Roadkill and space use data predict vehicle-strike hotspots and mortality rates in a recovering bobcat (Lynx rufus) population

Heidi L Bencin,Christa Rose,Suzanne Prange,Viorel D Popescu

doi:10.1038/s41598-019-50931-5

Heidi L Bencin, Christa Rose + Show 2 more

Open Access

https://doi.org/10.1038/s41598-019-50931-5

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Abstract

Roadways pose challenges for conserving wide-ranging animal species. As bobcat (Lynx rufus) populations recover in Ohio, an accurate evaluation of population metrics is critical to understanding future population trajectories. In this study, we integrated multiple datasets to examine overall road mortality rates in Ohio. First, we utilized a long-term vehicle-strike dataset (1978–2017) to determine landscape and local predictors of road mortality. We found that bobcats were killed at higher rates on interstates regardless of surrounding landscape composition, but that landscape variables were useful at predicting mortality on lower-traffic roads. To explore road avoidance behaviors, we used GPS telemetry data from 18 individuals to compare road crossings along trajectory paths with random road crossings simulated using Correlated Random Walks. Bobcats exhibited avoidance of certain route types (county, municipal, and US routes). Finally, by integrating traffic volume data, road crossing behavior, and accounting for the proportion of each route type present in the study area, we estimated that a minimum of 6% and up to 18% of the bobcat population in Ohio is lost to vehicle-strikes annually. To fully understand the population level impacts of this mortality, we recommend further monitoring of age structure and sex of roadkill animals. Our results identify potential areas for mitigation of vehicle-strikes and emphasize the importance of accounting for road mortality when making management decisions for Ohio’s recovering bobcat population.

Highlights

Roadways pose challenges for conserving wide-ranging animal species
They exhibit sensitivity towards urbanization[31], bobcats have been shown to cross developed areas and well-traveled roads to move between habitat fragments, causing mortality rates of up to 50% in areas with significant human development[5], lower rates have been recorded in other North American populations[22,32]
Our study revealed that the overall impacts of roads on Ohio’s recovering bobcat population, based on its current distribution, is high

Summary

Introduction

Roadways pose challenges for conserving wide-ranging animal species. As bobcat (Lynx rufus) populations recover in Ohio, an accurate evaluation of population metrics is critical to understanding future population trajectories. The negative effects of roadways and traffic on wildlife are far-reaching; it is well known that roads can create barriers to movement[3], cause habitat fragmentation[4,5], impede gene flow[6], and contribute to direct mortality[7,8,9,10] These effects further lead to decreases in animal species abundance and richness, especially for larger-bodied mammals[11]. Vehicle strikes are currently considered the main source of mortality for bobcats in Ohio[30], but the magnitude of the potential effect at the population level remains unknown They exhibit sensitivity towards urbanization[31], bobcats have been shown to cross developed areas and well-traveled roads to move between habitat fragments, causing mortality rates of up to 50% in areas with significant human development[5], lower rates have been recorded in other North American populations[22,32]. It is critical to understand the effects of road mortality at the population level in order to determine population viability and effectively guide future bobcat management and conservation

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