Spatial and temporal patterns of reptile roadkill in the north-west Australian tropics

Abstract

Roads present unavoidable challenges to wildlife, both in populated and in more remote regions. Both traffic infrastructure and road vehicles can have a detrimental impact on natural ecosystems and wildlife populations. This study aimed to gain a broad overview of the impacts of a stretch of road on native herpetofauna in north-Western Australia. Reptile roadkill was surveyed along a 31-km stretch of the main road in Broome, Western Australia for eight months, during both the wet and dry seasons. There was a significantly higher rate of road mortality in the wet season despite a decrease in traffic intensity. Incidence of roadkill varied between reptile clades, with varanids being the mostly frequently recorded as roadkill. Carcass persistence experiments, however, highlighted a potential significant underestimation in roadkill due to an extremely high rate of carcass removal, emphasising the need to consider this variable when using roadkill as a survey method. We recommend that carcass persistence should be further investigated in order to accurately assess extent of reptile roadkill in the region, and how roads and traffic may impact at-risk species and populations.