24 October 1999
Is that an elephant I can hear?
by Kate Melville
In an interesting new approach to wildlife conservation biologists and acoustic engineers from Cornell University have joined researchers in Africa to monitor the numbers and health of forest elephants by eavesdropping on the sounds they make. "Acoustic monitoring may give us crucial information on the elephants about which we know almost nothing because they live under the cover of forests," said Katharine Payne, a research associate in the Bioacoustics Research Program of the Cornell Laboratory of Ornithology. "With the increasing pressure on African elephants from the ivory trade and from illegal poachers, we desperately need to know how many animals are still alive and what they're doing," says Payne, whose discovery of long-distance infrasonic communication amongst was told in her book Silent Thunder.
One sound the biologists do not want to hear is the sound of poachers killing the elephants for their tusks. According to Steve Gulick, a recording engineer who first captured the calls of forest elephants in Gabon; "If we can maintain real-time access to microphone arrays via satellite or radio, we can keep track of some very wide areas. That monitoring of elephant and human activity is not feasible now; we only find out about poaching activity after the carnage, when we're walking through the fields of carcasses."
Gulick was one of five Africa-based researchers to meet with Cornell scientists at the Laboratory of Ornithology in hopes the survey will eventually be expanded to study, offering protection to other endangered animals like gorillas and rhinos.
"We are moving into an era when wild populations that were considered as common commodities are being depleted, and we're confronted with the fact that we know very little about these populations," says John Hart, a survey planner whose long-term studies in forest environments are supported by the Wildlife Conservation Society. "How can decisions at any level be made about the management or trade in endangered species without some knowledge about these populations?"
If we had some way of knowing when the elephants are moving up and down the valley, we could then get a handle on the reasons for that movement," says survey planner, Richard Barnes who has spent decades in Ghana
Using data-analysis programs that map a calling elephant's location from a four-microphone array, the researchers can tell exactly where the animal is. In past surveys researchers have been able to link an elephant's calls to its behavior and circumstances by watching simultaneously recorded videotapes. Other elephants' reactions to a call can be just as informative as actions of the calling animal itself.
The sound data is eagerly awaited by Andrea Turkalo, who spent the last nine years documenting the demography and behavior of some 2,000 forest elephants in the Central African Republic
One of the things that seems very odd about this project is that the Cornell researchers are actually ornithologists, who might seem to have little reason to be interested in elephants, however their involvement is explained by Cornell's Ornithology Director John Fitzpatrick in the following terms: "Our mission explicitly acknowledges that we are here for the protection and interpretation of the Earth's biological diversity. All organisms, large and small, are linked. Elephants just happen to be one of the bigger links."