The impact of anthropogenic disturbance on the behavior of Milne-Edwards Sportive Lemurs (Lepilemur edwardsi)

Effective conservation action requires more research on threatened primate species, particularly lemurs. Madagascar has experienced extensive habitat disturbance, affecting species such as the endangered Milne Edwards Sportive lemur (Lepilemur edwardsi), while its behaviour and responses to disturbance remain almost unknown. This study investigated if lemur abundance is affected by anthropogenic disturbance and whether vocalisations are related to habitat, animal abundance or light levels. This study was conducted over the June-July of 2016 in Mariarano, Northwest Madagascar, using systematic nocturnal surveys to determine abundance, opportunistic focal observations to record behaviour, and all occurrences recording of vocalisation across three sites with varying distances from areas of disturbance (village). More disturbed areas had lower abundance and increased activity, suggesting a negative response to disturbance, which implies they may not benefit from edge effects acting on leaf production, contrary to evidence in other folivores. Vocal rate increased with higher abundance, supporting a territory defence motive for vocalisations. With increased moonlight, vocal rate decreased, suggesting a predator avoidance response to changes in moonlight. These results shed more light on how L.edwardsi reacts to disturbance, the functions of vocalisations, responses to variation in moonlight, and provides a basis for further study. This information could help with evaluations of how much pressure from disturbance could be tolerated and so how important conservation action must be.