Mandrill (Mandrillus sphinx) Presence in Southeast Cameroon Confirmed By Camera Traps and Indigenous Knowledge

Determining primate geographic ranges is essential for understanding their ecology and developing their conservation policies, but it is particularly challenging for rare, cryptic, or widely distributed species. Science-based methods and Indigenous and local knowledge have mutually contributed to addressing this conundrum. Here, we report on a new camera-trap record of a solitary mandrill (Mandrillus sphinx) in Nki National Park, southeast Cameroon, and interviews with Baka people about encounters with mandrills. We placed 481 camera traps for 32,644 total days, obtaining one video of an adult male mandrill on 19 April 2021, 20.2 km north of the Dja River. We also interviewed 30 Baka people from two neighboring villages about their experiences of observing mandrills. Seven interviewees responded that they had observed mandrills in this area: three reported solitary males, and four reported large groups. All observations were in areas >30 km south of the villages and >20 years ago. The results suggest the presence, but also the rarity, of mandrills in this area, where only solitary males may range outside the species geographic distribution, possibly temporarily. However, we cannot conclude that large groups of mandrills are absent in this area because people are not allowed to stay in the park, so the Baka people’s knowledge of the remote areas has been severely limited. To determine the accurate distribution of primates and develop effective conservation actions, we need collaborative research and conservation platforms that further connect Indigenous and local people with scientists.