UC Davis

We attempted to deter crop-raiding elephants Elephas maximus by using playbacks of threatening vocalizations such as felid growls and human shouts. For this purpose, we tested two sound-playback systems in southern India: A wireless, active infrared beam-triggered system to explore the effects of night-time uncertainty in elephants' assessment of predatory threats, and a passive infrared motion detector-triggered system for closer-range playbacks. Using the first system, we deterred 90% of crop-raiding attempts using tiger Panthera tigris growls, 72.7% using leopard Panthera pardus growls, and 57.1% using human shouts, with no statistically significant difference among the three sounds. Using the second system, playbacks of tiger and lion Panthera leo growls deterred 100 and 83.3% of crop-raiding attempts, respectively, with no statistically reliable difference between the two, although video evidence indicated that elephants were more fearful of tiger growls. Our results indicate that playbacks of threatening sounds can be effective in mitigating human-elephant conflict, particularly in bolstering existing deterrent methods.