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
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: 68
Late season movement and habitat use by Oregon spotted frog (Rana pretiosa) in a large reservoir in Oregon, USA 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...
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 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...
Authors
Adam Duarte, Christopher Pearl, Brome McCreary, Jennifer Rowe, Michael J. Adams
Demography of the Oregon spotted frog along a hydrologically modified river 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...
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 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...
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 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...
Authors
J. 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 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...
Authors
Jay Bowerman, Christopher Pearl
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: 19
Annotated bibliography of grazing effects on amphibians and their habitats (ver. 2.0, February 2022) 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...
Capture-mark-recapture data for Oregon spotted frogs (Rana pretiosa) along the Deschutes River, Oregon, 2016-2019 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...
Oregon spotted frog (Rana pretiosa) monitoring data for metademographic analysis 2010-2018, Oregon 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 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 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...
Terrestrial salamander captures after the 2003 Clark Fire, Willamette National Forest, OR 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...
Science and Products
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: 68
Late season movement and habitat use by Oregon spotted frog (Rana pretiosa) in a large reservoir in Oregon, USA 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...
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 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...
Authors
Adam Duarte, Christopher Pearl, Brome McCreary, Jennifer Rowe, Michael J. Adams
Demography of the Oregon spotted frog along a hydrologically modified river 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...
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 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...
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 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...
Authors
J. 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 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...
Authors
Jay Bowerman, Christopher Pearl
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: 19
Annotated bibliography of grazing effects on amphibians and their habitats (ver. 2.0, February 2022) 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...
Capture-mark-recapture data for Oregon spotted frogs (Rana pretiosa) along the Deschutes River, Oregon, 2016-2019 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...
Oregon spotted frog (Rana pretiosa) monitoring data for metademographic analysis 2010-2018, Oregon 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 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 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...
Terrestrial salamander captures after the 2003 Clark Fire, Willamette National Forest, OR 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...