I am a member of the Adams Herpetological Research Team where I primarily hire, train, and supervise the lab’s seasonal field crew. I also lead the writing of our research Standard Operating Procedure sampling protocols.
I spent my childhood exploring and engrossed in the woods, streams and meadows on and around the small mountain farm where I grew up. My interest in amphibians began early, catching Coastal Giant Salamander larvae in our small stream and hatching Pacific Treefrog egg masses in mayonnaise jars on my bedroom windowsill, raising them to juvenile frogs and releasing them. This fostered a profound appreciation for the complexity and beauty of the natural world that quickly grew into a desire for life-long study. I am passionate about doing work and living a life that contributes to our understanding of the ecological systems around us.
My professional goals are to facilitate the precise, accurate and repeatable collection of data in the field during the completion of our scientific research while ensuring our lab personnel’s safety as they conduct field research in an often-unpredictable outdoor environment.
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: 13
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
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.
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
Long-term amphibian monitoring data from the Willamette Valley, Oregon (2004-2015)
This dataset contains information from surveys conducted 2004-2015 by USGS as part of a long-term amphibian monitoring effort in the Willamette Valley, Oregon. Data consist of site, survey, habitat, and species detection covariates.
Oregon Spotted Frog (Rana pretiosa) Monitoring at Jack Creek 2015-2018 (final)
This dataset contains information from mark-recapture and egg mass surveys conducted 2015-2018 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort at Jack Creek, Klamath County, Oregon. Data consist of spotted frog counts (handled by surveyors) aggregated by date, location, life stage, and sex, as well as data on environmental conditions at the time each survey. Not
Telemetry and habitat data for Oregon spotted frogs (Rana pretiosa) in Oregon, USA
We used radio-telemetry to study late-season movement and habitat use by the Oregon spotted frog (Rana pretiosa) at 9 sites from 4 populations along the Cascade Mountains in Oregon. This dataset includes individual frog morphometrics, location data, and habitat use during each tracking event that occurred roughly weekly between September and January of 2011, 2012, and 2016.
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: 23
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
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 W. 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 Smalling, Jennifer Rowe, Christopher Pearl, Luke R. Iwanowicz, Carrie E. Givens, Chauncey W. Anderson, Brome McCreary, Michael J. Adams
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
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
Late-season movement and habitat use by Oregon spotted frogs (Rana pretiosa) in Oregon, USA
Many amphibians use multiple habitats across seasons. Information on seasonal habitat use, movement between seasonal habitat types, and habitats that may be particularly valuable is important to conservation and management. We used radio-telemetry to study late-season movement and habitat use by Oregon Spotted Frog (Rana pretiosa) at nine sites from four populations along the Cascade Mountains in
Authors
Christopher Pearl, Brome McCreary, Jennifer Rowe, M. J. Adams
Effect of cattle exclosures on Columbia Spotted Frog abundance
Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians. Columbia Spotted Frog (Rana luteiventris) often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used by
Authors
M. J. Adams, Christopher Pearl, Thierry Chambert, Brome McCreary, Stephanie Galvan, Jennifer Rowe
Short-term occupancy and abundance dynamics of the Oregon spotted frog (Rana pretiosa) across its core range
The Oregon spotted frog (Rana pretiosa) occupies only a fraction of its original range and is listed as Threatened under the Endangered Species Act. We surveyed 93 sites in a rotating frame design (2010–13) in the Klamath and Deschutes Basins, Oregon, which encompass most of the species’ core extant range. Oregon spotted frogs are declining in abundance and probability of site occupancy. We did no
Authors
M. J. Adams, Christopher A. Pearl, Brome McCreary, Stephanie Galvan
Habitat and co-occurrence of native and invasive crayfish in the Pacific Northwest, USA
Biological invasions can have dramatic effects on freshwater ecosystems and introduced crayfish can be particularly impacting. We document crayfish distribution in three large hydrographic basins (Rogue, Umpqua, Willamette/Columbia) in the Pacific Northwest USA. We used occupancy analyses to investigate habitat relationships and evidence for displacement of native Pacifastacus leniusculus (Dana, 1
Authors
Christopher A. Pearl, M. J. Adams, Brome McCreary
Invasive crayfish in the Pacific Northwest
Invasive species directly threaten freshwater biodiversity, particularly in regions of high aquatic richness like the Pacific Northwest (PNW). Crayfish are among the most impactful of aquatic invasive species. Invasive crayfish are considered ecosystem engineers due to their ability to alter basic wetland properties, such as reducing vegetation and bank integrity and increasing turbidity. In areas
Authors
Christopher A. Pearl, Brome McCreary, Michael Adams
To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.
Science and Products
- Science
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. - Data
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: 13Oregon 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 hydrologicallCascade 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 poolOregon 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 (skinAnnotated 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 reCapture-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 establishOregon 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.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 100m2Long-term amphibian monitoring data from the Willamette Valley, Oregon (2004-2015)
This dataset contains information from surveys conducted 2004-2015 by USGS as part of a long-term amphibian monitoring effort in the Willamette Valley, Oregon. Data consist of site, survey, habitat, and species detection covariates.Oregon Spotted Frog (Rana pretiosa) Monitoring at Jack Creek 2015-2018 (final)
This dataset contains information from mark-recapture and egg mass surveys conducted 2015-2018 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort at Jack Creek, Klamath County, Oregon. Data consist of spotted frog counts (handled by surveyors) aggregated by date, location, life stage, and sex, as well as data on environmental conditions at the time each survey. NotTelemetry and habitat data for Oregon spotted frogs (Rana pretiosa) in Oregon, USA
We used radio-telemetry to study late-season movement and habitat use by the Oregon spotted frog (Rana pretiosa) at 9 sites from 4 populations along the Cascade Mountains in Oregon. This dataset includes individual frog morphometrics, location data, and habitat use during each tracking event that occurred roughly weekly between September and January of 2011, 2012, and 2016. - Multimedia
- Publications
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: 23Population 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 bAuthorsJennifer Rowe, Christopher Pearl, Adam Duarte, Brome McCreary, Michael J. AdamsLate 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. MovemAuthorsChristopher Pearl, Jennifer Rowe, Brome McCreary, Michael J. AdamsAn 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 resurAuthorsAdam Duarte, Christopher Pearl, Brome McCreary, Jennifer Rowe, Michael J. AdamsDemography 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 ofAuthorsJennifer Rowe, Adam Duarte, Christopher Pearl, Brome McCreary, Patricia Haggerty, John W. Jones, Michael J. AdamsMonitoring 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 MarshAuthorsKelly Smalling, Jennifer Rowe, Christopher Pearl, Luke R. Iwanowicz, Carrie E. Givens, Chauncey W. Anderson, Brome McCreary, Michael J. AdamsEstimation 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 reAuthorsAdam Duarte, James Peterson, Christopher Pearl, Jennifer Christine Rowe, Brome McCreary, Stephanie Galvan, Michael J. AdamsDisentangling 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 modiAuthorsJennifer Rowe, Adam Duarte, Christopher Pearl, Brome McCreary, Stephanie Galvan, James T. Peterson, Michael J. AdamsLate-season movement and habitat use by Oregon spotted frogs (Rana pretiosa) in Oregon, USA
Many amphibians use multiple habitats across seasons. Information on seasonal habitat use, movement between seasonal habitat types, and habitats that may be particularly valuable is important to conservation and management. We used radio-telemetry to study late-season movement and habitat use by Oregon Spotted Frog (Rana pretiosa) at nine sites from four populations along the Cascade Mountains inAuthorsChristopher Pearl, Brome McCreary, Jennifer Rowe, M. J. AdamsEffect of cattle exclosures on Columbia Spotted Frog abundance
Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians. Columbia Spotted Frog (Rana luteiventris) often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used byAuthorsM. J. Adams, Christopher Pearl, Thierry Chambert, Brome McCreary, Stephanie Galvan, Jennifer RoweShort-term occupancy and abundance dynamics of the Oregon spotted frog (Rana pretiosa) across its core range
The Oregon spotted frog (Rana pretiosa) occupies only a fraction of its original range and is listed as Threatened under the Endangered Species Act. We surveyed 93 sites in a rotating frame design (2010–13) in the Klamath and Deschutes Basins, Oregon, which encompass most of the species’ core extant range. Oregon spotted frogs are declining in abundance and probability of site occupancy. We did noAuthorsM. J. Adams, Christopher A. Pearl, Brome McCreary, Stephanie GalvanHabitat and co-occurrence of native and invasive crayfish in the Pacific Northwest, USA
Biological invasions can have dramatic effects on freshwater ecosystems and introduced crayfish can be particularly impacting. We document crayfish distribution in three large hydrographic basins (Rogue, Umpqua, Willamette/Columbia) in the Pacific Northwest USA. We used occupancy analyses to investigate habitat relationships and evidence for displacement of native Pacifastacus leniusculus (Dana, 1AuthorsChristopher A. Pearl, M. J. Adams, Brome McCrearyInvasive crayfish in the Pacific Northwest
Invasive species directly threaten freshwater biodiversity, particularly in regions of high aquatic richness like the Pacific Northwest (PNW). Crayfish are among the most impactful of aquatic invasive species. Invasive crayfish are considered ecosystem engineers due to their ability to alter basic wetland properties, such as reducing vegetation and bank integrity and increasing turbidity. In areasAuthorsChristopher A. Pearl, Brome McCreary, Michael Adams - News
To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.