Skip to main content
U.S. flag

An official website of the United States government

Herpetological Research Team (FRESC) Active

By Forest and Rangeland Ecosystem Science Center September 20, 2017

The Herpetological Research Team focuses on issues related to conservation and management of amphibians and other aquatic and semi-aquatic species. Among our current studies are effects of invasive species, disease, and land use change on the dynamics of amphibian communities to inform conservation and management decision making.

Many of our projects are supported by the USGS Amphibian Research and Monitoring Initiative (ARMI). ARMI works with Department of Interior (DOI) and other federal and state agencies to respond to information gaps that are critical to the implementation of effective conservation and management strategies for amphibian communities. ARMI’s work includes research on the status and threats of native species, development and evaluation of quantitative and field methods, and monitoring designs to address conservation and management information needs at multiple spatial and temporal scales.

Principal Investigator

Michael Adams - Supervisory Research Ecologist

Federal Staff

Brome McCreary - Wildlife Biologist

Christopher Pearl - Wildlife Biologist

Jennifer Rowe - Wildlife Biologist

Meredith Diskin - Biological Science Technician

Jennifer Fredrickson - Ecologist

Affiliate

Adam Duarte - Research Ecologist at Oregon State University

 

 

 

Science Themes of the FRESC Herpetological Research Team are highlighted below.

link
An American bullfrog.

American Bullfrog Invasion and Impacts on Native Species in the Pacific Northwest

The Herpetological Research Team at the USGS Forest and Rangeland Ecosystem Science Center uses innovative tools to investigate the invasion and spread of American bullfrogs in Washington and Oregon and understand how bullfrogs are interacting with native amphibians.
By
Forest and Rangeland Ecosystem Science Center
link

American Bullfrog Invasion and Impacts on Native Species in the Pacific Northwest

The Herpetological Research Team at the USGS Forest and Rangeland Ecosystem Science Center uses innovative tools to investigate the invasion and spread of American bullfrogs in Washington and Oregon and understand how bullfrogs are interacting with native amphibians.
Learn More
link
Parameterization of spatial multistate occupancy model for estimation of probability of Oregon spotted frog reproduction

Quantitative and Other Methods

Applying quantitative methods to evaluate ecological hypotheses for wild animal populations is inherently challenging due to the complexity of ecological systems and the sampling process that is used to monitor them.
By
Ecosystems Mission Area, Species Management Research Program, Forest and Rangeland Ecosystem Science Center
link

Quantitative and Other Methods

Applying quantitative methods to evaluate ecological hypotheses for wild animal populations is inherently challenging due to the complexity of ecological systems and the sampling process that is used to monitor them.
Learn More
link
Testing for Bsal

Disease

Disease is a major threat facing amphibian and reptile populations around the world. Our research addresses interactions between pathogens, the environment, and hosts to better understand ways to prevent the spread of disease.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Forest and Rangeland Ecosystem Science Center
link

Disease

Disease is a major threat facing amphibian and reptile populations around the world. Our research addresses interactions between pathogens, the environment, and hosts to better understand ways to prevent the spread of disease.
Learn More
link

Oregon Spotted Frog

The Oregon spotted frog ( Rana pretiosa ) is a medium-sized anuran native to the northwestern United States. Body coloration ranges from brown or tan to brick red, usually overlaid with dark, ragged spots. Oregon spotted frogs can be distinguished from other native species by their relatively short hind legs, orange or red wash of color on underside of abdomen and legs, and upturned chartreuse...
By
Species Management Research Program, Forest and Rangeland Ecosystem Science Center
link

Oregon Spotted Frog

The Oregon spotted frog ( Rana pretiosa ) is a medium-sized anuran native to the northwestern United States. Body coloration ranges from brown or tan to brick red, usually overlaid with dark, ragged spots. Oregon spotted frogs can be distinguished from other native species by their relatively short hind legs, orange or red wash of color on underside of abdomen and legs, and upturned chartreuse...
Learn More
link
Mink Lake Basin, Oregon

Aquatic Habitats and Communities

The Pacific Northwest includes a patchwork of public lands managed by numerous state and federal agencies. Our research informs and supports these agencies as they conserve and manage native amphibian species, including pre- and post-treatment assessment, decision support, long-term monitoring, population translocation, and habitat restoration.
By
Forest and Rangeland Ecosystem Science Center
link

Aquatic Habitats and Communities

The Pacific Northwest includes a patchwork of public lands managed by numerous state and federal agencies. Our research informs and supports these agencies as they conserve and manage native amphibian species, including pre- and post-treatment assessment, decision support, long-term monitoring, population translocation, and habitat restoration.
Learn More
link
Foothill yellow-legged frog

Declining Amphibians

Amphibian populations world-wide are declining for reasons that include disease, habitat loss, and invasive species. Our research addresses these threats as part of the Amphibian Research and Monitoring Initiative (ARMI), a nationwide, federally funded program. We work with resource managers to provide information that improves understanding of status of amphibians and the implications of...
By
Biological Threats and Invasive Species Research Program, Species Management Research Program, Forest and Rangeland Ecosystem Science Center
link

Declining Amphibians

Amphibian populations world-wide are declining for reasons that include disease, habitat loss, and invasive species. Our research addresses these threats as part of the Amphibian Research and Monitoring Initiative (ARMI), a nationwide, federally funded program. We work with resource managers to provide information that improves understanding of status of amphibians and the implications of...
Learn More
link
Bullfrog Young Adult

Aquatic Invasive Species

Aquatic invasive species, like bullfrogs, stocked fish, crayfish, and reed canarygrass can affect aquatic systems in a variety of ways and have been linked to declines in some amphibians.
By
Biological Threats and Invasive Species Research Program, Forest and Rangeland Ecosystem Science Center
link

Aquatic Invasive Species

Aquatic invasive species, like bullfrogs, stocked fish, crayfish, and reed canarygrass can affect aquatic systems in a variety of ways and have been linked to declines in some amphibians.
Learn More

If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

Filter Total Items: 21

Oregon spotted frog (Rana pretiosa) captures before and after drought mitigation at Jack Creek, Oregon 2009-2021

Amphibians are among the most sensitive taxa to climate change, and species inhabiting arid and semiarid landscapes at the extremes of their range are especially vulnerable to periods of drought. The Jack Creek, Oregon, USA population of Oregon spotted frogs (Rana pretiosa) faces unique challenges occupying the highest elevation site in the species’ extant range and one that has been hydrologicall
By
Forest and Rangeland Ecosystem Science Center

Mercury concentrations in amphibian tissues across the United States, 2016-2021

Comma-separated values (.csv) file containing data related to amphibian sampling across the United States between 2016 and 2021. Data files contain mercury concentrations in amphibian and dragonfly tissues, mercury concentrations in sediment, as well as amphibian morphometrics, and habitat and climate characteristics where the samples were collected.
By
Forest and Rangeland Ecosystem Science Center

Larval headwater stream amphibian captures from the Trask River Watershed Experimental Study of forest harvest impacts, 2008-2016

Forest harvest is one of the primary landscape-scale management actions affecting riparian forests of the Pacific Northwest, U.S, yet the effect of harvest on headwater steam amphibians is largely understudied. Existing information is often limited because of the difficulty separating movement and emigration processes from occupancy and abundance estimates. We designed a before-after control-impac
By
Forest and Rangeland Ecosystem Science Center

Cascade torrent salamander (Rhyacotriton cascadae) surveys in Oregon and Washington 2022

The US Fish and Wildlife Service (USFWS) is evaluating the status of the Cascade torrent salamander (Rhyacotriton cascadae) across its range to determine whether the species merits listing under the Endangered Species Act. The USGS conducted visual surveys for Rhyacotriton cascadae at 65 sites in Oregon and Washington that were historically occupied by the species. Sites were selected from a pool
By
Forest and Rangeland Ecosystem Science Center

Oregon spotted frog (Rana pretiosa) telemetry and habitat use at Crane Prairie Reservoir in Oregon, USA

We used radio-telemetry to study late-season movement and habitat use by Oregon spotted frogs (Rana pretiosa) at Crane Prairie Reservoir in Oregon. This dataset includes individual frog location data and habitat use during each tracking event that occurred roughly weekly between September and late November of 2018.
By
Forest and Rangeland Ecosystem Science Center

Oregon spotted frog (Rana pretiosa) observations in Oregon (ver. 5.0, January 2023)

This dataset contains information from surveys conducted 2016-2022 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort in Oregon. USGS research activities 2016-2022 were divided into seven study design categories: breeding (egg mass counts), mid-level (visual encounter surveys for occupancy monitoring), apex (mark-recapture), telemetry, trapping, water quality (skin
By
Forest and Rangeland Ecosystem Science Center

Annotated bibliography of grazing effects on amphibians and their habitats (ver. 2.0, February 2022)

This database contains literature citations and associated summaries pertaining to livestock grazing effects on amphibians and their habitats, with an emphasis on the Oregon spotted frog (Rana pretiosa) and other listed/sensitive wetland-breeding amphibians in the western United States. This is not meant to be an exhaustive list, nor did we perform a systematic meta-analysis; rather, literature re
By
Forest and Rangeland Ecosystem Science Center

Capture-mark-recapture data for Oregon spotted frogs (Rana pretiosa) along the Deschutes River, Oregon, 2016-2019

This dataset contains information from capture-mark-recapture sampling of Oregon spotted frogs (Rana pretiosa) conducted 2016-2019 by USGS as part of a study relating R. pretiosa survival and abundance to wetland inundation in the upper Deschutes River. Data consist of site, survey, habitat, and species detection covariates, as well as 10 years of hydrological and drought metrics used to establish
By
Forest and Rangeland Ecosystem Science Center

North Coast and Cascades Network consolidated amphibian database (1984-2005)

This data set is an amalgamation of twenty-nine original data sets, which represent amphibian surveys in the seven national parks comprising the North Coast and Cascades Network (NCCN) of the National Park Service. The data were collected from 1984-2005, and include the localities of 19 species of amphibians at various life stages, 18 native to the Pacific Northwest and one invasive species.
By
Forest and Rangeland Ecosystem Science Center

Oregon spotted frog (Rana pretiosa) monitoring data for metademographic analysis 2010-2018, Oregon

This dataset contains information from surveys conducted 2010-2018 by USGS as part of a long-term Oregon spotted frog monitoring effort in the central Oregon range. Data consist of site, survey, habitat, and species detection covariates, as well as inter-site distance measurements.
By
Forest and Rangeland Ecosystem Science Center

Oregon spotted frog (Rana pretiosa) telemetry and habitat use at Klamath Marsh National Wildlife Refuge in Oregon, USA

We used radio-telemetry to study late-season movement and habitat use by Oregon spotted frogs (Rana pretiosa) at Klamath Marsh National Wildlife Refuge in Oregon. This data release includes frog location and habitat use data, as well as visualizations of telemetry data. Tracking events occurred roughly weekly between August and December of 2017.
By
Forest and Rangeland Ecosystem Science Center

Nutrients, estrogenicity, and fecal indicators in surface water collected from wetlands in the Klamath Marsh National Wildlife Refuge, Oregon, 2017-2018

The data was gathered to determine the effects of cattle grazing on wetland water quality in the Klamath National Wildlife Refuge in Oregon. Surface water samples from sites representing a range of grazing histories were collected between June and October in 2017 and 2018. Samples were analyzed for nutrients (ammonia, nitrate plus nitrite, nitrite and orthophosphate), total coliforms, E. coli, ent
By
Forest and Rangeland Ecosystem Science Center

If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

Early action to address an emerging wildlife disease

A deadly fungal pathogen, Batrachochytrium salamandrivorans (Bsal) that affects amphibian skin was discovered during a die-off of European fire salamanders (Salamandra salamandra) in 2014. This pathogen has the potential to worsen already severe worldwide amphibian declines. Bsal is a close relative to another fungal disease known as Batrachochytrium dendrobatidis (Bd). Many scientists consider Bd
Authors
M. J. Adams, M. Camille Harris, Daniel A. Grear
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Forest and Rangeland Ecosystem Science Center, National Wildlife Health Center
Filter Total Items: 44

Chytrid infections exhibit historical spread and contemporary seasonality in a declining stream-breeding frog

Species with extensive geographical ranges pose special challenges to assessing drivers of wildlife disease, necessitating collaborative and large-scale analyses. The imperilled foothill yellow-legged frog (Rana boylii) inhabits a wide geographical range and variable conditions in rivers of California and Oregon (USA), and is considered threatened by the pathogen Batrachochytrium dendrobatidis (Bd
Authors
A.M. Belasen, R.A. Peek, A.J. Adams, I.D. Russell, M.E. De León, Michael J. Adams, J. Bettaso, K.G.H. Breedveld, A. Catenazzi, C.P. Dillingham, Daniel A. Grear, Brian J. Halstead, P.G. Johnson, Patrick M. Kleeman, M.S. Koo, C.W. Koppl, J.D. Lauder, G. Padgett-Flohr, J. Piovia-Scott, K.L. Pope, V. Vredenburg, M. Westphal, K. Wiseman, S.J. Kupferberg
By
Ecosystems Mission Area, National Wildlife Health Center, Western Ecological Research Center (WERC)

Broad-scale assessment of methylmercury in adult amphibians

Mercury (Hg) is a toxic contaminant that has been mobilized and distributed worldwide and is a threat to many wildlife species. Amphibians are facing unprecedented global declines due to many threats including contaminants. While the biphasic life history of many amphibians creates a potential nexus for methylmercury (MeHg) exposure in aquatic habitats and subsequent health effects, the broad-scal

Authors
Brian J. Tornabene, Blake R. Hossack, Brian J. Halstead, Collin Eagles-Smith, Michael J. Adams, Adam R. Backlin, Adrianne Brand, Colleen Emery, Robert N. Fisher, Jillian Elizabeth Fleming, Brad Glorioso, Daniel A. Grear, Evan H. Campbell Grant, Patrick M. Kleeman, David Miller, Erin L. Muths, Christopher Pearl, Jennifer Rowe, Caitlin Teresa Rumrill, J. Hardin Waddle, Megan Winzeler, Kelly L. Smalling
By
Ecosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Toxic Substances Hydrology, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, National Wildlife Health Center, New Jersey Water Science Center, Northern Rocky Mountain Science Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center

Population dynamics of the threatened Oregon spotted frog before and after drought mitigation

Amphibians are among the most sensitive taxa to climate change, and species inhabiting arid and semiarid landscapes at the extremes of their range are especially vulnerable to drought. The Jack Creek, Oregon, USA, population of Oregon spotted frogs (Rana pretiosa) faces unique challenges because it occupies the highest elevation site in the species' extant range and one that has been transformed b
Authors
Jennifer Rowe, Christopher Pearl, Adam Duarte, Brome McCreary, Michael J. Adams
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Adjacent and downstream effects of forest harvest on the distribution and abundance of larval headwater stream amphibians in the Oregon Coast Range

Forest harvest is a primary landscape-scale management action affecting riparian forests. Although concerns about impacts of forest harvest on stream amphibians is generally limited to areas adjacent to harvest, there is a paucity of information regarding potential downstream effects of forest harvest on these species. We designed a before-after, control-impact (BACI) experiment to quantify potent
Authors
Adam Duarte, Nathan Chelgren, Jennifer Rowe, Christopher Pearl, Sherri L Johnson, Michael J. Adams
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Late season movement and habitat use by Oregon spotted frog (Rana pretiosa) in a large reservoir in Oregon, USA

Dam-created reservoirs are common landscape features that can provide habitat for amphibians, but their water level fluctuations and nonnative predators can differ markedly from more natural habitats. We compared fall movement and habitat use by the Oregon Spotted Frog (Rana pretiosa) in the reservoir pool with nearby river and pond habitats at Crane Prairie Reservoir in central Oregon, USA. Movem
Authors
Christopher Pearl, Jennifer Rowe, Brome McCreary, Michael J. Adams
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Looking ahead, guided by the past: The role of U.S. national parks in amphibian research and conservation

Protected areas like national parks are essential elements of conservation because they limit human influence on the landscape, which protects biodiversity and ecosystem function. The role of national parks in conservation, however, often goes far beyond limiting human influence. The U.S. National Park Service and its system of land units contribute substantively to conservation by providing prote
Authors
Brian J. Halstead, Andrew M. Ray, Erin L. Muths, Evan H. Campbell Grant, Rob Grasso, Michael J. Adams, Kathleen Semple Delaney, Jane Carlson, Blake R. Hossack
By
Ecosystems Mission Area, Western Ecological Research Center (WERC)

An updated assessment of status and trend in the distribution of the Cascades frog (Rana cascadae) in Oregon, USA

Conservation efforts need reliable information concerning the status of a species and their trends to help identify which species are in most need of assistance. We completed a comparative evaluation of the occurrence of breeding for Cascades Frog (Rana cascadae), an amphibian that is being considered for federal protection under the U.S. Endangered Species Act. Specifically, in 2018–2019 we resur
Authors
Adam Duarte, Christopher Pearl, Brome McCreary, Jennifer Rowe, Michael J. Adams
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Demography of the Oregon spotted frog along a hydrologically modified river

Altered flow regimes can contribute to dissociation between life history strategies and environmental conditions, leading to reduced persistence reported for many wildlife populations inhabiting regulated rivers. The Oregon spotted frog (Rana pretiosa) is a threatened species occurring in floodplains, ponds, and wetlands in the Pacific Northwest with a core range in Oregon, USA. All life stages of
Authors
Jennifer Rowe, Adam Duarte, Christopher Pearl, Brome McCreary, Patricia Haggerty, John Jones, Michael J. Adams
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Enhanced between-site biosecurity to minimize herpetofaunal disease-causing pathogen transmission

Pathogens and their associated diseases have the potential to severely affect wildlife populations, including herpetofauna. Concern is increasing for transmission pathways of herpetofaunal diseases, especially for amphibians affected by the fungal pathogens Batrachochytrium dendrobatidis (Bd: Longcore et al. 1999) and B. salamandrivorans (Bsal: Martel et al. 2013), and amphibians and reptiles affe
Authors
Deanna H. Olson, Katherine H. Haman, Matthew J. Gray, Reid N. Harris, Tracy Thompson, Marley Iredale, Michelle Christman, Jennifer M. Williams, Michael J. Adams, Jennifer R. Ballard
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Forest and Rangeland Ecosystem Science Center

Monitoring wetland water quality related to livestock grazing in amphibian habitats

Land use alteration such as livestock grazing can affect water quality in habitats of at-risk wildlife species. Data from managed wetlands are needed to understand levels of exposure for aquatic life stages and monitor grazing-related changes afield. We quantified spatial and temporal variation in water quality in wetlands occupied by threatened Oregon spotted frog (Rana pretiosa) at Klamath Marsh
Authors
Kelly L. Smalling, Jennifer Rowe, Christopher Pearl, Luke R. Iwanowicz, Carrie E. Givens, Chauncey W. Anderson, Brome McCreary, Michael J. Adams
By
Ecosystems Mission Area, Water Resources Mission Area, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, New Jersey Water Science Center, Oregon Water Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Batrachochytrium salamandrivorans (Bsal) not detected in an intensive survey of wild North American amphibians

The salamander chytrid fungus (Batrachochytrium salamandrivorans [Bsal]) is causing massive mortality of salamanders in Europe. The potential for spread via international trade into North America and the high diversity of salamanders has catalyzed concern about Bsal in the U.S. Surveillance programs for invading pathogens must initially meet challenges that include low rates of occurrence on the l
Authors
Hardin Waddle, Daniel A. Grear, Brittany Mosher, Evan H. Campbell Grant, Michael J. Adams, Adam R. Backlin, William Barichivich, Adrianne B. Brand, Gary M. Bucciarelli, Daniel L. Calhoun, Tara Chestnut, Jon M. Davenport, Andrew E. Dietrich, Robert N. Fisher, Brad Glorioso, Brian J. Halstead, Marc P Hayes, R. Ken Honeycutt, Blake R. Hossack, Patrick M. Kleeman, Julio A. Lemos-Espinal, Jeffrey M. Lorch, Robert W. Atkinson, Erin L. Muths, Christopher Pearl, Katherine Richgels, Charles W Robinson, Mark F. Roth, Jennifer Rowe, Walter Sadinski, Brent H. Sigafus, Iga Stasiak, Samuel Sweet, Susan C. Walls, Gregory J Watkins-Colwell, C. LeAnn White, Lori A Williams, Megan E. Winzeler
By
Ecosystems Mission Area, Eastern Ecological Science Center, National Wildlife Health Center, Northern Rocky Mountain Science Center, Upper Midwest Environmental Sciences Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center

Oregon spotted frog (Rana pretiosa) migration from an aquatic overwintering site: Timing, duration, and potential environmental cues

Relatively few North American anurans overwinter in water and information is sparse on their movement from overwintering habitat to breeding sites. Oregon spotted frogs (Rana pretiosa) breed explosively in early spring and often overwinter submerged at sites that are distanced from breeding habitats. In montane parts of their range, wintering and breeding habitats can remain frozen for months. We
Authors
Jay Bowerman, Christopher Pearl
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Below are news stories associated with this project.

link
Image of Mike Adams

ARMI Scientist Michael Adams Receives 2020 PARC Honor

Dr. Michael Adams, Lead for the USGS Amphibian Research and Monitoring Initiative (ARMI) and Supervisory Research Ecologist at the USGS Forest and Rangeland Ecosystem Science Center, has been selected to receive the 2020 Partners in Amphibian and Reptile Conservation (PARC) Alison Haskell Award for Excellence in Herpetofaunal Conservation. 

By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center
Annotated Bibliography: Grazing Effects on Amphibians and Their Habitats

Annotated Bibliography: Grazing Effects on Amphibians and Their Habitats

Livestock grazing is one of the most common land uses in the western United States, where multiple amphibians of conservation concern use habitats...

Read Article
Invasive Amphibian Fungus Could Threaten US Salamander Populations

Invasive Amphibian Fungus Could Threaten US Salamander Populations

A deadly fungus causing population crashes in wild European salamanders could emerge in the United States and threaten already declining amphibians...

Read Article