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(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)
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B1 Intermediate US

【TED】Bernie Krause: The voice of the natural world (Bernie Krause: The voice of the natural world)

6462 Folder Collection
Max Lin published on January 14, 2016

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