Spatial variation in diversity of rodent species across habitat types in the Kavango East Region, Namibia

Abstract

This study aimed to investigate spatial variations in rodent species composition, abundance, richness, and diversity across three habitat types—fallow land, relatively undisturbed land and residential areas—in the Kavango East Region of Namibia. Rodent trapping was performed using PVC live traps deployed for three consecutive nights per habitat each month over a 12-month period. Across a total of 16 272 trap-nights, 285 individual rodents were captured, representing five species: Mastomys natalensis, Gerbilliscus leucogaster, Thallomys paedulcus, Saccostomus campestris and Steatomys pratensis. Hierarchical cluster analysis using the Bray–Curtis similarity index indicated 30% and 22% similarity in species composition among the three habitat types. A Kruskal–Wallis H test revealed statistically significant differences in species richness between fallow land and less-disturbed land, as well as between less-disturbed land and residential areas in Bagani (χ^² = 10.81, df = 35, p = 0.0026), and between fallow land and houses in Diyogha (χ^² = 12.18, df = 35, p = 0.001). Dunn’s post-hoc test confirmed significant differences in species richness between fallow and less-disturbed land (p = 0.006), and between less-disturbed land and houses (p = 0.001) in Bagani. In Diyogha, species richness also significantly differed between fallow land and houses (p < 0.002). Moreover, species diversity was significantly different between fallow land and houses (p = 0.0084). This study adds to the understanding of small mammal ecology in African dryland systems by showing how habitat type and human disturbance influence rodent species richness and diversity. The results highlight the role of habitat heterogeneity in maintaining rodent diversity, even where overall abundance does not differ significantly. By documenting dominant species, such as Mastomys natalensis, and linking their population patterns to climatic factors, the research provides useful insights for managing rodent pest species and assessing disease risks in rural areas.