Mammalian species richness and diversity in a heterogenous ecosystem

Abstract

Heterogeneous ecosystems are characterised by different habitat types and play a fundamental role in shaping the distribution, richness and diversity of mammalian species. Variations in vegetation structure, resource availability, microclimatic conditions and ecological gradients often create distinct ecological zones, commonly referred to as ecotones. Ecotone zones are transitional areas where two or more habitat types meet, serving as biodiversity hotspots by supporting species from adjacent habitats as well as specialised ecotone-adapted fauna. Identifying and characterising these ecotones is therefore crucial in understanding the spatial patterns of mammal distribution, as these influence species interactions, movement patterns and overall community composition. This study investigated mammalian species richness and diversity across five habitat types (woodland, grassland, riverine, wetland and waterpoint) at Nyangombe Safari Lodges, Kwekwe District, Zimbabwe. A comparative cross-habitat ecological survey design was employed using four complementary methods: road transit game counts, walking transects (scouting), spoor and dropping identification, and GIS-based spatial analysis incorporating NDVI and Kernel Density Estimation (KDE). A total of 88 detection records of 27 mammalian species were documented. Results demonstrated that woodland was the most species-rich and diverse habitat (S = 17 species; H' = 2.619), consistent with the habitat heterogeneity hypothesis. Eight habitat-specialist species were exclusively recorded in woodland, including Elephant, Giraffe, Leopard, Kudu and Monkey. Waterpoint emerged as the primary resource aggregation site with the highest species evenness (J' = 0.971). Eight ecotone boundaries were identified across the five habitats, with the Grassland-Wetland and Riverine-Waterpoint ecotones functioning as the most ecologically active transitional zones. Impala (Aepyceros melampus) was confirmed as the sole habitat generalist across all five habitats. Three primary environmental drivers of species distribution were identified: water availability, vegetation structure and open grassland cover. Road proximity was found to be a non-significant driver, indicating that current human disturbance levels do not significantly displace mammalian communities. These findings provide the first rigorous multi-habitat baseline biodiversity assessment for Nyangombe Safari Lodges and offer actionable recommendations for conservancy management, future research design and policy-level wildlife governance in Zimbabwe.