Long-term research presence mitigates hunting pressure and shapes mammal communities in the Congo Basin

Overhunting in tropical African forests threatens wild mammal populations and consequently the livelihoods of local communities dependent on wild meat. Long-term research sites can help mitigate hunting pressure and support wildlife, yet their influence on mammal communities remains understudied. Since 2002, the LuiKotale Bonobo Project has operated in the buffer zone of Salonga National Park, Africa's largest protected forest area. The study site spans approximately 500 km 2 , including areas reserved for research activities, and areas where hunting has taken place until recently. Using camera trapping data collected between June 2022 and August 2023, we assessed mammalian (1) diversity, (2) occupancy, (3) relative abundance and (4) community composition, in hunted vs. research areas. Species richness was higher in the research area (36 vs. 33 mammal species detected), while overall diversity was higher in the hunted forest. However, ungulates were 53 % more abundant in the research area, while rodent detections were 137 % higher in hunted zones, suggesting a shift in functional composition associated to subsistence hunting. Occupancy patterns revealed a non-linear association with distance from research camps and a linear, negative association with the number of human signs, with the highest occupancy probabilities predicted at intermediate distances and in areas of lower human disturbance. These findings highlight the influential role long-term research sites play in shaping mammal communities and emphasize the need for conservation strategies that effectively balance biodiversity preservation with local access to resources. • Long-term research sites can help mitigate hunting pressure on wild mammals. • Species richness is higher in the research than in the hunted area. • Ungulates dominate in the research area, rodents in the hunted area. • Occupancy declines with human signs and increases with distance from research camps. • Research presence mitigates hunting while shifting composition and distribution.