Societies of Sound in the Forest Evidence suggests at least one group of insects, the tiny treehopper, communicates using sound vibrations. Researcher Rex Cocroft has scoured a biologically rich piece of the Amazon in eastern Ecuador to record the sounds of the tiny insect.
NPR logo

Societies of Sound in the Forest

  • Download
  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript
Societies of Sound in the Forest

Societies of Sound in the Forest

  • Download
  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript


It's MORNING EDITION from NPR News. I'm Steve Inskeep.


And I'm Renee Montagne.

And this morning we rejoin a National Geographic Radio Expedition. This is part two. Yesterday, when we left NPR's Alex Chadwick in the rainforest of the Amazon in eastern Ecuador, he was following an insect researcher.

(Soundbite of the insect sounds)

ALEX CHADWICK reporting:

Of all the creatures we encounter, surely insects are the most alien. Evolutionarily speaking, we must share something. But, the segmented body parts, the hard-cased shells in neon colors, the weirdness, what's common with us? Listen...

(Soundbite of insect sounds)

CHADWICK: Listen, across perhaps 100 million years, and a few inches of green stem. They're calling to each other, just as we do.

(Soundbite of insect sounds)

CHADWICK: It's so hot, hot here. It's 8:30 in the morning.

These are trail men from Ecuador's Amazon region.

This is our second hike of the day. I'm completely drenched in sweat.

We are in the forest with a professor from the University of Missouri-Columbia. Rex Cocroft is looking for a group of insects called tree hoppers - the scientific name, Membracidae.

Professor REX COCROFT (Researcher and Professor, University of Missouri-Columbia): The more you understand about them, the more fascinating and beautiful they become.

CHADWICK: This forest, this part of the Amazon, has a reputation for more different kinds of life than anywhere on earth. There must be hundreds of species of Membracidae, but they're easily missed in this dazzling bio-kaleidoscope.

Prof. COCROFT: It, honestly, it's a bit like developing an eye for art.

CHADWICK: Rex studies the evolution of social communication. Tree hoppers are good subjects. They signal each other by vibrating the plant stems where they live. Scientists discovered this only relatively recently. Insect lives are much more complex than we had thought.

When you say that you are studying a previously unknown evolutionary radiation, what do you mean?

Prof. COCROFT: Like most biologists, we're very interested in the tremendous diversity of species. And, to understand biological diversity, we can't just have lists of species. But we need to look at their traits, their individual and unique adaptations, the things that enable them to survive and do well in their environment. And in this group of insects, the way that they are able to survive on plants is to be social and to live in groups. And what I found is that, within those social groups, individuals in those groups are communicating.

CHADWICK: Everything communicates here. Buzzing, beating, breathing - the Amazon is like a riot of sound and light and life. It rains for days. We don't so much hike parts of these trails as wade them.

Prof. COCROFT: The Nago Trail leads to the lake. And in the last 24-hours, the trail has become something of a lake itself. It's flooded (unintelligible).

CHADWICK: Let me see how deep.

Here, high ground again, and a clearing. Rex pauses.

Prof. COCROFT: Oh, this is a really great area. We should just spend a little time looking around.

CHADWICK: Okay. I see a lot of ants here, but not so many (unintelligible).

Prof. COCROFT: Well, they're quite small. So here's a group of about 30. They're nymphs. Here's another group of 30 or 40.


Prof. COCROFT: They're just very small. And they often do look like a part of the plant. So practically anywhere you look, here.

CHADWICK: Some of these creatures are the size of a grain of rice. But their various forms and colors can be elegant, dramatic even. I photograph a tree hopper that sort of resembles a tiny castle. Others are in brilliant patterns of yellow and orange and black and red.

Prof. COCROFT: By the first glance, you see that some of them are beautifully colored, or beautifully shaped. They're just fascinating. And some are specked. And that's before you ever listen to them. But yes, there is this entirely other aspect that comes in through very different senses of their communication signals, and their mating signals are often beautiful, or very eerie, or surprising, or even humorous to our ears, but a very, rich, complex set of sounds.

CHADWICK: Special pickups carefully clipped to a stem allow Rex to hear what a treehopper does. What the forest really sounds like.

Prof. COCROFT: We're really very much in a discovery phase. It might be like a lot of linguists or anthropologist might do to describe the diversity of languages in an area. So I've been here at Tiputini for three days and already I found kinds of communication signals very different from any of the ones that I've recorded before. I've been walking down the trail in lead here. A mistake. And I just noticed this web when I a few inches from it. And there's this creature that built it. A spider. Its body is more than an inch long. The legs are a couple of inches on each side of that. It's got a kind of a dark back, yellow-speckled belly, and enormous jaws. I've been watching this spider for a couple of minutes and it hasn't moved, but it just spit something out. The insect population in this forest is said to be the most diverse in the world, more different kinds of insects than anywhere else. I would just guess that that applies to spiders as well, 'cause I've seen many, many different spiders.

It can seem very strange to people, I think, and very ludicrous to see some grown person who's spending their time chasing around tiny, strange bugs in the woods, but I think of it like somebody who's a musician. You're not a pure musician in the abstract. You play something, and then once you pick up an instrument, all the principles of music are there. And if you're studying biology, then any individual living thing that you could study has all the principles of biology wrapped up in it. And it has a long, evolutionary history. It has solved a very impressive set of problems and challenges. It has a beautiful set of adaptation.

(Soundbite of howler monkey)

CHADWICK: What's that calling over there, Rex?

Prof. COCROFT: Howler monkeys.

CHADWICK: Those are howler monkeys. Many things are new to me here. And others normally familiar are grown to monstrous proportions: spiders, katydids, moths. But in the week I am here probably the most fantastic things I see, or hear, are the treehoppers.

Prof. COCROFT: They're just very different from us but they have just as many challenges in their lives and have very finely tuned adaptations for dealing with them. So they're not at all primitive or simple. They're actually very complex and advanced, if you will.

CHADWICK: That's Rex Cocroft studying animal communication, evolution and something calling from a very long time ago. And they are still calling now here in the Amazon. For Radio Expeditions at the Tiputini Biodiversity Research Station in Eastern Ecuador, this is Alex Chadwick, NPR News.

MONTAGNE: Radio Expeditions is a co-production of NPR and the National Geographic Society. To see the bright bugs, hear them and hear podcasts of the journey to Tiputini visit

Copyright © 2006 NPR. All rights reserved. Visit our website terms of use and permissions pages at for further information.

NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.