Greater Sage-grouse Research Articles

AN INVERTEBRATE ECOSYSTEM ENGINEER UNDER THE UMBRELLA OF SAGE-GROUSE CONSERVATION.

Conservation practitioners often rely on areas designed to protect species of greatest conservation priority to also conserve co-occurring species (i.e., the umbrella species concept). The extent to which vertebrate species may serve as suitable umbrellas for invertebrate species, however, has rarely been explored. Sage-grouse (Centrocercus spp.) have high conservation priority throughout much of the rangelands of western North America and are considered an umbrella species through which the conservation of entire rangeland ecosystems can be accomplished. Harvester ants are ecosystem engineers and play important roles in the maintenance and function of rangeland ecosystems. We compared indices of the abundance of western harvester ants (Pogonomyrmex occidentalis) and Greater Sage-Grouse (Centrocercus urophasianus) at 72 sites in central Wyoming, USA in 2012. The abundance of harvester ant mounds was best predicted by a regression model that included a combination of local habitat characteristics and the abundance of sage-grouse. When controlling for habitat-related factors, areas with higher abundances of sage-grouse pellets (an index of sage-grouse abundance and/or habitat use) had higher abundances of ant mounds than areas with lower abundances of sage-grouse pellets. The causal mechanism underlying this positive relationship between sage-grouse and ant mound abundance at the fine scale could be indirect (e.g., both species prefer similar environmental conditions) or direct (e.g., sage-grouse prefer areas with a high abundance of ant mounds because ants are an important prey item during certain life stages). We observed no relationship between a broad-scale index of breeding sage-grouse density and the abundance of ant mounds. We suspect that consideration of the non-breeding habitat of sage-grouse and finer-scale measures of sage-grouse abundance are critical to the utility of sage-grouse as an umbrella species for the conservation of harvester ants and their important role in rangeland ecosystems.

Statistical Population Reconstruction Using Wings from Harvested Northern Bobwhites Can Inform Management

Despite the widespread collection wings from harvested northern bobwhite (Colinus virginianus) by state wildlife agencies and private entities, age-at-harvest information has been largely underutilized for guiding management decisions for this species. Statistical population reconstruction (SPR) techniques can use age-at-harvest information and provide a valuable tool for monitoring trends and the status of bobwhite (and other game bird) populations. However, SPR has not been applied to bobwhite. We evaluated the utility of statistical population reconstruction models, which have been applied successfully to other species (e.g., elk, Cervus elaphus; blacktailed deer, Odocoilues hemonius; and greater sage-grouse, Centrocercus urophasianus), to reconstruct annual abundance and demographic attributes for a bobwhite population in southwest Georgia. During 1998 – 2016, we collected wings from harvested birds (n = 17,448; nannual = 969 ± 104) in conjunction with survival information from mark-recapture. We derived independent estimates of fall abundance from the same site using covey call counts and a standardized measure of hunting success (coveys moved per hour). SPR models suggested that population change was stable (λ = 1.00; CV = 0.19) compared to moderate population growth (λ = 1.05; CV = 0.29) indicated by the covey call quadrat method. Abundance estimates from SPR and covey call counts were moderately correlated (r = 0.48) with only 3 out 18 years statistically different. Abundance estimates from SPR and hunting success (coveys moved per hour) was highly correlated (r = 0.86). SPR provides valid, conservative abundance estimates for bobwhite age-at-harvest data. Therefore, we endorse the use of SPR for bobwhites where age-at-harvest, hunter effort and another source of auxiliary data are readily available. As such, given that the collection of harvested wings is simple and low cost, we recommend managers and state agencies consider incorporating this technique into their management program.

Conservation Credits—Evolution of a Market-Oriented Approach to Recovery of Species of Concern on Private Land

When species are listed as threatened or endangered under the Endangered Species Act, there are often real or perceived negative consequences for landowners that may produce perverse incentives and lead to the elimination rather than protection of habitat for the species on private land. In Texas, where approximately 95% of the land is privately owned, the listing of one species and the potential listing of another led to the creation of two innovative programs aimed at incentivizing landowners to protect and improve habitat for the two species: Recovery Credit System for the Golden-Cheeked Warbler and Conservation Recovery Award System for the Dunes Sagebrush Lizard. Both programs were based on multistakeholder collaborations that included federal and state agencies, nongovernmental organizations, and private landowners, and which resulted in quasimarket mechanisms for the voluntary protection of habitat by landowners for the species of concern. Key components of both programs included confidentiality of landowner conservation agreements with the state’s wildlife management agency and the creation of not-for profit organizations to implement contracts with landowners and disseminate payments for habitat conservation actions to landowners. These two programs have also informed efforts to protect the Lesser Prairie-Chicken and Greater Sage-Grouse, which are under threat on private land in multiple states. Seven lessons learned from protection programs for the four species presented in this article provide useful guidelines for the conservation of other at-risk species on private land elsewhere.

Effectiveness of Wyoming's Sage-Grouse Core Areas: Influences on Energy Development and Male Lek Attendance.

Greater sage-grouse (Centrocercus urophasianus) populations have declined across their range due to human-assisted factors driving large-scale habitat change. In response, the state of Wyoming implemented the Sage-grouse Executive Order protection policy in 2008 as a voluntary regulatory mechanism to minimize anthropogenic disturbance within defined sage-grouse core population areas. Our objectives were to evaluate areas designated as Sage-grouse Executive Order Core Areas on: (1) oil and gas well pad development, and (2) peak male lek attendance in core and non-core sage-grouse populations. We conducted our evaluations at statewide and Western Association of Fish and Wildlife Agencies management zone (MZ I and MZ II) scales. We used Analysis of Covariance modeling to evaluate change in well pad development from 1986-2014 and peak male lek attendance from 958 leks with consistent lek counts within increasing (1996-2006) and decreasing (2006-2013) timeframes for Core and non-core sage-grouse populations. Oil and gas well pad development was restricted in Core Areas. Trends in peak male sage-grouse lek attendance were greater in Core Areas compared to non-core areas at the statewide scale and in MZ II, but not in MZ I, during population increase. Trends in peak male lek attendance did not differ statistically between Core and non-core population areas statewide, in MZ I, or MZ II during population decrease. Our results provide support for the effectiveness of Core Areas in maintaining sage-grouse populations in Wyoming, but also indicate the need for increased conservation actions to improve sage-grouse population response in MZ I.

Nesting habitat selection influences nest and early offspring survival in Greater Sage-Grouse

ABSTRACT Adaptive habitat-selection theory predicts that individuals should use habitats that maximize lifetime fitness. However, trade-offs between life-history stages, environmental variability, and predator–prey dynamics can interact with individual preferences, which may result in individuals selecting suboptimal habitats. Understanding the distinction between adaptive and maladaptive animal use of habitat is central to effective species conservation, because use of maladaptive habitat is counter to conservation objectives. Our objectives were to assess whether habitat characteristics selected by Greater Sage-Grouse (Centrocercus urophasianus) were correlated with increased production of fledged young. We monitored 411 nests and 120 broods from 234 females between 2004 and 2012 in central Nevada, USA. We determined which habitat characteristics were selected as nesting habitat and assessed whether these characteristics influenced nest success and early offspring survival. The relationships between cha...

Greater Sage-Grouse Resource Selection Drives Reproductive Fitness Under a Conifer Removal Strategy

The link between individual variation in resource selection (e.g., functional response) and fitness creates a foundation for understanding wildlife-habitat relationships. Although many anthropogenic activities adversely affect these relationships, it is largely unknown whether projects implemented to benefit wildlife populations actually achieve this outcome. For sagebrush (Artemisia spp.) obligate species such as the greater sage-grouse (Centrocercus urophasianus; sage-grouse), expansion of juniper (Juniperus spp.) and pinyon-pine (Pinus spp.; conifers) woodlands into sagebrush ecosystems has been identified as a conservation threat. This threat is intensified when a sagebrush ecosystem is bounded by naturally unsuitable habitats. As such, federal, state, and private land managers have implemented landscape-level management to remove conifers on thousands of hectares of sagebrush habitat across the western United States. Despite the scale of contemporary conifer treatments, little was previously known whether sage-grouse will occupy these manipulated landscapes and whether occupancy has consequences on fitness components. To address these questions, we monitored nest and brood success rates for 96 radio-marked sage-grouse from 2012-2015 that inhabited conifer-dominated landscapes in the Box Elder Sage-grouse Management Area in Utah where mechanical conifer removal projects were completed. We then linked sage-grouse resource selection to individual nest (n = 95) and brood (n = 56) success by incorporating random-slope Resource Selection Functions as explanatory predictors in a logistic brood success model. Using the novel approach of random slope covariates, we demonstrated that sage-grouse selected for nest and brooding sites closer to conifer removal areas and that the probability of individual nest and brood success declined (β = −0.10 and β = −0.74, respectively) as sage-grouse females selected sites farther from conifer removal areas. Our research provided the first evidence that mechanical conifer removal treatments can increase suitable available breeding habitats for female sage-grouse and that individuals who occupied these areas experienced enhanced nest and brood success.

Wildfire, climate, and invasive grass interactions negatively impact an indicator species by reshaping sagebrush ecosystems

Iconic sagebrush ecosystems of the American West are threatened by larger and more frequent wildfires that can kill sagebrush and facilitate invasion by annual grasses, creating a cycle that alters sagebrush ecosystem recovery post disturbance. Thwarting this accelerated grass-fire cycle is at the forefront of current national conservation efforts, yet its impacts on wildlife populations inhabiting these ecosystems have not been quantified rigorously. Within a Bayesian framework, we modeled 30 y of wildfire and climatic effects on population rates of change of a sagebrush-obligate species, the greater sage-grouse, across the Great Basin of western North America. Importantly, our modeling also accounted for variation in sagebrush recovery time post fire as determined by underlying soil properties that influence ecosystem resilience to disturbance and resistance to invasion. Our results demonstrate that the cumulative loss of sagebrush to direct and indirect effects of wildfire has contributed strongly to declining sage-grouse populations over the past 30 y at large spatial scales. Moreover, long-lasting effects from wildfire nullified pulses of sage-grouse population growth that typically follow years of higher precipitation. If wildfire trends continue unabated, model projections indicate sage-grouse populations will be reduced to 43% of their current numbers over the next three decades. Our results provide a timely example of how altered fire regimes are disrupting recovery of sagebrush ecosystems and leading to substantial declines of a widespread indicator species. Accordingly, we present scenario-based stochastic projections to inform conservation actions that may help offset the adverse effects of wildfire on sage-grouse and other wildlife populations.

Forbs: Foundation for Restoration of Monarch Butterflies, other Pollinators, and Greater Sage-Grouse in the Western United States

Monarch butterflies (Danaus plexippus), other pollinators, and Greater Sage-Grouse (Centrocercus urophasianus) are currently the focus of increased conservation efforts. Federal attention on these fauna is encouraging land managers to develop conservation strategies, often without corresponding financial resources. This could foster a myopic approach when allocating resources and setting restoration priorities, and at best, allow for inefficiencies in the usage of land management resources, or, at worst, pit one species (or suite of species, e.g., pollinators) against another (e.g., sage-grouse). Instead, investing holistically by linking conservation of these fauna may provide improved leverage of available resources and more benefit to the landscape. Fortunately, on the western US rangelands, these fauna can all benefit from restoration that increases the abundance and diversity of forbs. Establishing high density islands of outplanted forb seedlings may be a way to expedite restoration. Managers establishing forbs for pollinators (including monarchs) would further increase food availability for greater sage-grouse and vice versa. Adding milkweeds (Asclepias spp.) in appropriate areas to forb mixtures for restoration is warranted because they are excellent nectar sources for pollinators in general and the sole host for monarch larvae in particular. Here, we provide an overview of why forb species are keystone for monarch butterflies, other pollinators, and Greater Sage-Grouse and how seeding and outplanting seedlings of specific forbs are critical to restoration efforts.

Hierarchical population structure in greater sage-grouse provides insight into management boundary delineation

Understanding population structure is important for guiding ongoing conservation and restoration efforts. The greater sage-grouse (Centrocercus urophasianus) is a species of concern distributed across 1.2 million km2 of western North America. We genotyped 1499 greater sage-grouse from 297 leks across Montana, North Dakota and South Dakota using a 15 locus microsatellite panel, then examined spatial autocorrelation, spatial principal components analysis, and hierarchical Bayesian clustering to identify population structure. Our results show that at distances of up to ~240 km individuals exhibit greater genetic similarity than expected by chance, suggesting that the cumulative effect of short-range dispersal translates to long-range connectivity. We found two levels of hierarchical genetic subpopulation structure. These subpopulations occupy significantly different elevations and are surrounded by divergent vegetative communities with different dominant subspecies of sagebrush, each with its own chemical defense against herbivory. We propose five management groups reflective of genetic subpopulation structure. These genetic groups are largely synonymous with existing priority areas for conservation. On average, 85.8 % of individuals within each conservation priority area assign to a distinct subpopulation. Our results largely support existing management decisions regarding subpopulation boundaries.

Ecosystem Water Availability in Juniper versus Sagebrush Snow-Dominated Rangelands

Western Juniper (Juniperus occidentalis Hook.) has greatly expanded in the past 150+ years and now dominates over 3.6 million ha of rangeland in the Intermountain Western United States. The impacts of juniper encroachment on critical ecohydrological relationships among snow distribution, water budgets, plant community transitions, and habitat requirements for wildlife, such as the greater sage grouse (Centrocercus urophasianus), remain poorly understood. The goal of this study is to better understand how juniper encroachment affects water availability for ecohydrologic processes and associated wildlife habitat in snow-dominated sagebrush (Artemisia spp.) steppe ecosystems. A 6-yr combined measurement and modeling study is conducted to explore differences in snow distribution, water availability, and annual water balances between juniper-dominated and sagebrush-dominated catchments. Although there is large interannual variability in both measured weather data and modeled hydrologic fluxes during the study, results indicate that juniper-dominated catchments have greater peak accumulations of snow water equivalent, earlier snow melt, and less streamflow relative to sagebrush-dominated catchments. Water delivery is delayed by an average of 9 days in the sagebrush-dominated scenario compared with the juniper-dominated scenario as a result of increased water storage in snow drifts. The delayed water input to sagebrush-dominated ecosystems in typical water years has wide-ranging implications for available surface water, soil water, and vegetation dynamics associated with wildlife habitat for sagebrush obligates such as sage grouse. Results from this study imply that the retention of high-elevation, sagebrush-dominated landscapes may become crucial for sage grouse habitat management if mid- and low-elevation precipitation continues to transition from snow to rain dominated.

Effectiveness of the toxicant DRC-1339 in reducing populations of common ravens in Wyoming

Common raven (Corvus corax) populations have increased several-fold in the western United States during the past century; these birds cause problems when they kill new-borne lambs and calves and depredate nests of greater sage-grouse (Centrocercus urophasianus). The toxicant DRC-1339 is used by U.S. Department of Agriculture/Animal and Plant Health Inspection Service Wildlife Services to manage common raven populations and reduce the severity of these problems, but it is difficult to determine how many ravens are killed by an application because carcasses are rarely found. We examined the effectiveness of DRC-1339 applications for preventative control of ravens at 3 landfills and 5 nearby roosts in Wyoming, USA, from 2013 through 2015. Wildlife Services removed 23%, 34%, and 7% of the radiomarked sample of ravens in southwestern Wyoming during 2013, 2014, and 2015, respectively, according to Kaplan–Meier survival estimates. During the 3 winters, 235 of 240 raven carcasses that we collected died from DRC-1339 poisoning. The following year, raven fecundity and immigration had offset most, but not all, of the mortality produced by the DRC-1339 program. Raven population estimates declined 9% from the 2013 winter to the 2014 winter and 12% from the 2014 winter to the 2015 winter, based on telemetry data and roost counts. Ravens did not avoid landfills after they were treated with DRC-1339 probably because few ravens died there. Estimated mortality rates from DRC-1339 applications based on carcass counts underestimated the actual rates by 79% and landfill counts of ravens underestimated it by 49%. Roost count estimates of mortality were within 15% of the actual mortality rate. © 2016 The Wildlife Society.

Assessing Greater Sage-Grouse Selection of Brood-Rearing Habitat Using Remotely-Sensed Imagery: Can Readily Available High-Resolution Imagery Be Used to Identify Brood-Rearing Habitat Across a Broad Landscape?

Greater sage-grouse populations have decreased steadily since European settlement in western North America. Reduced availability of brood-rearing habitat has been identified as a limiting factor for many populations. We used radio-telemetry to acquire locations of sage-grouse broods from 1998 to 2012 in Strawberry Valley, Utah. Using these locations and remotely-sensed NAIP (National Agricultural Imagery Program) imagery, we 1) determined which characteristics of brood-rearing habitat could be used in widely available, high resolution imagery 2) assessed the spatial extent at which sage-grouse selected brood-rearing habitat, and 3) created a predictive habitat model to identify areas of preferred brood-rearing habitat. We used AIC model selection to evaluate support for a list of variables derived from remotely-sensed imagery. We examined the relationship of these explanatory variables at three spatial extents (45, 200, and 795 meter radii). Our top model included 10 variables (percent shrub, percent grass, percent tree, percent paved road, percent riparian, meters of sage/tree edge, meters of riparian/tree edge, distance to tree, distance to transmission lines, and distance to permanent structures). Variables from each spatial extent were represented in our top model with the majority being associated with the larger (795 meter) spatial extent. When applied to our study area, our top model predicted 75% of naïve brood locations suggesting reasonable success using this method and widely available NAIP imagery. We encourage application of our methodology to other sage-grouse populations and species of conservation concern.

Microsite selection and survival of greater sage-grouse nests in south-central Wyoming

Greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) populations have declined across North America because of degradation of sagebrush (Artemisia spp.) ecosystems; thus, management for sage-grouse habitat is a high priority. Expansion of some energy development has put additional pressures on sage-grouse populations and their habitats. However, little is known about the effects wind energy development may have on sage-grouse populations. Population dynamics of sage-grouse are partially related to nest success, which may be influenced by the quality of nesting habitat. Consequently, knowledge of vegetation and structural characteristics associated with selection and survival of sage-grouse nests would help inform management decisions to improve nest success. As part of a study quantifying greater sage-grouse demographics prior to construction of a wind energy facility, we monitored female sage-grouse equipped with 30-g solar Argos global positioning system platform transmitter terminals during the breeding season in Carbon County, Wyoming to assess selection and survival of nests at nest area (30-m radius), nest patch (5-m radius), and nest bowl scales. Sage-grouse selected nest sites with increased visual obstruction from 22.9–45.7 cm in height at all scales, less forb cover at the nest area, and more sagebrush cover at the nest patch. Survival of nests to 27 days (i.e., incubation period) was 43.3% (95% CI: 31.8–59.1%) in 2011 (n = 49), 33.2% (95% CI: 21.5–51.3%) in 2012 (n = 40), and 25.1% (95% CI: 15.0–42.0%) in 2013 (n = 39). Grass height had a positive association with survival of nests at the nest area and nest patch, canopy cover of bunchgrasses and sagebrush had an interactive effect on survival of nests at the nest patch, and visual obstruction from 0–22.9 cm in height had a positive relationship with survival of nests at the nest bowl. The standardized precipitation-evapotranspiration index (SPEI), an index of drought, from the previous growing season was also negatively correlated with survival of nests. Our results suggest management for nesting sage-grouse should focus on a heterogeneous compilation of tall bunchgrasses >15 cm and patches of sagebrush cover >30%. Management for grasses >15 cm tall should be especially diligent during drought years, given SPEI was associated with nest survival the following year. Although there could be other factors important to selection or survival of nests that we did not evaluate, our results suggest scale-dependent management strategies at the microsite level may not be necessary. We encourage researchers and managers to use our baseline results in a before–after control-impact design with future, post-construction data to determine the potential effects of wind energy development on selection and survival of sage-grouse nests. © 2016 The Wildlife Society.

SUSCEPTIBILITY AND ANTIBODY RESPONSE OF VESPER SPARROWS (POOECETES GRAMINEUS) TO WEST NILE VIRUS: A POTENTIAL AMPLIFICATION HOST IN SAGEBRUSH-GRASSLAND HABITAT.

West Nile virus (WNV) spread to the US western plains states in 2003, when a significant mortality event attributed to WNV occurred in Greater Sage-grouse ( Centrocercus urophasianus ). The role of avian species inhabiting sagebrush in the amplification of WNV in arid and semiarid regions of the North America is unknown. We conducted an experimental WNV challenge study in Vesper Sparrows ( Pooecetes gramineus ), a species common to sagebrush and grassland habitats found throughout much of North America. We found Vesper Sparrows to be moderately susceptible to WNV, developing viremia considered sufficient to transmit WNV to feeding mosquitoes, but the majority of birds were capable of surviving infection and developing a humoral immune response to the WNV nonstructural 1 and envelope proteins. Despite clearance of viremia, after 6 mo, WNV was detected molecularly in three birds and cultured from one bird. Surviving Vesper Sparrows were resistant to reinfection 6 mo after the initial challenge. Vesper sparrows could play a role in the amplification of WNV in sagebrush habitat and other areas of their range, but rapid clearance of WNV may limit their importance as competent amplification hosts of WNV.

Sage-Grouse Nesting, Brood and Winter Habitat Characteristics in Montana

<p class="emsd"><span lang="EN-GB">Greater sage-grouse (Centrocercus urophasianus) habitat characteristics were studied in central Montana primarily on Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young) dominated rangeland. The primary objective was to compare shrub and herbaceous parameters within (use, random or non-use) and between seasonal habitats (nest, brood, winter). Two study sites (Musselshell and Golden Valley counties), and 2 years (2004 and 2005) were compared. Nest, brood, and random sites were compared for herbaceous cover, and grass height (n = 648). Nest, brood, random, winter use and winter non-use sites were evaluated for shrub cover, density, and height. All differences were considered significant at P ≤ 0.05. Sage-grouse nested in areas with greater total shrub cover and height, and taller live and residual grass than was randomly available. No differences were found between brood and paired random sites for any of the herbaceous or shrub parameters measured. Shrub cover and density were greater at winter use sites than non-use sites. Winter use sites had less shrub cover than nest sites. The nest and brood habitat had similar shrub cover, density, and height on the study area. Sage-grouse habitats should be managed to include sagebrush, forbs, and grass. Herbaceous vegetation was more important during nesting and brood rearing than during the winter. Therefore, some portions of <span>sage-</span>grouse habitat may benefit from management for greater herbaceous cover, but not at the expense of removing sagebrush. Sagebrush cover from 10 to 15 percent was the most consistent component of sage-grouse habitat.</span></p>

Spatial Analysis of Greater Sage-grouse Habitat Use in Relation to Landscape Level Habitat Structure

Greater sage-grouse (GSG; Centrocercus urophasianus) selectively utilize portions of sagebrush and sagebrush associated habitats within broad and heterogeneous landscapes. Until recently, sage-grouse research has generally focused on fine-scale vegetation structure and composition and less on landscape-scale habitat requirements. Insufficient information at broad scales limits a manager’s ability to interpret and predict habitat use patterns, assess habitat suitability, and target areas for conservation and ecological rehabilitation. We identified environmental attributes associated with GSG habitat use at broad spatial scales. In 2006, we captured 50 GSG, radio-collared each bird, and tracked each bird’s position within a 31,416 ha study area in central Oregon, USA. We monitored birds year-long between March 2006 and March 2008 across the study area. Each time a bird was located, we collected a coordinate position at the point where it was observed. We generated spatially explicit predictor variables in a Geographic Information System to quantify the association between landscape structure and GSG occurrence. Predictor variables included elevation, slope, aspect, curvature, solar radiation, landscape ruggedness, orientation, distance from roads, distance from leks, distance from mesic habitats, and cover type. We used spatial modeling (Maximum Entropy) to 1) develop predictive models of GSG seasonal resource use, 2) generate probability maps for visual assessment, and 3) characterize response curves associated with GSG habitat preference based on individual landscape predictor variables. Results indicate that during the breeding season GSG will use big sagebrush, low sagebrush or complexes of low and mountain big sagebrush cover types. During the summer season, GSG use low sagebrush, mountain big sagebrush, and mesic areas. Additionally, summer season use areas include higher elevation sites within or in close proximity to habitats that sustain succulent forbs throughout most of the growing season. Maps of modeled data identify spatially explicit areas of preferred habitat and predicted bird use patterns. This information can help managers identify and protect important GSG habitat across heterogeneous landscapes.

Lessons from the Greater Sage Grouse and Oregon Chub

Thomas E. Bigford tbigford@fisheries.orgThe Obama administration announced on September 22, 2015, that it would not list the greater sage grouse under the federal Endangered Species Act (ESA). That...

Large-scale control site selection for population monitoring: An example assessing sage-grouse trends

Human impacts on wildlife populations are widespread and prolific and understanding wildlife responses to human impacts is a fundamental component of wildlife management. The first step to understanding wildlife responses is the documentation of changes in wildlife population parameters, such as population size. Meaningful assessment of population changes in potentially impacted sites requires the establishment of monitoring at similar, nonimpacted, control sites. However, it is often difficult to identify appropriate control sites in wildlife populations. We demonstrated use of Geographic Information System (GIS) data across large spatial scales to select biologically relevant control sites for population monitoring. Greater sage-grouse (Centrocercus urophasianus; hearafter, sage-grouse) are negatively affected by energy development, and monitoring of sage-grouse population within energy development areas is necessary to detect population-level responses. We used population data (1995–2012) from an energy development area in Wyoming, USA, the Atlantic Rim Project Area (ARPA), and GIS data to identify control sites that were not impacted by energy development for population monitoring. Control sites were surrounded by similar habitat and were within similar climate areas to the ARPA. We developed nonlinear trend models for both the ARPA and control sites and compared long-term trends from the 2 areas. We found little difference between the ARPA and control sites trends over time. This research demonstrated an approach for control site selection across large landscapes and can be used as a template for similar impact-monitoring studies. It is important to note that identification of changes in population parameters between control and treatment sites is only the first step in understanding the mechanisms that underlie those changes. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Genetic structure of Greater Sage-Grouse (Centrocercus urophasianus) in a declining, peripheral population

ABSTRACT Loss of suitable habitat and subsequent fragmentation of populations are recognized as important factors in the decline and extinction of many species because they result in smaller, more isolated populations with reduced genetic diversity. The Greater Sage-Grouse (Centrocercus urophasianus), having declined in distribution and abundance throughout its range, is a candidate species under the U.S. Endangered Species Act and a species of special concern in California. Because the relationships between dispersal, gene flow, and genetic structure are interrelated and affect the long-term persistence of Greater Sage-Grouse, we assessed the genetic structure and patterns of dispersal among Greater Sage-Grouse in a declining, peripheral population in northeastern California. We genotyped 19 microsatellite loci from 167 individuals from 13 leks and 20 individuals captured off lek. Greater Sage-Grouse in northeastern California appear to maintain gene flow and genetic diversity across the sampled region. ...

Microhabitat Selection of Brood-Rearing Sites by Greater Sage-Grouse in Carbon County, Wyoming

Abstract. Declines in Greater Sage-Grouse (Centrocercus urophasianus, hereafter sage-grouse) populations could be attributed to low chick survival, which may be influenced by the availability of food and cover at sites used by females rearing broods. Habitat attributes important to broods may vary regionally; thus, it is necessary to understand factors affecting regional sage-grouse brood-rearing site selection, especially when estimating the impacts of development. We monitored brood-rearing female sage-grouse equipped with solar Argos Global Positioning System Platform Transmitter Terminals from 2011 to 2013 to assess microhabitat selection by broods in Carbon County, Wyoming. We measured vegetation and arthropod characteristics at diurnal sites used by broods (n = 42 in 2011, n = 31 in 2012, n = 32 in 2013) and at 3 paired-random sites associated with each used site (n = 315), located 50 m, 250 m, and 500 m from the used site. We fit conditional logistic models within an information-theoretic framework...