Global inequality in roadkill burden concentrates collision risk on threatened species in low- and middle-income countries.

Abstract

Global development relies on vast and expanding road networks, yet the global distribution of the wildlife mortality they cause remains poorly quantified. Here we show, using researcher-led surveys, global citizen-science records and a high-resolution national dataset for China, that wildlife-vehicle collisions disproportionately burden biodiversity in low- and middle-income countries. After standardising for species pools and sampling effort, low- and middle-income countries bear a heavier roadkill burden than high-income countries, with the strongest disparities reaching 2-4-fold for threatened vertebrates but much weaker contrasts for non-threatened species. This reflects elevated collision rates among threatened fauna rather than a broader list of affected species. In China, the same pattern unfolds along a land-use intensity gradient: transformed landscapes elevate risk for common generalists while progressively filtering threatened taxa from the roadscape. Overall, expanding transport networks concentrate contemporary collision burden on threatened biodiversity in low- and middle-income countries.