KATY PAYNE: I'd been interested in large, social animals for a long, long time, because we had found that humpback whales sing long, complicated songs. And I'd been for a number of years helping to record them at sea and discovering that their songs were continuously changing-- evidence of a complex mind, a more complex social system than people perhaps had suspected for these animals.
So what do you think of on land? What do you think of when you would like to be able to see the animal that you're recording? Elephants, of course. And with my old friend Bill Langbauer, we had been thinking about what elephants in captivity, particularly in India, and their mahouts must know about each other. After all, they lived together all their lives.
And I wondered whether there might be some way that we could find out how elephants think and what their communication system is like. So I went to a zoo, actually, at the tail end of a symposium about whales out in California.
And in the zoo, I had permission to sit next to the elephant cage for a week. That's exactly what I did. And saw little bits of evidence of the wonderful things that you hear about from the field research in Kenya.
A large, highly coordinated social groups in which some animals were more interested in others than in some others. But I didn't hear anything that I thought was evidence of anything that people didn't already know.
But I happened to notice after some days that every now and then, I was feeling a throbbing in the air. Kind of a pulsation in my ears. Sort of the feeling you get if the windows are rolled down wrong in your car.
And it occurred to me that this might be sound below the frequencies that I, as a human being, could hear, and eventually that it might be made by the elephants and they might be communicating with each other in ways folks didn't know about.
So sound. Maybe this was sound. Maybe not. But I came back to Cornell where I had just started working at the lab of Ornithology in what would later become the Bioacoustics Research Program and talked to Carl Hopkins and Bob Capranica, both acoustic biologists in neurobiology and behavior.
And they said, oh, my goodness. We aren't listening to that part of the acoustic spectrum. Take our equipment, go back to the zoo, take your old friend Bill, and see what you come up with.
So for a month, we recorded. Bill and Elizabeth Marshall Thomas and I recorded almost continually in the same zoo environment that had 11 elephants and kept track of all the behavior that we could see as well.
And what happened was nothing. We didn't hear very much. But every now and then, we would feel a pulsation. When I came back at the end of the month, I didn't think we had anything.
Went and saw Carl. We played back one of these sessions when the old female, who was acting like a matriarch, had walked to the end of the 90-foot cage flapping her ears loudly, blowing out loudly, and we had felt the throbbing in the air.
Liz had run outdoors to see what the male who was in the breeding condition called musth was doing. He had a huge sand yard. He was very irritable. He was throwing stuff at tourists.
But on this occasion, he had come right up to the outside of that same wall that the female was on the inside of. And they were only two feet apart from each other through a thick slab of concrete.
And lo and behold, when with Carl, we sped up the tape that I had recorded that it sounded like nothing except the flapping of the ears. Now, the ears-- --were like this. And in-between, we heard--
[IMITATING HIGH-PITCHED AND LOW-PITCHED ELEPHANT NOISES]
The voices of two animals now 2 and 1/2 octaves higher than what they had been when we recorded them.
[ELEPHANT SOUNDS PLAYING]
SPEAKER: This is the female. That's the male. Female. Male. Female. Male. Female and the male underneath.
KATY PAYNE: Well, it was a discovery, of course, that was interesting because we couldn't hear what the elephants could hear. But it was also interesting because very low frequency sound travels much better than higher sounds. And so this might be the basis of a long distance communication system.
And there had been a mystery in the recordings-- always visual records-- of elephant behavior in Amboseli Made by Cynthia Moss, Joyce Poole, Ian Douglas-Hamilton. Ian said, maybe there's ESP.
Because again and again, these researchers had discovered that an elephant at a great distance seemed to know what another elephant 2 miles away was doing. The males who lived separately from the females were able to find the females during the tiny window of four or five days out of four or five years when a female is in breeding condition. The males would come.
The females lived in groups that were coordinated with each other on many levels. There were some groups that were very close. Those are obviously genetically related. Old sisters would be the leaders of those groups.
But there were other groups that seemed to behave like friends. We didn't know at the time how they were related. And they, rather than staying together all the time, would forage separately at distances that could be reached if you were using infrasound and could not by any other means people knew about.
So we went to Africa. I went to Africa first to work with Joyce Poole, who was beginning to study acoustic communication in a population of elephants she and Cynthia Moss knew very well as individuals.
And there we did verify each of these hunches-- that the males were probably using female calls which were quite loud to find the females in breeding condition. And that there was all kinds of communication that seemed to be linking up females in groups and in related or friendly groups.
Look-- who are elephants, anyway? I mean, we had a sense already that they were immensely complicated. That their societies were maybe touching on what we know as human beings with all kinds of relationships-- friendly, unfriendly, suspicious, and desirous.
And so it seemed as though it might link all these many, many observations that people had been making over the years. But then, still, we didn't know that all this was happening. And Bill Langbauer, who had trained in zoo experimental work, took us back. We went back not to Kenya but to Etosha Park in Namibia.
And there, we did a series of experiments where we played back from a huge loudspeaker calls made by elephants whose original volume we knew to elephants a kilometer and two kilometers away.
And we were looking out for particular behaviors. Were these elephants that we were watching from the top of the tower down at a waterhole, would they suddenly freeze? Would they lift their ears? Would they tighten them like this as if something was going on that they needed to listen to?
Would they swing their heads from side to side? And if it was a female group, would the composition of the group change? Would they form a dense cluster?
We found that all of these things happened even from the calls that we played from two kilometers away.
[SOUND OF ELEPHANTS CRYING OUT]
And because we were only playing those calls at half volume, then we extrapolated that probably elephants could hear each other's calls considerably farther than two kilometers.
Well, then it became very interesting to know whether the environment was playing a role in the transmission of these calls. And a couple of atmospheric scientists from the University of Virginia, Mike Garstang and David Larom, did an experiment in Etosha Park where they established that there is every evening and throughout the night a so so-called temperature inversion.
That is to say, cold air has come in just before sunset and made a layer. And then the warm air has risen and formed a kind of a ceiling. Well, that layer of cold air produces a duct through which low frequency sound travels extremely well. It's even enhanced.
And these guys taking the measurements we had made of the original volume of the calls the elephants were making found out that when the temperature inversion is really there, about 80% of the time in the Savanna, these calls which we had measured carrying at least two kilometers-- at least causing behavioral changes over those distances-- these calls could maybe go as much as 10 kilometers at the very best.
And isn't that fascinating? And this all feeds in with all kinds of anecdotes about elephants in one place knowing that a call is occurring many miles away and so forth. So it begins to inform us about what their perceptual world is like.
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Elephants in the wild seem to coordinate their movements even when widely separated. Male elephants seem to be able to find females in estrous even over long distances.
Bioacoustics researcher Katy Payne and her colleagues have found that elephants use low frequency sounds to communicate. These sounds are mostly below the range of human hearing but we feel them as "pulsations" in the air. In Africa these sounds may travel as far as 10 km and serve to coordinate elephant herds.
Payne is co-founder of the Elephant Listening Project, which uses acoustic methods to study and aid in the conservation of forest elephants in Central Africa.