Diet and body size of North American mammal road mortalities

Previous studies suggest roadkill may not be evenly distributed among species or within species due to life history characteristics. We examine published data on mammalian roadkill surveys conducted in North America for a relationship between diet type, body size and roadkill frequency. Eight studies with comparable methods are used in the analysis for a combined survey mileage of 224,354 km that includes 3.101 individuals killed from 38 species. Carnivores were less likely to be found in roadkill surveys than omnivores or herbivores. After controlling for diet type, a peaked relationship was found between body size and roadkill frequency with the model predicting the highest roadkill for body sizes of about 1.06 kg. These results may be explained by both biological factors and sampling methods.