Greater sage-grouse (Centrocercus urophasianus; sage-grouse) currently occupy an estimated 56% of the potential range-wide pre-European settlement habitat. Population declines have been largely attributed to direct habitat loss and fragmentation related to anthropogenic activities that promote wildfires and the subsequent spread of invasive plants. Vegetation manipulations, including the seeding of plant species, such as forage kochia (Bassia prostrata), have been identified as potential strategies to mitigate the risk of wildfire and enhance sage-grouse habitat in areas at risk to wildfires. I evaluated the composition changes that occurred in a lower elevation sagebrush (Artemisia spp.) plant community within the Grouse Creek Watershed in western Box Elder County, Utah, USA, in response to prescribed vegetation manipulations (green-stripping through chain harrowing, juniper mastication, seeding forage kochia, applying Plateau℗ʼ herbicide) and studied the effect of these changes on sage-grouse habitat-use patterns and vital rates. I monitored 53 radio-collared sage-grouse throughout the Grouse Creek watershed from 2010-2012. Seasonal movements suggested local individual bird adaptations to annual variations in weather and habitat fragmentation. Sage-grouse selected for untreated areas; however, treated areas were used to expand the size of the lek. Untreated areas exhibited a higher percent composition of shrubs compared to areas that were chain harrowed to prepare a seedbed. Sage-grouse nest success and adult male survival rates during this study were relatively low compared to range-wide population estimates. Nest predation was higher for nests located closer to roads. The forage kochia seeded in the firebreaks emerged the season after seeding (2011). Using microhistological techniques, I detected small quantities of forage kochia in sage-grouse fecal pellets. Nutrient analysis confirmed that forage kochia samples collected from the sites exhibited a high protein content and low secondary metabolite content, similar to black sagebrush (Artemisia nova). Although green-stripping with forage kochia in lower elevation sagebrush communities may prove to be a beneficial technique for protecting rangelands from wildfire and provide a dietary source for wildlife, site preparation should be conducted to minimize the impact on existing sagebrush canopy cover habitats. Long-term monitoring should be implemented to determine extended effects of green-stripping treatments on sagebrush habitat and sage-grouse vital rates. Although individual sage-grouse demonstrated local adaptations to fragmentation and seasonal variations in weather, increased fragmentation and climate change in this part of the Great Basin may increase meta-population extirpation risks inhabiting lower elevation sagebrush areas in the Grouse Creek Watershed.
The greater sage-grouse (Centrocercus urophasianus; sage-grouse) has been a species of conservation concern since the early 20th century due to range-wide population declines. To contribute to knowledge of the ecology of sage-grouse populations that inhabit the Box Elder Sage Grouse Management Area (SGMA) in northwestern Utah and quantify their responses to landscape scale habitat manipulations, I monitored vital rates and habitat selection of 45 female sage-grouse from 2014 to 2015. Using telemetry locations of female sage-grouse with known nest and brood fates, I created Generalized Linear Mixed Models to estimate the influence of proximity to pinyon (Pinus spp.) and juniper (Juniperus spp.; conifer) encroachment, and removal projects may have on sagegrouse reproductive fitness in the Box Elder SGMA. The best fit model suggested that for every 1 km a nest was located away from a conifer removal area, probability of nest success was reduced by 9.1% (Îø = -0.096, P
The greater sage-grouse (Centrocercus urophasianus; sage-grouse) is the largest grouse species in North America and an indicator species for the condition of sagebrush (Artemisia spp.) ecosystems. The Box Elder Sage-Grouse Management Area (SGMA) in northwestern Utah encompasses one of the state0́9s largest sage-grouse populations. To fill knowledge gaps regarding the population inhabiting the Raft River subunit of the Box Elder SGMA, I captured, radio-marked, and monitored 123 (68 female, 55 male) sage-grouse from January 2012 through December 2013. My purpose was to describe how the seasonal movements, survival, and reproductive rates of this sage-grouse population are effected by small-scale habitat use and breeding season foraging patterns. Sage-grouse in the Raft River subunit have distinct winter and summer ranges, and some travelled long distances annually. Survival rates were similar to other Utah populations and range-wide averages. Nest and brood success rates were above range-wide averages and those reported in the adjacent Grouse Creek subunit of the same SGMA. Sage-grouse in the study area selected habitats with specific vegetation characteristics to fit their seasonal needs. Sage-grouse use sites differed from random sites with greater forb height, grass height, and shrub height and cover. Nest success rates were directly related to selected vegetation, as successful nests were located more often under sagebrush and within greater forb height and cover and grass and shrub height than unsuccessful nests. Brood sites were also greater in forb, grass, and shrub height than other use sites. In March and April of 2013, I located radio-marked sage-grouse at flock browse sites to observe their sagebrush diet selection patterns. Lab analyses showed no differences in nutritional quality or chemical composition between browsed sagebrush plants and non-browsed and random plants. However, browsed black sagebrush (A. nova) was lower in protein and higher in chemical content than browsed Wyoming big sagebrush (A. tridentata wyomingensis). Radio-marked females were frequently observed at sites where black sagebrush was browsed, and one individual chemical was considerably more concentrated in browsed plants associated with females that nested successfully. My research provides useful information regarding the seasonal habitat use patterns and vegetation preferences of sage-grouse in the Box Elder SGMA. To conserve the sage-grouse population in northwestern Utah, management actions must protect the seasonal habitats and vegetation that the species depends on for its productivity and survival.
Declining greater sage-grouse populations (Centrocercus urophasianus; hereafter sage-grouse) have led to increased concern regarding the long-term stability of the species. Previous research has identified factors contributing to the observed population declines. Habitat degradation and loss have been implicated as major factors in population declines. Although much is known about sage-grouse biology, more information is needed about population responses to specific management actions. This research was conducted to document sage-grouse responses to site-specific management actions. Additionally, I evaluated sage-grouse temporal and seasonal habitat-use and the comparability of techniques used by range and wildlife managers to measure vegetation responses of habitat management. Specifically, I evaluated 1) whether chemical analysis (gas chromatography) of sage-grouse fecal pellets could identify sagebrush species in sage-grouse winter diets, 2) the comparability of the line-point intercept and Daubenmire canopy cover methods for estimating canopy cover, 3) the response of sage-grouse broods to prescribed burns in a high elevation sagebrush community in northeastern Utah, and 4) the vegetation and insect characteristics of sites used by sage-grouse broods during a 24-hour period. I was able to determine wintering sage-grouse diets using gas chromatography by analyzing fecal pellets. This research also confirmed that black sagebrush (Artemisia nova) was an important component of sage-grouse winter diets in western Box Elder County and Parker Mountain populations. The line-point intercept and Daubenmire methods for estimating canopy cover are not comparable. Sage-grouse broods selected small (~25 ha) patchy prescribed burns in high elevation mountain big sagebrush (A. tridentata vaseyana) communities in northeastern Utah. Sage-grouse brood-site use in northwestern Utah did not differ during the diurnal hours, but nocturnal roost sites were characterized by shorter statured shrubs and more bare ground when compared to midday sites.
Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are a sagebrush obligate species and as such an indicator of sagebrush (Artemisia spp.) habitat quality and quantity. Sage-grouse populations have declined across western North America. This decline has been attributed to habitat loss and degradation of the sagebrush ecosystem. To determine factors that may cause localized declines in sage-grouse populations, managers may need site-specific information on the ecology and habitat use patterns of meta-populations. This information is currently lacking for sage-grouse populations that inhabit the Bear Lake Plateau and Valley (BLPV), encompassing parts of Idaho, Utah and Wyoming. I captured, radio-marked and monitored 153 sage-grouse in the BLPV from 20100́32012 to assess nest success, brood survival, mortality factors, and habitat use. Reproductive success was lower than range-wide averages, with especially low success in 2011. Nesting and brood rearing both showed higher success rates in 2012. Survival was very similar to estimates found elsewhere. Females had higher survival rates than males, and yearlings had higher survival probability than adults. Sage-grouse mortality was highest in summer and spring, and lowest in fall. Individual sage-grouse completed large scale movements, often using habitats in Idaho, Utah, and Wyoming. Important factors in sage-grouse habitat selection included distance to major road, distance to habitat edge, distance to vertical structure (i.e., communication towers, wind turbines, and transmission lines), and vegetation cover types. Sage-grouse tended to avoid major road and vertical structures (i.e., communication towers, wind turbines, and transmission lines). They also selected habitat further away from habitat edge. Vegetation types preferred by sage-grouse included shrubland habitats, wet meadows, and grassland. MaxEnt models did not place highest importance on sagebrush habitats, which are critical for sage-grouse presence. This could have occurred because the vegetation layers used in the model did not assess habitat quality. Models produced using the ten landscape variables and BLPV sage-grouse locations ranked good to excellent fits. State-defined habitat covered a larger extent than MaxEnt predicted habitat. MaxEnt predicted habitat areas may be used to further refine state identified core areas to assist in prioritization of conservation efforts to protect the BLPV sage-grouse population.
The greater sage-grouse (Centrocercus urophasianus; sage-grouse) is a species of conservation concern in Utah and range-wide due to declines in populations and threats to sagebrush habitat on which they depend. To effectively conserve the species, detailed site-specific knowledge of ecology and distribution is needed. To expand knowledge of local populations within the West Box Elder Sage Grouse Management Area (SGMA) and gain insights into the effectiveness of vegetation treatments intended to benefit sagegrouse, I radio marked and tracked 123 (68 female, 55 male) sage-grouse and conducted sage-grouse pellet surveys on 19 conifer removal projects. Widespread habitat restoration measures designed to benefit sage-grouse have highlighted the need for prioritization tools to optimize placement of sage-grouse habitat projects. I generated seasonal habitat models to predict sage-grouse habitat use within the West Box Elder SGMA using a suite of vegetation and topographical predictors and known sage-grouse locations. Model fit was good with brood, early summer, late summer, lekking (early spring), and non-breeding models reporting an AUC of >0.90; nest and winter models reported an AUC of 0.87 and 0.85, respectively. A vegetation disturbance history was built for the study area from 1985 to 2013; however, the vegetation disturbances mapped were not a strong predictor of sage-grouse seasonal habitat-use. To evaluate effectiveness of conifer reduction treatments I used fecal pellet and in concert with radio-telemetry data. Increased sage-grouse use of conifer treatments was positively associated with sage-grouse presence in adjacent habitats (P = 0.018), percent shrub cover (P = 0.039), and mesic environments within 1000 m of treatments (P = 0.048). Sage-grouse use of conifer treatments was negatively associated with conifer canopy cover (P = 0.048) within 1000 m of treatments. To investigate sample bias related to individual bird behavior or capture trauma I monitored 204 radio-marked sage-grouse within the West Box Elder and Rich-Morgan- Summit SGMAs in Utah between January 2012 and March 2013. Sage-grouse that flushed one or more times prior to capture had higher brood (P = 0.014) and annual survival (P = 0.027) than those that did not. Sage-grouse that experienced more capture trauma had decreased annual survival probabilities (P = 0.04).
The greater sage-grouse (Centrocercus urophasianus; sage-grouse) is a species of conservation concern that occupies sagebrush-dominated (Artemisia spp.) landscapes across the western United States and southern Canada. The U. S. Fish and Wildlife Service (USFWS) reviewed the status of the sage-grouse in September 2015 and determined that it did not warrant protection under the Endangered Species Act due to collaborative efforts between numerous public and private stakeholders. However, this decision hinged on federal and state commitments to continue science-based management of sagebrush habitats. As human development increases across the west, there is an increasing need for understanding the impacts of disturbance on sage-grouse. Filling this knowledge gap is important because it will allow us to predict how sage-grouse populations may respond to changes in the future. I assessed how two types of disturbance (wildfire and transmission line construction) influenced habitat use of a population of sage-grouse in southern Utah. I deployed Global Positioning System (GPS) transmitters on 26 (21 male and 5 female) sage-grouse in the Bald Hills Sage-Grouse Management Area in 2014 and 2015 to record what habitat sage-grouse were using during the summer and winter seasons. I compared these used locations to habitat that was seasonally available to the birds using resource selection functions. My models showed that in the summer, birds showed preference for areas burned and reclaimed within the last 10 years. I suggest that this may be occurring because the birds are seeking out vegetation that was seeded by the Bureau of Land Management (BLM) during wildfire reclamation. In the winter, my models showed an overall 3% decrease in predicted probability of use for winter habitat in the vicinity of the transmission line corridor, but this change did not immediately result in increased avoidance by sage-grouse when comparing spatial distributions for sage-grouse locations within winter habitat near the transmission line. I suggest that this is because the new transmission line was paired with a preexisting line which was already avoided by sage-grouse. However, the construction of the new line could have long-term consequences outside the two year scope of my study. These impacts could be delayed because sage-grouse are strongly tied to historic habitats and may not change habitat use immediately in spite of landscape changes. Additionally, the presence of the new line could cause indirect landscape changes which may only manifest over longer time periods such as increasing human activity in the area or changing the distribution of avian predators of sage-grouse that use the transmission line for perching. I recommend continued monitoring of sage-grouse in the area to determine if any changes in habitat use manifest in future years.
Admired for its elaborate breeding displays and treasured as a game bird, the Greater Sage-Grouse is a charismatic symbol of the broad open spaces in western North America. Unfortunately these birds have declined across much of their range—which stretches across 11 western states and reaches into Canada—mostly due to loss of critical sagebrush habitat. Today the Greater Sage-Grouse is at the center of a complex conservation challenge. This multifaceted volume, an important foundation for developing conservation strategies and actions, provides a comprehensive synthesis of scientific information on the biology and ecology of the Greater Sage-Grouse. Bringing together the experience of thirty-eight researchers, it describes the bird’s population trends, its sagebrush habitat, and potential limitations to conservation, including the effects of rangeland fire, climate change, invasive plants, disease, and land uses such as energy development, grazing, and agriculture.
Winter in temperate zones often represents a period of greatest energetic demand for vertebrate species. Animals respond to seasonal scarcity through behavioral strategies such as migration and selecting specific habitats characteristics to maximize resource acquisition and/or minimize energy expenditures. Migration or differential habitat use in winter can complicate goals of defining and conserving core habitat for species across increasingly fragmented landscapes. Greater sage-grouse (Centrocercus urophasianus, hereafter “sage-grouse”) is a species of conservation concern endemic to sagebrush (Artemisia spp.) steppe whose populations are most threatened by anthropogenic disturbance and concomitant degradation to sagebrush communities. Conservation of sage-grouse habitat is complicated by a partially-migratory annual cycle in most populations. Seasonal ranges (spring, summer/fall, and winter) may be integrated to any degree or non-overlapping. Efforts to conserve core habitat for sage-grouse have focused primarily on breeding ranges, which may not capture the needs of sage-grouse during other seasons, with winter habitat being least protected. Greater understanding of winter habitat requirements is needed to improve conservation for sage-grouse throughout their annual cycle. My thesis focused on multi-scale winter habitat ecology of greater sage-grouse (Centrocercus urophasianus) in the Red Desert of southcentral Wyoming, using GPS location data from winters 2018/2019, 2019/2020, and 2020/2021. My research encompassed a 1) landscape-scale validation of management guidelines for winter concentration areas as the second phase to a state-wide analysis, 2) habitat selection and behavior within home- and population-range scales as influenced by winter weather conditions, and 3) a fine-scale evaluation of microhabitat within home- and population-range scales during winter 2020/2021. My results support consideration of winter habitats in conservation plans for sage-grouse populations in rapidly changing landscapes. In Chapter 1, I conducted a systematic review of literature published in the last 46 years (1977–2022) on sage-grouse winter habitat selection and survival. Out of 32 compiled publications, I found that 59.4% of sage-grouse winter habitat literature was published in the last 10 years (2013–2022) and 53.1% of articles over the last 46 years reported avoidance of anthropogenic disturbance by sage-grouse during winter. The most recent recommendations for defining year-round priority habitat for sage-grouse recommend implementation of resource selection modeling for all seasonal periods. In Chapter 2, my research fulfilled the second phase of a larger effort to answer questions posed by the Wyoming Sage-Grouse Implementation Team, through the Winter Concentration Area Subcommittee, regarding sage-grouse winter habitat selection and response to anthropogenic disturbance. Phase 1 used existing datasets of sage-grouse GPS locations from 6 regions across Wyoming to model winter habitat selection and avoidance patterns of disturbance statewide. Results from Phase I formed the basis for developing recommendations for management of sage-grouse winter concentration areas in Wyoming. The purpose of my research in Chapter 2 was to validate results of Phase I modeling and evaluate if the statewide model accurately described sage-grouse winter habitat selection and anthropogenic avoidance in regions not considered in that modeling effort. I used 44,968 locations from 90 individual adult female grouse identified within winter habitat from winters 2018/2019, 2019/2020, and 2020/2021 in the Southern Red Desert region (my study area) for out-of-sample validation. The intent of my validations was to assess if models generated statewide or from a nearby region (Northern Red Desert) would be more effective in predicting sage-grouse habitat selection patterns in areas with little information. The statewide model better predicted sage-grouse habitat use at within-population scales and the near-region model was more predictive at within-home-range scales. I found some variation between regions and the statewide model but similar trends in environmental characteristics and avoidance of anthropogenic features even at low densities. My results from the Southern Red Desert support the recommendation from Phase 1 that anthropogenic surface disturbance should be limited to low levels (≤ 2.5%) within winter concentration areas to conserve sage-grouse winter habitat. In Chapter 3, my research focused on shifting environmental conditions that influence patterns of sage-grouse winter habitat selection. Sage-grouse are physically well adapted to winter conditions; it’s a common assumption that winter weather has little effect on sage-grouse. However, research results have varied in support of this assumption, with significant die-offs correlated to periods of extreme winter weather. My research used daily winter weather conditions to explain sage-grouse winter behavior and habitat selection. I used sage-grouse GPS locations from the Southern Red Desert over winters 2018/2019 and 2019/2020 and obtained local weather conditions for each winter from SnowModel. SnowModel used available meteorological data, landscape characteristics, and snow physics to predict weather conditions at a 30-m resolution and daily scale. By comparing habitat selection and behavior across fine temporal scales, I found that sage-grouse responded to daily weather conditions by selecting refugia habitat more than altering daily activity levels. My results suggest that, in addition to landscape features, sage-grouse selected home ranges at the population scale for warmer wind chill temperatures and greater windspeed. Within home ranges, sage-grouse appeared to respond to harsher weather (lower wind chill temperature and high wind speeds) by selecting greater sagebrush cover and leeward sides of ridges. Our research underlines the importance of examining winter habitat at narrower temporal scales than the entire winter season to identify important refugia features that may only be used periodically. Additional research into quantifying weather refugia for wintering sage-grouse populations may provide greater insight to the future sustainability of winter ranges. In Appendix A, I compared winter microhabitat characteristics at 90 sage-grouse use sites from the 2019/2020 winter with 90 available sites within the population range and 90 available sites within home ranges. I predicted habitat characteristics at grouse use locations would be more similar to paired random locations within the home range than to random locations within the population range. I also predicted that, because sage-grouse select specific habitat characteristics, there would be fewer differences when comparing random available locations between the home and population range than comparisons of used and available habitat. I found no support for my first prediction and strong support for my second prediction. Sage-grouse dung piles were 7.0- and 9.9-times higher at used locations than random locations within home and population ranges, respectively. Our results suggested that sage-grouse are highly selective for microhabitat. Sage-grouse selected areas with higher big sagebrush (Artemisia spp.) and overall canopy cover, big sagebrush height, and visual obstruction compared to random locations within home and population ranges. Our results indicate concealment cover is important to sage-grouse throughout their annual cycle.
"This Technical Note is primarily a review of literature on the fundamental habitat requirements of sage grouse and habitat management methods that may be used to perpetuate the species. It does not reiterate the life history, past distribution, species characteristics, and population dynamics"--Page 1.
