Immediate impact of fires on roadkilling of wild vertebrates on a highway in southeast Brazil

Abstract

Fires cause wild vertebrates to try to escape, thereby leading to an increase in attempts to cross roads and consequently an increase in the number of roadkills. However, the study of the impact of fires on roadkilling of wild vertebrates is practically nonexistent. In this study, we analyzed the relationship between fires near a 180 km highway stretch in Southeast Brazil and wild vertebrate roadkills using a 7-year dataset on roadkills and satellite data on fires, hypothesizing that roadkills would increase after fires. We found that the number of roadkilled wild vertebrates increased by about 144% (P = 0.020) in highway sections up to 1 km from fires, within 7–8 days after the fires. The number of roadkills in highway sections affected by fires was also higher than that of neighboring (control) section (P = 0.028). Taken together, these results show there was a significant increase in the number of roadkills on road sections close to or within burned areas. This work emphasizes the importance of analyzing the synergistic effects of fires and roadkill of wild vertebrates and guides research on adopting an experimental design which allows for temporal and spatial controls using retrospective data on fires and roadkilling. We recommend decreasing traffic flow and/or vehicle speed near areas recently affected by fires, as a preventive management strategy.