Citizen science reveals widespread negative effects of roads on amphibian distributions

• Published in: Biological conservation Vol. 180; pp. 31 - 38
• Main Authors: Cosentino, Bradley J., Marsh, David M., Jones, Kara S., Apodaca, Joseph J., Bates, Christopher, Beach, Jessica, Beard, Karen H., Becklin, Kelsie, Bell, Jane Margaret, Crockett, Christopher, Fawson, George, Fjelsted, Jennifer, Forys, Elizabeth A., Genet, Kristen S., Grover, Melanie, Holmes, Jaimie, Indeck, Katherine, Karraker, Nancy E., Kilpatrick, Eran S., Langen, Tom A., Mugel, Stephen G., Molina, Alessandro, Vonesh, James R., Weaver, Ryan J., Willey, Anisha
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-12-2014; Elsevier
• Subjects: Amphibia; Amphibia. Reptilia; Amphibian; Animal, plant and microbial ecology; Anura; Applied ecology; Biological and medical sciences; Composition effects; Conservation; Conservation, protection and management of environment and wildlife; Density; Environmental degradation: ecosystems survey and restoration; Fundamental and applied biological sciences. Psychology; General aspects; Habitat fragmentation; Habitat loss; Habitats; Landscape structure; Landscapes; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Road traffic; Roads; Urbanization; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Wetlands; USA; Habitat fragmentation; Urbanization; Road traffic; Landscape structure; Habitat loss; Amphibian; Landscape; Highway; Amphibia; Ecological damage; Vertebrata; Sciences; Fragmented habitat; Anthropogenic factor; Environmental protection
• ISSN: 0006-3207; 1873-2917
• DOI: 10.1016/j.biocon.2014.09.027

•Landscape modification is a significant threat to amphibian diversity.•We examined how landscape features affect anuran distributions across U.S. regions.•Roads had negative effects on anuran distributions across species and regions.•Negative effects of roads were associated with traffic volume and road density.•Amphibian conservation strategies will likely require mitigating road disturbance.
Landscape structure is important for shaping the abundance and distribution of amphibians, but prior studies of landscape effects have been species or ecosystem-specific. Using a large-scale, citizen science-generated database, we examined the effects of habitat composition, road disturbance, and habitat split (i.e. the isolation of wetland from forest by intervening land use) on the distribution and richness of frogs and toads in the eastern and central United States. Undergraduates from nine biology and environmental science courses collated occupancy data and characterized landscape structure at 1617 sampling locations from the North American Amphibian Monitoring Program. Our analysis revealed that anuran species richness and individual species distributions were consistently constrained by both road density and traffic volume. In contrast, developed land around wetlands had small, or even positive effects on anuran species richness and distributions after controlling for road effects. Effects of upland habitat composition varied among species, and habitat split had only weak effects on species richness or individual species distributions. Mechanisms underlying road effects on amphibians involve direct mortality, behavioral barriers to movement, and reduction in the quality of roadside habitats. Our results suggest that the negative effects of roads on amphibians occur across broad geographic regions, affecting even common species, and they underscore the importance of developing effective strategies to mitigate the impacts of roads on amphibian populations.