Katharine B. Payne has discovered that elephants emit "infrasonic" vocalizations, calls with sound frequencies below the range that is audible by people. Much evidence suggests that these low-frequency calls of free-ranging African elephants function over long distances and play an important role in the organization of elephant society. For instance, Rowan B. Martin has tracking data on elephant matriarchs in the Sengwa Research Area in Zimbabwe, showing a long history of movements that are coordinated even between elephants separated by 1 to 10 kilometers of woodlands. To study this phenomenon, Payne, Langbauer, and Martin will will attach radio microphones and transmitters to the collars of the same Sengwa elephants, and will simultaneously monitor their vocalizations and movement patterns over at least two months. Behavioral observations from aircraft and ground vehicles will supplement the continuous tracking and acoustic data, which will be entered into a computer in the field and later analyzed at Cornell University. In a collaborative study, blood samples from the collared elephants will be analyzed using DNA-fingerprinting techniques, to determine whether or not close genetic relatives are more likely to call to each other and to coordinate their movements. The researchers' long-term goals are to describe the structure of elephants' acoustic communication system and the behavioral patterns it affects, both at the level of the individual and of the society. The findings of this project will also contribute to conservation of severely threatened populations of elephants. In Africa, the major cause of a disastrous decline (57% of East Africa's elephants have disappeared in the last 10 years) is potentially reversible, for it is related to a booming international trade in ivory that makes poaching extremely lucrative in countries where management is difficult. Public education, including presentation of the results of this project, will be important in the effort to stabilize the elephant populations.
