Bonobo (Pan paniscus) Density and Distribution in Central Africa's Largest Rainforest Reserve: Long-term Survey Data Show Pitfalls in Methodological Approaches and Call for Vigilance

Salonga National Park, Democratic Republic of the Congo, stands as a critical stronghold for bonobos (Pan paniscus), potentially housing between 8,244 and 18,308 mature individuals with an estimated density of 0.31 individuals per km². A long-term study spanning 2002 to 2018, involving 8,310 km of transect walks and 27,045 days of camera trapping across ~42,000 km²—representing about 27% of bonobo-suitable habitat—revealed non-significant population decline but underscored the park's importance. The study highlighted methodological discrepancies: nest counts yielded lower density estimates in areas with Marantaceae understorey and farther from rivers, while camera traps provided higher estimates in regions with lower human presence. Bonobos were rarer near villages but more abundant in dense forest cover and proximity to ranger posts. These findings emphasize the need for continued vigilance and monitoring to preserve this biologically and culturally significant site.

Bessone, M., Kühl, H. S., Herbinger, I., Hohmann, G., N’Goran, K. P., Asanzi, P., Blake, S., Basele, M., Bofeko, M., Bondjengo, N., Bondo, P. W., Booto, R., da Costa, P. B., Dérozier, V., Emetshu, M., Fotsing, E. D. B., Grossmann, F., Guislain, P., Hart, J., et al. (2024). Bonobo (Pan paniscus) Density and Distribution in Central Africa’s Largest Rainforest Reserve: Long-term Survey Data Show Pitfalls in Methodological Approaches and Call for Vigilance. International Journal of Primatology, 46(2), 436–474. https://doi.org/10.1007/s10764-024-00468-w