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.
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: 38
Oak mistletoe (Phoradendron villosum) is linked to microhabitat availability and avian diversity in Oregon white oak (Quercus garryana) woodlands
Mistletoes are parasitic or hemi-parasitic flowering plants that parasitize woody plants around the globe. Important food and cover resources provided by mistletoes have been related to strong patterns of positive association between wildlife diversity and mistletoe density. Mistletoes also create microhabitat features known to be important to wildlife by causing deformations in their host trees.
Authors
Kyle R. Pritchard, Joan Hagar, David C. Shaw
North Cascades National Park Service Complex
Natural Resource Condition Assessments (NRCAs) evaluate current conditions for a subset of natural resources and resource indicators in national parks. NRCAs also report on trends in resource condition (when possible), identify critical data gaps, and characterize a general level of confidence for study findings. The resources and indicators emphasized in a given project depend on the park’s resou
Authors
Robert Hoffman, Andrea Woodward, Patricia K. Haggerty, Kurt J. Jenkins, Paul C. Griffin, M. J. Adams, Joan Hagar, Tonnie Cummings, Dan Duriscoe, Karen Kopper, Jon Riedel, Lelaina Marin, Guillaume S. Mauger, Karen Bumbaco, Jeremy S. Littell
Modeling marbled murrelet (Brachyramphus marmoratus) habitat using LiDAR-derived canopy data
LiDAR (Light Detection And Ranging) is an emerging remote-sensing tool that can provide fine-scale data describing vertical complexity of vegetation relevant to species that are responsive to forest structure. We used LiDAR data to estimate occupancy probability for the federally threatened marbled murrelet (Brachyramphus marmoratus) in the Oregon Coast Range of the United States. Our goal was to
Authors
Joan C. Hagar, Bianca N.I. Eskelson, Patricia K. Haggerty, S. Kim Nelson, David G. Vesely
Mount Rainier National Park
Natural Resource Condition Assessments (NRCAs) evaluate current conditions for a subset of natural resources and resource indicators in national parks. NRCAs also report on trends in resource condition (when possible), identify critical data gaps, and characterize a general level of confidence for study findings. The resources and indicators emphasized in a given project depend on the park’s resou
Authors
Robert Hoffman, Andrea Woodward, Patricia K. Haggerty, Kurt J. Jenkins, Paul C. Griffin, M. J. Adams, Joan Hagar, Tonnie Cummings, Dan Duriscoe, Karen Kopper, Jon Riedel, Barbara Samora, Lelaina Marin, Guillaume S. Mauger, Karen Bumbaco, Jeremy S. Littell
Bird-vegetation associations in thinned and unthinned young Douglas-fir forests 10 years after thinning
Quantitative associations between animals and vegetation have long been used as a basis for conservation and management, as well as in formulating predictions about the influence of resource management and climate change on populations. A fundamental assumption embedded in the use of such correlations is that they remain relatively consistent over time. However, this assumption of stationarity has
Authors
Svetlana Yegorova, Matthew G. Betts, Joan Hagar, Klaus J. Puettmann
Management, morphological, and environmental factors influencing Douglas-fir bark furrows in the Oregon Coast Range
Many land managers in the Pacific Northwest have the goal of increasing late-successional forest structures. Despite the documented importance of Douglas-fir tree bark structure in forested ecosystems, little is known about factors influencing bark development and how foresters can manage development. This study investigated the relative importance of tree size, growth, environmental factors, and
Authors
Christopher D. Sheridan, Klaus J. Puettmann, Manuela M.P. Huso, Joan C. Hagar, Kristen R. Falk
Habitat selection by juvenile Swainson’s thrushes (Catharus ustulatus) in headwater riparian areas, northwestern Oregon, USA
Lower order, non-fish-bearing streams, often termed “headwater streams”, have received minimal research effort and protection priority, especially in mesic forests where distinction between riparian and upland vegetation can be subtle. Though it is generally thought that breeding bird abundance is higher in riparian zones, little is known about species distributions when birds are in their juvenil
Authors
Stephanie R. Jenkins, Matthew G. Betts, Manuela M. Huso, Joan C. Hagar
Survey of bats on Columbia National Wildlife Refuge, Washington, December 2011-April 2012
Bats are diverse and abundant in many ecosystems worldwide. They perform important ecosystem functions, particularly by consuming large quantities of insects (Cleveland and others, 2006; Jones and others, 2009; Kuhn and others, 2011). The importance of bats to biodiversity and to ecosystem integrity has been overlooked in many regions, largely because the challenges of detecting and studying these
Authors
Joan C. Hagar, Tom Manning, Jenny Barnett
Summary of bird-survey and banding results at W.L. Finley National Wildlife Refuge, 1998-2008
With some of the best remaining examples of oak habitats in the Willamette Valley, the Willamette Valley National Wildlife Refuge Complex (WVNWRC) has been implementing restoration efforts to reverse the successional trend towards Douglas-fir and maple that is threatening existing oak woodlands. The restoration work has been considered a model for other public and private efforts within the Willam
Authors
Joan Hagar
Arthropod prey for riparian associated birds in headwater forests of the Oregon Coast Range
Headwater riparian areas occupy a large proportion of the land base in Pacific Northwest forests, and thus are ecologically and economically important. Although a primary goal of management along small headwater streams is the protection of aquatic resources, streamside habitat also is important for many terrestrial wildlife species. However, mechanisms underlying the riparian associations of some
Authors
Joan C. Hagar, Judith Li, Janel Sobota, Stephanie Jenkins
Thinning of young Douglas-fir forests decreases density of northern flying squirrels in the Oregon Cascades
Large-scale commercial thinning of young forests in the Pacific Northwest is currently promoted on public lands to accelerate the development of late-seral forest structure for the benefit of wildlife species such as northern spotted owls (Strix occidentalis caurina) and their prey, including the northern flying squirrel (Glaucomys sabrinus). Attempts to measure the impact of commercial thinning o
Authors
Tom Manning, Joan C. Hagar, Brenda C. McComb
A comparison of selected parametric and imputation methods for estimating snag density and snag quality attributes
Snags (standing dead trees) are an essential structural component of forests. Because wildlife use of snags depends on size and decay stage, snag density estimation without any information about snag quality attributes is of little value for wildlife management decision makers. Little work has been done to develop models that allow multivariate estimation of snag density by snag quality class. Usi
Authors
Bianca N.I. Eskelson, Joan Hagar, Hailemariam Temesgen
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
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Filter Total Items: 38Oak mistletoe (Phoradendron villosum) is linked to microhabitat availability and avian diversity in Oregon white oak (Quercus garryana) woodlands
Mistletoes are parasitic or hemi-parasitic flowering plants that parasitize woody plants around the globe. Important food and cover resources provided by mistletoes have been related to strong patterns of positive association between wildlife diversity and mistletoe density. Mistletoes also create microhabitat features known to be important to wildlife by causing deformations in their host trees.AuthorsKyle R. Pritchard, Joan Hagar, David C. ShawNorth Cascades National Park Service Complex
Natural Resource Condition Assessments (NRCAs) evaluate current conditions for a subset of natural resources and resource indicators in national parks. NRCAs also report on trends in resource condition (when possible), identify critical data gaps, and characterize a general level of confidence for study findings. The resources and indicators emphasized in a given project depend on the park’s resouAuthorsRobert Hoffman, Andrea Woodward, Patricia K. Haggerty, Kurt J. Jenkins, Paul C. Griffin, M. J. Adams, Joan Hagar, Tonnie Cummings, Dan Duriscoe, Karen Kopper, Jon Riedel, Lelaina Marin, Guillaume S. Mauger, Karen Bumbaco, Jeremy S. LittellModeling marbled murrelet (Brachyramphus marmoratus) habitat using LiDAR-derived canopy data
LiDAR (Light Detection And Ranging) is an emerging remote-sensing tool that can provide fine-scale data describing vertical complexity of vegetation relevant to species that are responsive to forest structure. We used LiDAR data to estimate occupancy probability for the federally threatened marbled murrelet (Brachyramphus marmoratus) in the Oregon Coast Range of the United States. Our goal was toAuthorsJoan C. Hagar, Bianca N.I. Eskelson, Patricia K. Haggerty, S. Kim Nelson, David G. VeselyMount Rainier National Park
Natural Resource Condition Assessments (NRCAs) evaluate current conditions for a subset of natural resources and resource indicators in national parks. NRCAs also report on trends in resource condition (when possible), identify critical data gaps, and characterize a general level of confidence for study findings. The resources and indicators emphasized in a given project depend on the park’s resouAuthorsRobert Hoffman, Andrea Woodward, Patricia K. Haggerty, Kurt J. Jenkins, Paul C. Griffin, M. J. Adams, Joan Hagar, Tonnie Cummings, Dan Duriscoe, Karen Kopper, Jon Riedel, Barbara Samora, Lelaina Marin, Guillaume S. Mauger, Karen Bumbaco, Jeremy S. LittellBird-vegetation associations in thinned and unthinned young Douglas-fir forests 10 years after thinning
Quantitative associations between animals and vegetation have long been used as a basis for conservation and management, as well as in formulating predictions about the influence of resource management and climate change on populations. A fundamental assumption embedded in the use of such correlations is that they remain relatively consistent over time. However, this assumption of stationarity hasAuthorsSvetlana Yegorova, Matthew G. Betts, Joan Hagar, Klaus J. PuettmannManagement, morphological, and environmental factors influencing Douglas-fir bark furrows in the Oregon Coast Range
Many land managers in the Pacific Northwest have the goal of increasing late-successional forest structures. Despite the documented importance of Douglas-fir tree bark structure in forested ecosystems, little is known about factors influencing bark development and how foresters can manage development. This study investigated the relative importance of tree size, growth, environmental factors, andAuthorsChristopher D. Sheridan, Klaus J. Puettmann, Manuela M.P. Huso, Joan C. Hagar, Kristen R. FalkHabitat selection by juvenile Swainson’s thrushes (Catharus ustulatus) in headwater riparian areas, northwestern Oregon, USA
Lower order, non-fish-bearing streams, often termed “headwater streams”, have received minimal research effort and protection priority, especially in mesic forests where distinction between riparian and upland vegetation can be subtle. Though it is generally thought that breeding bird abundance is higher in riparian zones, little is known about species distributions when birds are in their juvenilAuthorsStephanie R. Jenkins, Matthew G. Betts, Manuela M. Huso, Joan C. HagarSurvey of bats on Columbia National Wildlife Refuge, Washington, December 2011-April 2012
Bats are diverse and abundant in many ecosystems worldwide. They perform important ecosystem functions, particularly by consuming large quantities of insects (Cleveland and others, 2006; Jones and others, 2009; Kuhn and others, 2011). The importance of bats to biodiversity and to ecosystem integrity has been overlooked in many regions, largely because the challenges of detecting and studying theseAuthorsJoan C. Hagar, Tom Manning, Jenny BarnettSummary of bird-survey and banding results at W.L. Finley National Wildlife Refuge, 1998-2008
With some of the best remaining examples of oak habitats in the Willamette Valley, the Willamette Valley National Wildlife Refuge Complex (WVNWRC) has been implementing restoration efforts to reverse the successional trend towards Douglas-fir and maple that is threatening existing oak woodlands. The restoration work has been considered a model for other public and private efforts within the WillamAuthorsJoan HagarArthropod prey for riparian associated birds in headwater forests of the Oregon Coast Range
Headwater riparian areas occupy a large proportion of the land base in Pacific Northwest forests, and thus are ecologically and economically important. Although a primary goal of management along small headwater streams is the protection of aquatic resources, streamside habitat also is important for many terrestrial wildlife species. However, mechanisms underlying the riparian associations of someAuthorsJoan C. Hagar, Judith Li, Janel Sobota, Stephanie JenkinsThinning of young Douglas-fir forests decreases density of northern flying squirrels in the Oregon Cascades
Large-scale commercial thinning of young forests in the Pacific Northwest is currently promoted on public lands to accelerate the development of late-seral forest structure for the benefit of wildlife species such as northern spotted owls (Strix occidentalis caurina) and their prey, including the northern flying squirrel (Glaucomys sabrinus). Attempts to measure the impact of commercial thinning oAuthorsTom Manning, Joan C. Hagar, Brenda C. McCombA comparison of selected parametric and imputation methods for estimating snag density and snag quality attributes
Snags (standing dead trees) are an essential structural component of forests. Because wildlife use of snags depends on size and decay stage, snag density estimation without any information about snag quality attributes is of little value for wildlife management decision makers. Little work has been done to develop models that allow multivariate estimation of snag density by snag quality class. UsiAuthorsBianca N.I. Eskelson, Joan Hagar, Hailemariam TemesgenNon-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.
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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