Effects of Roadway Traffic on Wild Ungulates: A Review of the Literature and Case Study of Elk

Roads have been recognized as a threat to wildlife species for over 80 years. Studies on the effects of roads on ungulates species did not begin till the 1970’s. We identified 53 literature sources that suggested or examined traffic levels or road types and their effects on ungulate-vehicle collisions, ungulate distribution and roadway perme¬ability. Seventy-one percent of these suggested an effect of traffic level on ungulates. Only 47% of the papers suggested deer (Odocoileus spp.) were affected by traffic while in contrast studies on elk (Cervus elaphus) and moose (Alces alces) were at 84% and 82%, respectively. In studies that suggested no effect of traffic, other factors such as ungulate populations, ungulate behavior, driver behavior, and landscape variables were generally considered reasons for fluctuations in collisions. Although several studies examined ungulate distribution along roads, very few adequately looked at fluctuating traffic levels along highways. Highways have a greater potential for ungulate-vehicle collisions and are more likely to provide a barrier to ungulates than low traffic roads. Our further understanding of ungulate move¬ments and behavior in relationship to highways may be important in helping to mitigate ungulate-vehicle collisions and ungulate habitat fragmentation. Our State Route 260 project in central Arizona has