roadkill

Roadkill refers to non-human animals that are killed or seriously injured by vehicular collisions on roads. The term is widely used to describe incidents across a broad range of taxa, including mammals, birds, reptiles, amphibians, and invertebrates, though larger species are more frequently reported due to higher visibility and stronger media attention. Roadkill can occur on any road type, from rural highways to urban streets.

Causes include high vehicle speeds, heavy traffic, and road layout that fragments animal habitat. Animals attempting to cross roads for foraging, migration, or dispersal face elevated risk, particularly at night or during breeding seasons. Weather, illumination, and road salt can affect animal movement and visibility. The permanence of road networks creates barriers that alter dispersal and local population dynamics.

Common victims include large mammals such as deer, moose, and elk, as well as small mammals like raccoons and opossums, and reptiles, amphibians, and ground-dwelling birds during migration or breeding periods.

Impacts include direct mortality that can affect local populations, disruption of ecological interactions, and safety risks to drivers. Carcasses can attract scavengers and create temporary road hazards. In some ecosystems, roadkill provides carrion that supports scavenger guilds, though this can alter foraging patterns and energy flow.

Data on roadkill come from surveys, carcass-removal records, and citizen science, but figures vary with road type and reporting practices and are often undercounted due to scavenging and rapid removal.

Mitigation strategies include wildlife crossings such as underpasses and overpasses, fencing to direct animals toward crossings, reduced speed limits, seasonal or area-specific traffic management, and public awareness campaigns. Advances in road design and monitoring aim to reduce roadkill while maintaining transportation needs.