Field evidence supporting monitoring of chemical information on pathways by male African elephants

Abstract

When animals move along well-established pathways, sensory cues along the path may provide valuable information concerning other individuals that have used the same route. Yet the extent to which animals use pathways as sources of public social information is poorly understood. Here we quantify wild African savannah elephants (Loxodonta africana) responsiveness to olfactory information along natural elephant pathways, habitual routes that link predictable critical resources in the environment. By monitoring the behaviour of elephants travelling on pathways in a predominantly male study population, we found that elephants were highly olfactorily responsive to pathway substrate. Lone travellers were more responsive than elephants travelling in groups, suggesting elephants without social companions may be more dependent on olfactory cues on pathways during navigation. Furthermore, by experimentally presenting olfactory cues on pathways we provide evidence that male African elephants exhibit focused olfactory responses to urine cues of same-sex conspecifics for at least 48 hours from 3 time of deposition, and that urine from adult elephants was more likely to elicit vomeronasal system responses compared to subadult urine. African elephants may therefore potentially be able to discern the age and maturity of individuals they can expect to encounter in the environment from remote urine cues on pathways. We suggest elephant pathways act as a public information resource, assisting navigating elephants via the deposition of urine and dung by previous travellers on the route. These results could help inform elephant management, which may manipulate olfactory information on pathways in high human-wildlife conflict areas, or could use olfactory urine cues to improve the efficiency of corridors that link protected areas for elephants.