Spatial analysis of vehicular trauma and identification of hotspots in North Carolina chelonians

Abstract

Vehicular trauma is the most common cause of chelonians being brought to the Turtle Rescue Team (TRT) at the North Carolina State University College of Veterinary Medicine. Many chelonian species are declining throughout their range, and anthropogenic stressors are a major cause. This study aims to use retrospective analysis of turtles admitted for vehicular trauma from 2005–2019 to determine factors associated with increased observed mortality and to identify hotspots of reported vehicular collisions. Factors hypothesized to influence where reported vehicular collisions with turtles occurred included traffic volume and the proximity to water, protected areas, and TRT. Of all turtles admitted for vehicular collisions (n = 2,553), 40.8% survived to be released and 53.8% died or were euthanized. Most patients arrived between April and September (n = 2,315), with eastern box turtles (Terrapene carolina carolina) being the most admitted species (n = 1,096). We obtained geocoded locations for 67.4% of all incidents (n = 1,721). Logistic regression of geocoded locations within 60 km of TRT (n = 1,439) showed the likelihood of dying or being euthanized at the wildlife hospital from vehicular trauma was not associated with any of the hypothesized factors. We identified 9 hotspots based on the high spatial aggregation of collisions. By identifying these hotspots of vehicular collisions with turtles, targeted management measures such as signage, fencing, or corridors can be implemented. The substantial vehicular mortality rate in chelonians demonstrates the need for collision prevention as a conservation priority.