Until now electric fences and trenches have been the best way to protect farms and villages from nighttime raids by hungry elephants. Now, there may be a better way: the recorded sound of angry predators.
For a new study, researchers set up infrared sensor playback systems where elephants triggered the sound of growling tigers, leopards, and angry shouts of villagers as they approached farmers’ fields.
In 41 attempted raids, tiger sounds stopped the elephants 90 percent of the time, the sound of leopards deterred them 73 percent of the time, and human shouts prevented 57 percent of the attempts.
Hungry, hungry elephants
“This technique was tested using static devices. Although the elephants shied away from the specific area they would eventually find another way into the field,” says Vivek Thuppil, assistant professor of psychology at University of Nottingham Malaysia Campus.
“So static recordings like this would work in locations where there is a narrow path of entry to farmland.
“Now I am interested in investigating how an elephant would respond to threatening sounds if they were not emanating from a stationary source. To accomplish this, there would be a network of speakers and an intruding elephant’s location would be tracked continuously with only the speaker nearest the elephant being activated. This would simulate persistent tracking of an elephant by a predator.”
Fool me once—but not twice
Elephants live off roots, grasses, fruit, and bark and the Earth’s largest land mammal needs to consume over 275 pounds of food in a single day to satisfy its huge appetite. As the Asian elephant’s natural habitat is squeezed to make way for agriculture, new roads, and development, conflict between elephants and humans is an increasing problem.
For the study, published in Oryx—the International Journal of Conservation, researchers tested two infrared systems, one that was more complex and realistic, and one that was simple enough for farmers to set up around their fields.
Both were effective in deterring elephants. But it seems an elephant never does forget, and those that encountered the noises more than once were less likely to be fooled.
Thuppil will next collaborate with the Management and Ecology of the Malaysian Elephant, a research project at UNMC led by Dr Ahimsa Campos-Arceiz that is fitting wild elephants with specially designed collars packed with satellite and cell phone technology. The aim is to learn more about the Asian elephant and how to mitigate the growing problem of human-elephant conflict.
Richard G. Coss from the University of California, Davis, is a coauthor of the study.
Source: University of Nottingham