Surprising communication between elephants

2001/09/02 Mendiburu, Joana - Elhuyar Zientziaren Komunikazioa

• Zoologia

The elephants collect the signs by observation and the horn.

Elephants seem to be able to perceive distant storms and hunters 50 kilometers away. It is impossible to take advantage of hearing or smell in such large areas, but then, what pushes them to react like this? What are the signals they receive? The zoologist Lynette Hart is convinced that, thanks to the help of other experts, he has answered this question. It is certain that elephants communicate with each other through acoustic and seismic waves. But elephants are ingenious and the study of elephant groups seems more than a surprise.

Initial curiosity: Initial curiosity

The first real suspicions that elephants can feel remote vibrations arise in 1992, when Caitlin O'Connell-Rodwell saw this peculiar way of proceeding from Namibian elephants: "They stand, bend forward and raise a foot." Despite its rarity, this behavior was known to the researcher and it is not surprising that, when feeling silent noises, some insects saw doing the same. O’Connell-Rodwell explained this: "Raising a foot, they join better to the ground with the other three feet", so they feel better the movements of the soil. But he returned to the United States without defining what he feels exactly.

They are able to notice a storm 150 kilometers away.

On his return he told Lynette Hart what he saw and surprised him. It was suspected that elephants communicate through waves, but, as the proverb says, the corrupt belief. Suspicions should be checked, for which it was essential to analyze groups of elephants and perform seismic measurements. Fortunately, Lynette Hart had no difficulty finding the person who would help him to do so. Without going further, his brother Byron, geophysical, gave him a blow of hand. With the necessary material and knowledge in hand, together with all the others, he went to listen, see and learn to a sanctuary in Texas.

Thus began the work that investigated the way elephants acted and that at least contributed part of the answer to the initial questions.

Measuring signs sent

His feet are more sensitive than expected.

Byron Arnasa, analyzing the measurements of air and terrestrial waves, concluded that the signs of communication of elephants had adequate characteristics to be transported by the ground. To measure air vibrations, microphones were placed in a circumference of 10 to 45 meters from the elephants and geophones to measure terrestrial waves. Thus they realized that the acoustic and seismic waves did not have the same speed. In addition, they measured at what rhythm they disappeared and saw that they remain longer in the soil than in the air. On the other hand, they assured that the sound emitted by elephants does not disappear before 10 kilometers and that when they complain or nervous they spread 32 kilometers.

How do the signs of communication receive?

To complete the communication system, the receiver is as important as the transmitter. Therefore, knowing that they send waves causes a second question to be asked. How are acoustic and seismic waves performed? The first part of the question was answered by the expert of the Oregon Institute of Science and Technology, Bets Rasmuss. Rasmussen, recalling the work done in India to investigate how elephants use their developed smell, responded: "I think they perceive the signals with the trumpet."

To catch the signs of communication, the elephants stop, bend forward and lift a foot.

In Rasmuss he was the first to investigate elephant trumpets and, in his work, he investigated how elephants perceive pheromones. Pheromones are substances that an animal throws into the medium in small amounts and that cause certain behaviors in the same species. In the case of elephants, it was already known that pheromones are detected thanks to special organs that have on the palate, but Rasmussen's research went further. In addition to the palate he noticed that they have chemical receptors at the tip of the tube.

In his research with Lynette Hart he found no chemical signal. However, specialized cells that detect waves discovered the so-called blood cells in Panicia. These cells, like an onion, are formed by overlapping layers. The latter, by action of the waves, deform and send the signal to the brain. These blood cells have also been found in other mammals, such as human hermitages, but at a much lower concentration than in elephants.

Despite reaching these surprising conclusions, Lynette Hart and O’Connell-Rowell still had another pending question. If you detect waves with the tube, why do you usually lift your foot? Shortly after continuing to investigate, he was found an answer to this question.

Elephants are found on the fingers and these are fixed in adipose tissue under the foot. Seismic waves inflate adipose tissue, which stimulates not only the special cells in the trunk, but also the feet. As discussed above, being on the three feet helps to feel the waves better.

This research provoked great expectation among experts and the conclusions served to explain other ways of acting. For example, the researchers knew that an elephant, when found another dead, caresses with the foot, but did not understand why. Now, with this new research, it is believed that the feet of elephants are more sensitive than expected.

Lynette Hart and O’Connell-Rodwell’s research has been important in understanding the importance of elephant communication. It is now clear that, despite being dispersed by large extensions, seismic and acoustic waves make elephants have no problem in circulating in the same direction. In addition, elephants are considered to repel acoustic and seismic waves to determine the origin distance of the signal. Likewise, to define the meaning of the signal, it is sufficient to take into account the foot from which they receive the signal.

A thousand questions in the air

As already mentioned, research has served to understand the behavior of elephants and the importance of what the human being cannot feel or see. But like all studies, this, after an answer, generates a thousand new questions.

For example, since changes from one wave to another are based solely on their duration and frequency, the emitted signals must be simple. But how do they identify them? What is the meaning of each sign? Does a group 50 kilometers away perceive the waves of the hunters' helicopter or the elephant race in danger? How is a storm 150 kilometers away?

This type of questions are pending in response. There is still much to learn and, in addition, it does not seem that the answers to these questions are immediately discovered. As has already been indicated, the elephant is an intelligent animal and, despite detecting the wave, it has no special importance or someone knows why, it can ignore it and that makes it very difficult to define what wave is capable of detecting.

Published in the supplement Natura de Gara.