Gila Monster Road Mortality In and Near Saguaro National Park: An Analysis of Road and Landscape Characteristics that Affect Roadkill
PublisherThe University of Arizona.
AbstractRoad and landscape characteristics that affect Heloderma suspectum are crucial for understanding factors that increase road mortality, predicting roadkill hotspots, and implementing effective mitigation measures. We investigated the impact of urbanization on Gila monster roadkill incidence through five factors: traffic density, speed limit, housing density, road density, and the number of lanes on the roads. We conducted field searches in Saguaro National Park and in nearby neighborhoods outside the park to record the date and GPS location of Gila monster road mortalities between 2011 and 2015. During this study, we recorded a total of 24 Heloderma suspectum road mortalities. The traffic density (vehicles/km) of roads had the most significant correlation with number of roadkill (p < 0.01) and we found that speed limit, housing density, road density, and number of lanes alone are not sufficient to predict roadkill hotspots. These findings suggest that a combination of these factors with the addition of proximity to high population densities will give a better insight on predicting Gila monster roadkill hotspots and determining effective mitigation methods.