Diversity and biogeographic patterns of non-volant small mammals in Afrotropical montane rainforests in Rwanda

Non-volant small mammals in Afrotropical regions are a species-rich group of vertebrates, yet their diversity, distribution, and community structure remain insufficiently analysed. Here, we examined them at four locations in Afromontane tropical rainforests in Rwanda across two seasons, with a primary focus on Nyungwe National Park (NNP), comprising Nyungwe and Cyamudongo forests. Using standardised live-trapping and DNA analysis, applied systematically for the first time in this region, we documented 25 species, including 22 rodents, two shrews, and one golden mole. We confirmed most of the species previously recorded in NNP, but sequencing of the mitochondrial cytb gene and comparison with specimens from across Africa revealed one new species record, Lophuromys cinereus, for NNP and the country. The most abundant species were in the genera Praomys, Hybomys, Lophuromys, and Hylomyscus. Our study provides preliminary insights into the effects of season and patch size on non-volant small mammals in NNP: generally, seasonality did not show significant effects on community composition, whereas all species found in the small Cyamudongo fragment were also found in the main forest block of NNP. We highlight gaps worthy of further investigation, including clarification of the influence of biogeographic and ecological factors, e.g. altitudinal ranges, microhabitats, and edge effects, on non-volant small mammals. We also urge the inclusion of non-volant small mammals among target groups to understand the dynamics of Nyungwe ecosystems, demonstrate Afromontane diversity, and inform ecological monitoring and park management plans.