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: 64
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
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
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
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
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
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
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
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
By
Ecosystems, Fish & Wildlife Disease (unpublished), Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, National Wildlife Health Center, Northern Rocky Mountain Science Center, Patuxent Wildlife Research Center, Western Ecological Research Center (WERC)
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
Quantifying climate sensitivity and climate-driven change in North American amphibian communities
Changing climate will impact species’ ranges only when environmental variability directly impacts the demography of local populations. However, measurement of demographic responses to climate change has largely been limited to single species and locations. Here we show that amphibian communities are responsive to climatic variability, using >500,000 time-series observations for 81 species across 8
By
Ecosystems, Water Resources, Species Management Research Program, Patuxent Wildlife Research Center, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, John Wesley Powell Center for Analysis and Synthesis, Northern Rocky Mountain Science Center, South Atlantic Water Science Center (SAWSC), Southwest Biological Science Center, Upper Midwest Environmental Sciences Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center
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
Regional variation in drivers of connectivity for two frog species (Rana pretiosa and R. luteiventris) from the U.S. Pacific Northwest
Comparative landscape genetics has uncovered high levels of variability in which landscape factors affect connectivity among species and regions. However, the relative importance of species traits versus environmental variation for predicting landscape patterns of connectivity is unresolved. We provide evidence from a landscape genetics study of two sister taxa of frogs, the Oregon spotted frog (R
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: 14
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
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.
Vegetation data from Columbia spotted frog (Rana luteiventris) exclosure study in eastern Oregon
We studied the short-term effects of full and partial livestock grazing exclosures on Columbia Spotted Frog (CSF; Rana luteiventris) populations using a controlled manipulative field experiment with pre- and post-treatment data. This dataset includes vegetation data collected 2002-2010 and 2013 at 94 lakes and ponds in and around the Blue Mountains in eastern Oregon. Data collection followed stand
Science and Products
- 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: 64Late 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. MovemAn 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 resurDemography 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 ofMonitoring 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 MarshBatrachochytrium 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 lOregon 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. WeEstimation 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 reEffect 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 hierarchicaByEcosystems, Fish & Wildlife Disease (unpublished), Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, National Wildlife Health Center, Northern Rocky Mountain Science Center, Patuxent Wildlife Research Center, Western Ecological Research Center (WERC)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 modiQuantifying climate sensitivity and climate-driven change in North American amphibian communities
Changing climate will impact species’ ranges only when environmental variability directly impacts the demography of local populations. However, measurement of demographic responses to climate change has largely been limited to single species and locations. Here we show that amphibian communities are responsive to climatic variability, using >500,000 time-series observations for 81 species across 8ByEcosystems, Water Resources, Species Management Research Program, Patuxent Wildlife Research Center, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, John Wesley Powell Center for Analysis and Synthesis, Northern Rocky Mountain Science Center, South Atlantic Water Science Center (SAWSC), Southwest Biological Science Center, Upper Midwest Environmental Sciences Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research CenterLate-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 inRegional variation in drivers of connectivity for two frog species (Rana pretiosa and R. luteiventris) from the U.S. Pacific Northwest
Comparative landscape genetics has uncovered high levels of variability in which landscape factors affect connectivity among species and regions. However, the relative importance of species traits versus environmental variation for predicting landscape patterns of connectivity is unresolved. We provide evidence from a landscape genetics study of two sister taxa of frogs, the Oregon spotted frog (R - 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: 14Oregon 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.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, entTerrestrial 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.Vegetation data from Columbia spotted frog (Rana luteiventris) exclosure study in eastern Oregon
We studied the short-term effects of full and partial livestock grazing exclosures on Columbia Spotted Frog (CSF; Rana luteiventris) populations using a controlled manipulative field experiment with pre- and post-treatment data. This dataset includes vegetation data collected 2002-2010 and 2013 at 94 lakes and ponds in and around the Blue Mountains in eastern Oregon. Data collection followed stand - News