The biogeography of the Anura of sub-equatorial Africa and the prioritisation of areas for their conservation

There is an increasing need for protected areas to conserve biodiversity efficiently. The Anura of sub-equatorial Africa have received little attention, but we quantitatively analyse a database containing presence-only data for anurans of sub-equatorial Africa to determine patterns of distribution and species richness, and discuss the roles of present and past environmental conditions in shaping these patterns. We consider the distribution of areas rich in endemic, range-restricted and Red Data Book (RDB) species to identify areas of significance to conservation. The Eastern Highlands of Zimbabwe and adjacent area in Mozambique, southeastern Malawi and the northern coast of KwaZulu/Natal are particularly species rich, whereas the southwestern Cape of South Africa and northwestern Zambia exhibit high degrees of endemism. Four major biogeographical sub-regions are identified, which can be further subdivided into provinces. All statistically significant, current environmental factors together account for 52.6% of species richness. Annual maximum rainfall, soil type variation, minimum temperature and range of elevation were all positively correlated with species richness. Thus, both habitat influences and history appear to have influenced patterns of anuran richness in the region. Generally, areas of high species richness coincide with those high in range-restricted, endemic and RDB species. In South Africa, the northeastern coast and southwestern Cape are hypothesised to have been both refugia and centres of speciation. Results suggest that the current reserve system in sub-equatorial Africa is inadequate for the conservation of the full complement of anuran species in the region.