In this review we provide a conceptual framework of the evolution of bat diversity patterns in the Savanna Biome in southern Africa, focusing on different niches and variables across spatio-temporal scales. At a regional scale, speciation mediated by historic geomorphic and climatic events has driven bat diversity of the regional species pool. The high taxonomic and phylogenetic diversity in the region is maintained by stable wet and warm climatic conditions and high habitat heterogeneity. Low replacement rate among bioclimatic regions suggest the selective extinction of savanna species with large or small body sizes and small geographic ranges. Processes at the meso-scale appear to play a minor role as the high mobility of bats enables them to select habitat patches even in human-dominated urban and agricultural landscapes. Multiple biotic processes, including competition and prey defenses operate at a local scale as well as a point scale, but non-random patterns are not ubiquitous within and across variables. Long-term data on births, deaths, migration and range expansion over many generations are necessary to quantitatively describe the feedback loop between local and regional scales. Additionally, data are needed to conceptually link the regional and biogeographic species pools. We provide suggestions for fields particularly worthy of future research with respect to bat assemblages in savanna ecosystems.