Aaron Johnston, Ph.D.
Aaron Johnston studies extinction dynamics and microrefugia of the American pika as a Mendenhall Fellow with Erik Beever. He is also an Affiliate Assistant Professor in the School of Environmental and Forest Sciences at the University of Washington.
Research Interest
Aaron is broadly interested in wildlife research that advances ecological theories and management of natural resources. His previous studies have involved a wide range of taxa in terrestrial and aquatic systems for investigations on rare species, invasive species, interspecific competition, forest management, and grazing effects on wildlife. Aaron is especially excited about innovative approaches to wildlife research facilitated by new remote-sensing technologies that describe habitat features across landscapes at high spatiotemporal resolutions. His recent studies on tree squirrels, red tree voles, and pikas have explored novel applications of airborne LiDAR that improved habitat modeling and hypothesis testing for these species. His current study involves developing new models for microtopography, microclimate, phenology, and snowpack dynamics from land-, air-, and space-based sensors to advance understanding of pika distributions and responses to climate change.
Education and Certifications
Ph.D. 2013. Wildlife Science, University of Washington
M.S. 2006. Wildlife Science, Oregon State University
B.S. 2000. Wildlife Ecology, Texas A&M University
Science and Products
Hoary Marmot Abundance in North Cascades National Park 2007-2008 and 2016-2017
USGS and NPS biologists used distance sampling to estimate abundance of hoary marmots (Marmota caligata) in North Cascades National Park, Washington, USA during 2007-2008 and 2016-2017. Biologists resurveyed hoary marmots in 2016 and 2017 at 78 point-count stations across 19 sites surveyed by NPS in 2007-2008. Data include marmot detection distances and survey conditions used to estimate...
Counts of American Pikas and Hoary Marmots in North Cascades National Park 2016-2017
USGS scientists counted American pikas (Ochotona princeps) and hoary marmots (Marmota caligata) in North Cascades National Park, Washington, USA during 2016. Hoary marmots were resurveyed in 2017, primarily by the National Park Service. Pika and marmot counts were collected to assess effects of weather and snowpack dynamics on these species. Counts are measures of relative abundance that...
Filter Total Items: 21
Beyond presence mapping: Predicting fractional cover of non-native vegetation in Sentinel-2 imagery using an ensemble of MaxEnt models
Non-native species maps are important tools for understanding and managing biological invasions. We demonstrate a novel approach to extend presence modeling to map fractional cover (FC) of non-native yellow sweet clover Melilotus officinalis in the Northern Great Plains, USA. We used ensembles of MaxEnt models to map FC across landscapes from satellite imagery trained from regional...
Authors
Todd M. Preston, Aaron N. Johnston, Kyle Gregory Ebenhoch, Robert H. Diehl
Wind-energy development alters pronghorn migration at multiple scales
Migration is a critical behavioral strategy necessary for population persistence and ecosystem functioning, but migration routes have been increasingly disrupted by anthropogenic activities, including energy development. Wind energy is the world's fastest growing source of electricity and represents an important alternative to hydrocarbon extraction, but its effects on migratory species...
Authors
Megan C. Milligan, Aaron N. Johnston, Jeffery L. Beck, Kaitlyn L. Taylor, Embere Hall, Lee Knox, Teal Cufaude, Cody F. Wallace, Geneva W. Chong, Matthew Kauffman
Eyes on the herd: Quantifying ungulate density from satellite, unmanned aerial systems, and GPScollar data
Novel approaches to quantifying density and distributions could help biologists adaptively manage wildlife populations, particularly if methods are accurate, consistent, cost-effective, rapid, and sensitive to change. Such approaches may also improve research on interactions between density and processes of interest, such as disease transmission across multiple populations. We assess how...
Authors
Tabitha A. Graves, Michael Yarnall, Aaron N. Johnston, Todd M. Preston, Geneva W. Chong, Eric K. Cole, William Michael Janousek, Paul C. Cross
Foreword to the special Issue on ‘The rapidly expanding role of drones as a tool for wildlife research’
Drones have emerged as a popular wildlife research tool, but their use for many species and environments remains untested and research is needed on validation of sampling approaches that are optimised for unpiloted aircraft. Here, we present a foreword to a special issue that features studies pushing the taxonomic and innovation boundaries of drone research and thus helps address these...
Authors
Aaron J Wirsing, Aaron N. Johnston, Jeremy J. Kiszka
Variable effects of wind-energy development on seasonal habitat selection of pronghorn
In the face of climate change, wind energy represents an important alternative to oil and gas extraction to meet increasing energy demands, but it has the potential to disrupt wildlife populations. Because behavioral adjustments, such as altered habitat selection, are a primary way that long-lived species respond to novel disturbances, we evaluated effects of wind energy development on...
Authors
Megan C. Milligan, Aaron N. Johnston, Jeff L Beck, Kurt T. Smith, Kaitlyn L. Taylor, Embere Hall, Lee Knox, Teal Cufaude, Cody F. Wallace, Geneva W. Chong, Matthew Kauffman
U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2018 annual report
The Wyoming Landscape Conservation Initiative (WLCI) was established in 2007 as a collaborative interagency partnership to develop and implement science-based conservation actions. During the past 11 years, partners from U.S. Geological Survey (USGS), State and Federal land management agencies, universities, and the public have collaborated to implement a long-term (more than 10 years)...
Authors
Patrick J. Anderson, Cameron L. Aldridge, Jason S. Alexander, Timothy J. Assal, Steven Aulenbach, Zachary H. Bowen, Anna D. Chalfoun, Geneva W. Chong, Holly Copeland, David R. Edmunds, Stephen S. Germaine, Tabitha A. Graves, Julie A. Heinrichs, Collin Homer, Christopher Huber, Aaron N. Johnston, Matthew Kauffman, Daniel J. Manier, Ryan R. McShane, Cheryl Miller, Kirk A. Miller, Adrian Pierre-Frederic Monroe, Michael S. O'Donnell, Anna C. Ortega, Annika W. Walters, Daniel J. Wieferich, Teal B. Wyckoff, Linda Zeigenfuss
Non-USGS Publications**
Vander Haegen, W. M., G. R. Orth, A. N. Johnston and M. J. Linders. 2018. Endemic diseases affect population dynamics of tree squirrels in contrasting landscapes. Journal of Wildlife Management 82:328–343.
Johnston, A. N. and L. M. Moskal. 2017. High-resolution habitat modeling with airborne LiDAR for red tree voles. Journal of Wildlife Management 81:58–72.
Johnston, A. N. and R. G. Anthony. 2014. Brush mouse (Peromyscus boylii) occurrences in southern Oregon. Northwestern Naturalist 95:54–56.
Ramsey, F. L. and A. N. Johnston. 2009. Trap mortality in mark-recapture studies. Environmental and Ecological Statistics 16:427–438.
Johnston, A. N. and R. G. Anthony. 2008. Small-mammal microhabitat associations and response to grazing in Oregon. Journal of Wildlife Management 72:1736–1746.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Hoary Marmot Abundance in North Cascades National Park 2007-2008 and 2016-2017
USGS and NPS biologists used distance sampling to estimate abundance of hoary marmots (Marmota caligata) in North Cascades National Park, Washington, USA during 2007-2008 and 2016-2017. Biologists resurveyed hoary marmots in 2016 and 2017 at 78 point-count stations across 19 sites surveyed by NPS in 2007-2008. Data include marmot detection distances and survey conditions used to estimate...
Counts of American Pikas and Hoary Marmots in North Cascades National Park 2016-2017
USGS scientists counted American pikas (Ochotona princeps) and hoary marmots (Marmota caligata) in North Cascades National Park, Washington, USA during 2016. Hoary marmots were resurveyed in 2017, primarily by the National Park Service. Pika and marmot counts were collected to assess effects of weather and snowpack dynamics on these species. Counts are measures of relative abundance that...
Filter Total Items: 21
Beyond presence mapping: Predicting fractional cover of non-native vegetation in Sentinel-2 imagery using an ensemble of MaxEnt models
Non-native species maps are important tools for understanding and managing biological invasions. We demonstrate a novel approach to extend presence modeling to map fractional cover (FC) of non-native yellow sweet clover Melilotus officinalis in the Northern Great Plains, USA. We used ensembles of MaxEnt models to map FC across landscapes from satellite imagery trained from regional...
Authors
Todd M. Preston, Aaron N. Johnston, Kyle Gregory Ebenhoch, Robert H. Diehl
Wind-energy development alters pronghorn migration at multiple scales
Migration is a critical behavioral strategy necessary for population persistence and ecosystem functioning, but migration routes have been increasingly disrupted by anthropogenic activities, including energy development. Wind energy is the world's fastest growing source of electricity and represents an important alternative to hydrocarbon extraction, but its effects on migratory species...
Authors
Megan C. Milligan, Aaron N. Johnston, Jeffery L. Beck, Kaitlyn L. Taylor, Embere Hall, Lee Knox, Teal Cufaude, Cody F. Wallace, Geneva W. Chong, Matthew Kauffman
Eyes on the herd: Quantifying ungulate density from satellite, unmanned aerial systems, and GPScollar data
Novel approaches to quantifying density and distributions could help biologists adaptively manage wildlife populations, particularly if methods are accurate, consistent, cost-effective, rapid, and sensitive to change. Such approaches may also improve research on interactions between density and processes of interest, such as disease transmission across multiple populations. We assess how...
Authors
Tabitha A. Graves, Michael Yarnall, Aaron N. Johnston, Todd M. Preston, Geneva W. Chong, Eric K. Cole, William Michael Janousek, Paul C. Cross
Foreword to the special Issue on ‘The rapidly expanding role of drones as a tool for wildlife research’
Drones have emerged as a popular wildlife research tool, but their use for many species and environments remains untested and research is needed on validation of sampling approaches that are optimised for unpiloted aircraft. Here, we present a foreword to a special issue that features studies pushing the taxonomic and innovation boundaries of drone research and thus helps address these...
Authors
Aaron J Wirsing, Aaron N. Johnston, Jeremy J. Kiszka
Variable effects of wind-energy development on seasonal habitat selection of pronghorn
In the face of climate change, wind energy represents an important alternative to oil and gas extraction to meet increasing energy demands, but it has the potential to disrupt wildlife populations. Because behavioral adjustments, such as altered habitat selection, are a primary way that long-lived species respond to novel disturbances, we evaluated effects of wind energy development on...
Authors
Megan C. Milligan, Aaron N. Johnston, Jeff L Beck, Kurt T. Smith, Kaitlyn L. Taylor, Embere Hall, Lee Knox, Teal Cufaude, Cody F. Wallace, Geneva W. Chong, Matthew Kauffman
U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2018 annual report
The Wyoming Landscape Conservation Initiative (WLCI) was established in 2007 as a collaborative interagency partnership to develop and implement science-based conservation actions. During the past 11 years, partners from U.S. Geological Survey (USGS), State and Federal land management agencies, universities, and the public have collaborated to implement a long-term (more than 10 years)...
Authors
Patrick J. Anderson, Cameron L. Aldridge, Jason S. Alexander, Timothy J. Assal, Steven Aulenbach, Zachary H. Bowen, Anna D. Chalfoun, Geneva W. Chong, Holly Copeland, David R. Edmunds, Stephen S. Germaine, Tabitha A. Graves, Julie A. Heinrichs, Collin Homer, Christopher Huber, Aaron N. Johnston, Matthew Kauffman, Daniel J. Manier, Ryan R. McShane, Cheryl Miller, Kirk A. Miller, Adrian Pierre-Frederic Monroe, Michael S. O'Donnell, Anna C. Ortega, Annika W. Walters, Daniel J. Wieferich, Teal B. Wyckoff, Linda Zeigenfuss
Non-USGS Publications**
Vander Haegen, W. M., G. R. Orth, A. N. Johnston and M. J. Linders. 2018. Endemic diseases affect population dynamics of tree squirrels in contrasting landscapes. Journal of Wildlife Management 82:328–343.
Johnston, A. N. and L. M. Moskal. 2017. High-resolution habitat modeling with airborne LiDAR for red tree voles. Journal of Wildlife Management 81:58–72.
Johnston, A. N. and R. G. Anthony. 2014. Brush mouse (Peromyscus boylii) occurrences in southern Oregon. Northwestern Naturalist 95:54–56.
Ramsey, F. L. and A. N. Johnston. 2009. Trap mortality in mark-recapture studies. Environmental and Ecological Statistics 16:427–438.
Johnston, A. N. and R. G. Anthony. 2008. Small-mammal microhabitat associations and response to grazing in Oregon. Journal of Wildlife Management 72:1736–1746.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.