

then preserving its biodiversity,

and that means every single bit of it, is vital.

The release of these ancient creatures into their natural habitat

is helping to do just that.

What an absolute privilege.

In 1999, people thought that the Siamese crocodile was effectively extinct

and I just got to help release one, two, three, ten.

And the truth is, absolutely none of it would have been possible

without these incredible scientists

and without this incredible local community.

The pressure on natural resources

across Southeast Asia continues to build.

Ecosystems are collapsing

and species teetering on the brink of extinction.

But it is no longer happening behind closed doors.

Thanks to communities like this one, expert scientists,

and emerging technology, our eyes are open.

The world is watching and we're starting to see ripples of action

that I hope, over the coming years, will become a flood of change.

I'm shocked to find out that, here in Kenya,

such a beautiful country,

the relationship between people and elephants

is being destroyed by drought.

We're in a really desperate situation, not just in Tsavo,

but in the rest of Kenya at the moment.

Lucy tells me how the situation has reached breaking point.

When I first came here in 2009, the conflict was there,

but it wasn't catastrophic.

Now, we're just seeing such an increased level of conflict

that's becoming lethal.

If it's this bad now,

what happens if it doesn't rain for another year or another ten years?

When you say "lethal" and "catastrophic",

I mean they're big words, what do you mean?

Really meaning lethal for both sides.

It can certainly be lethal for elephants

because communities can be throwing stones,

throwing fire, they can shoot them with bows and arrows.

But of course, it can really be lethal for people.

One lady who we knew just came out of her house one morning

and just got picked up by an elephant and slammed against the house and her neck was broken.

Oh... Oh, my. Yeah, so really lethal.

And we've also had elephants killed in the farms,

and not for tusks, you know, not for poaching.

That's not the issue.

The issue is people don't want elephants in their farms.

Traditionally, you had a level of tolerance in the communities

and certainly a cultural respect for elephants,

which was very strong in Kenya.

That starts to erode very fast when kids are killed

or an old lady is, you know, killed in her house, in her doorway.

For 16 years, Lucy has been studying and protecting elephants here.

But the focus is changing.

As human-elephant conflict escalates,

Lucy knows we need to protect people in order to save elephants.

Food insecurity is elephant insecurity,

they are absolutely tied together.

Communities and elephants, they coexist,

and they fall or die together.

How are you? Fine.

Using elephant biology and behavioural science,

Lucy creates tools for repelling elephants and reducing conflict.

People need real solutions, but they also have to be affordable.

So, it's all very well saying, "Let's put up an electric fence around every farm."

It's just not practical. It's not realistic. It's too expensive.

And it'll use up a lot of energy as well. And it uses up a lot of energy.

So, I'm much more interested in holistic approaches to this challenge.

Lucy made a discovery

that changed her entire approach to mitigating conflict.

Nature offers solutions.

We found out that elephants were running away from bees.

They were scared of being stung,

and they wouldn't forage in trees which had beehives in.

So those trees were being naturally protected against elephant foraging.

So we took that natural idea and I turned that into this beehive fence,

which is a practical application -

keeping elephants out of smallholder farms

using their natural fear of bees.

Lucy helps farmers like Charity install beehive fences.

They protect her crops and provide her with honey that she can sell.

How effective is it?

We've studied this for a long time now in many sites around Africa

and our core study site here, it's around 80% effective.

And that extra 20%... 80%?

Yeah, I know. 80%. I mean, think...

I mean that's really, really effective.

As a result, the fences are very popular.

So far, more than 11,000 hives have been installed.

But there's now a problem with this brilliant fix.

If you don't have good floral diversity,

the bees don't have anything to feed on

and of course floral diversity comes with rain.

Oh, yeah. So we're back to that old challenge again.

So now, so many of our beehives are empty.

Lucy and the team at Save the Elephants

have pulled together every conceivable method

of deterring elephants from raiding crops without harming them,

and they've created a practical manual

for communities struggling with conflict.

We need multiple tools, multiple solutions,

and often they need to be rotated throughout the year.

And we call that the tool box.

This "how-to" guide is currently being distributed

to communities across Africa and Asia.

The solutions are based in science, they're affordable,

they're adaptable, they are nonlethal...

..and, most importantly, they work.

Jones, this is the tool box.

Human-elephant coexistence tool box.

I thought it was a metal tool with tools inside!

Ah, no, no, no. So, we have one that we call the buzz box.

Have you ever seen this one?

No, but I'm ready to learn.

The tool box provides a wide range of ideas

so that farmers can adapt as seasons and events change.

One of the tools is a high-tech version

of Lucy's beehive fence - fake bees.

So, this is what we call a buzz box.

It has a solar panel on the roof which charges the whole unit,

and it sits on top of the post

and it has an infra-red signal that comes out here,

and whatever goes in front of it, up to about 30 foot,

will trigger sounds to come out of it.

But the one we're using is bees.

The guide includes plans for watch towers

that provide early warning systems for whole communities,

as well as simple, home-made deterrents based on science.

Elephants have extremely good hearing, very good smell and very poor eyesight.

So we're using that biology of the elephants to come up with new solutions.

What doesn't an elephant like to smell?

So, they have about 40,000 muscles in their trunk,

full of incredible sensors.

They're smelling much more than you and I are.

Some of the things that they hate smelling

and can actually burn the inside of their trunk a little bit is chilli.

Jones has started experimenting with a new deterrent,

called the condom-chilli-bomb.

As the firecracker explodes, it splits the condom, and it goes poof,

and you get a shower of chilli over the elephant. Oh, man.

It doesn't cause any long-term harm to the elephants,

but it does put them off approaching Jones' farm.

As well as being inspired to try new methods,

Jones has recently contributed to the tool box

with his own non-invasive device

that will be shared with farmers across Africa and Asia.

LOUD CLANGING

Wow, that's a noisy gun!

We're just having to think differently

about how are we going to live with a changing climate.

So, I really believe in this tool box.

I think it is the solution and I think it can always be expanded.

It's not finite.

It's a completely evolving, exciting thing that everyone can contribute to.

Over the next two years,

the tool box will be in the hands of thousands of subsistence farmers

and has already reached 167 project partners across 40 countries.

The hope is that it will save lives on both sides.

Keen to know if the rains had arrived,

I caught up with Jones in November 2022.

They hadn't.

But his relationship with the elephants

had taken a surprising turn.

80% of the cattle in the village have already died.

We are trying to save what we can.

We had to look for ways through which we could get something to feed the cows.

I discovered that elephants were uprooting these tubers.

These tubers are called maduye.

They're thirst-quenching and fibre-rich.

Elephants dig them up when other food runs out.

Elephants are my neighbours, so we have to learn from our neighbour.

So, I realised they are surviving out of this.

I realised I can also save the few remaining cows

by feeding them with these tubers.

Jones and his family copied the elephants and began digging.

So, I tried now to go and feed the cows

and I discovered that they were eating.

Understanding elephant behaviour has saved Jones and his cows,

and also helped reduce conflict.

Now, people are learning survival techniques from their five-tonne neighbours

that might help sustain them through the ongoing drought.

It breaks my heart to think just...

..how tough things have been

for the people here and for the elephants.

But the one thing that does give me hope

is just the fact that the farmers now

are finding a way to co-exist with the elephants.

Astonishing natural solutions mixed with human ingenuity.

What a combination.

At the end of year two of this extraordinary project,

it's clear to see that working with nature

and recognising it as our strongest ally

is the most powerful way of safeguarding

the health of our planet.

Over the coming years,

we'll be keeping up with the determined people we've met

and their inspiring work across our changing planet.