Roads do not increase carrion use by a vertebrate scavenging community

Jacob E Hill,James C Beasley,Travis L Devault,Jerrold L Belant,Olin E Rhodes

doi:10.1038/s41598-018-34224-x

Abstract

Wildlife-vehicle collisions introduce a considerable amount of carrion into the environment, but scavenger use of this resource has not been extensively investigated. Scavengers may use roads for reliable foraging opportunities, but might also use roads for other purposes and encounter carrion opportunistically. We examined scavenging of carrion along linear features by placing 52 rabbit carcasses in each of three treatments in forested habitat during winter (Dec 2016-Mar 2017) in South Carolina, USA: roads, power line clearings (linear feature with fewer carcasses than roads due to lack of road kill), and forest interior. We used motion-activated cameras to compare arrival times and presence of vertebrate scavengers among treatments. There was no difference in proportion of carcasses scavenged or scavenger arrival time across treatments. No species arrived at roads quicker than other treatments. Turkey vultures (Cathartes aura) and coyotes (Canis latrans) scavenged equally across treatments, whereas gray foxes (Urocyon cinereoargenteus) scavenged along roads and power lines, but not in forests. We suggest that scavenger use of carrion near roads at this location during winter relates to factors other than carrion availability. Because some scavengers readily consumed carrion on roads, this resource has the potential to influence the ecology of these species.

Highlights

Human development is increasingly encroaching into natural areas
Considerable research has assessed the effects of roads on wildlife populations, little attention has been focused on the fate of carcasses resulting from vehicle collisions, which result in substantial additions of carrion to the environment
We explored the influence of roads on vertebrate scavenging by comparing scavenging of rabbit carcasses placed along road verges, along linear features without roads, and in the forest interior

Summary

Introduction

Human development is increasingly encroaching into natural areas. Roads are an important means by which this occurs as roads fragment habitat[1], facilitate transport of pollutants into the environment[2], and aid the spread of invasive species[3,4]. Across all treatments we documented 17 species scavenging on carcasses, including species in forest, species in power line, and 11 species in road trials (Table 1). There was no difference in whether a carcass was scavenged across treatments (Table 2); 90% of forest, 92% of power line, and 86% of road trials were scavenged.

Results

Conclusion