Geology topics

Brian G. Prochazka

Publications and source records attributed to Brian G. Prochazka.

At least 19 recordsLinked to original sources

USGS2026

Range-wide population trend analysis for greater sage-grouse ( Centrocercus urophasianus )—Updated 1960–2025

Greater sage-grouse ( Centrocercus urophasianus ; hereafter sage-grouse) are at the center of State and national land-use policies largely because of their unique life-history traits as an ecological indicator for the health of sagebrush ecosystems. This updated population analysis provides State and Federal land and wildlife managers with the best available science to help guide management and conservation plans aimed at benefitting sage-grouse populations and the ecosystems they inhabit. This analysis relied on previously published population modeling methodology from Coates and others (2021, 2022a) and incorporates population lek count data for 1960–2025. Included in this report are methodological updates to period terminology, expanded reporting of trends across all nadir-to-nadir combinations, and revised extirpation probability estimation that utilizes every historic population nadir to forecast abundance. Each of these updates are detailed under individual Modification sections. Additional updates include simulation analyses that evaluate the effects of progressively longer exclusions of Wyoming lek count data (Wyoming Game and Fish Department has not provided access to a complete lek count data set since 2023) on trends, extirpation probabilities, and targeted annual warning system signals. State-space models estimated a 2.7-percent average annual decline in sage-grouse populations between 1966 and 2021 (Period 1–7, six population oscillations) across their geographical range. The average annual decline among climate clusters for the same number of oscillations ranged between 2.0 and 3.5 percent. Cumulative declines were 42.4, 61.7, and 77.9 percent range-wide in Period 5–7 (19 years [two oscillations]), Period 3–7 (36 years [four oscillations]), and Period 1–7 (55 years), respectively. Between 2024 and 2025 (1-year, non-trend timeframe), range-wide population size declined 1.9 percent ( 95-percent credible interval [CRI]= −4.71–1.48). Simulations of missing data from Wyoming showed that progressively longer gaps produced more negative trend estimates and higher extirpation probabilities, predominantly within Wyoming. Effects on targeted annual warning system signals were more nuanced, with missed warnings occurring inside and outside Wyoming and false warnings occurring predominantly within Wyoming.

California, Colorado, Idaho, Montana, Nevada, Nort↗

USGS2026

Estimating greater sage-grouse population sizes within Oregon, 2017–24

We fit a binomial mixture ( N -mixture) model to lek (breeding area) count data to estimate annual population sizes of greater sage-grouse ( Centrocercus urophasianus ; sage-grouse) within Oregon between 2017 and 2024. Population estimates were delineated among 24 priority areas for conservation, and additional sources of information were considered, including male-to-female sex ratios, lek attendance rates, numbers of unmodeled leks, and the existence of unsampled/unknown leks. In 2024, Oregon was estimated to contain approximately 41,875 sage-grouse (95-percent credible interval [CRI=38,980–54,634]), which was down from a high of 50,869 (95-percent CRI=41,794–66,238) in 2017. A nadir (low point) was identified during 2019, when the median statewide population estimate was 30,644 birds. A complete population oscillation was not evident during the inferential period based on local maxima that were observed during the start (2017) and stop (2024) years of analysis. In addition to estimating population sizes, we evaluated N -mixture model estimates for precision and accuracy after randomly removing single and repeat counts in 10-percent increments (relative to total sample size). We estimated an increase in absolute bias of approximately 1.6 percent for every 10-percent reduction in effort.

Oregon↗

USGS2026

Estimating greater sage-grouse population sizes within the state of Oregon, USA 2017–2024

We fit an N -mixture model to lek (breeding area) count data to estimate annual population sizes of greater sage-grouse ( Centrocercus urophasianus ; sage-grouse) within the state of Oregon, USA between 2017–2024. Population estimates were delineated among 24 Priority Areas for Conservation (PACs) and considered additional sources of information including male-to-female sex ratios, lek attendance rates, numbers of unmodeled leks, and the existence of unsampled/unknown leks. In 2024, the state of Oregon was estimated to contain approximately 41,875 sage-grouse (95% credible interval [CRI] = 38,980–54,634), which was down from a high of 50,869 (95% CRI = 41,794–66,238) in 2017. A nadir (low point) was identified during 2019, when the median statewide population estimate was 30,644 birds. A complete population oscillation was not evident during the inferential period based on local maxima that were observed during the start (2017) and stop (2024) years of analysis. In addition to estimating population sizes, we evaluated N -mixture model estimates for precision and accuracy after randomly removing single and repeat counts in 10% increments (relative to total sample size). We estimated an increase in absolute bias of approximately 1.6% for every 10% reduction in effort.

BioRxiv↗

USGS2026

Changes in spatial distribution and abundance together determine potential for population persistence for greater sage-grouse

Aim Population ecologists often focus on changes in the distribution and abundance of wildlife species, which are useful for trend analyses and status assessments. However, rarely are these responses evaluated simultaneously for a single species, despite their unique contributions to fully assess a species' viability. For example, focusing solely on total abundance can mask important losses in overall distribution within a metapopulation structure that may contribute to long-term population instability that results from the extirpation of small peripheral populations. Location Bi-State region of Nevada and California, USA. Methods We simultaneously evaluated changes in population abundance and distribution for greater sage-grouse (hereafter sage-grouse; Centrocercus urophasianus ) within the Bi-State Distinct Population Segment (DPS), a genetically distinct and isolated population straddling the border of Nevada and California. We combined population counts, demographic data, and information on space use from marked individuals to evaluate changes in population distribution and abundance over three time periods that corresponded to the three most recent population nadirs (1995–2019, 2002–2019 and 2008–2019). Results The Bi-State DPS exhibited evidence of ~1.2%–2.5% declines annually, over the short/medium-term (1995–2019; λ^ = 0.987, 95% CRI: 0.970–0.999), short-term (2002–2019; λ^ = 0.975, 95% CRI: 0.963–0.985) and recent-term (2008–2019; λ^ = 0.988, 95% CRI: 0.973–1.001). Since 1995, the spatial distribution of sage-grouse abundance in the Bi-State DPS shifted amongst subpopulations, with peripheral subpopulations suffering the largest declines. Main Conclusions Gains in abundance and distribution amongst expanding subpopulations did not offset losses in the remaining subpopulations, with a net loss in occupied distribution of 156 km 2 since 1995. Reductions in spatial distribution could have implications for metapopulation persistence as peripheral populations become more vulnerable to stochastic events, which would not have been apparent from the evaluation of overall metapopulation abundance on its own.

California, Nevada↗

USGS2025

Range-wide population trend analysis for greater sage-grouse (Centrocercus urophasianus)—Updated 1960–2024

California, Colorado, Idaho, Montana, Nevada, Nort↗

USGS2025

Conservation translocation immediately reverses decline in imperiled sage-grouse populations

Conservation translocation (hereafter translocation), the intentional movement of organisms from one location to another as a management tool, can be an extremely useful conservation action to increase the abundance of isolated populations following successful habitat restoration. However, managers seek to weigh the benefits against costs to the source population from which individuals are removed. Using two small and imperiled greater sage-grouse ( Centrocercus urophasianus ; hereafter sage-grouse) populations, we demonstrated the usefulness of translocation as a conservation management tool and the value of evaluating the potential consequences of translocation action. Using integrated population models and a before-after-control-impact (BACI) design, we quantified the extent to which translocation influenced the finite rate of change ( λ "> λ ) of apparent abundance ( N "> N ) in both reinforced and source populations. We also assessed changes in underlying demographic rates in one population, allowing for identification of the specific mechanisms causing differences in population trends following translocation. In both reinforced populations, λ ̂ "> λ̂ substantially increased following translocation. In the population for which we had sufficient demographic data, the increase in λ ̂ "> λ̂ resulted from a 179 % increase in egg hatchability following reinforcement. In one translocation, we did not observe adverse effects on the source populations. The source population for the second translocation exhibited reduced population growth rates after translocation, although BACI ratios indicated causes for population declines independent of translocation effects, highlighting the need to investigate processes together with observed patterns. Overall, we demonstrated the ability to rescue isolated sage-grouse populations via translocation, preserving population viability and metapopulation persistence.

California, Montana, Nevada, North Dakota, South D↗

USGS2025

Post-fire abundances of soil cyanobacteria relate more to variations in sparse tree cover and soil properties than to fire history, in semiarid shrub steppe

The frequency and extent of wildfire are increasing globally, and understanding the ecosystem impacts of fire can help guide management of burned areas. Cyanobacteria are widespread in surface soils of semi-arid and arid rangelands and confer soil stabilization and resistance to exotic-plant invasions. We examined the probability of encountering cyanobacteria of the order Oscillatoriales in 2022, via microscopic counts of rewetted soils in the lab, following nine recent wildfires that burned as recently as 2012–2017 and up to four times repeatedly until then, in the northern Great Basin of the western U.S. Much of the variability in Oscillatoriales was attributed to the identity of the wildfire, i.e. unexplained variation. Tree cover estimated from gridded satellite-based models was scarce before and especially after fire yet was the second-most predictive covariate. Estimated cover of Oscillatoriales (lab derived) was 0.48 where trees were absent compared to 0.42 where tree cover was detected in the 30-m pixel surrounding soil samples. Presence of sand conferred nearly the opposite effect, which was counter to expectations but could be related to reduced vegetative cover on coarser soils. Other site factors including climatic precipitation and soil fertility were also predictive of Oscillatoriales. Cyanobacteria are considered to be cosmopolitan, i.e. ubiquitous in soils, but these spatial patterns of Oscillatoriales indicate relationships to landscape factors that have not been considered before. Understanding these relationships could aid land managers in identifying post-fire conditions most favorable to soil stabilizing cyanobacteria, which, in turn, could help achieve management goals of moderating soil erosion and additional invasion of fire-promoting exotic plants.

Idaho, Nevada, Oregon, Utah↗

USGS2024

Brood translocation increases post-release recruitment and promotes population restoration of Centrocercus urophasianus (Greater Sage-Grouse)

Wildlife managers translocate Centrocercus urophasianus (Greater Sage-Grouse) to augment small populations, but translocated C. urophasianus often fail to reproduce post-release, hampering conservation objectives. We performed 2 C. urophasianus translocations in California and North Dakota from 2017 to 2020 using 2 methods at both sites: an established method of translocating females prior to nesting (i.e., a pre-nesting translocation), and a novel method wherein females were translocated with chicks after successfully hatching nests in source populations (i.e., a brood translocation). We radio-marked and monitored 135 translocated females and 284 source population females and used count data from leks in recipient and source populations to evaluate each method. Using an integrated population model (IPM), we estimated demographic parameters, including recruitment, by females translocated with each method. We estimated the finite rate of change in abundance (ˆ λ) in recipient and source populations given multiple simulated translocation strategies using each method and evaluated them using a cost–benefit metric (i.e., a ratio of the simulated change in abundance at recipient and source sites). We found that recruitment in recipient populations was substantially higher when brood translocations were employed compared to when pre-nesting translocations were employed. Most females translocated pre-nesting forewent reproduction entirely, whereas most females translocated with their broods successfully reared offspring in recipient populations. A per capita comparison revealed that brood translocations resulted in ˆ λ that were 11–30% greater than pre-nesting translocations, but also revealed that the removal of brood-rearing females from source populations resulted in larger reductions in ˆ λ when compared with prenesting translocations. However, reductions in ˆ λ were small and the estimated cost–benefit metrics indicated that translocation of females with broods was a more effective method at spurring growth in recipient populations while minimizing impacts to source populations.

California, North Dakota, Wyoming↗

USGS2024

Geographic principles applied to population dynamics: A spatially interpolated integrated population model

A major impediment to wildlife conservation and management, from a quantitative perspective, is dealing with high degrees of uncertainty associated with population estimates. Integrated population models (IPMs) can help alleviate that challenge, but they are often limited to narrow spatial or temporal windows owing to the financial and logistical burdens of acquiring requisite datasets. To expand the spatiotemporal scope of practical IPM implementation, we developed a novel method that expresses demographic relatedness among sampled and unsampled locations using geographic principles of spatial autocorrelation. We interpolated demographic parameters at unsampled locations using parameter estimates from data-informed locations. Errors attributable to the interpolative process were corrected using a joint likelihood and locally recorded count data (‘cheaper’ and broadly distributed). We evaluated the spatially interpolated IPM (SIIPM) for precision and accuracy under variable levels of spatial autocorrelation using simulated data and a Leave-One-Out Cross-Validation (LOOCV) technique. Conventional IPMs and state-space models (SSM) were fit to the same simulated datasets to provide a comparative assessment of the novel method. In a final, empirical demonstration we fit the SIIPM to data collected from Greater Sage-Grouse ( Centrocercus urophasianus ; sage-grouse) populations located in Nevada, U.S.A. during 2013–2021. SIIPMs outperformed conventional IPMs when fit to data possessing moderate-to-high levels of spatial autocorrelation. Under moderate levels of autocorrelation, the average improvement in parameter estimation was 13.6% for survival, 65.3% for recruitment and 23.7% for rate of population change (𝜆). When spatial autocorrelation was low, the SIIPM still outperformed contemporary approaches in areas that were geographically close (<67 km) to sampling locations. Under low autocorrelation-near distance scenarios, we observed SIIPM parameters that were 30.8% (recruitment), 32.5% (𝜆; IPM comparison) and 54.0% (𝜆; SSM comparison) more precise than contemporary models. Spatial autocorrelation is often assumed but rarely tested when comparing population dynamics across regions of large geographic extent. We demonstrated that SIIPMs can improve precision of species' vital rate estimation when extrapolating model inference beyond populations for which long-term monitoring data exists. Specific to sage-grouse, these results support previous conclusions of broad-scale spatial autocorrelation in population dynamics and a reproductive-survival trade-off previously documented at smaller scales.

Methods in Ecology and Evolution↗

USGS2024

Status of greater sage-grouse in the Bi-State Distinct Population Segment—An evaluation of population trends, habitat selection, and efficacy of conservation actions

Preface This study was completed to provide timely scientific information regarding greater sage-grouse population trends, habitat selection, and the efficacy of previous conservation actions implemented to benefit the Bi-State Distinct Population Segment (DPS). Specifically, we provide these analyses to inform the current (2024) status review and pending listing decision for the DPS being undertaken by the U.S. Fish and Wildlife Service. These findings provide updated, detailed, and comprehensive information regarding the status of a geographically isolated and genetically distinct population of a species of high conservation concern and their habitat. Importantly, this report also provides information on the efficacy of previously implemented conservation actions targeting the Bi-State DPS in a framework that is transferable throughout the species’ range.

California, Nevada↗

USGS2024

Range-wide population trend analysis for greater sage-grouse (Centrocercus urophasianus)—Updated 1960–2023

Greater sage-grouse ( Centrocercus urophasianus ) are at the center of state and national land-use policies largely because of their unique life-history traits as an ecological indicator for health of sagebrush ecosystems. This updated population trend analysis provides state and federal land and wildlife managers with best-available science to help guide management and conservation plans aimed at benefitting sage-grouse populations. This analysis relied on previously published population trend modeling methodology from Coates and others (2021, 2022a) and incorporates population lek count data for 1960–2023. Included in this update are changes in terminology. Specifically, we now use the terms Period 1 (previously Long), Period 2 (previously Medium/Long), Period 3 (previously Medium), Period 4 (previously Short/Medium), Period 5 (previously Short), and Period 6 (previously Recent) to identify specific trends. State-space models estimated 2.8-percent average annual decline in sage-grouse populations between 1966 and 2021 (Period 1, six population oscillations) across their geographical range. Average annual decline among climate clusters for the same number of oscillations ranged between 2.1 and 3.1 percent. Cumulative declines were 41.1, 64.5, and 78.4 percent range-wide during Period 5 (19 years), Period 3 (35 years), and Period 1 (55 years), respectively. Population growth during 2022 and 2023 continue to point to 2021 as the most recent range-wide nadir.

Data Report↗

USGS2024

Cooperative conservation actions improve sage-grouse population performance within the Bi-State Distinct Population Segment

Developing a robust monitoring framework that integrates efficacy assessments of cooperative conservation and restoration actions in relation to population viability is critical for successful long-term recovery of target ecosystems and species. However, often it is difficult to quantify conservation action efficacy because of the complex, dynamic nature of ecosystem processes and practical limitations associated with assessing target species’ population dynamics. Here, we present an analytical framework that allows for quantification of conservation action efficacy using greater sage-grouse ( Centrocercus urophasianus ; hereafter, sage-grouse) within the Bi-State Distinct Population Segment which borders Nevada and California. This framework utilizes web-based repositories of conservation efforts carried out in sagebrush ecosystems and readily fits within contemporary sagebrush conservation design strategies. We employed a state-space model within a Bayesian framework to estimate abundance (N) as inputs for a progressive change before-after-control-impact paired series (BACIPS) design. Count data from 57 leks (monitored between 2003–2021) coupled with 85 unique actions (initiated between 2012–2019) provided clear evidence that conservation actions increased population abundance, on average, by 4.4% annually across the study area, resulting in a 37.4% cumulative increase since 2012. Population gains varied by the type of conservation action and according to the number of lag years following its implementation.

California, Nevada↗

USGS2024

State of the sagebrush: Implementing the sagebrush conservation design to save a biome

This special issue of Rangeland Ecology and Management is dedicated to applying the Sagebrush Conservation Design (SCD) to improve conservation outcomes across the sagebrush biome in the face of pervasive ecosystem threats. This special issue provides new science and real-world examples of how we can implement the SCD to save a biome. The SCD is a tool to identify intact sagebrush areas and address the largest threats to the ecosystem. The SCD focuses on first protecting intact and functioning sagebrush ecosystems, called Core Sagebrush Areas, then works outward toward more degraded areas (i.e., “Defend the Core”). The premise behind the Defend the Core approach is simple: focus resources first on preventative actions that retain ecosystem services in Core Sagebrush Areas because they are more cost-effective and more likely to be successful. The opening article of this special issue creates a foundation for the 19 following papers, providing a coherent path for implementing the SCD. The overarching themes are: 1) Business-As-Usual Won't Save the Sagebrush Sea, 2) Better Spatial Targeting Can Improve Outcomes, 3) Conservation Planning is Needed to Develop Realistic Business Plans, 4) Targeted Ecosystem Management: Monitoring Shows Managing for Sagebrush Ecological Integrity is Working, 5) Maintaining Sagebrush Ecological Integrity is Ecologically Relevant, and 6) There is Only Hope if We Manage Change. The collective articles show that there is no shared plan to save the biome, yet a business plan for the biome could ensure realistic goals. The sagebrush biome still has vast expanses of open spaces with high ecological integrity at a scale that is rare in other ecological systems within the lower 48 states. If we focus on the common ground of the main drivers of ecosystem change, implementing the SCD and Defending the Core are viable strategies to help save a biome.

Rangeland Ecology & Management↗

USGS2024

Evaluating the sagebrush conservation design through the lens of a sagebrush indicator species

Sagebrush ecosystems support a suite of unique species such as the emblematic greater sage-grouse ( Centrocercus urophasianus ; sage-grouse) but are under increasing pressure from anthropogenic stressors such as annual grass invasion, conifer encroachment, altered wildfire regimes, and land use change. We examined the ability of an ecosystem-based framework for sagebrush conservation, the sagebrush conservation design (SCD) strategy, and the associated model of sagebrush ecological integrity (SEI), to identify and rank priority habitats for sage-grouse, a sagebrush indicator species. We compared sage-grouse population trends from 1996–2021 across the three ranked SEI categories. We then modeled those trends directly as a function of the same landcover predictors underlying SEI, used the median trend estimates to recategorize the sage-grouse’s range, and used spatial correlation methods to compare our sage-grouse performance categories with those of SEI. Finally, we compared the sage-grouse condition categories, predicted by our landcover-based model, to empirical trends derived from population count data. We found that the SCD and SEI were effective tools for identifying and ranking priority habitats for sage-grouse. Population trends were stable in the core areas identified by SEI but declining in the lower (i.e., growth and other) condition categories. As a result, core areas encompassed an increasingly larger share of the total sage-grouse population in a disproportionately smaller area. Our model supports the general functional relationships between landcover and sage-grouse performance suggested by SEI. We found strong spatial congruence between our categories of predicted sage-grouse population performance, the condition categories of SEI, and empirical trends derived from population count data. Our analysis demonstrates that proactive ecosystem-based approaches to the conservation of the sagebrush biome can help optimize the return on limited conservation resources and benefits for sagebrush obligate species and help reduce some of the real and perceived conflicts inherent in single-species management.

Arizona, California, Colorado, Idaho, New Mexico, ↗

USGS2023

Wildfire immediately reduces nest and adult survival of greater sage-grouse

Wildfire events are becoming more frequent and severe on a global scale. Rising temperatures, prolonged drought, and the presence of pyrophytic invasive grasses are contributing to the degradation of native vegetation communities. Within the Great Basin region of the western U.S., increasing wildfire frequency is transforming the ecosystem toward a higher degree of homogeneity, one dominated by invasive annual grasses and declining landscape productivity. Greater sage-grouse ( Centrocercus urophasianus ; hereafter sage-grouse) are a species of conservation concern that rely on large tracts of structurally and functionally diverse sagebrush ( Artemisia spp.) communities. Using a 12-year (2008–2019) telemetry dataset, we documented immediate impacts of wildfire on demographic rates of a population of sage-grouse that were exposed to two large wildfire events (Virginia Mountains Fire Complex—2016; Long Valley Fire—2017) near the border of California and Nevada. Spatiotemporal heterogeneity in demographic rates were accounted for using a Before-After Control-Impact Paired Series (BACIPS) study design. Results revealed a 40% reduction in adult survival and a 79% reduction in nest survival within areas impacted by wildfires. Our results indicate that wildfire has strong and immediate impacts to two key life stages of a sagebrush indicator species and underscores the importance of fire suppression and immediate restoration following wildfire events.

California, Nevada↗

USGS2023

Range-wide population trend analysis for greater sage-grouse (Centrocercus urophasianus)—Updated 1960–2022

Greater sage-grouse ( Centrocercus urophasianus ) are at the center of state and national land-use policies largely because of their unique life-history traits as an ecological indicator for health of sagebrush ecosystems. This updated population trend analysis provides state and federal land and wildlife managers with best-available science to help guide current management and conservation plans aimed at benefitting sage-grouse populations. This analysis relied on previously published population trend modeling methodology from Coates and others (2021, 2022a) and incorporated population lek count data through 2022. Bayesian state-space models estimated 2.9 percent average annual decline in sage-grouse populations across their geographical range, which varied among subpopulations at the largest scale of analysis, termed climate clusters (2.2–4.7). Cumulative declines were 40.9, 65.0, and 79.6 percent range-wide across short (19 years), medium (35 years), and long (55 years) temporal periods, respectively. These results indicate that the most recent nadir for range-wide populations occurred during 2021. However, growth during 2022 was modest, making 2021 a tentative final nadir at this point.

Data Report↗

USGS2023

A genetic warning system for a hierarchically structured wildlife monitoring framework

Genetic variation is a well-known indicator of population fitness yet is not typically included in monitoring programs for sensitive species. Additionally, most programs monitor populations at one scale, which can lead to potential mismatches with ecological processes critical to species' conservation. Recently developed methods generating hierarchically nested population units (i.e., clusters of varying scales) for greater sage-grouse ( Centrocercus urophasianus ) have identified population trend declines across spatiotemporal scales to help managers target areas for conservation. The same clusters used as a proxy for spatial scale can alert managers to local units (i.e., neighborhood-scale) with low genetic diversity, further facilitating identification of management targets. We developed a genetic warning system utilizing previously developed hierarchical population units to identify management-relevant areas with low genetic diversity within the greater sage-grouse range. Within this warning system we characterized conservation concern thresholds based on values of genetic diversity and developed a statistical model for microsatellite data to robustly estimate these values for hierarchically nested populations. We found that 41 of 224 neighborhood-scale clusters had low genetic diversity, 23 of which were coupled with documented local population trend decline. We also found evidence of cross-scale low genetic diversity in the small and isolated Washington population, unlikely to be reversed through typical local management actions alone. The combination of low genetic diversity and a declining population suggests relatively high conservation concern. Our findings could further facilitate conservation action prioritization in combination with population trend assessments and (or) local information, and act as a base-line of genetic diversity for future comparison. Importantly, the approach we used is broadly applicable across taxa.

Ecological Applications↗

USGS2023

Geothermal energy production adversely affects a sensitive indicator species within sagebrush ecosystems in western North America

Growing demand for renewable energy has resulted in expansion of energy infrastructure across sagebrush ecosystems of western North America. Geothermal power is an increasingly popular renewable energy source, especially within remote areas, but little is known about the impacts it may have on local wildlife populations. Investigations are warranted given similarities to more conventional surface disturbance activities with well-documented impacts. Using a novel 2-pronged analytical approach, we estimated effects of geothermal energy production activities (hereafter, geothermal) on populations of greater sage-grouse ( Centrocercus urophasianus ; hereafter, sage-grouse), a species of high conservation concern. First, we applied a before-after-control-impact paired series design at two geothermal sites in Nevada, USA, to estimate absence rates of male sage-grouse from lek sites (breeding grounds) and changes in predicted apparent abundance ( λ ̂ "> �̂ ) in relation to geothermal energy infrastructure. We then estimated effects of geothermal energy infrastructure and other environmental covariates on demographic rates. We found λ ̂ "> �̂ declined ∼24 % within 5 km of geothermal sites, while lek absence rates (e.g., indicating local extirpation) increased by ∼730 % within 2 km. Our demographic models revealed decreased nest survival in association with proximity to geothermal infrastructure, reduced topographic impedance surface (TIS; a proxy for sound and light dispersion emanating from geothermal infrastructure), and increased density of common ravens ( Corvus corax ), an effective nest predator. Models also estimated decreases in adult survival in relation to TIS. Finally, we applied population matrix models within a quantitative decision support framework to help guide locations for future geothermal development that balance the need for domestic energy production while minimizing adverse effects on wildlife populations.

Biological Conservation↗