Chimpanzee conservation status in the World Heritage Site Taï National Park, Côte d'Ivoire

Effective conservation of African ape populations that have dramatically declined over the last decades requires updated information on the population status and habitat. However, at many sites, the densities and the spatial distribution of chimpanzees as well as the threats faced by the species are poorly described and not updated. To contribute towards filling these gaps, we conducted a survey along a total of 701.5km line transects to collect signs of chimpanzee and human activities over two years in the Ta? National Park, Côte d'Ivoire. Encounter rates for signs of chimpanzee presence were low in most locations with less than two signs observed per kilometer walked. This was notably true within and around areas subject to the permanent existence of illegal human activities, such as the presence of plantations in the peripheral eastern regions. Using distance sampling methods, we estimated that the overall density of chimpanzees in 2008 was 0.087 individuals/km2 and 464 weaned individuals in the park. Ta? National Park is a world heritage site but its biodiversity is threatened by human pressures. We further suggested work on the spatio-temporal modeling of the factors influencing the distribution and abundance of species to improve management and to optimize conservation decision-making.