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Amphibian Research and Monitoring Initiative

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Species and their Ecology


Mark Roth
M. Roth (ARMI) installing an acoustic recorder and water-level and water-temperature loggers at an amphibian breeding site in the St. Croix National Scenic Riverway in WI. Photo by: P. Boma.
» Phylum: Chordata
» Class: Amphibia
» Order: Anura (formerly Salientia): Frogs and toads
» Order: Caudata (formerly Urodela): Salamanders
» Order: Gymnophiona: Caecelians

The U.S. is home to approximately 287 of the world’s estimated 6,000 amphibian species. The number of known species changes periodically as new species are discovered and new genetic techniques (e.g. molecular genetics) allow scientists to distinguish among cryptic species.

Brad Glorioso
B. Glorioso (ARMI) with American bullfrog in Atchafalaya Basin, LA conducting amphibian surveys. Photo by: L. Elston.

Amphibian Taxonomy

» Scientific and standard names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. (Crother, B.I. (chair). 2008. Publisher: Society for the Study of Amphibians and Reptiles)

» Amphibian species of the world 5.4, an online reference. (Frost, D. 2010. Publisher: American Museum of Natural History)

» Standard common and current scientific names for North American amphibians, turtles, reptiles and crocodillians. (Collins, J.T., and T.W. Taggart. 2009. Publisher: Center for North American Herpetology)

ARMI conducts research on the natural history of species; writing reports and describing the ecology of America’s amphibians. ARMI also collaborates with federal and state partners to design, implement, and evaluate management actions that benefit T&E and other imperiled amphibian species.

Federal and State Partners: Information about the status, management, and conservation of amphibians is found throughout the ARMI web site [e.g. Products Database and Topics Sections]. Please consult the “National Amphibian Atlas” to identify the approximate range of the species of interest.

Resources

National Amphibian Atlas.

ARMI Products on Species and their Ecology

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This is an ARMI Product. Additive impacts of experimental climate change increase risk to an ectotherm at the Arctic’s edge
Authors: Davenport JM, Hossack BR, Fishback L | Outlet: Global Change Biology
Globally, Arctic and Subarctic regions have experienced the greatest temperature increases during the last 30 years. These extreme changes have amplified threats to the freshwater ecosystems that dominate the landscape in many areas by altering water budgets. Several studies in temperate environments have examined the adaptive capacity of organisms to enhance our understanding of the potential repercussions of warming and associated accelerated drying for freshwater ecosystems. However, few experiments have examined these impacts in Arctic or Subarctic freshwater ecosystems, where the climate is changing most rapidly. To evaluate the capacity of a widespread ectotherm to anticipated environmental changes, we conducted a mesocosm experiment with wood frogs (Rana sylvatica) in the Canadian Subarctic. Three warming treatments were fully crossed with three drying treatments to simulate a range of predicted changes in wetland environments. We predicted wetland warming and drying would act synergistically, with water temperature partially compensating for some of the negative effects of accelerated drying. Across all drying regimes, a 1°C increase in water temperature increased the odds of survival by 1.79, and tadpoles in 52-day and 64-day hydroperiod mesocosms were 4.1–4.3 times more likely to survive to metamorphosis than tadpoles in 45-day mesocosms. For individuals who survived to metamorphosis, there was only a weak negative effect of temperature on size. As expected, increased temperatures accelerated tadpole growth through day 30 of the experiment. Our results reveal that one of the dominant herbivores in Subarctic wetlands, wood frog tadpoles, are capable of increasing their developmental rates in response to increased temperature and accelerated drying, but only in an additive manner. The strong negative effects of drying on survival, combined with lack of compensation between these two environmental drivers, suggest changes in the aquatic environment that are expected in this ecosystem will reduce mean fitness of populations across the landscape.

This is an ARMI Product. Evaluating within-population variability in behavior and demography for the adaptive potential of a dispersal-limited species to climate change.
Authors: Muñoz DJ, Hesed KM, Grant EHC, Miller DAW | Outlet: Ecology and Evolution
Multiple pathways exist for species to respond to changing climates. However, responses of dispersal-limited species will be more strongly tied to ability to adapt within existing populations as rates of environmental change will likely exceed movement rates. Here, we assess adaptive capacity in Plethodon cinereus, a dispersal-limited woodland salamander. We quantify plasticity in behavior and variation in demography to observed variation in environmental variables over a 5 year period. We found strong evidence that temperature and rainfall influence P. cinereus surface presence, indicating changes in climate are likely to affect seasonal activity patterns. We also found that warmer summer temperatures reduced individual growth rates into the autumn, which is likely to have negative demographic consequences. Reduced growth rates may delay reproductive maturity and lead to reductions in size-specific fecundity, potentially reducing population level persistence. To better understand within-population variability in responses, we examined differences between two common color morphs. Previous evidence suggests that the color polymorphism may be linked to physiological differences in heat and moisture tolerance. We found only moderate support for morph-specific differences for the relationship between individual growth and temperature. Measuring environmental sensitivity to climatic variability is the first step in predicting species’ responses to climate change. Our results suggest phenological shifts and changes in growth rates are likely responses under scenarios where further warming occurs, and we discuss possible adaptive strategies for resulting selective pressures.  

This is an ARMI Product. Amphibian dynamics in constructed ponds on a wildlife refuge: developing expected responses to hydrological restoration
Author: Hossack BR | Date: 2016 | Outlet: Hydrobiologia
Management actions are based upon predictable responses. To form expected responses to restoration actions, I estimated habitat relationships and trends (2002‒2015) for four pond-breeding amphibians on a wildlife refuge (Montana, USA) where changes to restore historical hydrology to the system greatly expanded (≥8 times) the flooded area of the primary breeding site for western toads (Anaxyrus boreas). Additional restoration actions are planned for the near future, including removing ponds that provide amphibian habitat. Multi-season occupancy models based on data from 15 ponds sampled during 7 years revealed that the number of breeding subpopulations increased modestly for Columbia spotted frogs (Rana luteiventris) and was stationary for long-toed salamanders (Ambystoma macrodactylum) and Pacific treefrogs (Pseudacris regilla). For these three species, pond depth was the characteristic that was associated most frequently with occupancy or changes in colonization and extinction. In contrast, a large decrease in colonization by western toads explained the decline from eight occupied ponds in 2002 to two ponds in 2015. This decline occurred despite an increase in wetland area and the colonization of a newly-created pond. These changes highlight the challenges of managing for multiple species and how management responses can be unpredictable, possibly reducing the efficacy of targeted actions.


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