Species and their Ecology
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.
B. Glorioso (ARMI) with American bullfrog in Atchafalaya Basin, LA conducting amphibian surveys. Photo by: L. Elston.
» 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.
National Amphibian Atlas.
ARMI Products on Species and their Ecology
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North-facing slopes and elevation shape asymmetric genetic structure in the range-restricted salamander Plethodon shenandoah
Authors: Mulder K, Cortes-Rodriguez N, Grant EHC, Brand AB, Fleischer RC | Outlet: Ecology and Evolution
Species with narrow environmental preferences are often distributed across fragmented patches of suitable habitat, and dispersal among subpopulations can be difficult to directly observe. Genetic data collected at population centers can help quantify gene flow, which is especially important for vulnerable species with a disjunct range. Plethodon shenandoah is a Federally Endangered salamander known only from three mountaintops in Virginia, USA. To reconstruct the evolutionary history and population connectivity of this species, we generated both mitochondrial and nuclear data using sequence capture for all three populations and found strong population structure that was independent of geographic distance. Both the nuclear markers and mitochondrial genome indicated a deep split between the most southern population and the combined central and northern population. Although there was some mitochondrial haplotype-splitting between the central and northern populations, there was complete admixture in nuclear markers. This is indicative of either a recent split or current male-biased dispersal among mountain isolates. Models of landscape resistance found that dispersal across north-facing slopes at mid-elevation levels best explain the observed genetic structure among populations. These unexpected results highlight the importance of landscape features in understanding and predicting movement and fragmentation of salamanders across space.
Timing of first and last calls and median calling peaks for Pseudacris crucifer, and of the first call for Hyla chrysoscelis/versicolor, at six wetlands in the St. Croix National Scenic Riverway from 2008-2012
Authors: Sadinski W, Roth M | Date: 2018-09-06 | Outlet: U.S. Geological Survey data release, https://doi.org/10.5066/F7CR5SBH.
To better understand relations of annual calling phenophases for Pseudacris crucifer, and of the first calls of the season for Hyla chrysoscelis/versicolor, to the timing of the start of the calling season, we compared these dynamics for six wetlands in the St. Croix National Scenic Riverway from 2008 to 2012. We installed an acoustic recorder at each site prior to the start of each calling season and programmed it to record for five minutes at the top of every hour until late summer. We then used the Songscape option in Songscope software to generate annual summaries of all acoustic files recorded at each site. We created contour plots of the summarized median dB values across bandwidths in each recording and then assessed individual calls and calling peaks by visually examining these plots to identify first (and last) calls via the unique call signatures for these two species. We examined individual five-minute recordings aurally and visually as necessary when sound images represented on the contour plots were confounded and to ensure that the calling peaks described below were dates when calling activity was relatively intense. We also determined the daily median dB levels for frequencies across 2900 to 3200 Hz during 2100 to 2300 h, the bandwidth that typically encompassed the primary energy peak in P. crucifer calls and a time period during which P. crucifer typically called most consistently throughout their calling season. We did this for each day from the date when P. crucifer first called during each year to the date when they last called during each year. Because calling activity could vary from one hour to the next, we integrated the area under the curve for the daily median dB levels from 2900 to 3200 Hz during 2100 to 2300 h. We removed dates when overlapping sounds from storms or other sources rendered comparisons to calls of P. crucifer inaccurate. We used the resultant set of integrands to represent the relative sound intensity (as an indicator of calling activity) for P. crucifer across those hours for each date. We then used these integrands to determine the three highest peak calling dates for this species and used the median of those three dates as the overall median peak date for each site in each year.
The eight-day interval during which amphibians first called annually at individual study wetlands across four study areas.
Authors: Sadinski W, Roth M | Date: 2018-09-06 | Outlet: U.S. Geological Survey data release, https://doi.org/10.5066/F7CR5SBH
To help determine when winter conditions were changing to spring conditions annually in our four study areas, we determined the first eight-day interval (in accordance with the scale limitations of satellite data we used to assess the presence of snow) during which the first amphibian of the season called at each of our study wetlands in those areas. To do this, we examined contour plots of summaries of all the acoustic data we collected at that site in a given year to identify the unique call signatures of individual amphibian species by date and time. When necessary due to potential confounding on a contour plot, we also examined relevant individual five-minute recordings aurally and visually to confirm whether a call occurred. When we confirmed the date of the first call we recorded in a given season, we identified the eight-day interval in which that date fell, with the first such interval beginning on January 1 of each year.