A century documenting roads’ toll on global biodiversity

Abstract

The 100th anniversary of the first scientific account of roadkill recognizes the growing awareness of roads’ ecological impacts. Since the first scientific record of roadkill in 1925, global road networks have expanded to over 21.6 million km. Roads result in the mortality of millions of animals annually, threatening biodiversity by reducing populations, fragmenting habitats, and raising extinction risks. Although it was not until the early 2000s that road ecology became formally established as a discipline, research has since advanced substantially. A recent global roadkill dataset spanning 2283 species in 54 countries is an example of this advancement, and it highlights the urgency of this issue. As road expansion accelerates, especially into intact habitats, it is essential to align infrastructure development with both ecological sustainability and economic objectives. We need to build better roads that meet human needs while safeguarding biodiversity, promoting conservation, and preventing another century of major ecological harm.