Elevated wildlife-vehicle collision rates during the COVID-19 pandemic

Joel O Abraham,Matthew A Mumma

doi:10.1038/s41598-021-99233-9

Abstract

Wildlife-vehicle collisions threaten both humans and wildlife, but we still lack information about the relationship between traffic volume and wildlife-vehicle collisions. The COVID-19 pandemic allowed us to investigate the effects of traffic volume on wildlife-vehicle collisions in the United States. We observed decreased traffic nationwide, particularly in densely populated states with low or high disease burdens. Despite reduced traffic, total collisions were unchanged; wildlife-vehicle collisions did decline at the start of the pandemic, but increased as the pandemic progressed, ultimately exceeding collisions in the previous year. As a result, nationwide collision rates were higher during the pandemic. We suggest that increased wildlife road use offsets the effects of decreased traffic volume on wildlife-vehicle collisions. Thus, decreased traffic volume will not always reduce wildlife-vehicle collisions.

Highlights

Wildlife-vehicle collisions threaten both humans and wildlife, but we still lack information about the relationship between traffic volume and wildlife-vehicle collisions
Comparisons of traffic volumes across the United States between the insurance year preceding the pandemic (July 2018–June 2019) and the insurance year including the beginning of the pandemic (July 2019–June 2020) revealed a 7.2% reduction in traffic volume across the entire United States (Fig. 2A), consistent with other work documenting substantial declines in road traffic globally with the onset of the pandemic[10,12,13,20]
Reductions in annual traffic were ubiquitous across states (t50 = − 6.20, P < 0.05) (Fig. 3A) and were related to human population density and local disease burden (Table S4); traffic declined most in densely populated states, such as Connecticut and Rhode Island, and declines in traffic were greatest in states with either low or high disease burdens, including Hawai’i and New Jersey (Fig. 4)

Summary

Introduction

Wildlife-vehicle collisions threaten both humans and wildlife, but we still lack information about the relationship between traffic volume and wildlife-vehicle collisions. Because of the appeal of roads and roadsides to wildlife[10,11,12,13], declines in traffic volume might reduce the perceived risk of using roads by wildlife, thereby leading to greater use of areas near roads and more frequent crossing of roads Such changes in wildlife risk perception might counteract the effects of lower traffic volume on WVCs, potentially causing net increases in collision rates between vehicles and wildlife (WVCs/traffic volume)[3], and resulting in a non-linear relationship between traffic volume and WVCs. potential changes in animal behavior create uncertainty regarding how changes in traffic volume affect the number and rate of WVCs. The onset of the COVID-19 pandemic presents a natural experiment by which to examine the relationship between traffic volume and W VCs17. Compensatory changes in animal behavior might have offset any effects of lower traffic volume on the frequency of WVCs during the pandemic, resulting in little net change in the number of WVCs

Methods

Results

Conclusion