Annotated Bibliography: Amphibians and Trails and Road Surfaces

Many people are not familiar with amphibians and the impact of trails and roads, especially in parks, on their behaviors. KEC has compiled this list of references for you to explore. Thanks to Dr. Tom Doty for these references.

Bleiler, J., Pillard, D., Barclift, D., Hawkins, A., & Speicher, J. (2004). Development of a standardized approach for assessing potential risks to amphibians exposed to sediment and hydric soils. ENSR International.

The guidance manual presents a standardized two-tiered risk assessment protocol for evaluating potential risks to amphibians. The Tier I Amphibian ERA Protocol comprises a screening level ERA. This approach uses readily available information to identify potential amphibian exposure pathways at a site and determine which exposure pathways are potentially complete. The Tier 1 protocol includes effects-based and background screening steps to determine whether or not potentially complete exposure pathways have the potential to pose a significant environmental risk. Ultimately, the results of the Tier 1 protocol are used to determine whether or not additional amphibian ERA is warranted.

Bommarito, T., Sparling, D. W., & Halbrook, R. S. (2010). Toxicity of coal-tar pavement sealants and ultraviolet radiation to Ambystoma maculatum. Ecotoxicology, 19(1), 1147-1156.

Polycyclic aromatic hydrocarbons (PAHs) can affect amphibians in lethal and many sublethal ways. This study exposes larvae of the spotted salamander (Ambystoma maculatum) to determine if coal tar sealant can have negative effects on aquatic amphibians and if coal tar toxicity is influenced by ultraviolet radiation.

Cayuela, H., Bonnaire, É., Astruc, G., & Besnard, A. (2019). Transport infrastructure severely impacts amphibian dispersal regardless of life stage. Scientific Reports, 9(1), 1-10.

Transport infrastructure such as roads has been reported to negatively affect dispersal. Their effects on dispersal are thought to be complex, depending on the characteristics of the structure and the intensity of the traffic using it. In addition, individual factors, such as age, may strongly affect dispersal decisions and success when individuals are confronted with transport infrastructure. The authors examined the effects on two kinds of infrastructure, gravel tracks and paved roads, on the dispersal of an endangered amphibian, the yellow-bellied toad (Bombina variegata). The study revealed that emigration rates increased with an individual’s age, while dispersal distance decreased. It also showed that both tracks and roads had negative effects on immigration. The negative effect of roads was stronger than that of tracks. The authors additionally found that the effect of tracks on dispersal slightly decreased with a toad’s age. In contrast, the negative effect of roads was severe and relatively similar across age classes.

Croteau, M. C., Hogan, N., Gibson, J. C., Lean, D., & Trudeau, V. L. (2008). Toxicological threats to amphibians and reptiles in urban environments. In J. C. Mitchell, R. E. Jung Brown, & B. Bartholomew (Eds.), Urban herpetology (pp. 197-209). Society for the Study of Amphibians and Reptiles.

Transformation of natural and agricultural areas into towns and cities increases the number of people living in urban areas. Altogether, this has led to contamination of soil, pollution of surrounding water systems, and increase of airborne chemicals and dust. In this review, the authors discuss specific urban sources of contaminants and how they affect amphibians and reptiles in urban areas.

Florida State University. (2020, July 15). Sun and rain transform asphalt binder into potentially toxic compounds. ScienceDaily.

A dramatic oil spill, such as the Deepwater Horizon accident in the Gulf of Mexico a decade ago, can dominate headlines for months while scientists, policymakers and the public fret over what happens to all that oil in the environment. However, far less attention is paid to the fate of a petroleum product that has been spread deliberately across the planet for decades: asphalt binder.

Forman, R. T., & Alexander, L. E. (1998). Roads and their major ecological effects. Annual review of ecology and systematics, 29(1), 207-231.

Road density and network structure are informative landscape ecology assays. Australia has huge road-reserve networks of native vegetation, whereas the Dutch have tunnels and overpasses perforating road barriers to enhance ecological flows. Based on road-effect zones, an estimated 15–20% of the United States is ecologically impacted by roads.

Jochimsen, D. M., Peterson, C. R., Andrews, K. M., & Gibbons, J. W. (2004). A literature review of the effects of roads on amphibians and reptiles and the measures used to minimize those effects. Idaho Fish and Game Department, USDA Forest Service.

Based on a literature review of over 200 references, this report addresses the adverse ecological effects of roads and traffic on amphibians and reptiles and examines methods to mitigate these effects. The report provides recommendations for future work to understand and mitigate the effects of roads on amphibians and reptiles.

Langton, T. E. S., & Clevenger, A. P. (2020). Measures to reduce road impacts on amphibians and reptiles in California: Best management practices and technical guidance. Western Transportation Institute for California Department of Transportation, Division of Research, Innovation and System Information.

The Best Management Practices and Technical Guidance describes known best practices for retaining or improving habitat connectivity for amphibians and reptiles in the state of California. This guidance relates to the vulnerabilities of California herpetofauna species that are a function of their life cycle needs and behaviors. It shares current understanding at the time of writing of the performance of various passage mitigation measures in California and elsewhere.

Mehta, Y., Ali, A., Yan, B., McElroy, A. E., & Yin, H. (2017). Environmental impacts of reclaimed asphalt pavement (RAP). New Jersey Department of Transportation & U.S. Department of Transportation.

The primary goal of this study was to investigate the environmental impacts of reclaimed asphalt pavement (RAP) while it is freshly processed (i.e., fresh HMA) and after subjecting it to accelerated weathering. The results of these experiments showed that high molecular weight polycyclic aromatic hydrocarbons (PAHs) can elute from the weathered RAP materials, but none was above EPA guidelines. Based on the results, RAP may be used as an unbound material in all environments except those which are highly acidic (i.e., pH ≤ 4).

Relyea, R. A. (2011). Amphibians are not ready for Roundup©. In J. E. Elliott, C. A. Bishop, & C. A. Morrissey (Eds.), Wildlife ecotoxicology: Forensic Approaches (pp. 267-300). Springer.

The herbicide glyphosate, sold under a variety of commercial names including Roundup® and Vision®, has long been viewed as an environmentally friendly herbicide. In the 1990s, however, after nearly 20 years of use, the first tests were conducted on the herbicide’s effects on amphibians in Australia. The researchers found that the herbicide was moderately toxic to Australian amphibians. As one reflects over the past decade, it becomes clear that our understanding of the possible effects of glyphosate-based herbicides on amphibians has moved from a position of knowing very little and assuming no harm to a position of more precise understanding of which concentrations and conditions pose a serious risk.

Rico, A., Kindlmann, P., & Sedláček, F. (2007). Barrier effects of roads on movements of small mammals. Folia Zool, 56(1), 1-12.

Roads and highways represent one of the most important anthropogenic impacts on natural areas and contribute to habitat fragmentation, because they are linear features that can inhibit animal movement, thereby causing barrier effects by subdividing the populations adjacent to the roads. This study aims to determine, to which extent roads act as a barrier, subdividing populations of three species of small forest mammals: bank vole, yellow-necked mouse and common shrew, and what is the relative importance of road width and traffic intensity on the barrier effect.

Schuett-Hames, J. P., Schuett-Hames, D. E., Waterstrat, F. T., & Lund, E. M. (2019). Amphibian movement across a new residential road in western Washington state. Northwestern Naturalist, 100(3), 186-197.

In this exploratory study, the authors investigated amphibian movement across a new 1.4-km residential road system adjacent to a wetland complex in Thurston County, Washington. This study illustrates the importance of understanding the spatial and temporal patterns in pond-breeding amphibian migrations to effectively plan and implement measures to reduce amphibian road mortality. Prior to new development, the authors encourage proactive planning, such as connectivity, traffic, and traffic calming analyses to identify amphibian migration locations and reduce mortality. In areas with existing roads, such as the study site, the authors suggest implementation of mitigation measures paired with effectiveness monitoring.

Sparling, D. W., Halbrook, R., & Bommarito, T. (2009). Acute and chronic effects of coal tar and asphalt sealants on salamanders. Cooperative Wildlife Research Laboratory, Southern Illinois University.

The Barton Springs salamander (Eurycea sosorum) is a federally endangered species inhabiting pools of the Edwards aquifer in the City of Austin, Texas. The presence of polycyclic aromatic hydrocarbons (PAH) in these pools elicited concern for the conservation of the species because PAHs have acute and chronic effects on aquatic organisms, including amphibians. To determine if Barton Springs salamanders could be a risk to these PAHs three laboratory experiments were funded by the Barton Springs Conservation Foundation and conducted by at Southern Illinois University. These experiments used adult eastern newts (Notophthalmus viridescens), larval spotted salamanders (Ambystoma maculatum) and adults of the closely related San Marcos salamander (Eurycea nana) as surrogates. The respective primary objectives of the experiments were to assess: 1) a dose/response relationship between concentrations of PAHs and acute or chronic effects using asphalt and coal tar sealants; 2) if exposure to realistic levels of ultraviolet radiation affect the toxicity of PAHs from coal tar sealant; and 3) the comparative toxicity of E. nana to the other surrogates’ species.

Stuart, S. N., Chanson, J. S., Cox, N. A., Young, B. E., Rodrigues, A. S. L., Fischman, D. L., & Waller, R. W. (2004). Status and trends of amphibian declines and extinctions worldwide. Science, 306(5702), 1783-1786.

The first global assessment of amphibians provides new context to the well-publicised phenomenon of amphibian declines. Amphibians are more threatened, and are declining more rapidly, than either birds or mammals. Although many declines are due to habitat loss and over-utilization, other, unidentified processes threaten 48% of rapidly declining species, and are driving species most quickly to extinction. Declines are non-random in terms of species’ ecological preferences, geographic ranges and taxonomic associations, and are most prevalent among Neotropical montane, stream-associated species. The lack of conservation remedies for these poorly understood declines means that hundreds of amphibian species now face extinction.

Vredenburg, V. T. & Wake, D. B. (2007). Global declines of amphibians. In S. A. Rice (Ed.), Encyclopedia of biodiversity. Elsevier, Inc.

Global Declines of Amphibians refers to the phenomenon where amphibian species are experiencing severe population declines around the world. This encyclopedia entry includes a summary of amphibian biodiversity, dimensions of the problem, factors responsible for the declines, challenges and opportunities for the future, and implications for the biodiversity crisis.

Walker, K. (2014). Effects of petroleum distillates on amphibian development (Theses and Dissertations, Publication No. 2318) [Thesis, University of Arkansas, Fayetteville]. ScholarWorks@UARK.

Petroleum distillates are widely used as an energy source and the extraction and disposal of these chemicals are done with little consideration of their effects on aquatic environments. Amphibians are considered excellent ecological indicators, but little research has examined effects of petroleum distillates on aquatic species. The author evaluated the lethal and sublethal effects on larval amphibians with exposure to petroleum distillates associated with various venues of pollution including hydraulic fracturing and found that petroleum distillate exposure through open waste ponds or leakage of petroleum distillates is a concern for amphibians.

Yale Conrey, R. C., & Mills, L. S. (2001). Do highways fragment small mammal populations. In C. L. Irwin, P. Garrett, & K. P. McDermott (Eds.), Proceedings of the 2001 International Conference on Ecology and Transportation ICOET (Australia) (pp. 446-457). Center for Transportation and the Environment, North Carolina State University.

Small mammal populations separated by highways may be partially or completely isolated from one another due to low dispersal capabilities, low probability of surviving highway crossing attempts, and/or avoidance of areas adjacent to highways. Threats to small mammals are problematic at the ecosystem level because of their importance as seed dispersers and their role as prey for predators, such as marten, wolverine, and raptors. The authors’ objective is to determine how movement and gene flow are affected by two- and four-lane highways for small mammals in forested areas of western Montana.