How did the elephant cross the fence? Electric fence crossing by elephants in Udawalawe, Sri Lanka

Abstract

Electric fences are widely used in human–elephant conflict mitigation. However, elephants constantly challenge and overcome fences, which is a growing concern. We studied how elephants crossed the perimeter electric fence around the Udawalawe National Park (UWNP), Sri Lanka. Using camera traps, we monitored 18 fence posts and an open gate in the fence over 605 days from 2016 to 2019. Photographs of 3097 fence crossings were analysed to obtain demographic data for fence crossing elephants, crossing methods, and the daily and seasonal timing of fence crossing. We identified 77 adult males and 12 adult females that crossed the fence, which represent about 17% of the adult elephants in UWNP. Most of the crossings were through the open gate at night. Elephants used a variety of crossing methods, comprised of crossing at the open gate, at previously toppled posts, by crashing through wires and stepping over wires, as well as by using the trunk or forefeet to topple posts. Fence voltage was not a determinant of fence crossing. The frequency and timing of fence crossings varied between locations with later exits and less time spent outside, at crossing points bordering human dominated areas. Our results emphasis on the importance of taking into account the problem solving abilities of elephants in fence design and location, such as energising fence posts and constructing exclosure fences at the boundaries of crop fields and settlements, in employing electric fences to mitigate human‐elephant conflict.