Understanding The Impacts Of Deforestation And Road Infrastructure Development On Chimpanzees Outside Protected Areas

The majority of the critically endangered chimpanzees (Pan troglodytes verus) occur outside protected areas. Ensuring their long-term survival in such areas implies addressing people-chimpanzee coexistence challenges. Using origin data of confiscated chimpanzees from two chimpanzee sanctuaries in West Africa, i.e. the Chimpanzee Conservation Center (CCC), Guinea and the Tacugama Chimpanzee Sanctuary, Sierra Leone, and forest loss data from 2001 to 2015, we highlight how deforestation exacerbates interactions between people-chimpanzees and acts as a driver for the killing and capture of chimpanzees in the region. Finally, we present results from a systematic camera trapping survey (24 camera traps deployed across 27 1.25x1.25 km grids) conducted in the Moyamba district in south-western Sierra Leone in an area dominated by subsistence agricultural activities and practically devoid of forest. We employed a hierarchical Bayesian framework accounting for spatial autocorrelation to explore ecological and anthropogenic factors influencing chimpanzee relative abundance across the landscape. Our findings revealed that chimpanzees in such landscapes, where people are relatively tolerant of their presence, tend to avoid roads, including untarmacked secondary roads, and prefer to range in close proximity to more intact habitats such as swamps. Unexpectedly, they showed no preference for abandoned settlements where fruit orchard persist. Finally, although chimpanzees in this area did not avoid human settlements or areas frequented by people, areas of spatial overlap between the two species revealed temporal divergence in utilization. Altogether, these studies emphasize the urgent need to understand better factors that influence chimpanzee abundance and distribution outside protected areas, especially in the context of the rate of forest loss, and for aligning land use planning and infrastructure development to serve both the needs of people and chimpanzees.