All language subtitles for Earthsounds.S01E12.ATVP.WEB-DL.DDP5.1.H.264-NTb.en[cc]

Over the last three years,

the Earthsounds team has captured
the sounds of the natural world

across all seven continents
like never before.

That's a lovely rumble.

But these recordings tell a bigger story.

As our planet faces climate change
and is losing wildlife...

we're discovering
that listening to nature...

Wow, this is brilliant.

...could provide vital clues
to help us protect it.

In this special episode...

There it is. Yeah. Right there.

...we follow scientists
who are using sound in revolutionary ways...

to help save endangered species

and our wildest places.

The pioneering idea of using sound
for conservation

started 50 years ago with sound
recording legend Bernie Krause.

And we're recording.

Bernie has been returning to
Sugarloaf Ridge State Park in California

at the same time each spring

to capture a sonic snapshot
of the entire habitat.

What we're doing
is recording the dawn chorus

and the dawn chorus is the time of day

when the animals really express themselves
at their most vital.

It's a magical moment.

Well, right now I'm hearing
California quail.

Song sparrows.

I'm hearing a pileated woodpecker
knocking in the background.

And let's see what else?

I hear my stomach rumbling.

These natural sounds
are known as a biophony,

the richness of a soundscape.

This biophony is the sound
of the natural world. It's its voice.

When it sounds robust,

when all the animals
have a place in the choir,

it's a healthy habitat.

When they don't, it's not.

The importance of Bernie's recordings

became clear
when disaster struck California's forests.

Well, in October 2017,
there was a huge fire.

California's Thomas Fire
already more than 270 square miles.

And 70% of this part was burned.

The destruction was extreme.

But clues that the forests were
already suffering from a warming climate

can be heard in the bird song
years before the fires hit.

Right now, we're looking at soundscapes
from Sugarloaf Ridge State Park

and what we have on the screen
is a spectrogram,

a graphic illustration of sound.

And what I'm showing is
the change that's occurred over time

as a result of climate change.

When Bernie's study started,
Sugarloaf Ridge was full of life.

In 1993, the density and diversity
of the birds is fabulous.

There are probably 20, maybe 25,
different species of birds.

But as California's climate warmed up,

the bird song started to change.

When we move to 2014,
the birds have dropped off precipitously.

Now, Bernie was picking up
only a quarter of what was there before.

Hardly hear anything at all.

This was an early warning

that the forests
were dangerously heating up

and worse was to come.

So, when we get to 2015,
things have really changed.

We have finally come to
what I call a silent spring.

There are almost no birds.

It's the first time in my life
I've ever heard a silent spring.

We're just losing all
of this wonderful orchestra.

Eight of the ten
hottest years ever recorded in California

have been in the last decade.

But Bernie's studies show
if we listen to nature,

we can hear powerful clues
about the health of our wild places.

After 50 years of this work,
I'm just seeing and hearing less and less.

And it's not because
I'm losing my hearing.

It's because these things
are going really fast,

and we've got to
figure out a way to protect that.

One solution could lie in
taking Bernie's approach

and supersizing it
in the wildest places on the planet.

Tropical forests are home to more
endangered species than anywhere else.

But each year over 20 million acres
of forest are cut down,

putting animals under increasing pressure.

I think we may have found our tree.

- That one?
- Yeah.

To help protect them,

conservation group Rainforest Connection
is taking sound recording to another level

in a new branch of acoustic science.

Bioacoustics is the study
of species through sound.

Majority of the species are vocal.

Being able to listen and understand
why they're vocalizing,

it's a really amazing way
of ultimately conserving them.

Bourhan Yassin and Kris Harmon

want to track Puerto Rico's
noisiest forest residents,

especially
one of the world's rarest birds,

the Puerto Rican parrot.

The reason that we're monitoring
the parrot, it's critically endangered.

There are only a handful that are left,

so it's really important to know
what is going on with them.

They plan to do this
by miking up 4,000 acres

in Rio Abajo State Forest,

using a network of
high-tech recorders called guardians.

The guardian device is a mobile
computer in the middle of the forest.

So it has a lot of capability
to not just record audio

but also understand its surrounding
and analyze the audio.

There's a microphone that gets
plugged in in the front of the box.

To eavesdrop on the entire forest,

the best place to position the recorders...

Incoming.

...is over 100 feet up
at the top of the canopy.

Kris, can you hear me okay?

- Yeah, I've got you. No problem.
- I don't think I can go any higher.

I have a beautiful view
of the valley in front of me.

- We'll get started on the installation.
- Awesome. Good luck.

Just doing a quick mic test
on the guardian mic.

Yeah, that came through crystal clear.

- You're good.
- Awesome.

I think we're good to go man.

This is the first guardian
installed in Rio Abajo.

How cool is that?

No, that's perfect.
Honestly, couldn't ask for better.

Each device can detect sounds
from up to a mile away

and uses artificial intelligence to
pick out the calls of specific animals.

The AI is running, and we have it set
to pick up I think 40 different species

and automatically identify those.

So instead of any of us having to
go in and look for anything

and sort of manually find the species,
the model is constantly running,

and so, we'll have output really 24-7.

As well as Puerto Rico,

this technology is up and running
in 35 countries,

constantly listening for the calls
of over 3,000 species.

But the guardians
can do something even more amazing.

They can pick out the telltale sounds
of illegal logging

and send an alert to rangers
on the ground.

There is no other system,
that I'm aware of,

where within a handful of minutes
you can detect a threat,

send a message to enforcement,
and have a patrol respond to that threat.

Detecting the calls
of animals and illegal logging

in dense jungle is remarkable.

But off the coast of Hawaii,

cutting-edge technology is also being used

to follow the ocean's greatest singers.

Humpback whales
are the Pacific's long-distance travelers.

But to protect them,
we need to know where they roam.

They're known to migrate
from their Hawaiian breeding grounds

thousands of miles to
their northern feeding grounds.

But where else they travel
is largely a mystery.

All right. You guys, are you ready?

- We're ready.
- All right.

Cool. We're ready to rock and roll here.

So excited to do this.

And marine biologist
Beth Goodwin and her team

are hoping to solve this...

Oh, yeah.

...by tracking the humpbacks
using their remarkable song.

This is great.

These whales are going off,
they're groaning and creaking and...

You know, when I listen to these songs,
I am just in awe,

but I'd like to know more.

To find out where the whales travel

means searching thousands of miles
of open ocean...

...and conventional technology
just won't work.

We've developed tracking devices,

tags,
that you can put on the humpback whale.

But those tags,
they don't last four or five months.

So they've come up
with an ingenious sonic solution.

Murray, I'm taking the break off.

Going down, Europa.

A self-propelled,
acoustic probe called a Wave Glider

that can travel across oceans
for up to a year at a time.

A Wave Glider is a two-part vehicle
that has a surface component,

and it's attached to an underwater part.

We call it the sub.

The sub has six set of wings or fins.

The float's not steering,
it's literally just a bobber,

and as it bobs these wings are
kind of going up and down all the time.

And it just takes the tiniest bit
of ripple in the water for it to move.

What's really cool is we've attached
a smart hydrophone underneath the sub

so we can download and listen where the
Wave Glider is and what she's hearing.

Okay. Are you ready?

This Wave Glider, nicknamed Europa,

is heading out to search 5,000 miles
of ocean between Hawaii and Mexico.

What are the odds of this ten-foot-long,
autonomous vehicle intersecting a whale?

I mean, really, it's like searching
for a needle in a haystack.

Ready?

- Ready.
- Yup.

And the time has come...

to set it off.

And there she goes.

Wow.

We did it.

- Wow.
- Have a good trip, Europa!

In five months' time,

if Europa can navigate
safely back to Hawaii...

it could redefine what we know
about where these ocean giants roam.

On the other side of the planet...

another pioneering acoustic project
is gathering vital clues...

to help save
one of the world's rarest predators.

African wild dogs.

Less than 700 packs are left in the wild
and their numbers are dropping.

In recent years,
their home in Southern Africa

has experienced more frequent and intense
heat waves because of climate change.

Scientists believe this could be
contributing to their decline...

and that's where sound can help.

If you see a wild dog let me know.

Kasim Rafiq
from the University of Washington

is teaming up with conservation group
Wild Entrust...

Okay. Let's go see the dogs.

...to identify the most important places
wild dogs hunt and raise their pups

by tapping
into their highly chatty nature.

Sound is a key way in which
the animals of this area communicate.

But it's also a key way
for us as researchers

to understand what's happening.

But tracking fast-moving predators

that roam over 500 square miles
is no easy task.

African wild dogs
are very, very hard to follow

because they move very, very fast
across these landscapes

that are dotted with these massive holes

from elephants and, like,
aardvarks and warthogs.

And often if you try and follow them
when they're hunting...

you just drive your Land
Rover straight into it.

So the team
has come up with a novel approach:

miking up the dogs
with a lightweight, acoustic collar.

A normal wildlife tracking collar
tells us where the animals are going,

but it doesn't tell us what
the animals are doing in those areas.

The acoustic part...
So, it's a little box that we designed

and that fits onto the side
of a normal wildlife tracking collar,

and it allows us to hear exactly
what the animals are getting up to.

Using these acoustic collars,

the team will be able to
monitor the pack 24-7.

But first, they need to
find a healthy adult to collar.

They're probably under there.

And vet Rob Jackson
and Kasim know just the individual.

Let me just ID the dog first.

Where is Jessie?

One of the pack's large males, Jessie,

will give them
the best chance to eavesdrop

into the heart of wild dog family life.

- Okay, well, can we dart?
- Yeah.

The anesthetic dart is harmless
and will sedate him for 20 minutes.

Okay, have you got that blindfold?

Okay, you can come out, Kas.

Let's get the collar on,
let's get the dart out.

It's a chance
to give Jessie a health check.

The teeth gives an indication
of how healthy it is.

They should be very strong to
bring down their preys and stuff.

Yeah, he's moving. Perfect.

He's breathing nicely. He appears healthy.

All good.

The onboard mic starts picking up
the family's most intimate calls...

closer than ever before.

A few days later,

the collar captures a key sound
that the team has been hoping for.

One of my favorite vocalizations

occurs when the wild dogs
are getting ready to move.

They create this weird sound
that sounds like birds twittering.

And I love that for two reasons.

One, you get, like,
caught up in the emotion of it.

And two, it means that something
really exciting is gonna happen.

This twittering call is a sign the pack...

- Let's go.
- ...is preparing to hunt.

Mike, Mike, you can follow us.

The dogs can cover up to five miles
of rough ground on a hunt,

and Kasim knows
he can't track them for long.

It looks like they spotted something.

Yeah, impala, impala.

I think we might lose them.

Now,
the acoustic collar comes into its own.

The GPS tracks exactly where the dogs go...

and the microphone reveals
key information about their behavior.

This time, a successful hunt.

Over five months,
the team collects 900 hours of audio.

And by listening to the dogs
around the clock,

these onboard recordings will help them
better understand

how the pack's ability to hunt
is being affected by rising temperatures.

The acoustic collars
are gonna give us this ability

to translate exactly
what the animals have been doing.

And I think that's really important
because it's gonna give us insights

into how climate change is impacting
the ability of these animals to survive.

And that's very, very exciting.

From the African Savannah
to the polar ice caps...

the impacts of climate change are
being seen and heard across the planet.

Temperatures in the Arctic are rising
four times faster than anywhere else.

The loss of ice is affecting wildlife
and raising sea levels.

But it's also creating another problem.

Ocean noise pollution.

As the Arctic ice cap thins and shrinks,

shipping lanes are opening up
in places never possible before.

For Arctic wildlife,

the dramatic increase in ships
is disastrous.

It's something that Norwegian
sound recordist, Jana Winderen,

is experiencing in her work to capture
the sounds of the Arctic's animals...

including its most endearing heavyweights...

walrus.

The breeding season is approaching,

and Jana is hoping to record
their incredible underwater calls.

There is a knocking sound.

I can hear them really well,
but I can't see it just right now.

Tick, tick, tick, tick, tick, tick, tick.
Like this.

That is the courtship sound of the walrus.

Wow, this is brilliant.

She's just like... They're just over there.
Look.

Walrus are masters of underwater sound.

Their courtship knocks carry for miles,

helping them find mates
in this icy wilderness.

That's the first time
I've seen walruses so close.

You can see like the eyes looking,
you know.

It's brilliant.

But the walrus calls
are increasingly being drowned out.

Yeah, I can hear the boat.

And even if I don't see the boat,
I can hear it.

It's really worrying, because it's...

You know, with this shipping lane,
it will separate habitats from each other.

Species that are migrating

or they're going to a particular area
to feed...

They might have suddenly, like, a shipping
lane right through their dinner table,

and they can't hear each other, you know?

And they can't meet each other.
They can't meet a mate.

So, it's like eating dinner every day
in the middle of a motorway.

Recent studies show
underwater noise pollution in the Arctic

has doubled in just six years...

but we still have time to tackle it.

There is regulations that can be done in
terms of how much sound the ship makes,

or what time of year
you're having the traffic.

This is the mating ground and, you know,

we don't need to kind of just
drive straight through it all year around.

Sound pollution is one of the
more straightforward

types of pollutants to deal with.

You simply turn it off
or at least turn it down.

Recordings like Jana's will help
scientists identify key hot spots

that marine mammals use
to broadcast their courtship calls...

helping us better protect
them throughout the Arctic Ocean.

Okay, you guys good?

Okay, we're ready? Okay, here we go.

Back in the Pacific,

it's been five months since Beth and her
team launched the acoustic Wave Glider.

All clear.

Now it's time to retrieve it
and discover if their efforts

to track humpback whales through sound
have paid off.

Right now, as of about five minutes ago,

she was off of this bay right here,
about ten miles offshore.

This is our time. We're gonna go get her.

Let's do this, okay?

Europa has been traveling
all the way to Mexico and back

in search for humpback whale song

in unidentified areas where people
aren't expecting to hear them.

If Europa has recorded humpback song,

it could shed new light on the whales'
migration routes

throughout the North Pacific.

The team just needs to find it
and bring it safely aboard...

but the ocean has other plans.

Not liking that weather moving in.

The swell's picking up here a little bit.
Okay, watch these...

Oh, yeah.

All eyes out. We should be right on it.

There it is. Yeah. Right there.
Where the birds are.

All set
for a lively recovery on the high seas.

Don't fall off up there.

All right, Murray, I've got the helm!

Oh, yeah. Okay!

Yeehaw, this is rough.

Yeah.

If the team don't get this right,

all of Europa's precious data
could be lost.

I'm getting you a little closer.

- Come on!
- Go, go stretch.

- One more. Yeah, here we go.
- We're on!

All right.

Look at her, she's looking great!

Watch... Watch...

- Okay. Break off.
- We got her.

- All right.
- Nice!

So, we got Europa back.

She's got quite a few gooseneck barnacles
growing on her.

A little bit of algae,
but basically she looks in great shape.

As the crew head for home,

Beth can't wait to check out
what Europa has been recording.

Let's download an audio file
from a thousand miles offshore.

If it's captured whale song,

it'll be proof of humpbacks
in the mid-Pacific.

Okay. Here we go. Let me listen.

Yeah, yeah, yeah!
It's a song, that's pretty clear.

Okay. Here we go. Here's another one.

Yes, those are even louder.

- Those are even clearer.
- Wow.

It's the sound that Beth
and the team have waited for for so long.

Oh, my God. We heard whales.
All right, you guys. That's great.

That's so great. Cool.

- Good job.
- Yay.

Europa ended up being out
on this mission 150 days,

and she traveled 5,000 nautical miles,

and we collected 1,700 hours
of audio data.

Incredibly, Europa captured
thousands of humpback recordings

which show that as well as migrating north
to the feeding grounds,

the whales are also traveling between
Hawaii and Mexico

in numbers never recorded before.

Not only could the whales
be migrating back and forth

between Mexico and Hawaii,
within the same season,

but they could be actually lingering

or having a group of them out there,
traveling back and forth.

Or they could even be out there
breeding and calving.

This discovery of a corridor
between Hawaii and Mexico

will help us better understand
and protect these ocean giants

on their travels across the North Pacific.

The fact that we heard any
at all is quite phenomenal

for the technology
of the Wave Glider and the hydrophone,

but also for the discovery
of having them out there.

So I feel pretty pleased about that.

It's pretty impressive, really.

It's just one of the remarkable ways

we're now able to track
and protect animals...

simply by listening...

to the sounds of our planet.