Seasons of death : patterns of predation on wild lemurs and other fauna by endemic and introduced predators

Abstract

Introduced species can negatively impact endemic flora and fauna. Studies have primarily utilized camera trap observations and occupancy modelling to better clarify the presence/absence and temporal overlap of endemic and exotic predators. Longitudinal data from field research sites are important as they can provide a finer understanding of predator dynamics and their effects on endemic species. One such site is the Bezà Mahafaly Special Reserve, in southern Madagascar. Protected since the 1970s, the local human population around Bezà Mahafaly Special Reserve has greatly expanded, leading to habitat disturbance in the surrounding forests and increased contact between local wildlife, people and their livestock and dogs. Here we use a combination of scat sampling, field observations of successful and attempted predations, locations of scat samples with identifiable lemur remains, and camera trap data to better assess the predator ecology at Bezà Mahafaly Special Reserve. Our results indicate that forest cats (Felis catus), are effective predators of both adult and infant lemurs and appear to be a constant mammalian predator, utilizing mammal prey more than dogs. Dogs are both predators and scavengers of lemurs. Civets focus on small prey, such as insects and rodents as well as plant material. The fosa, Cryptoprocta ferox, are also present but may not hunt in the area continuously. The killing of an adult ring-tailed lemur by two men from outside the area indicate culturally imposed taboos against lemur killing may no longer be effective given that new arrivals may not share the same local cultural restrictions. Scat sampling of exotic predators is one way to expand our understanding of exotic and endemic predator impact on lemur populations, and long-term studies with multiple assessments of predation can provide a clearer understanding of how non-endemic and endemic predators affect endangered species survival.