Christopher A Pearl
I am a Wildlife Biologist at the USGS Forest and Rangeland Ecosystem Science Center in Corvallis, OR.
I work on research and monitoring studies for a variety of aquatic and terrestrial species in the Pacific Northwest. I am particularly interested in restoration of wetland and riparian systems, herpetology, and interactions between native and invasive species.
Professional Experience
2001-Present: Wildlife Biologist, USGS Forest and Rangeland Ecosystem Science Center, Corvallis, OR
The Nature Conservancy
Faculty Research Associate, Oregon State University, Corvallis, OR
Education and Certifications
M.S., Environmental Studies, University of Oregon (1999)
B.S., Community Forestry and Horticulture, University of Vermont, Burlington, VT (1988)
Science and Products
Herpetological Research Team (FRESC)
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.
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: 18
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
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.
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
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
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.
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
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
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
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.
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.
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
Terrestrial salamander captures after the 2003 Clark Fire, Willamette National Forest, OR
Data are the result of fixed-area, time-constrained searches for terrestrial salamanders within and nearby a wildfire-affected area of the Willamette National Forest, OR. The spatial extent of the study was within one kilometer of the border of the Clark fire that burned an area of 2,009 ha in 2003. Site surveys occurred during March and April, 2005. An important feature of the data is that 100m2
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: 64
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 A. 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
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
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
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
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
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
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
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
Estimation of metademographic rates and landscape connectivity for a conservation-reliant anuran
ContextAmphibian conservation efforts commonly assume populations are tied to waterbodies that collectively function as a metapopulation. This assumption is rarely evaluated, and there is a need to understand the degree of connectivity among patches to appropriately define, manage, and conserve biological populations.ObjectivesOur objectives were to quantify local persistence, colonization, and re
Authors
Adam Duarte, James Peterson, Christopher Pearl, Jennifer Christine Rowe, Brome McCreary, Stephanie Galvan, Michael J. Adams
Effect of amphibian chytrid fungus (Batrachochytrium dendrobatidis) on apparent survival of frogs and toads in the western USA
Despite increasing interest in determining the population-level effects of emerging infectious diseases on wildlife, estimating effects of disease on survival rates remains difficult. Even for a well-studied disease such as amphibian chytridiomycosis (caused by the fungus Batrachochytrium dendrobatidis [Bd]), there are few estimates of how survival of wild hosts is affected. We applied hierarchica
Authors
Robin E. Russell, Brian J. Halstead, Brittany Mosher, Erin L. Muths, Michael J. Adams, Evan H. Campbell Grant, Robert N. Fisher, Patrick M. Kleeman, Adam R. Backlin, Christopher Pearl, R. Ken Honeycutt, Blake R. Hossack
Disentangling effects of invasive species and habitat while accounting for observer error in a long-term amphibian study
The invasive American bullfrog (Lithobates catesbeianus) and a variety of non‐native sport fish commonly co‐occur in lowland lentic habitats of the western United States. Both invasive taxa are implicated in declines of native amphibians in this region, but few long‐term studies of communities exist. Further, field studies of invasive–native interactions are complicated by confounding habitat modi
Authors
Jennifer Rowe, Adam Duarte, Christopher Pearl, Brome McCreary, Stephanie Galvan, James T. Peterson, Michael J. Adams
Science and Products
Herpetological Research Team (FRESC)
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.
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: 18
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
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.
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
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
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.
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
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
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
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.
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.
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
Terrestrial salamander captures after the 2003 Clark Fire, Willamette National Forest, OR
Data are the result of fixed-area, time-constrained searches for terrestrial salamanders within and nearby a wildfire-affected area of the Willamette National Forest, OR. The spatial extent of the study was within one kilometer of the border of the Clark fire that burned an area of 2,009 ha in 2003. Site surveys occurred during March and April, 2005. An important feature of the data is that 100m2
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: 64
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 A. 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
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
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
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
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
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
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
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
Estimation of metademographic rates and landscape connectivity for a conservation-reliant anuran
ContextAmphibian conservation efforts commonly assume populations are tied to waterbodies that collectively function as a metapopulation. This assumption is rarely evaluated, and there is a need to understand the degree of connectivity among patches to appropriately define, manage, and conserve biological populations.ObjectivesOur objectives were to quantify local persistence, colonization, and re
Authors
Adam Duarte, James Peterson, Christopher Pearl, Jennifer Christine Rowe, Brome McCreary, Stephanie Galvan, Michael J. Adams
Effect of amphibian chytrid fungus (Batrachochytrium dendrobatidis) on apparent survival of frogs and toads in the western USA
Despite increasing interest in determining the population-level effects of emerging infectious diseases on wildlife, estimating effects of disease on survival rates remains difficult. Even for a well-studied disease such as amphibian chytridiomycosis (caused by the fungus Batrachochytrium dendrobatidis [Bd]), there are few estimates of how survival of wild hosts is affected. We applied hierarchica
Authors
Robin E. Russell, Brian J. Halstead, Brittany Mosher, Erin L. Muths, Michael J. Adams, Evan H. Campbell Grant, Robert N. Fisher, Patrick M. Kleeman, Adam R. Backlin, Christopher Pearl, R. Ken Honeycutt, Blake R. Hossack
Disentangling effects of invasive species and habitat while accounting for observer error in a long-term amphibian study
The invasive American bullfrog (Lithobates catesbeianus) and a variety of non‐native sport fish commonly co‐occur in lowland lentic habitats of the western United States. Both invasive taxa are implicated in declines of native amphibians in this region, but few long‐term studies of communities exist. Further, field studies of invasive–native interactions are complicated by confounding habitat modi
Authors
Jennifer Rowe, Adam Duarte, Christopher Pearl, Brome McCreary, Stephanie Galvan, James T. Peterson, Michael J. Adams