Hit and Run: Effects of Scavenging on Estimates of Roadkilled Vertebrates

Researchers often use road corridors to collect data on diversity, life history, or population parameters of vertebrates. In areas with high abundances of scavengers, road surveys may be biased due to removal of carcasses from roads. Thus, the rates at which scavenged items are removed from roads are of considerable interest to field biologists who use roads when collecting data. We experimentally investigated scavenging rates along a road on the Atlantic coast of central Florida using both bird and snake carcasses. We found extremely high rates of carcass removal by scavengers: 60–97% disappeared within 36 hours of their placement along roads. Additionally, scavenging rates were higher for snakes than birds, although snake body size did not affect scavenging rates. Bird carcasses placed in the center of the road were removed at faster rates than those placed at road edges. Researchers should use extreme caution when interpreting data based on roadkill; since scavengers can remove roadkill rapidly, such data may not be representative of populations in habitats surrounding roads.