Preliminary survey of non-human Primates in four forest areas of Yewa River Basin at the Nigeria-Benin Republic transboundary

Information on species’ geographic distribution is essential in setting up key areas of conservation priorities and management policies. To date, there is a paucity of information on the primate species that inhabit some forest areas, including the forests along the Yewa River Basin located at the Nigeria-Benin Republic transboundary. To address this, we conducted a field survey across four relatively unexplored fragmented forest areas (Eggua, Igbo-Iju, Ibese and Ebute) within the Yewa River Basin. We recorded 441 individuals belonging to four species - Cercopithecus erythrogaster erythrogaster , Cercopithecus mona , Chlorocebus aethiops and Erythrocebus patas . Our observation record shows that C. mona has the highest encounter rate, while E. patas has the lowest. Our result reveals a seasonal displacement of individuals with the high number of individuals encountered during the rainy season. Most of the primate species ( C. e. erythrogaster , C. mona , and E. patas ) are of high conservation concern and are categorized as threatened species according to the International Union for the Conservation of Nature. Our study improves knowledge of the primate species within some forests of the Yewa River Basin. We also recommend continuous survey and monitoring of primate species in this area and encourage community-based conservation policies to protect the primates and habitat.