Socio-economic factors strongly determine megafauna biomass in African savanna protected areas

Abstract

The persistence of African megafauna (herbivores >10 kg) in savannas is at risk from anthropogenic pressures including land–use change, bush–meat hunting and poaching. The mitigation of these risks, while still ensuring socio-economic improvement, is a crucial challenge to megafauna conservation and sustainable development across Africa. Protected areas are designed to diminish these risks, yet evidence from individual protected areas and countries suggests that megafauna populations within protected areas are increasingly affected by negative human influence. However, on the continental scale, it remains unclear to what degree megafauna in African savanna protected areas are affected by human influences relative to natural drivers. We quantified the relative influence of human and natural drivers on biomass from 47 megafauna species, estimated from aerial surveys across 296 survey areas in 12 African countries, spanning 550,452 km2 of protected savanna. The Human Development Index (HDI) emerged as the strongest predictor of megafauna biomass within protected areas across Africa, exceeding the importance of the main natural drivers (natural savanna habitat, water availability) and other human–related drivers (roads, environmental governance, and livestock density). Importantly, our findings show that megafauna biomass is suppressed to <= 3600 kg km-2 at low HDI (0.50), compared to 6800 kg km-2 at higher HDI (> 0.50). This indicates that improving socioeconomic conditions surrounding savanna protected areas could substantially enhance megafauna conservation across the continent, while addressing numerous sustainable development goals for local communities.