Attenborough's Wonder of Song (2022) - full transcript

On a clear spring morning like this,

the dawn chorus is at its peak.

There are surely few more enchanting

natural soundscapes than this.

But this avian choir

does not sing for us.

These are songs of seduction

and weapons of war.

Males are defending territories

and attracting mates.

Singing is dangerous.

It reveals the bird's

location to predators.

But it also offers a huge reward -

the chance to attract a female and

pass on genes to the next generation.

That, Charles Darwin said,

is why song evolved.

It was an example

of what he called sexual selection.

But, today, new discoveries are

transforming those long-held ideas.

For this programme,

I've chosen some of my favourite

recordings from the natural world

that have revolutionised

our understanding of song.

There are seven recordings of it

that have particular interest for me.

Some are lovely,

some are surprising,

and one almost broke my heart.

But all of them broke new ground.

I've recorded many sounds of

the natural world over the years...

..and I've learned that there is,

perhaps surprisingly,

no scientific definition of song.

We tend to use the word

to describe sounds that seem,

to our ears, beautiful.

It is, in truth,

a somewhat whimsical label,

but it has been attached to

some of nature's greatest marvels.

Just listen to this.

Each of my seven chosen songs

was recorded in my lifetime.

The oldest was made when I was five.

The most recent, just a few years ago.

None is closer to my heart than

the first one...

..which I made back in 1960.

Recording audio in the field

in remote parts of the world

was almost unheard of.

There was certainly no money in the

BBC budget for a sound recordist,

but I did manage to get hold

of a very rare thing indeed -

a battery-driven portable tape recorder -

so that I could record sounds myself.

It was a cumbersome piece of kit,

but cutting-edge at the time,

and I was determined to use it

to record a singer

that no-one had ever recorded before.

Madagascar's largest lemur, the indri.

This noise was no bird call.

I had never heard anything

like it before.

It must be the voice of the indris.

Using my new equipment,

I made the first-ever

audio recording of the indri.

But could we also capture them

on camera as well?

The song was

so loud that it seemed impossible

that the animals could be

more than 20 or 30 yards away,

but where were they?

Until now, no-one had even managed

to photograph a living one,

let alone film it.

Infuriatingly, the bush was so thick

that I could see no sign of them,

whatever.

So the question was,

how could we get close enough

to get a clear view of them

without frightening them?

"Well," I thought, "what about

doing it the other way around

"and trying to persuade them

to get closer to us

"by playing their calls?"

And they did

exactly what I hoped they would do.

They called in return,

came down close to us,

stared at us, still calling.

I was thrilled -

we had recorded their song

and filmed them singing.

But why had this trick worked?

Well, because they thought

that the song I was playing

meant a competitor was close by,

and their response was to sing.

And this suggested one thing.

There are such things as battle songs.

Songs that say,

"Get out, this is my territory!"

It seemed to be a clear example

of Darwin's theory of sexual selection.

A male singing to defend

his breeding patch.

But this was still just guesswork.

We suspected that songs

could be weapons of war,

but it was the next recording

that proved it.

This is the song of a male great tit.

A call, a very simple song.

It was recorded by a scientist

who's been a pioneer

in understanding animal song.

Professor John Krebs.

He was the one who proved

for the first time

exactly why my playback trick

in Madagascar had worked.

Spring 1975.

Back then, John was a young lecturer

at the University of Oxford,

researching the birds in woodland

just outside the city.

First, he plotted the territories

of all the pairs of great tits.

Next, he recorded the songs of the males.

Female great tits do not sing.

Then, on a particular morning

in February,

I came out with mist nets

to catch the birds,

and I caught all the pairs of birds

that were in the woods.

Now there were no great tits,

just empty great tit territories.

In some, John replaced

the great tits with loudspeakers

that played the sounds of the birds

that he had temporarily removed.

If the song was a "keep out" signal,

then new great tits

would avoid these patches.

Other territories were left silent.

No speakers, no great tit song.

New great tits should realise these

spaces were empty and available,

and settle there quickly.

But how would John know

that it was due to a great tit song

that newcomers had been deterred?

Perhaps any sound would

have had the same effect.

So, in some territories, he played

a recording of a tin whistle.

He could have chosen anything,

as long as it sounded

nothing like a great tit.

And then I watched to see what happened,

and new birds came into the wood,

because this is a prime breeding area,

so birds love to come here to breed.

John discovered that the first

territories that were taken

were the silent territories,

and the ones with the tin whistle.

Crucially, the territories in which

the great tit song was played

remained empty of new great tits.

By looking at the detail

of that pattern of settling,

I was able to show experimentally

that song is an effective

"keep out" signal.

Professor Krebs' predictions

were exactly right.

Song was a "keep out" signal

to other great tits.

For the very first time,

there was scientific evidence

that song was being used

to intimidate rivals,

just as I had seen with the indris

in Madagascar in the '60s.

How astonishing that it was only in 1975

that this was proved for the first time.

The song of the great tit

had made history.

Open a window in spring,

and these are the singers

that serenade us.

Songbirds.

They make up about half

of the 10,000

species of birds in the world.

Five of my sevens songs are sung by them.

Birds have the most advanced vocal

organs in the entire natural world.

We have our voice box

at the top of our windpipe,

but their equivalent

is at the base of theirs -

it's an organ called a syrinx.

They're the only creatures

on Earth to have one of these,

and the syrinx of the songbird

is the most complex of them all.

As breath passes through it,

muscles contract and vibrate,

creating the sounds we call song.

It can produce different notes

from the left and right sides

simultaneously.

It's like having two voice boxes

that can operate at the same time.

So this is how songbirds can perform

such unparalleled feats

of vocal gymnastics.

But working out WHY they do

is far more complex.

Each note lasts just a tiny moment

and then disappears.

That presents anyone who wants

to study it with a problem.

But there are two

relatively recent inventions

that have helped us to capture songs.

It was with a gun mic like this,

inside its windshield,

that John Krebs caught the fleeting

sound of the great tit.

But it was the ability

to take that recorded sound

and then turn it into a visual picture

that enabled us to analyse that sound

and reveal its full complexity.

This is an animation

of the male great tit song,

generated by a machine

called a spectrograph.

It changes the song into an image

that's possible to read.

Slowed down, we can see that the

great tit song is relatively simple.

It's composed of two notes -

one high and one low - repeated.

What we hear is very similar

to what we can see on the spectrograph.

But compare that to the song

of the male wren.

What we hear is not what the bird hears.

Birds live on a different timescale,

at a different pace from us.

And they can hear details in their song

that are impossible for us to hear.

It's only when we use a spectrogram

that these details are revealed

A trill...

..a connecting note...

..another trill...

..and then a rapid

burst of trills at the end.

Now we can see that there

are perhaps 100 notes

or more in a song that may

last only a few seconds.

What the spectrograms show are

these songs are far more complicated

and complex than we could

possibly have imagined.

But why complicate things so?

The calls of the indri and the great tit

worked perfectly well.

The answer, of course, is sex.

That is the reason why so many birds

have such complex mating songs.

Females seem to prefer them.

The more intricate and detailed

the song is,

the better the male's chances.

And my third song helps to explain why.

It's a recording of a nightingale

that is my next chosen song.

This is a male singing for a mate.

Just as with the great tit,

the females do not sing.

But they are the ones the males

are singing for.

So why do they prefer more complex songs?

It's a question that has puzzled

scientists for centuries.

Charles Darwin's answer

was that the females

have an aesthetic sense.

After all, human beings

appreciate beauty.

Why shouldn't other animals do so too?

But the question Darwin didn't answer was

WHY should the females

have an aesthetic sense?

Here on the streets of Berlin,

we might just find the answer.

Spring attracts over 2,000

nightingales to this city each year.

They flock to Berlin because

it's filled with green space,

much of which has been left untamed.

And it's these wild places

that they love.

In one of its most popular parks,

a male nightingale.

He, like the other males, arrived

from Africa a few weeks ago

and has spent his time singing

to defend a breeding patch.

But tonight, when the lights go out,

he will change his tune

because the females have arrived.

Nightingales migrate at night,

and when the females fly in,

under cover of dark, they are met

with songs of seduction.

Dr Conny Landgraf made our

recording of the nightingale's song.

So right now, there's one...

Oh, no there is a second male.

So it's already two males

in a vocal contest.

What the females do is that they do

not take the first male that comes

their way, but they prospect and

inspect different male territories.

And this is like a

speed dating that is actually

going on in the middle of the night.

Each male sings his heart out

and the females listen.

Time's up!

What does the next potential

mate sound like?

Time's up again.

Does the next one have a better song?

Nightingales have extremely large

song repertoires, up to 250 songs.

And also they are able

to produce really challenging

syllables and phrases, thinking

of trill or bass elements.

So these are very fast,

repeated single notes.

So this is remarkable.

The more complex his song,

the more beautiful it seems

to the female.

But why? Does the female have

an aesthetic sense,

as Darwin suggested?

Conny and her team set up

an experiment to find out.

First, they recorded males singing

at the beginning of spring.

Then they set up cameras to record

nightingale nests

later in the season.

Male nightingales play a crucial

role in feeding chicks.

What we found in the end

was that there was indeed

a very strong correlation

between his song

and feeding rates at the nest.

So it's like a promise

that the males give to the females

to be good fathers.

So, for example, a male could be saying,

"Hey, there, I'm a healthy, strong man,

"I know this area and all the

best feeding places very well,

"so come settle down

and mate with me."

Females, Darwin said, chose

the males with the most beautiful

songs, and my third recording

has demonstrated why.

Better singers are better fathers.

Songs can be a promise

of devoted parenthood.

There are some songs

that it's impossible for me

to imagine life without.

Songs that accompany our daily lives.

It's one of the most characteristic

sounds, and to my ear

is one of the most delightful

of the English winter -

the song of the robin.

These are the songs that Charles Darwin

would have listened to as a boy.

And much of our research into song

has centred on British species.

Indeed, for much of the last

century, we thought birdsong

originated here in northern latitudes.

But what if Darwin had been raised

on the other side of the world?

Would his theories about song

have been different?

The forests of Australia.

Out here, scientists are

in the process of changing

many of our old ideas about song.

They found fossil and

DNA evidence of early songbirds,

which show that this, in fact,

is where song began.

It was here in Australia

that the ancestors

of all songbirds first evolved.

Song number four is from one

of the original songbirds'

most remarkable descendants.

And it's one that amazes me

every time I hear it.

It was recorded in the forests

just outside Melbourne,

and it was the first time

that wild birdsong had ever

been broadcast in Australia.

The song of the lyrebird, in my

view, is one of the most complex

and beautiful in the whole

of the natural world.

And what gives it its complexity

is the talent that a lyrebird has

for mimicry.

Crimson parrot.

The kookaburra.

The descendants

of that lyrebird, I'm happy to say,

are still singing in those forests,

and I've been lucky enough to listen

to one of them myself.

It was the 1990s when the BBC series

Life Of Birds took me to Australia.

I wanted to film a lyrebird

who was the most astounding mimic.

To persuade females to come close

and admire his plumes, he sings

the most complex song he can manage,

and he does that by copying

the songs of all the other birds

he hears around him,

such as the kookaburra.

He can imitate the calls

of at least 20 different species.

He also, in his attempt to out-sing

his rivals, incorporates other

sounds that he hears in the forest.

That was a camera shutter.

And again.

And now a camera with a motor drive.

And that's a car alarm.

And now the sounds of foresters

and their chainsaws working nearby.

Since this remarkable clip

was broadcast, millions of people

have watched it online.

Scientists have discovered

a lot more about lyrebird song

since that recording was made.

That particular bird was accustomed

to the presence of human beings

nearby, but much wilder

birds produce something

even more fascinating.

Sunrise, Sherbrooke Forest, today.

One voice in the dawn chorus

is louder than any other -

the male lyrebird.

It's the breeding season and they're

busy trying to attract mates.

Clearing undergrowth

from the forest floor creates

an arena for his mating display.

Once the stage is set,

the show can begin.

It's unlike any other in

the natural world.

Since I heard this song,

scientists have analysed it

and broken it down into parts.

Song A comes first.

Now song B, a loud low shriek,

which alternates with song C,

a quiet, very soft clicking sound.

A female arrives.

But no, she loses interest.

What he does next will need

to be even more impressive.

Few have analysed the grand finale

of the male lyrebird song

more intensively than

Dr Anastasia Dalziell.

She and her team were the first ones

to film it properly.

We thought no-one's going to believe

us until we've actually filmed it.

It's really not like anything else

that has been described previously

in birds or any other animals.

It was by studying the recordings

from their remote camera

that the team were able

to understand the real secret

of the male lyrebird song.

And it's this footage together

with our own that enables us to show

this remarkable behaviour

on television for the first time.

Having sung A, B and C

and been rejected, the male now

begins Song D.

So this final song,

it's the sound of a flock

of small birds mobbing,

reacting to a stationary or

a hidden predator like a snake.

And this was totally bizarre.

So why is he imitating a flock of birds?

Well, a predator means danger.

So at the sound of an alarm call,

the female freezes.

The forest is no longer a safe place.

Now the male takes advantage

of her panic.

He jumps on top of her to mate.

It's hard for us to see

her under his feathers,

and it's hard for her

to see out from under them.

He's doing everything he can

to disorientate and confuse her.

The male is actually

telling her a big fib -

don't leave me because out there,

there's a hidden predator

that you haven't seen.

To put it another way, it's like saying,

"Baby, it's dangerous outside.

"Come back here with me

where it's nice and safe."

The lyrebird is, in fact,

a bird that tells lies.

His song is an acoustic illusion.

Up to now, scientists have thought

that song was an honest

signal from the male.

But it seems song can also

be manipulative and false.

Not far away, in the Blue Mountains

near Sydney,

scientist Victoria Austin

is studying the female lyrebird.

What she's listening for

is something very few people have heard.

So what I'm doing now is

just preparing my recorder

because we're about to head to a

nest and we're hoping to be able

to record the female lyrebird

that resides in that area.

The female lyrebird

is the opposite of her flashy mate.

She's secretive.

When she is seen, she's often

mistaken for a juvenile male.

To most people, she's invisible,

but Victoria knows how to find her.

This old nest suggests

that she may be nearby.

And there she is.

This rarely heard sound

is her whistle song.

In Darwin's theory of sexual selection,

males sing to attract females,

and females drive the evolution

of song by preferring

ever more complex songs.

The females themselves do not sing.

Yet here we are listening

to a female lyrebird singing.

So what is the function of her song?

Well, the female raises her chicks alone.

The male plays no part,

so it's extremely important

for her to maintain her territory

and the food within it.

She uses song to let everyone know

that it's her patch.

And Victoria is also researching

whether song helps her in other ways.

In the last few years,

she's been recording their songs

across the Blue Mountains.

This is one of them -

a female mimicking a goshawk.

It's very accurate.

If you were to play this call

alongside an actual goshawk,

it'd be very difficult to tell

the difference, if you were able

to tell the difference at all.

So what is the purpose of

this perfect impersonation?

She's using it to deceive predators

into thinking she's more dangerous

than she actually is.

She is just as talented

as the more famous male.

So the biggest purpose of

what we're doing working

with these female lyrebirds is to

dispel this long-held myth that only

recently was shown not to be true,

and that is the idea that female

birds don't sing,

or that it's very rare.

And that's just simply not the case.

This surely challenges Darwin's theory,

as does my next revolutionary song.

My fifth song was also

recorded in Australia.

It, too, like the song of the female

lyrebird, has rarely been heard.

It's important because its

existence changes our idea

of what song actually is.

This is a fairly common Australian

bird called a fairy wren.

We filmed these birds for a BBC

series back in the 1990s.

We went there to film it

because it's extremely promiscuous.

Both male and female will mate

with many different partners.

But what few people realised

at the time, and I certainly didn't,

was that it's not just

the male that sings.

The female does, too.

This is Canberra Botanical Gardens.

Professor Naomi Langmore

was the scientist

who made our fairy wren recording.

She was one of the first to realise

the significance of female song.

The male fairy wren, with glorious,

iridescent blue and striking

black plumage is rather

difficult to miss.

So where is the female?

Well, not at the top of a perch

like the male,

but instead here, hiding in the bushes.

She is comparatively rather dull -

a drab brown.

Because females are often less

flashy and eye-catching than males,

it's very easy to miss female song.

But sing she does.

Just as male song is used in

competition with other males,

female song seems to be in

competition with other females.

But why didn't we hear her before now?

Is it really just because she's less

noticeable than the male?

In the history of the study of birdsong,

most research was done in the

northern hemisphere, in Europe

and North America, and in those regions,

female song is comparatively rare.

And so researchers working

in those regions generalised

from what they were observing

in their local birds and assumed

that male song was the norm

throughout the world.

A male-biased view of birdsong had,

to an extent, deafened us to female song.

So when I was doing my research,

it was basically assumed

that it's the male that sings

and the female doesn't.

Maybe that's because most

of the scientists were males

who were studying birdsong.

But now there's a new generation

of female scientists coming through

studying birdsong all around the world

and discovering that actually female

song is very common

and occurs in more species than not.

And it's only now that

they're properly being heard.

Naomi and her colleagues

have discovered that in 64%

of all songbird species, females sing.

And that, in the distant past,

the ancestors of all songbirds

would have had both male

and female singers.

When birdsong began,

perhaps all female birds sang.

So why don't all female birds sing today?

The answer is migration.

Male migrants like the nightingale

arrive in their breeding grounds

before the female. They set

up and defend the breeding

territories, so the females

don't need to sing.

In species that don't migrate,

like the lyrebird and fairy wren,

then often the females

will have their own territory.

And they will sing to defend it.

This female song challenges the way

scientists have thought about

sexual selection for

the last hundred years.

This recent discovery

is a paradigm shift.

It's extremely exciting,

and it really forces us again

to reconsider what we think

of as birdsong.

Birdsong was fundamental to

the formulation of Darwin's theory

of sexual selection,

and the discovery that females sing

as well

makes us challenge that theory.

Because our perception

of birdsong has been biased

towards the northern hemisphere,

we have been unaware of some

of the most thrilling bird songs

on the planet, but that view is changing.

Our understanding of song

is continually developing,

and all the time we're

learning new things.

It's a mystery that needs real

research to unravel it,

and we're still learning.

How exciting it is to think

of the discoveries

that are about to be made about birdsong.

This next ground-breaking recording

reminds us just how thrilling

those new discoveries could be...

..because it revealed to us

an entirely different world of song.

Few animal songs are more beautiful

than the ones that are recorded

on this disc, and yet had it not

been for recent technological

advances, we would never have known

that such songs existed.

The waters off the coast of Bermuda.

US Navy engineers are using

underwater microphones called

hydrophones to listen

for enemy submarines.

This is what they pick up.

It's not a submarine or indeed

any kind of man-made noise.

I'll always remember the first

time I heard those songs.

It brought back to my mind

the stories of sailors

in the old sailing ship days

out at sea in their bunks,

hearing those wonderful, eerie

sounds resonating through the ship.

It didn't come, of course, from

a mermaid, but something perhaps

even more extraordinary - a gigantic

creature weighing many tonnes.

A whale.

Almost unbelievably, this was

the first time that anyone had ever

identified the sound of a whale.

When biologist Dr Roger Payne

heard it, he was thrilled.

It was back in 1967 about that I met

a fellow named Frank Watlington,

who became a great friend,

and he played a sound to me

of humpback whales.

It was the most beautiful thing

I had ever heard from nature.

The first time I ever went swimming

with a whale that was singing,

it's such an incredible experience,

it's completely shattering.

It feels like, when you get

close to one, that something

has put its hands on your chest

and is shaking you

until your teeth rattle.

My first thought was, I wonder

if I can stand this, I wonder

if this is actually going

to kill me somehow.

The question was, would we call

these sounds songs?

Some were short, like birdcalls,

but others were longer,

some up to half an hour.

Speeded up, this is what

they sounded like.

They sounded like birdsong.

Roger called them songs.

In the late 1970s, I too went

swimming with humpback whales.

I remember seeing this creature

below me and then hearing its song.

It was thought they sing

for the same reason as birds -

males singing to rivals

and potential mates.

But no-one has ever seen

a female listening.

In truth, no-one really knows

why whales sing.

But one thing is certain - the sound

of their song saved them from us.

In 1970, Roger released an album

called Songs Of The Humpback Whale.

At the time, we had been killing whales,

mainly for their oil, for centuries.

We were very close to exterminating

them out of sheer greed.

Then we heard their song.

Whole bunches of people in several

countries began making organisations

to save the whales and the Save

the Whales movement was born,

and in many ways that

was sort of the beginning

of the conservation movement.

The conscience of the world was

woken by this song of the whale.

We heard it just in time to save them.

But for my next and final singer,

there was no such reprieve.

There are few songs

more haunting than this.

It's a male Hawaiian 'o'o bird

calling for a mate.

But is he singing into silence?

Habitat destruction

and the introduction of invasive

species have decimated

many Hawaiian

songbirds, including the 'o'o.

It may well be that by the time

this recording was made,

there were no females left alive.

It's the sound of a male singing

for a mate who no longer exists.

The 'o'o has since been declared extinct.

He was the last of an entire bird

family found nowhere else on Earth.

Now gone.

There is no more dramatic reminder

of this loss than this sound.

And how many more songs have we lost

in other parts of the planet?

Here in Britain, it's estimated

that 38 million birds

have disappeared from our skies

in the last 60 years.

One in five gone.

Climate change, habitat deterioration

and the resulting

decrease in food and other resources

are thought to be the main factors

behind this catastrophic decline.

It's now up to us to decide how many

more songs

we will allow

to fade into silence.

These songs enrich our lives, too.

They're surely amongst

the loveliest in the universe.

And without them, our lives

would truly be impoverished.

And what is lost when the songs

fall silent is more than just

an enchanting operatic backdrop

to our own lives,

because for the creatures that sing

them, songs are far more than that.

They are a weapon of war...

..a serenade, a promise

of parenthood, a daring deceit...

..or perhaps something

even more astonishing

that we are yet to discover.

Each one a marvellous example of

the spectacular survival strategies

that animals have developed

in order to stay alive.

That is why I'll never cease to wonder at

the beautiful sounds

we call song.

Few sounds of nature are

more beloved by this nation

than that of the nightingale.

And there's one more recording

of it that I have memories

of listening to as a child.

It was made by the BBC two years

before I was born, in May 1924.

It's a cello accompanied

by a nightingale.

In this country, it was ground-breaking.

It is, in fact, the first live

broadcast of any wild animal song.

The idea came from a celebrated

cellist called Beatrice Harrison.

One night when

I'd been playing for hours,

I suddenly heard the note

of the most heavenly bird,

and it struck me how lovely it

would be if he could be broadcast.

The nation held its breath

while Beatrice played.

It was the first time

that the wild world of nature

came straight into your living room.

Perhaps a million listeners tuned

in to that first broadcast.

It was so popular, the BBC

made it an annual event.

The performance became so celebrated

that Beatrice was asked to recreate

it for a 1943 film

with Sir Laurence Olivier.

It was far from the first time,

of course, that the nightingale

had made a cultural appearance.

The nightingale has inspired poets

and musicians for ages, and perhaps

the most famous poem of all

is by John Keats.

Thou was not born for death,

immortal Bird!

No hungry generations tread thee down,

The voice I hear this

passing night was heard

In ancient days by emperor and clown.

Keats wrote those lines

in Hampstead in London,

but he wouldn't hear

a nightingale there today.

There are no nightingales in London now.

In fact, we've lost over 90%

of nightingales in this country

in the last 50 years.

What a tragedy.

The causes are still not

fully understood...

..but habitat deterioration probably

played a significant part.

In one small corner of Britain,

however, there is a place trying

to provide the nightingale

with a safe haven.

The Knepp Estate in West Sussex -

3,500 acres that was once farmland.

But the soil here wasn't suited

to modern-day intensive agriculture.

Since 2001, it's been left to nature.

There aren't many rewilding projects

in Britain as pioneering as this.

Wildlife now thrives here...

..including some of the country's

rarest species.

This, for many of Britain's

best-loved songbirds,

is an ideal place for shelter and food.

The nightingale is one of many

species found at Knepp.

Here, dense, almost

impenetrable thorny scrub

provides their ideal nesting site.

Today, it's late spring and one nest

of chicks is being ringed.

This makes it possible to gather

vital information that can help

monitor population numbers.

There are estimated to be more

than 40 nightingale territories

in this area of the estate.

Back when it was intensively farmed,

there were only nine.

Few places in Britain have

nightingales increasing

in such numbers.

It gives us hope, perhaps,

that the British countryside

could once more be filled

with the nightingale's

beautiful and iconic song.

How wonderful it would be if each of

us could say we've heard the songs

of the Earth and we've saved them.