Joan C Hagar
I am a Research Wildlife Biologist at the U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center. My research focuses on providing information to support management and conservation of native wildlife species and their habitats.
My research interests include forest and wildlife ecology, conservation of biodiversity in managed forests, conservation and management of native Willamette Valley ecosystems, and riparian songbird response to floodplain restoration. Much of my work has focused on the biologically and economically important conifer forests of the PNW that are intensively managed for multiple uses and represent a large area in public domain. My research projects are designed to increase understanding of how conifer forest management affects biodiversity across a range of spatial and temporal scales, and to provide science-based information that can be directly applied in an adaptive management framework.
Professional Experience
2003-Present: Research Wildlife Biologist, USGS, Forest and Rangeland Ecosystem Science Center, Corvallis, OR
1998-2004: Graduate Research Assistant, Department of Forest Science, Oregon State University, Corvallis, OR
1993-1998: Sr. Faculty Research Assistant, Department of Forest Science, Oregon State University, Corvallis, OR
Education and Certifications
Ph.D., Forest Ecology, Oregon State University, Corvallis, OR (2004)
M.S., Forest Ecology, Oregon State University, Corvallis, OR (1993)
B.S., Biological Aspects of Conservation, University of Wisconsin, Madison, WI (1984)
Affiliations and Memberships*
2004-Present: Affiliate Faculty, Oregon State University, Forest Ecosystems and Society
2008-Present: Graduate Faculty, Oregon State University, Master of Natural Resources Program
American Ornithological Society
Association of Field Ornithologists
Oregon Birding Association
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.
Mesocarnivore Survey of Oregon Caves National Monument and Preserve, Klamath Network, 2017 (ver. 2.1, July 2022) Mesocarnivore Survey of Oregon Caves National Monument and Preserve, Klamath Network, 2017 (ver. 2.1, July 2022)
Remote camera stations were set up in Oregon Caves National Monument and Preserve from February through April 2017 to document occurrence of mesocarnivores and other wildlife. Fifteen cameras were set up at four primary sampling units (clusters of three to four cameras) throughout the park. Random locations for primary sampling units were chosen using a 3-km sampling grid over the park...
Forest management and cervid herbivory data from Western Oregon, USA, 2012 Forest management and cervid herbivory data from Western Oregon, USA, 2012
Land management practices often directly alter vegetation structure and composition, but the degree to which ecological processes such as herbivory interact with management to influence biodiversity is less well understood. We hypothesized that intensive forest management and large herbivores have compounding effects on early-seral plant communities and plantation establishment (i.e...
Estimated Probabilities from Lidar Models for Marbled Murrelet (Brachyramphus marmoratus) Occupancy in Forest Vegetation Stands in the Siuslaw National Forest, Oregon Estimated Probabilities from Lidar Models for Marbled Murrelet (Brachyramphus marmoratus) Occupancy in Forest Vegetation Stands in the Siuslaw National Forest, Oregon
We developed a LiDAR-based habitat model for the threatened Marbled Murrelet (MAMU) in the Siuslaw National Forest, Oregon, using a two-step approach. First, we tested the applicability of the LiDAR-based model developed for the Coos Bay District of the Bureau of Land Management (BLM) to the Siuslaw N.F. In the second step, we tested alternative habitat models developed with forest...
Created snag characteristics and cavity-nesting bird associations in the CFIRP stands, McDonald-Dunn Research Forest, Corvallis, OR, USA, 2016 Created snag characteristics and cavity-nesting bird associations in the CFIRP stands, McDonald-Dunn Research Forest, Corvallis, OR, USA, 2016
Snags provide critical habitat for nearly one-third of wildlife species in forests of the Pacific Northwest, so historic declines in snags are thought to have had a strong impact on biodiversity. Resource managers often create snags to mitigate the scarcity of snags within managed forests, but information regarding the function and structure of created snags across long time periods (20...
Avian abundance and oak mistletoe survey data from the Willamette Valley, Oregon, 2013-2015 Avian abundance and oak mistletoe survey data from the Willamette Valley, Oregon, 2013-2015
This dataset includes two spreadsheets: The "Avian_abundance_oak_mistletoe_bird_data" spreadsheet contains data regarding Oregon White Oak tree (Quercus garryana) measurements such as height, diameter and crown volume along with microhabitat data including number of mistletoe infections, number of cavities, amount of dead wood, amount of loose/missing bark, amount of poison oak, amount...
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.
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: 39
Western purple martin (Progne subis arboricola) occurrence on the Siuslaw National Forest, Summer 2019 Western purple martin (Progne subis arboricola) occurrence on the Siuslaw National Forest, Summer 2019
The western subspecies of the purple martin (Progne subis arboricola) is currently listed as a “critically” sensitive species in four ecoregions of western Oregon: Coast Range, Klamath Mountains, West Cascades, and Willamette Valley (Oregon Department of Fish and Wildlife, 2019). Importantly distinct from the abundant and widespread eastern subspecies (Progne subis subis), the western...
Authors
Joan Hagar, Eric Branch
The snag’s the limit: Habitat selection modeling for the western purple martin in a managed forest landscape The snag’s the limit: Habitat selection modeling for the western purple martin in a managed forest landscape
The western purple martin (Progne subis arboricola), an avian insectivore, is a species of conservation concern throughout the Pacific Northwest. Compared to the well-studied eastern subspecies (Progne subis subis), little is known of the life history and biology of the western subspecies. Availability of breeding habitat is believed to be a major limiting factor for western purple...
Authors
Lorelle M. Sherman, Joan Hagar
Removal of cattle grazing correlates with increases in vegetation productivity and in abundance of imperiled breeding birds Removal of cattle grazing correlates with increases in vegetation productivity and in abundance of imperiled breeding birds
Livestock grazing is the most prevalent land use practice in the western United States and a widespread cause of degradation of riparian vegetation. Riparian areas provide high-quality habitat for many species of declining migratory breeding birds. We analyzed changes in vegetation and bird abundance at a wildlife refuge in southeastern Oregon over 24 years, following cessation of 120...
Authors
Sharon A. Poessel, Joan Hagar, Patricia Haggerty, Todd E. Katzner
Herbicides and herbivory interact to drive plant community and crop‐tree establishment Herbicides and herbivory interact to drive plant community and crop‐tree establishment
Land management practices often directly alter vegetation structure and composition, but the degree to which ecological processes such as herbivory interact with management to influence biodiversity is less well understood. We hypothesized that large herbivores compound the effects of intensive forest management on early seral plant communities and plantation establishment (i.e., tree...
Authors
Thomas D. Stokely, Jake Verschuyl, Joan Hagar, Matthew G. Betts
Use of created snags by cavity‐nesting birds across 25 years Use of created snags by cavity‐nesting birds across 25 years
Snags are important habitat features for many forest‐dwelling species, so reductions in the number of snags can lead to the loss of biodiversity in forest ecosystems. Intentional snag creation is often used in managed forests to mitigate the long‐term declines of naturally created snags, yet information regarding the use of snags by wildlife across long timescales (>20 yr) is lacking and...
Authors
Amy M. Barry, Joan Hagar, James W. Rivers
Modeling habitat for Marbled Murrelets on the Siuslaw National Forest, Oregon, using lidar data Modeling habitat for Marbled Murrelets on the Siuslaw National Forest, Oregon, using lidar data
Habitat models using lidar-derived variables that quantify fine-scale variation in vegetation structure can improve the accuracy of occupancy estimates for canopy-dwelling species over models that use variables derived from other remote sensing techniques. However, the ability of models developed at such a fine spatial scale to maintain accuracy at regional or larger spatial scales has...
Authors
Joan C. Hagar, Ramiro Aragon, Patricia Haggerty, Jeff P. Hollenbeck
Non-USGS Publications**
Hagar, J.C., Howlin, S., Ganio, L., 2004, Short-term response of songbirds to experimental thinning of young Douglas-fir forests in the Oregon Cascades: Forest Ecology and Management, v. 199, p. 333-347.
Hagar, J.C., Stern, M.A., 2001, Avifauna in oak woodlands of the Willamette Valley, Oregon: Northwestern Naturalist, v. 82, p. 12-15.
Hagar, J.C., McComb, W.C., Emmingham, W.H., 1996, Bird communities in commercially thinned and unthinned Douglas-fir stands of western Oregon: Wildlife Society Bulletin, v. 24, no. 2, p. 353-366.
Dellasala, D.A., Hagar, J.C., Engel, K.A., McComb, W.C., Fairbanks, R.L., Campbell, E.G., 1996, Effects of silvicultultural modifications of temperate rainforest on breeding and wintering bird communities, Prince of Wales Island, southeast Alaska: The Condor, v. 98, p. 706-721.
**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.
To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.
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.
Mesocarnivore Survey of Oregon Caves National Monument and Preserve, Klamath Network, 2017 (ver. 2.1, July 2022) Mesocarnivore Survey of Oregon Caves National Monument and Preserve, Klamath Network, 2017 (ver. 2.1, July 2022)
Remote camera stations were set up in Oregon Caves National Monument and Preserve from February through April 2017 to document occurrence of mesocarnivores and other wildlife. Fifteen cameras were set up at four primary sampling units (clusters of three to four cameras) throughout the park. Random locations for primary sampling units were chosen using a 3-km sampling grid over the park...
Forest management and cervid herbivory data from Western Oregon, USA, 2012 Forest management and cervid herbivory data from Western Oregon, USA, 2012
Land management practices often directly alter vegetation structure and composition, but the degree to which ecological processes such as herbivory interact with management to influence biodiversity is less well understood. We hypothesized that intensive forest management and large herbivores have compounding effects on early-seral plant communities and plantation establishment (i.e...
Estimated Probabilities from Lidar Models for Marbled Murrelet (Brachyramphus marmoratus) Occupancy in Forest Vegetation Stands in the Siuslaw National Forest, Oregon Estimated Probabilities from Lidar Models for Marbled Murrelet (Brachyramphus marmoratus) Occupancy in Forest Vegetation Stands in the Siuslaw National Forest, Oregon
We developed a LiDAR-based habitat model for the threatened Marbled Murrelet (MAMU) in the Siuslaw National Forest, Oregon, using a two-step approach. First, we tested the applicability of the LiDAR-based model developed for the Coos Bay District of the Bureau of Land Management (BLM) to the Siuslaw N.F. In the second step, we tested alternative habitat models developed with forest...
Created snag characteristics and cavity-nesting bird associations in the CFIRP stands, McDonald-Dunn Research Forest, Corvallis, OR, USA, 2016 Created snag characteristics and cavity-nesting bird associations in the CFIRP stands, McDonald-Dunn Research Forest, Corvallis, OR, USA, 2016
Snags provide critical habitat for nearly one-third of wildlife species in forests of the Pacific Northwest, so historic declines in snags are thought to have had a strong impact on biodiversity. Resource managers often create snags to mitigate the scarcity of snags within managed forests, but information regarding the function and structure of created snags across long time periods (20...
Avian abundance and oak mistletoe survey data from the Willamette Valley, Oregon, 2013-2015 Avian abundance and oak mistletoe survey data from the Willamette Valley, Oregon, 2013-2015
This dataset includes two spreadsheets: The "Avian_abundance_oak_mistletoe_bird_data" spreadsheet contains data regarding Oregon White Oak tree (Quercus garryana) measurements such as height, diameter and crown volume along with microhabitat data including number of mistletoe infections, number of cavities, amount of dead wood, amount of loose/missing bark, amount of poison oak, amount...
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.
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: 39
Western purple martin (Progne subis arboricola) occurrence on the Siuslaw National Forest, Summer 2019 Western purple martin (Progne subis arboricola) occurrence on the Siuslaw National Forest, Summer 2019
The western subspecies of the purple martin (Progne subis arboricola) is currently listed as a “critically” sensitive species in four ecoregions of western Oregon: Coast Range, Klamath Mountains, West Cascades, and Willamette Valley (Oregon Department of Fish and Wildlife, 2019). Importantly distinct from the abundant and widespread eastern subspecies (Progne subis subis), the western...
Authors
Joan Hagar, Eric Branch
The snag’s the limit: Habitat selection modeling for the western purple martin in a managed forest landscape The snag’s the limit: Habitat selection modeling for the western purple martin in a managed forest landscape
The western purple martin (Progne subis arboricola), an avian insectivore, is a species of conservation concern throughout the Pacific Northwest. Compared to the well-studied eastern subspecies (Progne subis subis), little is known of the life history and biology of the western subspecies. Availability of breeding habitat is believed to be a major limiting factor for western purple...
Authors
Lorelle M. Sherman, Joan Hagar
Removal of cattle grazing correlates with increases in vegetation productivity and in abundance of imperiled breeding birds Removal of cattle grazing correlates with increases in vegetation productivity and in abundance of imperiled breeding birds
Livestock grazing is the most prevalent land use practice in the western United States and a widespread cause of degradation of riparian vegetation. Riparian areas provide high-quality habitat for many species of declining migratory breeding birds. We analyzed changes in vegetation and bird abundance at a wildlife refuge in southeastern Oregon over 24 years, following cessation of 120...
Authors
Sharon A. Poessel, Joan Hagar, Patricia Haggerty, Todd E. Katzner
Herbicides and herbivory interact to drive plant community and crop‐tree establishment Herbicides and herbivory interact to drive plant community and crop‐tree establishment
Land management practices often directly alter vegetation structure and composition, but the degree to which ecological processes such as herbivory interact with management to influence biodiversity is less well understood. We hypothesized that large herbivores compound the effects of intensive forest management on early seral plant communities and plantation establishment (i.e., tree...
Authors
Thomas D. Stokely, Jake Verschuyl, Joan Hagar, Matthew G. Betts
Use of created snags by cavity‐nesting birds across 25 years Use of created snags by cavity‐nesting birds across 25 years
Snags are important habitat features for many forest‐dwelling species, so reductions in the number of snags can lead to the loss of biodiversity in forest ecosystems. Intentional snag creation is often used in managed forests to mitigate the long‐term declines of naturally created snags, yet information regarding the use of snags by wildlife across long timescales (>20 yr) is lacking and...
Authors
Amy M. Barry, Joan Hagar, James W. Rivers
Modeling habitat for Marbled Murrelets on the Siuslaw National Forest, Oregon, using lidar data Modeling habitat for Marbled Murrelets on the Siuslaw National Forest, Oregon, using lidar data
Habitat models using lidar-derived variables that quantify fine-scale variation in vegetation structure can improve the accuracy of occupancy estimates for canopy-dwelling species over models that use variables derived from other remote sensing techniques. However, the ability of models developed at such a fine spatial scale to maintain accuracy at regional or larger spatial scales has...
Authors
Joan C. Hagar, Ramiro Aragon, Patricia Haggerty, Jeff P. Hollenbeck
Non-USGS Publications**
Hagar, J.C., Howlin, S., Ganio, L., 2004, Short-term response of songbirds to experimental thinning of young Douglas-fir forests in the Oregon Cascades: Forest Ecology and Management, v. 199, p. 333-347.
Hagar, J.C., Stern, M.A., 2001, Avifauna in oak woodlands of the Willamette Valley, Oregon: Northwestern Naturalist, v. 82, p. 12-15.
Hagar, J.C., McComb, W.C., Emmingham, W.H., 1996, Bird communities in commercially thinned and unthinned Douglas-fir stands of western Oregon: Wildlife Society Bulletin, v. 24, no. 2, p. 353-366.
Dellasala, D.A., Hagar, J.C., Engel, K.A., McComb, W.C., Fairbanks, R.L., Campbell, E.G., 1996, Effects of silvicultultural modifications of temperate rainforest on breeding and wintering bird communities, Prince of Wales Island, southeast Alaska: The Condor, v. 98, p. 706-721.
**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.
To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government