Impact of Hunting on the Lesula Monkey ( Cercopithecus lomamiensis ) in the Lomami River Basin, Democratic Republic of the Congo

Understanding the impact of hunting on wildlife is necessary to protect biodiversity in remote, endangered ecosystems, where rural communities depend on bushmeat as sources of food and income. Unsustainable hunting has led to a major decline in mammal population densities across Africa, especially for ungulates and primates. The objectives of this study were to (1) quantify the impact of hunting on lesula ( Cercopithecus lomamiensis ), a semiterrestrial and poorly known monkey in the Democratic Republic of the Congo, and (2) assess the species’ relative abundance in the context of its behavioral ecology and local hunting practices. We compared the relative abundance of lesula to prey species preferred by hunters using data collected from camera trap surveys (5,960 days) and primate vocalization surveys (n = 174) and assessed species-specific hunting pressure in the buffer zone using data collected from surveillance patrols (2,255 km), hunter follows (n = 16), and semistructured interviews (n = 21). We found that the abundance of terrestrial mammal and primate species was negatively impacted by hunting in the buffer zone, but the abundance of lesula appeared relatively similar throughout its range. Our results suggest that the relative tolerance of lesula in the buffer zone was associated with its ecological niche and the specific behavior of local hunters. Lesula is a threatened, endemic monkey of the Congo Basin rainforest, and this study provides data to enable its continuous monitoring and long-term population management. Some primate populations, such as lesula, may be able to persist under specific conditions despite being subject to high hunting pressure.