Rethinking Spatial Prioritisation for Primate Conservation in an Unprotected Intact Forest Landscape in the Gulf of Guinea

ABSTRACT While protected areas are the cornerstones of biodiversity, unprotected areas are also critical for primate conservation. It is essential to understand primate responses to human pressure in such areas to guide conservation planning. The unprotected Yabassi Key Biodiversity Area (YKBA), Cameroon, comprising the Ebo, Ndokbou and Makombe forests, is one of the largest remaining tracts of intact forests in the Gulf of Guinea biodiversity hotspot. Unfortunately, knowledge of its primate community remains very limited. Only the Ebo forest, known for its small gorilla population, benefits from consistent conservation attention. This neglect diminishes recognition of YKBA's broader significance for primates. From January to December 2019, we conducted primate surveys across the YKBA, covering over 1500 km of reconnaissance walks and recorded eight of its 10 known diurnal primate species. We overlaid 1x1 km grid cells across the area and applied Bayesian regression models to examine how species richness and occurrence probabilities vary across the three forest blocks and respond to anthropogenic pressure gradients. Our findings revealed higher species richness in Ebo and Ndokbou compared to Makombe. While Preuss's monkeys were absent and chimpanzees and red‐capped mangabeys were very uncommon in Makombe, the predicted occurrence probabilities of other species were relatively similar across the three sites. Species richness increased strongly with distance from roads and moderately with elevation. Yet individual species showed variable patterns along anthropogenic gradients, resulting in contrasting predicted species distribution in the landscape, which suggests that spatial prioritisation based solely on remoteness may fail to conserve species inhabiting easily accessible areas. These results underscore the greater importance of the YKBA for primate conservation than previously recognised. The considerable distribution of primates in Ndokbou and Makombe highlights the need for conservation interventions beyond Ebo. We recommend expanding conservation efforts to encompass the entire YKBA, with a focus on mitigating hunting and land conversion to ensure long‐term human‐primate coexistence.