The sensory ecology of fear: African elephants show aversion to olfactory predator signals

Abstract

Human–elephant conflict is a persistent problem across elephant home ranges, that results in economic damage to commercial and subsistence farmers, and physical harm and death to humans and elephants. This problem is likely to intensify with increased development, dwindling of natural habitats, and climate change-driven environmental shifts. Various methods to mitigate human–elephant conflict have been employed, but to date these have been hampered by financial and logistical considerations. Based on the fact that African elephants are predated by lions and possess a remarkable sense of smell, we hypothesize that elephants are strongly averse to olfactory signals of lion presence, and that this can be utilized to create invisible barriers which elephants will not cross. We conducted a series of tests that show that lion dung is an effective deterrent of elephants. We conducted chemical analyses of lion dung and identified the main compounds. We then used synthetic mixtures containing these compounds, and show that they successfully elicit the deterrence effect, even in miniscule concentrations. These results indicate that elephants can be deterred using simple and low-concentration mixtures based on available commercial products, that can be developed into products that offer a safe, sustainable, and cost-effective method to mitigate human–elephant conflict.