Listening to the Call of the Wild: Tracking Deer Movements Using Sound Researchers from The University of Tokyo have designed a new type of system using listening devices to detect and track deer positions in the wild Tokyo, Japan — In the marshland of Japan’s Oze National Park, keeping track of the deer population has been a difficult and time-consuming task for the park rangers. Now their lives could get much easier, thanks to a novel technique for tracking deer movements using unmanned listening devices developed by researchers at the Institute of Industrial Science, a part of The University of Tokyo.