Chimpanzee research and conservation in Bossou and the Nimba Mountains: a long-term international collaborative effort in West Africa.

The Nimba Mountains are a West African Natural World Heritage site located in the range of the Guineo-equatorial evergreen rainforest, renowned for its rich biodiversity with a high level of endemism. In 1976, Yukimaru Sugiyama from Kyoto University initiated the long-term study of chimpanzees at Bossou, a Guinean village situated 5 km from the northern foothills of Nimba. This Japanese initiative has provided key discoveries and insights on our closest living evolutionary relatives over the 40 past years, and has grown to become an international collaboration with a research focus extended to adjacent chimpanzee communities.

Density estimates and nesting-site selection in chimpanzees of the Nimba Mountains, Côte d'Ivoire, and Guinea.

We investigated nesting behavior of non habituated chimpanzees populating the Nimba Mountains to document their abundance and their criterions of nesting-site selection. During a 19-month study we walked 80 km of transects and recces each month, and recorded 764 nests (mean group size = 2.23 nests) along with characteristics of vegetation structure and composition, topography, and seasonality.