An objective road risk assessment method for multiple species: ranking 166 reptiles and amphibians in California
Context
Transportation and wildlife agencies may consider the need for barrier structures and safe wildlife road-crossings to maintain the long-term viability of wildlife populations. In order to prioritize these efforts, it is important to identify species that are most at risk of extirpation from road-related impacts.
Purpose
Our goal was to identify reptiles and amphibians in California most susceptible to road mortality and fragmentation. With over 160 species and a lack of species-specific research data, we developed an objective risk assessment method based upon road ecology science.
Methods
Risk scoring was based upon a suite of life history and space-use characteristics associated with negative road effects applied in a hierarchical manner from individuals to species. We evaluated risk to both aquatic and terrestrial connectivity and calculated buffer distances to encompass 95% of population-level movements. We ranked species into five relative categories of road-related risk (very-high to very-low) based upon 20% increments of all species scores.
Results
All chelonids, 72% of snakes, 50% of anurans, 18% of lizards and 17% of salamander species in California were ranked at high or very-high risk from negative road impacts. Results were largely consistent with local and global scientific literature in identifying high risk species and groups.
Conclusions
This comparative risk assessment method provides a science-based framework to identify species most susceptible to negative road impacts. The results can inform regional-scale road mitigation planning and prioritization efforts and threat assessments for special-status species. We believe this approach is applicable to numerous landscapes and taxonomic groups.
Citation Information
Publication Year | 2018 |
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Title | An objective road risk assessment method for multiple species: ranking 166 reptiles and amphibians in California |
DOI | 10.1007/s10980-018-0640-1 |
Authors | Cheryl S. Brehme, Stacie A. Hathaway, Robert N. Fisher |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Landscape Ecology |
Index ID | 70198525 |
Record Source | USGS Publications Warehouse |
USGS Organization | Western Ecological Research Center |