I am a Wildlife Biologist at the USGS Forest and Rangeland Ecosystem Science Center
Science and Products
Integrating stream gage records, water presence observations, and models to improve hydrologic prediction in stream networks
Develop a process-guided deep learning modeling framework to integrate high-frequency streamflow data from gages, discrete streamflow measurements, surface water presence/absence observations, and streamflow model outputs to improve hydrological predictions on small streams.
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.
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
Air and stream temperature and pressure for HJ Andrews Experimental Forest, Western Oregon, 2020
This dataset includes temperature and pressure data from 26 sites in the HJ Andrews Experimental Forest in western Oregon. Stream and Air data loggers were deployed in June of 2020 and downloaded in October 2020. The HJ_Andrews_Temperature file contains temperature data (in C) by logger serial number, site, and usage for the study period. The HJ_Andrews_Pressure file contains pressure data (in kPa
FLOwPER Database: StreamFLOw PERmanence field observations, April 2020 - Nov 2020
IMPORTANT NOTE: This dataset includes spatial locations where streamflow permanence observations (continuous flow, discontinuous flow, and dry) were recorded using the FLOwPER (FLOw PERmanence) field survey available in the Survey 123 and S1 mobile application. Additional information to describe the field conditions are included as part of the survey. Field observations in the FLOwPER Database hav
FLOwPER Database: StreamFLOw PERmanence field observations, August 2019 - October 2019
IMPORTANT NOTE: More recent versions of these data release are available at this link. This dataset includes spatial locations where streamflow permanence observations (continuous flow, discontinuous flow, and dry) were recorded using the FLOwPER (FLOw PERmanence) field survey available in the Survey 123 and S1 mobile application. Additional information to describe the field conditions are includ
Trask Watershed Study Amphibian Survival and Movement Data, 2008-2015
This data set contains mark-recapture information for individuals of Dicamptodon tenebrosus and Ascaphus truei marked for individual recognition. Amphibians represented in this data set were captured in 14 first-order perennial and seasonally intermittent streams in the East Fork of the South Fork of the Trask River in the northern Oregon Coast Range. Individuals are larval and mature aquatic Dica
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: 26
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
Combining expert knowledge of a threatened trout distribution with sparse occupancy data for climate-related projection
ObjectiveTo evaluate the vulnerability of Bull Trout Salvelinus confluentus to potential climate changes across its range in Oregon, we compiled disparate expert knowledge of the distribution of spawning and rearing and combined these probabilistic statements as data along with documented records of breeding and rearing in a joint occupancy model.MethodsThe joint expert knowledge–occupancy model,
Authors
Nathan Chelgren, Jason Dunham, Stephanie L Gunckel, David P Hockman-Wert, Chris S Allen
Northwest Forest Plan — The first 25 years (1994–2018): Watershed condition status and trends
This report describes status and trends in watershed condition across the Northwest Forest Plan (NWFP) area over the first 25 years since its inception in 1994. The program charged with this task is the Aquatic and Riparian Effectiveness Monitoring Program (AREMP), which has assembled information from field data collection, spatial datasets, and a host of landscape models to evaluate the status an
Authors
Jason Dunham, Christine Hirsch, Sean Gordon, Rebecca L. Flitcroft, Nathan Chelgren, Marcía N. Snyder, David P Hockman-Wert, Gordon H. Reeves, Heidi V. Andersen, Scott K. Anderson, William A. Battaglin, Tom A. Black, Jason Brown, Shannon Claeson, Lauren Hay, Emily D. Heaston, Charles H. Luce, Nathan Nelson, Colin Penn, Mark Raggon
Fish response to successive clearcuts in a second-growth forest from the central Coast range of Oregon
Research dating back to the 1950 s has documented negative effects from harvesting of primeval forests on stream ecosystems of the Pacific Northwest. By the early 1990 s, state and federal forest practice rules governing timber harvest were modified throughout North America to better protect aquatic habitats and biotic resources, principally salmonids. These rules inspired a generation of studies
Authors
D. S. Bateman, Nathan Chelgren, Robert E. Gresswell, Jason B. Dunham, David Hockman-Wert, D. W. Leer, K. D. Bladon
FLOwPER user guide—For collection of FLOw PERmanence field observations
The accurate mapping of streams and their streamflow conditions in terms of presence or absence of surface water is important to both understanding physical, chemical, and biological processes in streams and to managing land, water, and ecological resources. This document describes a field form, FLOwPER (FLOw PERmanence), available within a mobile application (app), for standardized data collectio
Authors
Kristin L. Jaeger, Jonathan Burnett, Emily D. Heaston, Steve M. Wondzell, Nathan Chelgren, Jason B. Dunham, Sherri Johnson, Mike Brown
Application of multiple-population viability analysis to evaluate species recovery alternatives
Population viability analysis (PVA) is a powerful conservation tool, but one that remains unapproachable for many species. This is particularly true for species with multiple, broadly-distributed populations for which collecting suitable data can be challenging. A recently-developed method of multiple population viability analysis (MPVA), however, addresses many limitations of traditional PVA.
Authors
Helen M. Neville, Douglas R. Leasure, Daniel C. Dauwalter, Jason B. Dunham, Robin Bjork, Kurt A. Fesenmyer, Nathan Chelgren, Mary M. Peacock, Charles H. Luce, Daniel J. Isaak, Lee Ann Carranza, Jon Sjoberg, Seth J. Wenger
Hierarchical multi-population viability analysis
Population viability analysis (PVA) uses concepts from theoretical ecology to provide a powerful tool for quantitative estimates of population dynamics and extinction risks. However, conventional statistical PVA requires long-term data from every population of interest, whereas many species of concern exist in multiple isolated populations that are only monitored occasionally. We present a hierarc
Authors
Douglas R. Leasure, Seth J. Wenger, Nathan Chelgren, Helen M. Neville, Daniel C. Dauwalter, Robin Bjork, Kurt A. Fesenmyer, Jason B. Dunham, Mary M. Peacock, Charlie H. Luce, Abby C. Lute, Daniel J. Isaak
Inference of timber harvest effects on survival of stream amphibians is complicated by movement
The effects of contemporary logging practices on headwater stream amphibians have received considerable study but with conflicting or ambiguous results. We posit that focusing inference on demographic rates of aquatic life stages may help refine understanding, as aquatic and terrestrial impacts may differ considerably. We investigated in-stream survival and movement of two stream-breeding amphibia
Authors
Nathan Chelgren, M. J. Adams
Viability analysis for multiple populations
Many species of conservation interest exist solely or largely in isolated populations. Ideally, prioritization of management actions among such populations would be guided by quantitative estimates of extinction risk, but conventional methods of demographic population viability analysis (PVA) model each population separately and require temporally extensive datasets that are rarely available in pr
Authors
Seth J. Wenger, Douglas R. Leasure, Daniel C. Dauwalter, Mary M. Peacock, Jason B. Dunham, Nathan Chelgren, Helen M. Neville
Mercury and drought along the lower Carson River, Nevada: IV. Snowy egret post-fledging dispersal, timing of migration and survival, 2002–2004
This telemetry study is an extension of our 1997–2006 research on historical mercury contamination on snowy egrets (Egretta thula) up to ~ 20 days of age. Findings from initial studies at the mercury-contaminated Carson River colony at Lahontan Reservoir (LR) and a similar-sized reference (REF) colony on the Humboldt River included mercury-related physiological, biochemical, histopathological and
Authors
Charles J. Henny, Elwood F. Hill, Robert A. Grove, Nathan Chelgren, Patricia K. Haggerty
Occupancy patterns of mammals and lentic amphibians in the Elwha River riparian zone before dam removal
The downstream transport of sediments and organics and upstream migration of anadromous fishes are key ecological processes in unregulated riverine ecosystems of the North Pacific coast, but their influence on wildlife habitats and populations is poorly documented. Removal of two large hydroelectric dams in Washington’s Elwha Valley provides an unprecedented opportunity to study long-term response
Authors
Kurt J. Jenkins, Nathan Chelgren, K.A. Sager-Fradkin, P.J. Happe, M. J. Adams
Comparison of electrofishing techniques to detect larval lampreys in wadeable streams in the Pacific Northwest
We evaluated the probability of detecting larval lampreys using different methods of backpack electrofishing in wadeable streams in the U.S. Pacific Northwest. Our primary objective was to compare capture of lampreys using electrofishing with standard settings for salmon and trout to settings specifically adapted for capture of lampreys. Field work consisted of removal sampling by means of backpac
Authors
Jason B. Dunham, Nathan D. Chelgren, Michael P. Heck, Steven M. Clark
Science and Products
- Science
Integrating stream gage records, water presence observations, and models to improve hydrologic prediction in stream networks
Develop a process-guided deep learning modeling framework to integrate high-frequency streamflow data from gages, discrete streamflow measurements, surface water presence/absence observations, and streamflow model outputs to improve hydrological predictions on small streams. - 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.
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-impacAir and stream temperature and pressure for HJ Andrews Experimental Forest, Western Oregon, 2020
This dataset includes temperature and pressure data from 26 sites in the HJ Andrews Experimental Forest in western Oregon. Stream and Air data loggers were deployed in June of 2020 and downloaded in October 2020. The HJ_Andrews_Temperature file contains temperature data (in C) by logger serial number, site, and usage for the study period. The HJ_Andrews_Pressure file contains pressure data (in kPaFLOwPER Database: StreamFLOw PERmanence field observations, April 2020 - Nov 2020
IMPORTANT NOTE: This dataset includes spatial locations where streamflow permanence observations (continuous flow, discontinuous flow, and dry) were recorded using the FLOwPER (FLOw PERmanence) field survey available in the Survey 123 and S1 mobile application. Additional information to describe the field conditions are included as part of the survey. Field observations in the FLOwPER Database havFLOwPER Database: StreamFLOw PERmanence field observations, August 2019 - October 2019
IMPORTANT NOTE: More recent versions of these data release are available at this link. This dataset includes spatial locations where streamflow permanence observations (continuous flow, discontinuous flow, and dry) were recorded using the FLOwPER (FLOw PERmanence) field survey available in the Survey 123 and S1 mobile application. Additional information to describe the field conditions are includTrask Watershed Study Amphibian Survival and Movement Data, 2008-2015
This data set contains mark-recapture information for individuals of Dicamptodon tenebrosus and Ascaphus truei marked for individual recognition. Amphibians represented in this data set were captured in 14 first-order perennial and seasonally intermittent streams in the East Fork of the South Fork of the Trask River in the northern Oregon Coast Range. Individuals are larval and mature aquatic Dica - 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: 26Adjacent 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 potentAuthorsAdam Duarte, Nathan Chelgren, Jennifer Rowe, Christopher Pearl, Sherri L Johnson, Michael J. AdamsCombining expert knowledge of a threatened trout distribution with sparse occupancy data for climate-related projection
ObjectiveTo evaluate the vulnerability of Bull Trout Salvelinus confluentus to potential climate changes across its range in Oregon, we compiled disparate expert knowledge of the distribution of spawning and rearing and combined these probabilistic statements as data along with documented records of breeding and rearing in a joint occupancy model.MethodsThe joint expert knowledge–occupancy model,AuthorsNathan Chelgren, Jason Dunham, Stephanie L Gunckel, David P Hockman-Wert, Chris S AllenNorthwest Forest Plan — The first 25 years (1994–2018): Watershed condition status and trends
This report describes status and trends in watershed condition across the Northwest Forest Plan (NWFP) area over the first 25 years since its inception in 1994. The program charged with this task is the Aquatic and Riparian Effectiveness Monitoring Program (AREMP), which has assembled information from field data collection, spatial datasets, and a host of landscape models to evaluate the status anAuthorsJason Dunham, Christine Hirsch, Sean Gordon, Rebecca L. Flitcroft, Nathan Chelgren, Marcía N. Snyder, David P Hockman-Wert, Gordon H. Reeves, Heidi V. Andersen, Scott K. Anderson, William A. Battaglin, Tom A. Black, Jason Brown, Shannon Claeson, Lauren Hay, Emily D. Heaston, Charles H. Luce, Nathan Nelson, Colin Penn, Mark RaggonFish response to successive clearcuts in a second-growth forest from the central Coast range of Oregon
Research dating back to the 1950 s has documented negative effects from harvesting of primeval forests on stream ecosystems of the Pacific Northwest. By the early 1990 s, state and federal forest practice rules governing timber harvest were modified throughout North America to better protect aquatic habitats and biotic resources, principally salmonids. These rules inspired a generation of studiesAuthorsD. S. Bateman, Nathan Chelgren, Robert E. Gresswell, Jason B. Dunham, David Hockman-Wert, D. W. Leer, K. D. BladonFLOwPER user guide—For collection of FLOw PERmanence field observations
The accurate mapping of streams and their streamflow conditions in terms of presence or absence of surface water is important to both understanding physical, chemical, and biological processes in streams and to managing land, water, and ecological resources. This document describes a field form, FLOwPER (FLOw PERmanence), available within a mobile application (app), for standardized data collectioAuthorsKristin L. Jaeger, Jonathan Burnett, Emily D. Heaston, Steve M. Wondzell, Nathan Chelgren, Jason B. Dunham, Sherri Johnson, Mike BrownApplication of multiple-population viability analysis to evaluate species recovery alternatives
Population viability analysis (PVA) is a powerful conservation tool, but one that remains unapproachable for many species. This is particularly true for species with multiple, broadly-distributed populations for which collecting suitable data can be challenging. A recently-developed method of multiple population viability analysis (MPVA), however, addresses many limitations of traditional PVA.AuthorsHelen M. Neville, Douglas R. Leasure, Daniel C. Dauwalter, Jason B. Dunham, Robin Bjork, Kurt A. Fesenmyer, Nathan Chelgren, Mary M. Peacock, Charles H. Luce, Daniel J. Isaak, Lee Ann Carranza, Jon Sjoberg, Seth J. WengerHierarchical multi-population viability analysis
Population viability analysis (PVA) uses concepts from theoretical ecology to provide a powerful tool for quantitative estimates of population dynamics and extinction risks. However, conventional statistical PVA requires long-term data from every population of interest, whereas many species of concern exist in multiple isolated populations that are only monitored occasionally. We present a hierarcAuthorsDouglas R. Leasure, Seth J. Wenger, Nathan Chelgren, Helen M. Neville, Daniel C. Dauwalter, Robin Bjork, Kurt A. Fesenmyer, Jason B. Dunham, Mary M. Peacock, Charlie H. Luce, Abby C. Lute, Daniel J. IsaakInference of timber harvest effects on survival of stream amphibians is complicated by movement
The effects of contemporary logging practices on headwater stream amphibians have received considerable study but with conflicting or ambiguous results. We posit that focusing inference on demographic rates of aquatic life stages may help refine understanding, as aquatic and terrestrial impacts may differ considerably. We investigated in-stream survival and movement of two stream-breeding amphibiaAuthorsNathan Chelgren, M. J. AdamsViability analysis for multiple populations
Many species of conservation interest exist solely or largely in isolated populations. Ideally, prioritization of management actions among such populations would be guided by quantitative estimates of extinction risk, but conventional methods of demographic population viability analysis (PVA) model each population separately and require temporally extensive datasets that are rarely available in prAuthorsSeth J. Wenger, Douglas R. Leasure, Daniel C. Dauwalter, Mary M. Peacock, Jason B. Dunham, Nathan Chelgren, Helen M. NevilleMercury and drought along the lower Carson River, Nevada: IV. Snowy egret post-fledging dispersal, timing of migration and survival, 2002–2004
This telemetry study is an extension of our 1997–2006 research on historical mercury contamination on snowy egrets (Egretta thula) up to ~ 20 days of age. Findings from initial studies at the mercury-contaminated Carson River colony at Lahontan Reservoir (LR) and a similar-sized reference (REF) colony on the Humboldt River included mercury-related physiological, biochemical, histopathological andAuthorsCharles J. Henny, Elwood F. Hill, Robert A. Grove, Nathan Chelgren, Patricia K. HaggertyOccupancy patterns of mammals and lentic amphibians in the Elwha River riparian zone before dam removal
The downstream transport of sediments and organics and upstream migration of anadromous fishes are key ecological processes in unregulated riverine ecosystems of the North Pacific coast, but their influence on wildlife habitats and populations is poorly documented. Removal of two large hydroelectric dams in Washington’s Elwha Valley provides an unprecedented opportunity to study long-term responseAuthorsKurt J. Jenkins, Nathan Chelgren, K.A. Sager-Fradkin, P.J. Happe, M. J. AdamsComparison of electrofishing techniques to detect larval lampreys in wadeable streams in the Pacific Northwest
We evaluated the probability of detecting larval lampreys using different methods of backpack electrofishing in wadeable streams in the U.S. Pacific Northwest. Our primary objective was to compare capture of lampreys using electrofishing with standard settings for salmon and trout to settings specifically adapted for capture of lampreys. Field work consisted of removal sampling by means of backpacAuthorsJason B. Dunham, Nathan D. Chelgren, Michael P. Heck, Steven M. Clark - News