African savanna raptors show evidence of widespread population collapse and a growing dependence on protected areas

Abstract

The conversion of natural habitats to farmland is a major cause of biodiversity loss, and poses the greatest extinction risk to birds worldwide. Tropical raptors are of particular concern, being relatively slow-breeding, apex predators and scavengers, whose disappearance can trigger extensive cascading effects. Many of Africa’s raptors are at significant risk from habitat conversion, prey-base depletion and persecution, driven principally by human population expansion. Here, we describe multi-regional trends among 42 African raptor species, 88% of which had declined over a c. 20–40 year period; 69% exceeding IUCN criteria classifying species at risk of extinction. Large raptors had experienced significantly steeper declines than smaller species, and this disparity was more pronounced on unprotected land. Declines were greater in West Africa than elsewhere, and more than twice as severe outside of protected areas (PAs) than within. Worryingly, species suffering the steepest declines had become significantly more dependent on PAs, demonstrating the importance of expanding conservation areas to cover 30% of land by 2030; a key target agreed at CBD COP15. Our findings also highlight the significance of a recent African-led proposal to strengthen PA management; initiatives considered fundamental to safeguarding global biodiversity, ecosystem functioning and climate resilience.