How to pronounce "owls"

(Nature sounds)

When I first began recording wild soundscapes

45 years ago,

I had no idea that ants,

insect larvae, sea anemones and viruses

created a sound signature.

But they do.

And so does every wild habitat on the planet,

like the Amazon rainforest you're hearing behind me.

In fact, temperate and tropical rainforests

each produce a vibrant animal orchestra,

that instantaneous and organized expression

of insects, reptiles, amphibians, birds and mammals.

And every soundscape that springs from a wild habitat

generates its own unique signature,

one that contains incredible amounts of information,

and it's some of that information I want to share with you today.

The soundscape is made up of three basic sources.

The first is the geophony,

or the nonbiological sounds that occur

in any given habitat,

like wind in the trees, water in a stream,

waves at the ocean shore, movement of the Earth.

The second of these is the biophony.

The biophony is all of the sound

that's generated by organisms in a given habitat

at one time and in one place.

And the third is all of the sound that we humans generate

that's called anthrophony.

Some of it is controlled, like music or theater,

but most of it is chaotic and incoherent,

which some of us refer to as noise.

There was a time when I considered wild soundscapes

to be a worthless artifact.

They were just there, but they had no significance.

Well, I was wrong. What I learned from these encounters

was that careful listening gives us incredibly valuable tools

by which to evaluate the health of a habitat

across the entire spectrum of life.

When I began recording in the late '60s,

the typical methods of recording were limited

to the fragmented capture of individual species

like birds mostly, in the beginning,

but later animals like mammals and amphibians.

To me, this was a little like trying to understand

the magnificence of Beethoven's Fifth Symphony

by abstracting the sound of a single violin player

out of the context of the orchestra

and hearing just that one part.

Fortunately, more and more institutions

are implementing the more holistic models

that I and a few of my colleagues have introduced

to the field of soundscape ecology.

When I began recording over four decades ago,

I could record for 10 hours

and capture one hour of usable material,

good enough for an album or a film soundtrack

or a museum installation.

Now, because of global warming,

resource extraction,

and human noise, among many other factors,

it can take up to 1,000 hours or more

to capture the same thing.

Fully 50 percent of my archive

comes from habitats so radically altered

that they're either altogether silent

or can no longer be heard in any of their original form.

The usual methods of evaluating a habitat

have been done by visually counting the numbers of species

and the numbers of individuals within each species in a given area.

However, by comparing data that ties together

both density and diversity from what we hear,

I'm able to arrive at much more precise fitness outcomes.

And I want to show you some examples

that typify the possibilities unlocked

by diving into this universe.

This is Lincoln Meadow.

Lincoln Meadow's a three-and-a-half-hour drive

east of San Francisco in the Sierra Nevada Mountains,

at about 2,000 meters altitude,

and I've been recording there for many years.

In 1988, a logging company convinced local residents

that there would be absolutely no environmental impact

from a new method they were trying

called "selective logging,"

taking out a tree here and there

rather than clear-cutting a whole area.

With permission granted to record

both before and after the operation,

I set up my gear and captured a large number of dawn choruses

to very strict protocol and calibrated recordings,

because I wanted a really good baseline.

This is an example of a spectrogram.

A spectrogram is a graphic illustration of sound

with time from left to right across the page --

15 seconds in this case is represented —

and frequency from the bottom of the page to the top,

lowest to highest.

And you can see that the signature of a stream

is represented here in the bottom third or half of the page,

while birds that were once in that meadow

are represented in the signature across the top.

There were a lot of them.

And here's Lincoln Meadow before selective logging.

(Nature sounds)

Well, a year later I returned,

and using the same protocols

and recording under the same conditions,

I recorded a number of examples

of the same dawn choruses,

and now this is what we've got.

This is after selective logging.

You can see that the stream is still represented

in the bottom third of the page,

but notice what's missing in the top two thirds.

(Nature sounds)

Coming up is the sound of a woodpecker.

Well, I've returned to Lincoln Meadow 15 times

in the last 25 years,

and I can tell you that the biophony,

the density and diversity of that biophony,

has not yet returned to anything like it was

before the operation.

But here's a picture of Lincoln Meadow taken after,

and you can see that from the perspective of the camera

or the human eye,

hardly a stick or a tree appears to be out of place,

which would confirm the logging company's contention

that there's nothing of environmental impact.

However, our ears tell us a very different story.

Young students are always asking me

what these animals are saying,

and really I've got no idea.

But I can tell you that they do express themselves.

Whether or not we understand it is a different story.

I was walking along the shore in Alaska,

and I came across this tide pool

filled with a colony of sea anemones,

these wonderful eating machines,

relatives of coral and jellyfish.

And curious to see if any of them made any noise,

I dropped a hydrophone,

an underwater microphone covered in rubber,

down the mouth part,

and immediately the critter began

to absorb the microphone into its belly,

and the tentacles were searching out of the surface

for something of nutritional value.

The static-like sounds that are very low,

that you're going to hear right now.

(Static sounds)

Yeah, but watch. When it didn't find anything to eat --

(Honking sound)

(Laughter)

I think that's an expression that can be understood

in any language.

(Laughter)

At the end of its breeding cycle,

the Great Basin Spadefoot toad

digs itself down about a meter under

the hard-panned desert soil of the American West,

where it can stay for many seasons

until conditions are just right for it to emerge again.

And when there's enough moisture in the soil

in the spring, frogs will dig themselves to the surface

and gather around these large, vernal pools

in great numbers.

And they vocalize in a chorus

that's absolutely in sync with one another.

And they do that for two reasons.

The first is competitive, because they're looking for mates,

and the second is cooperative,

because if they're all vocalizing in sync together,

it makes it really difficult for predators like coyotes,

foxes and owls to single out any individual for a meal.

This is a spectrogram of what the frog chorusing looks like

when it's in a very healthy pattern.

(Frogs croaking)

Mono Lake is just to the east of Yosemite National Park

in California,

and it's a favorite habitat of these toads,

and it's also favored by U.S. Navy jet pilots,

who train in their fighters flying them at speeds

exceeding 1,100 kilometers an hour

and altitudes only a couple hundred meters

above ground level of the Mono Basin,

very fast, very low, and so loud

that the anthrophony, the human noise,

even though it's six and a half kilometers

from the frog pond you just heard a second ago,

it masked the sound of the chorusing toads.

You can see in this spectrogram that all of the energy

that was once in the first spectrogram is gone

from the top end of the spectrogram,

and that there's breaks in the chorusing at two and a half,

four and a half, and six and a half seconds,

and then the sound of the jet, the signature,

is in yellow at the very bottom of the page.

(Frogs croaking)

Now at the end of that flyby,

it took the frogs fully 45 minutes

to regain their chorusing synchronicity,

during which time, and under a full moon,

we watched as two coyotes and a great horned owl

came in to pick off a few of their numbers.

The good news is that, with a little bit of habitat restoration

and fewer flights, the frog populations,

once diminishing during the 1980s and early '90s,

have pretty much returned to normal.

I want to end with a story told by a beaver.

It's a very sad story,

but it really illustrates how animals

can sometimes show emotion,

a very controversial subject among some older biologists.

A colleague of mine was recording in the American Midwest

around this pond that had been formed

maybe 16,000 years ago at the end of the last ice age.

It was also formed in part by a beaver dam

at one end that held that whole ecosystem together

in a very delicate balance.

And one afternoon, while he was recording,

there suddenly appeared from out of nowhere

a couple of game wardens,

who for no apparent reason,

walked over to the beaver dam,

dropped a stick of dynamite down it, blowing it up,

killing the female and her young babies.

Horrified, my colleagues remained behind

to gather his thoughts

and to record whatever he could the rest of the afternoon,

and that evening, he captured a remarkable event:

the lone surviving male beaver swimming in slow circles

crying out inconsolably for its lost mate and offspring.

This is probably the saddest sound

I've ever heard coming from any organism,

human or other.

(Beaver crying)

Yeah. Well.

There are many facets to soundscapes,

among them the ways in which animals taught us to dance and sing,

which I'll save for another time.

But you have heard how biophonies

help clarify our understanding of the natural world.

You've heard the impact of resource extraction,

human noise and habitat destruction.

And where environmental sciences have typically

tried to understand the world from what we see,

a much fuller understanding can be got from what we hear.

Biophonies and geophonies are the signature voices

of the natural world,

and as we hear them,

we're endowed with a sense of place,

the true story of the world we live in.

In a matter of seconds,

a soundscape reveals much more information

from many perspectives,

from quantifiable data to cultural inspiration.

Visual capture implicitly frames

a limited frontal perspective of a given spatial context,

while soundscapes widen that scope

to a full 360 degrees, completely enveloping us.

And while a picture may be worth 1,000 words,

a soundscape is worth 1,000 pictures.

And our ears tell us

that the whisper of every leaf and creature

speaks to the natural sources of our lives,

which indeed may hold the secrets of love for all things,

especially our own humanity,

and the last word goes to a jaguar from the Amazon.

(Growling)

Thank you for listening.

(Applause)