Virtual fencing of captive Asian elephants fitted with an aversive geofencing device to manage their movement

Abstract

Aversive Geofencing Devices (AGDs) are designed to emit audible warning signals followed by electric shocks when animals reach virtual fences (VFs) with the intent that animals will learn to turn away at audio warnings and thereby avoid receiving shocks. AGDs are a potentially useful tool for mitigating human-elephant conflict, but a greater understanding of captive elephant responses to AGDs is required before they might be confidently used on wild elephants. We conducted experiments with eight, female captive Asian elephants using a modified dog-training collar to deliver mild electric shocks (4 kV) of varying strength (pulse frequencies) to determine the ideal location on the neck to deliver the stimuli and the optimum strength of the shock required to generate desired aversive responses. Ten shocks (<1 s duration) of different strengths were delivered during a 10 min session (i.e., one shock per minute) at two positions on one side of the elephant’s neck. Results indicated that elephants were more likely to display desirable aversive behaviours at the upper position tested on the neck (odds ratio=0.47, 95% CI 0.25–0.87, P = 0.018) and at higher stimuli strengths (odds ratio=1.03, 95% CI 1.01–1.04, P ≤ 0.001). A conditioning experiment was then conducted several months later with five of the same elephants. These were individually trained to walk along a ∼100 m path to a food reward on three consecutive days, wearing a dummy collar. On the next three days and on one other day few months later, the elephants were fitted with a similar shock collar (positioned at the upper neck location, and with the highest strength tested earlier) to determine if the AGD could prevent the elephants from accessing the food reward. Three VFs were established at ∼30 m, ∼50 m and ∼60 m points along the path. As the elephant approached the food, a mild audio warning, a more aggressive audio warning, and an electric shock was administered at the first, second and third VFs respectively. Warnings and shocks were not delivered if elephants heeded earlier warnings. A maximum of five such trials were attempted. The VFs successfully kept elephants from reaching the food 77.8% of the time, with elephants responding to the audio warnings and avoiding electric stimulation 47.2% of the trials. These findings suggest that AGDs are a promising method to manage elephant movement, but further research is needed to develop a reliable approach for wild elephants.