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Filters: Contacts: David J Delehanty (X)

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This USGS data release represents geospatial data for the sage-grouse habitat mapping project. This study provides timely and highly useful information about greater sage-grouse over a large area of the Great Basin. USGS researchers and their colleagues created a template for combining landscape-scale occurrence or abundance data with habitat selection data in order to identify areas most critical to sustaining populations of species of conservation concern. The template also identifies those areas where land use changes have minimal impact. To inform greater sage-grouse conservation planning, the researchers developed greater sage-grouse habitat management categories based on habitat selection indices (HSI) and...
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We used a hierarchical Bayesian modeling framework to estimate resource selection functions and survival for early and late brood-rearing stages of sage-grouse in relation to a broad suite of habitat characteristics evaluated at multiple spatial scales within the Great Basin from 2009 to 2019. Sage-grouse selected for greater perennial grass cover, higher relative elevations, and areas closer to springs and wet meadows during both early and late brood-rearing. Terrain characteristics, including heat load and aspect, were important in survival models, as was variation in shrub height. We also found strong evidence for higher survival for both early and late broods within previously burned areas, but survival within...
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Ranked habitat classes for sage-grouse brood-rearing productivity at each 90 m pixel. Habitat classes represent areas where high brood selection and high brood survival intersected, whereas the lowest ranks represent areas where high brood habitat selection intersected with the low brood survival. Hierarchical models of brood selection and survival were fit to landscape covariates within a Bayesian modeling framework in Nevada and California from 2009 - 2017 to develop spatially explicit information about brood habitat selection and survival.
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We evaluated the expected success of habitat recovery in priority areas under 3 different restoration scenarios: passive, planting, and seeding. Passive means no human intervention following a fire disturbance. Under a planting scenario, field technicians methodically plant young sagebrush saplings at the burned site. The seeding scenario involves distributing large amounts of sagebrush seeds throughout the affected area.
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We examined nest survival of Greater Sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) in relation to fine-scale habitat patterns that influenced nest site selection, using data from nests of telemetered females at 17 sites across 6 years in Nevada and northeastern California, USA. Importantly, sites spanned mesic and xeric average precipitation conditions and concomitant vegetation community structure across cold desert ecosystems of the North American Great Basin. Vegetative cover immediately surrounding sage-grouse nests was important for both nest site selection and nest survival, but responses varied between mesic and xeric sites. For example, while taller perennial grass was selected at xeric...
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Predictions of raven occurrence in the absence of anthropogenic environmental effects. Raven point counts were related to landscape covariates using Bayesian hierarchical occupancy models and the means of the posterior distributions for relevant effects were used to generate the predictions.
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Map of cumulative 38-day nest survival predicted from a Bayesian hierarchical shared frailty model of sage-grouse nest fates. The midpoint of coefficient conditional posterior distributions of 38-day nest survival were used for prediction at each 30 meter pixel across the landscape.
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We evaluated nest site selection and nest survival both before and after a fire disturbance occurred. We then combined those surfaces to determine the areas which were most heavily impacted by the fire.
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These data represent habitat selection of greater sage-grouse at the 50 day mark of their brood rearing process. Sage-grouse and their broods were monitored on their own individual time lines, so one group's 50th day may not necessarily be the same as any other bird's 50th day.
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Predictions of raven occurrence in the absence of natural environmental effects. Raven point counts were related to landscape covariates using Bayesian hierarchical occupancy models and the means of the posterior distributions for relevant effects were used to generate the predictions.
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We monitored Greater Sage-Grouse (Centrocercus urophasianus; hereafter, Sage-Grouse) nests and various habitat characteristics at the nest locations near Susanville in northeastern California, crossing over into northwestern Nevada. We employed a before-after-control-impact (BACI) experimental design to account for spatiotemporal heterogeneity in the system and to derive estimates of relative change in survival parameters. Sage-Grouse nest survival decreased after the Rush Fire but decreased more in the burned area relative to the unburned area. Although female Sage-Grouse continued to occupy burned areas, nest survival was reduced from 52 percent to 19 percent. Using a BACI ratio approach we found that nest survival...
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Managers require quantitative yet tractable tools that can identify areas for restoration yielding effective benefits for targeted wildlife species and the ecosystems they inhabit. A spatially explicit conservation planning tool that guides effective sagebrush restoration for sage-grouse can be made more effective by integrating baseline maps describing existing (pre-restoration) habitat suitability, and the distribution and abundance of breeding sage-grouse. Accordingly, we provide two rasters. The first is a floating point raster file informed by lek data, and derived from: 1) utilization distributions weighted by lek attendance, and 2) a non-linear probability of space-use relative to distance to lek. The second...
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Ranked index of model-projected nest site selection integrated with nesting productivity (i.e., nest survival), demonstrating the spatial distribution of adaptive vs. maladaptive habitat selection at each 30 m pixel. Hierarchical models of nest selection and survival were fit to landscape covariates within a Bayesian modeling framework in Nevada and California from 2009 through 2017 to develop spatially explicit information about nest site selection and survival consequences across the landscape. Habitat was separated into 16 classes ranking from high (1) to low (16). Habitat ranked highest where the top nest selection and survival classes intersected (adaptive selection), whereas the lowest rank occurred where...
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These data include encounter histories, nest attempts, hatched egg counts, brood counts, time-varying matrices, survival statistics, and lek counts, all used in an integrated population model (IPM) to determine the status of a population of translocated Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus; CSTG) in Nevada. Sharp-tailed grouse were translocated to a remote site in Nevada starting in 2013 through 2017. These data support the following publication: Mathews, S.R., ​Coates, P.S., Prochazka, B.G., Espinosa, S.P., and Delehanty, D.J., 2021, Offspring of translocated individuals drive the successful reintroduction of Columbian Sharp-tailed Grouse in Nevada, USA, Ornithological Applications,...
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Expanding human enterprise across remote environments impacts many wildlife species, including sage-grouse (Centrocercus urophasianus), an indicator species whose decline is at the center of national conservation strategies and land use policies. Anthropogenic resources provide subsidies for generalist predators, potentially leading to cascading effects on sensitive prey species at lower trophic levels. In semi-arid western ecosystems, common ravens (Corvus corax) are expanding in distribution and abundance, and may be negatively affecting sage-grouse reproductive success at broad spatial scales. Ravens are a common predator of sage-grouse nests, and potentially prey on chicks as well. This research aimed to address...
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A hierarchical occupancy model adapted from Royle & Dorazio (2008) and Rota et al. (2011) for use in R. References: Royle, J.A. and Dorazio, R.M., 2008. Hierarchical modeling and inference in ecology: the analysis of data from populations, metapopulations and communities. Academic Press. doi:10.1016/B978-0-12-374097-7.50001-5 J. Andrew Royle, Robert M. Dorazio, Rota, C. T., Fletcher Jr, R. J., Dorazio, R. M. and Betts, M. G. (2009), Occupancy estimation and the closure assumption. Journal of Applied Ecology, 46: 1173-1181. doi:10.1111/j.1365-2664.2009.01734.x
map background search result map search result map Integrating Spatially Explicit Indices of Abundance and Habitat Quality: An Applied Example for Greater Sage-grouse Management Data for: A conservation planning tool for greater sage-grouse using indices of species distribution, resilience, and resistance Data from: Broad-scale occurrence of a subsidized avian predator: reducing impacts of ravens on sage-grouse and other sensitive prey Raven study site locations in the Great Basin, derived from survey locations 2007 - 2016 Predictions of raven occurrence in the absence of natural environmental effects in the Great Basin, 2007-2016 (Fig. 4A) Predictions of raven occurrence in the absence of anthropogenic environmental effects in the Great Basin, 2007-2016 (Fig. 4B) Prediction of raven occurrence intersected with high impact areas for sage-grouse populations in the Great Basin, 2007-2016 (Fig. 5A) Hierarchical Occupancy Model Code for R and Accompanying Files Greater Sage-grouse Nest Survival, Nevada and California 2019 Greater Sage-grouse Nest Site Source-Sink, Nevada and California 2019 Data to Inform an Integrated Population Model of Translocated Columbian Sharp-Tailed Grouse, Nevada 2013 - 2017 Greater Sage-Grouse Nest Observations Before and After Wildfire Disturbance in Northeastern California (2007-2018) Spatially-Explicit Predictive Maps of Greater Sage-Grouse Brood Selection Integrated with Brood Survival in Nevada and Northeastern California, USA Habitat Suitability Index for Greater Sage-Grouse 50 Days into the Brood Rearing Life Stage, Nevada and California Habitat Suitability Index for Greater Sage-Grouse During the Late Brood Rearing Life Stage, Nevada and California Ranked Habitat Classes for Sage-Grouse Brood-Rearing Productivity, Nevada and California Greater Sage-Grouse Relative Survival During the Late Brood Rearing Life Stage, Nevada and California Sagebrush Restoration Under Passive, Planting, and Seeding Scenarios Following Fire Disturbance in the Virginia Mountains, Nevada (2018) Post-Fire Change in Greater Sage-Grouse Nest Selection and Survival in the Virginia Mountains, Nevada (2018) Microhabitat Characteristics Influencing Sage-Grouse Nest Site Selection and Survival, Nevada and California (2012-2017) Post-Fire Change in Greater Sage-Grouse Nest Selection and Survival in the Virginia Mountains, Nevada (2018) Sagebrush Restoration Under Passive, Planting, and Seeding Scenarios Following Fire Disturbance in the Virginia Mountains, Nevada (2018) Greater Sage-Grouse Nest Observations Before and After Wildfire Disturbance in Northeastern California (2007-2018) Data to Inform an Integrated Population Model of Translocated Columbian Sharp-Tailed Grouse, Nevada 2013 - 2017 Data for: A conservation planning tool for greater sage-grouse using indices of species distribution, resilience, and resistance Integrating Spatially Explicit Indices of Abundance and Habitat Quality: An Applied Example for Greater Sage-grouse Management Greater Sage-grouse Nest Site Source-Sink, Nevada and California 2019 Greater Sage-grouse Nest Survival, Nevada and California 2019 Spatially-Explicit Predictive Maps of Greater Sage-Grouse Brood Selection Integrated with Brood Survival in Nevada and Northeastern California, USA Habitat Suitability Index for Greater Sage-Grouse 50 Days into the Brood Rearing Life Stage, Nevada and California Habitat Suitability Index for Greater Sage-Grouse During the Late Brood Rearing Life Stage, Nevada and California Ranked Habitat Classes for Sage-Grouse Brood-Rearing Productivity, Nevada and California Greater Sage-Grouse Relative Survival During the Late Brood Rearing Life Stage, Nevada and California Microhabitat Characteristics Influencing Sage-Grouse Nest Site Selection and Survival, Nevada and California (2012-2017) Raven study site locations in the Great Basin, derived from survey locations 2007 - 2016 Prediction of raven occurrence intersected with high impact areas for sage-grouse populations in the Great Basin, 2007-2016 (Fig. 5A) Hierarchical Occupancy Model Code for R and Accompanying Files Data from: Broad-scale occurrence of a subsidized avian predator: reducing impacts of ravens on sage-grouse and other sensitive prey Predictions of raven occurrence in the absence of natural environmental effects in the Great Basin, 2007-2016 (Fig. 4A) Predictions of raven occurrence in the absence of anthropogenic environmental effects in the Great Basin, 2007-2016 (Fig. 4B)