Severe conservation risks of roads on apex predators

The global expansion of road networks threatens apex predator conservation and ecosystem functioning. This occurs through wildlife-vehicle collisions, habitat loss and fragmentation, reduced genetic connectivity and increased poaching. We reviewed road impacts on 36 apex predator species and assessed their risk from current roads based on road exposure and species vulnerability. Our findings reveal all apex predators are exposed to road impacts. Eight of the ten species with the highest risk occur in Asia, although other high-risk species are present in the Americas, Africa and Europe. The sloth bear suffers the highest risk of all apex predators, followed by the tiger and dhole. Based on species risk from roads, we propose a widely applicable method to assess the potential impact of future roads on apex predators. We applied this method to proposed road developments in three areas: the Brazilian Amazon, Africa, and Nepal, to locate high-impact road segments. Roughly 500 protected areas will be intersected by these roads, threatening core apex predator habitats. We advocate the need for rigorous road development planning to apply effective mitigation measures as an urgent priority and to avoid construction in wilderness areas and predator strongholds.

Automated summary

The global expansion of road networks poses a threat to apex predator conservation and ecosystem functioning. This is due to wildlife-vehicle collisions, habitat loss and fragmentation, reduced genetic connectivity, and increased poaching. Our review of 36 apex predator species shows that all are exposed to road impacts. The highest risk species are predominantly found in Asia, with others in the Americas, Africa, and Europe. To mitigate future road impacts, we propose a method to assess potential impact on apex predators, which is applied to proposed road developments in the Amazon, Africa, and Nepal. Around 500 protected areas will be affected by these roads, endangering core apex predator habitats. It is urgent to implement rigorous road development planning and effective mitigation measures to avoid construction in wilderness areas and predator strongholds.