Life without vocal communication is quite hard to imagine. Humans rely on communication for social interactions and to exchange information — many animals also use vocal communication to develop complex social networks. However, research into animal communication has only picked up in the last 50 years.

The Bioacoustics Research Program (BRP), a unit in the Cornell Lab of Ornithology, researches the communication of whales, elephants, birds and many other animals. Started as a small group studying animal communication, the division has grown to accommodate engineers, computer scientists, and wildlife researchers. While the members of the BRP come from many different backgrounds, their research aims to use knowledge of animal communication for conservation.

Katy Payne, the now retired head and founder of the Elephant Listening Project (ELP) originally became interested in studying animal communication after graduating from Cornell as a Music major. She began studying humpback whale songs and made several discoveries about the role of sound in the social relationships of whales.

“Females were probably choosing males on the basis of their songs,” Payne explained. Her research also showed that whale songs evolved very rapidly. “The guess is that it’s sexual selection, that females are choosing males with slightly different songs,” Payne said. This discovery contributed to the greater body of evidence that complex social networks existed in groups of non-human animals.

Describing her experiences at the Portland zoo while observing elephants in 1984, Payne explained, “Every now and then I would feel a throbbing in the air. And I thought, maybe this is sound below the frequencies that I, as a human being, am sensitive to.” She eventually discovered that elephants communicate with frequencies below the limit of human hearing, or infrasound. This breakthrough led to almost two decades of research on elephant communication.

In 1999, Payne initially established the ELP to study the communication of forest elephants. “Forest elephants can’t be surveyed,” Payne explained. “They can’t be studied visually, because they live in these little clearings in a big forest.” However, studying their calling behavior can tell researchers about the size and composition of the population. This basic biological information about the health of a population is essential to understanding how to protect these animals, an ultimate goal of the conservation-oriented Elephant Listening Program.

Research from the ELP indicates that elephants express emotion, intention, physical characteristics and other complex information through vocal communication. According to research assistant Liz Rowland, the ELP hopes to record the sounds of many other organisms found in the forests of Africa in order to analyze the biodiversity of these areas in the future.

Dr. Christopher Clark, I. P. Johnson director of Bioacoustics at the Cornell Lab of Ornithology and an engineer by training, conducts research on whale communication. Like research in the ELP, his research is also conservation-oriented. “I look at [my research] as acoustic ecology,” Clark explained. In order to communicate and maintain a social fabric, whales need a quiet ocean to communicate. However, due to the noise created by humans, this communication system is falling apart. Clark found that whales have raised their songs by an octave in pitch in an effort to be heard, and that mothers had decreased in weight and were unable to have calves as frequently. “There are strong biological indicators that about 80% of the time, chances of communication between individuals are gone,” explained Clark. Finding connections between scientific data and population impact, he asserted, is part of the conservation-oriented research conducted at the BRP.

As director of Bioacoustics, Clark fosters interaction between scientists of many different backgrounds. “The scale of what we’re trying to do has only been achieved by having a multifaceted group with people that are immensely talented,” he said.

In order to study animal communication, researchers from the BRP set up recording devices around the periphery of the area where the species to be studied is located. They pinpoint which individuals produce each call based on the direction from which the sound was received on the recording device. These sounds can then be differentiated using a spectrogram, which provides a visual image of the changes in frequency of the sound, and spectrogram patterns can be used to identify the call of a particular species. These techniques are common to whale, elephant and bird communication research.

Currently, the BRP is developing Automatic Recording Units — small devices with low power usage that can record data underwater or on land for several months without attention from the researcher. Engineers at the BRP are also developing methods and technology for radio-tagging animals, which would allow researchers to study how communication affects their movements and interactions.

Although bioacoustics is still a fledgling area of scientific research, the BRP’s impact on conservation is already visible. According to Rowland, the presence of the Elephant Listening Project and their research on the effects of human noise on elephants in Gabon caused a Chinese oil company to tighten their protocol on oil exploration activity in the area, so that their noise would be less disturbing to the elephant communication and the researchers in that area.

The whale research conducted by Dr. Christopher Clark helped to enact laws controlling the speed of ships that travel where whales are feeding or passing through, in order to reducing the chances that the boats will kill the whales.

“[Bioacoustics] is a very juicy way to enter the field of conservation,” stated Payne. “If you are studying animals that are vocal and hidden from view, as whales and elephants are, it really behooves you to learn about their vocal communication. They have everything to say to each other!”

For more on bioacoustics, visit the following websites:

BRP Site: http://www.birds.cornell.edu/brp

ELP Site: http://www.birds.cornell.edu/brp/elephant/index.html

Listen to elephant greetings: http://www.birds.cornell.edu/brp/elephant/Sections/cyclotis/families/gre...