Our study helps understand how fragmented forests affect bonobos forest use. Previous studies already reveal that habitat types influence bonobos’ densities, but forests’ spatial structure could also have an impact. In the current context of deforestation and increasing illegal concessions, approaching such questions should help orient future conservation programs. We focus on the influence of edge effect on bonobos forest use, presuming that they avoid areas with non mature forests and increased human pressure. We travelled along transects (113km total) to define habitat types and to record bonobos indices (tracks, food remains and nesting sites) in 200km² of forests in Southwestern Lake Tumba Region. Our results show that bonobos clearly prefer specific habitats for nesting, and, within these nest-forest types, an understory of Marantaceae Haumania sp. is preferentially chosen. To evaluate edge effect on nesting behavior, we counted nesting sites in 100m distance classes from the forest edge. Our results indicate a uniform distribution of nesting sites, but with a negative edge effect in the first 100m. When we analyzed tracks and food remains distribution, we didn’t find any habitat type preferences or any edge effect. These results indicate that, although bonobos are known to favor dense forests, they can also adapt to fragmented forests environment. Habitat types appear to be more relevant to understand their distribution and range
