Local distribution and density estimates of primates in the transboundary reserve of the Mono River, Togo (West Africa)

The reserve of biosphere of Mono river is located in the Dahomey Gap, which is the relatively arid interruption in the West African forest belt that stretches from the Accra Plains in Ghana across the Volta River through Togo to the eastern border of Benin. This West African climate discontinuity is characterized by mosaics of dense semi-deciduous forests, Guinean savannahs, swampy meadows, marshes, mangroves and bodies of water, mosaics of agroforest, farms and fallow land. In this reserve, centered on the Mono valley between Togo and Benin, with 2042.18 km(2) area, we assessed the status of populations of primate species. Overall, 9 species were recorded: Galago senegalensis, Galagoides demidojj; Perodicticus potto, Papio anubis, Colobus vellerosus, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Erythrocebus patas and Chlorocebus tantalus. The populations of these species are distributed in four basic units of the reserve: the Asmara forest, the Togodo protected area complex, the Godje-Godjin sacred forest and the Akissa sacred forest. Our works clearly established a seasonal and regular displacement of primate species populations among different ecological units. The Togodo protected areas complex is the sanctuary for primate populations in southern Togo and Benin, and mainly for the Red-bellied Monkey (Cercopithecus erythrogaster erythrogaster), which is considered a Critically Endangered species on the IUCN Red List.