My research interest include avian ecology, conservation of threatened and endangered species, population dynamics of forest and rangeland raptor species
Education and Certifications
Ph.D., Wildlife Science, Oregon State University, Corvallis, OR (2012)
M.S., Ecology, Colorado State University, Fort Collins, CO (2004)
B.S., Environmental Science, Northern Arizona University, Flagstaff, AZ (1993)
Science and Products
Effects of Experimental Removal of Barred Owls on Population Demography of Northern Spotted Owls in the Pacific Northwest
Fire Refugia in Old-Growth Forests: Predicting Habitat Persistence to Support Land Management in an Era of Rapid Global Change
Threat of Invasive Barred Owls to Northern Spotted Owls and their Habitats
Golden Eagles and Renewable Energy Development in the Western U.S.
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.
Detection/non-detection data on territorial pairs of golden eagles in coastal southern California, 2016-2017
Anticoagulant rodenticide exposure in Barred Owls (Strix varia) collected in Washington and Oregon 2015-2017
Count and detection-nondetection survey data of barred owls (Strix varia) in historical breeding territories of Northern Spotted Owls (Strix occidentalis caurina) in the Oregon Coast Range, 1995-2016
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.
Long-term monitoring in transition: Resolving spatial mismatch and integrating multistate occupancy data
Range-wide sources of variation in reproductive rates of northern spotted owls
Golden Eagle (Aquila chysaetos)
Taricha granulosa (Rough-skinned newt) predation
Golden eagle occupancy surveys and monitoring strategy in coastal southern California, United States
Golden eagle population surveys in the vicinity of the Altamont Pass Wind Resource Area, California, 2014–21
Invader removal triggers competitive release in a threatened avian predator
Conspecific and congeneric interactions shape increasing rates of breeding dispersal of northern spotted owls
Distribution and abundance of Aquila chrysaetos (golden eagles) in East Contra Costa County Habitat Conservation Plan/Natural Community Conservation Plan area, California
Effects of barred owl (Strix varia) removal on population demography of northern spotted owls (Strix occidentalis caurina) in Washington and Oregon—2019 annual report
Anticoagulant rodenticides in Strix owls indicate widespread exposure in west coast forests
Effects of experimental removal of Barred Owls on population Demography of Northern Spotted Owls in Washington and Oregon—2018 Progress Report
To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.
Northern Spotted Owl Still Fights for Survival
Three studies highlight how the interactions between northern spotted owl and the invasive barred owl are intertwined.
Science and Products
- Science
Effects of Experimental Removal of Barred Owls on Population Demography of Northern Spotted Owls in the Pacific Northwest
Barred owls (Strix varia) have expanded their geographic range from eastern to western North America, and their newly expanded range now completely overlaps that of the federally threatened northern spotted owl (S. occidentalis caurina; Gutiérrez et al. 2007, Livezey 2009, USFWS 2013). Evidence from long-term demographic studies indicates that the presence of barred owls has contributed...Fire Refugia in Old-Growth Forests: Predicting Habitat Persistence to Support Land Management in an Era of Rapid Global Change
Mature, old-growth forests in the Pacific Northwest provide critical habitat for threatened and endangered species, including the northern spotted owl and marbled murrelet. Dominated by large Douglas-firs and western hemlocks, these established forests range in age from 200 to 1,000 years old. Yet wildfire activity is increasing across western North America, heightening concerns about severe firesThreat of Invasive Barred Owls to Northern Spotted Owls and their Habitats
As an apex predator and fiercely territorial invader, barred owls at high densities have the potential to affect a variety of native wildlife through competition, niche displacement, and predation. Such impacts may be especially problematic for conservation of the federally threatened northern spotted owl, whose populations have continued to decline despite widespread protection of old forest...Golden Eagles and Renewable Energy Development in the Western U.S.
Development of wind-power and solar facilities is expected to increase dramatically in areas occupied by golden eagles in the western U.S. Renewable energy development in areas used by golden eagles poses a unique challenge to natural resource managers because of this species’ vulnerability to collisions with wind turbines and sensitivity to changes in human land-use. - 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.
Detection/non-detection data on territorial pairs of golden eagles in coastal southern California, 2016-2017
This dataset contains detection-nondetection data for territorial pairs of Golden Eagles at survey sites randomly selected from a grid of equal-sized (13.9 km2) hexagonal sample cells overlaid across the region of interest in Coastal Southern California during 2016 and 2017. We partitioned surveys within seasons based on approximate transition dates for stages in the breeding cycle of golden eagleAnticoagulant rodenticide exposure in Barred Owls (Strix varia) collected in Washington and Oregon 2015-2017
This dataset includes anticoagulant rodenticide (AR) screening results of 40 Barred Owls (Strix varia) collected in forested landscapes of Washington and Oregon from 2015-2017. Liver tissue was collected from each owl and screened for exposure to eight AR compounds, including 4 first-generation ARs (warfarin, diphacinone, chlorophacinone, and coumachlor), and 4 second-generation ARs (brodifacoum,Count and detection-nondetection survey data of barred owls (Strix varia) in historical breeding territories of Northern Spotted Owls (Strix occidentalis caurina) in the Oregon Coast Range, 1995-2016
This dataset contains count and detection-nondetection data of Barred Owls from 106 historical breeding territories of Northern Spotted Owl territories (i.e. sites) in the Oregon Coast Ranges from 1995 to 2016. Data collected from 1995 to 2014 are partitioned into 2-week periods from 1 March - 31 August each year, totaling 12 possible sampling periods per year. Data collected from 2015 and 2016 ar - Multimedia
- 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: 29Long-term monitoring in transition: Resolving spatial mismatch and integrating multistate occupancy data
The success of long-term wildlife monitoring programs can be influenced by many factors and study designs often represent compromises between spatial scales and costs. Adaptive monitoring programs can iteratively manage this tension by adopting new cost-efficient technologies, which can provide projects the opportunity to reallocate costs to address new hypotheses, adapt to changing ecological conRange-wide sources of variation in reproductive rates of northern spotted owls
We conducted a range-wide investigation of the dynamics of site level reproductive rate of northern spotted owls using survey data from 11 study areas across the sub-species geographic range collected during 1993–2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed further inGolden Eagle (Aquila chysaetos)
The golden eagle (Aquila chrysaetos) is commonly recognized as an indicator of ecosystem health and was selected as an important indicator species for the ecological health of lands owned and managed by East Bay Stewardship Network (Network) partner agencies within the area of focus for this project (See map, Chapter 1). Based on national conservation goals and past and current golden eagle researTaricha granulosa (Rough-skinned newt) predation
We found skeletal remains of fully digested Taricha granulosa in the stomach contents of 4 free-ranging, presumably healthy Strix varia (Barred Owl) collected from Roseburg, Oregon. This study recorded stomach contents from S. varia collected as part of a lethal removal experiment in localities near Cle Elum, Washington, Alsea, Oregon, and Roseburg, Oregon. In the stomach of one S. varia, we identGolden eagle occupancy surveys and monitoring strategy in coastal southern California, United States
Golden eagles (Aquila chrysaetos) are of increasing conservation concern in western North America. Effective conservation measures for this wide-ranging, federally protected raptor species require monitoring frameworks that accommodate strong inference on the status of breeding populations across vast landscapes. We used a broad-scale sampling design to identify relationships between landscape conGolden eagle population surveys in the vicinity of the Altamont Pass Wind Resource Area, California, 2014–21
Golden Eagles (Aquila chrysaetos) are among the highest profile species killed by collisions with wind turbines at the Altamont Pass Wind Resource Area (APWRA) in the northern Diablo Range of west-central California. Understanding the distribution, site occupancy, and nesting status of eagles near the APWRA is needed to identify and minimize possible population-level impacts. We established a broaInvader removal triggers competitive release in a threatened avian predator
Invasive species can cause extinctions of native species and widespread biodiversity loss. Invader removal is a common management response, but the use of long-term field experiments to characterize effectiveness of removals in benefitting impacted native species is rare. We used a large-scale removal experiment to investigate the demographic response of a threatened native species, the northern sConspecific and congeneric interactions shape increasing rates of breeding dispersal of northern spotted owls
Breeding dispersal, the movement from one breeding territory to another, is rare for philopatric species that evolved within relatively stable environments, such as the old-growth coniferous forests of the Pacific Northwest. Although dispersal is not inherently maladaptive, the consequences of increased dispersal on population dynamics in populations whose historical dispersal rates are low couldDistribution and abundance of Aquila chrysaetos (golden eagles) in East Contra Costa County Habitat Conservation Plan/Natural Community Conservation Plan area, California
The East Contra Costa County Habitat Conservation Plan/Natural Community Conservation Plan (HCP/NCCP) Preserve System was designed to protect and enhance ecological diversity and function in eastern Contra Costa County, California. Aquila chrysaetos (golden eagle) is a special-status species expected to benefit from biological goals of the HCP/NCCP. As part of a broader study, we estimated site-ocEffects of barred owl (Strix varia) removal on population demography of northern spotted owls (Strix occidentalis caurina) in Washington and Oregon—2019 annual report
Strix occidentalis caurina (northern spotted owl; hereinafter referred to as spotted owl) have rapidly declined throughout the subspecies’ geographic range. Competition with invading Strix varia (barred owl) has been identified as an immediate cause of those declines. A pilot study in California showed that removal of barred owls coupled with conservation of suitable habitat conditions can slow orAnticoagulant rodenticides in Strix owls indicate widespread exposure in west coast forests
Exposure of nontarget wildlife to anticoagulant rodenticides (AR) is a global conservation concern typically centered around urban or agricultural areas. Recently, however, the illegal use of ARs in remote forests of California, USA, has exposed sensitive predators, including the federally threatened northern spotted owl (Strix occidentalis caurina). We used congeneric barred owls (S. varia) as aEffects of experimental removal of Barred Owls on population Demography of Northern Spotted Owls in Washington and Oregon—2018 Progress Report
Populations of Northern Spotted Owls (Strix occidentalis caurina; herineafter referred to as Spotted Owl) have declined throughout the subspecies’ geographic range. Evidence indicates that competition with invading Barred Owls (S. varia) has contributed significantly to those declines. A pilot study in California showed that removal of Barred Owls coupled with conservation of suitable habitat cond - News
To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.
Northern Spotted Owl Still Fights for Survival
Three studies highlight how the interactions between northern spotted owl and the invasive barred owl are intertwined.