Diversity and dynamics in a community of small mammals in coastal Guinea, West Africa

In order to investigate dynamics and reproduction in Mastomys erythroleucus inhabiting a high rainfall area in coastal Guinea, West Africa, a small mammal study was carried out through a I-year longitudinal survey. Sampling was by standardized trapping in houses, cultivations, forest and savanna. Identification of the small mammals was based on morphology, and by molecular technique for sibling species. As a part of a larger survey on reservoirs of Lassa virus in Guinea, 106/289 specimens were screened for arenavirus and were found negative. The most abundant species was M. erythroleucus (46%) which occurred in all habitats, with a preference for savanna close to the cultivations. Its reproduction was seasonal and lasted for 8 months, beginning in the early rainy season and finishing in the early dry season. It was syntopic with Lophuromys sikapusi (13%) and Praomys rostratus (10%), which probably migrated from forest/orchards to cultivations in the late rainy season. Reproduction was high in many species in the late rainy season, but P. rostratus seemed to reproduce actively in the dry season, in contrast to L. sikapusi. Pygmy mice, Mus (Nannomys) spp., were abundant in the early rainy season only. The high species richness (14) is explained by the combined influence of Sudanian-Guinean-Congolian habitats. The role of the absence of bush fires is also debated in that context.