-
(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 Rain Forest you're hearing behind me.
-
In fact, temperate and tropical rain forests
-
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 some of that information I want to share with you today.
-
The soundscape is made up 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 a thousand 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
-
— fifteen 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 the 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.
-
(Laughter)
-
But I can tell you that they do express themselves.
-
Whether or not we understand it is a different story.
-
I was walking along a shore in Alaska,
-
and I came across this tide pool
-
filled with a colony of sea anemones,
-
these wonderful eating machines,
-
relatives or 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 those 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 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 the 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 that 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 spacial context,
-
while soundscapes widen that scope
-
to a full 360 degrees, completely enveloping us.
-
And while a picture maybe worth a thousand words,
-
a soundscape is worth a thousand 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)