In the dense forests of Africa, there is a species of forest elephant that has proved very difficult to study. Indeed, even simple questions like how many elephants there are and where they are located have been impossible to answer.

Katy Payne's discovery of low frequency communication systems in elephants has provided a new way to study elephant behavior. Automatic recording units make it possible to monitor the elephants' communication signals and researchers use this information to begin to understand something of the forest elephant's biology.

Peter Wrege, director of the Elephant Listening Project, describes the techniques and what has been learned about the biology of these wild, elusive animals.