South-central Wyoming Research Articles

Survival of juvenile greater sage‐grouse in Wyoming

An understanding of vital rate contributions to population growth is necessary for species of conservation concern, such as greater sage‐grouse Centrocercus urophasianus. Sage‐grouse demographic rates are generally well described; however, a notable exception is juvenile survival during the post‐fledging period. We evaluated juvenile survival at two study areas in central and south–central Wyoming. We captured and monitored 124 juvenile sage‐grouse (77 females and 47 males) in 2017–2019 in the central Wyoming study area and 68 (29 females and 39 males) in 2020–2021 in the south–central Wyoming study area. Monthly survival generally increased from September to March in each year and study area. In both study areas, we found no evidence that monthly mortality risk differed between male and female juvenile sage‐grouse. In central Wyoming, seven‐month survival estimates from September to March were 0.28 (85% CI: 0.18–0.44) from 2017–2018, 0.28 (85% CI: 0.20–0.39) from 2018–2019, and 0.43 (85% CI: 0.34–0.55) from 2019–2020. In south‐central Wyoming, survival estimates were 0.34 (85% CI: 0.25–0.47) from 2020–2021 and 0.78 (85% CI: 0.68–0.90) from 2021–2022. Overall, we found evidence that body condition at time of capture and weather (temperature and precipitation) during the pre‐fledging period influenced juvenile mortality risk, but the most supported intrinsic and extrinsic factors varied between study areas. Our results provide additional estimates of juvenile survival that will be useful for understanding sage‐grouse demography. However, the spatial and temporal variation in juvenile survival that we documented should be accounted for when evaluating how management actions may influence sage‐grouse populations.

Diet selection, commonness, and rarity in a pair of smooth-toothed pocket gophers

Abstract Understanding the determinants of species rarity is a perennial challenge for ecologists and conservation biologists. In addition to resource specialization, competitive interactions may limit the abundance and distribution of species, thereby accentuating rarity. However, resource partitioning can reduce or altogether offset such competitive effects, and thus permit species to thrive alongside more common, widespread competitors within a narrow range of environmental conditions. In south-central Wyoming, the Wyoming Pocket Gopher (Thomomys clusius) is restricted to areas dominated by Gardner’s Saltbush (Atriplex gardneri); it inhabits a geographic range that is entirely encompassed by a relatively abundant and widespread congener (T. talpoides, the Northern Pocket Gopher). However, the consumer–resource dynamics underlying the relationships among Wyoming pocket gophers, northern pocket gophers, and Gardner’s Saltbush are poorly understood. We assessed one dimension of consumer–resource interactions—diet selection—between Wyoming pocket gophers, northern pocket gophers, and Gardner’s Saltbush, using a combination of path analysis, DNA metabarcoding, and cafeteria-style feeding experiments. We rejected the null hypothesis that Wyoming pocket gophers and Gardner’s Saltbush co-occur solely because they require similar soil conditions. Although we could not distinguish between obligate and facultative specialization by Wyoming pocket gophers, the checkerboard-like distributions of these two Thomomys likely reflect the outcome of selection and avoidance of Gardner’s Saltbush. We suggest that Wyoming pocket gophers can persist within their small geographic range by capitalizing on Gardner’s Saltbush, a halophyte that probably requires some combination of physiological, morphological, and behavioral adaptations to exploit. Low abundances, restricted geographic ranges, or both are hallmarks of rarity, each of which are shaped by diet selection and other consumer–resource interactions. Quantifying consumer–resource interactions can therefore provide a mechanistic basis for the further refinement and testing of hypotheses on the abundance and distribution of closely related species.

Wind-energy development alters pronghorn migration at multiple scales.

Migration is a critical behavioral strategy necessary for population persistence and ecosystem functioning, but migration routes have been increasingly disrupted by anthropogenic activities, including energy development. Wind energy is the world's fastest growing source of electricity and represents an important alternative to hydrocarbon extraction, but its effects on migratory species beyond birds and bats are not well understood. We evaluated the effects of wind-energy development on pronghorn migration, including behavior and habitat selection, to assess potential effects on connectivity and other functional benefits including stopovers. We monitored GPS-collared female pronghorn from 2010 to 2012 and 2018 to 2020 in south-central Wyoming, USA, an area with multiple wind-energy facilities in various stages of development and operation. Across all time periods, we collected 286 migration sequences from 117 individuals, including 121 spring migrations, 123 fall migrations, and 42 facultative winter migrations. While individuals continued to migrate through wind-energy facilities, pronghorn made important behavioral adjustments relative to turbines during migration. These included avoiding turbines when selecting stopover sites in spring and winter, selecting areas farther from turbines at a small scale in spring and winter, moving more quickly near turbines in spring (although pronghorn moved more slowly near turbines in the fall), and reducing fidelity to migration routes relative to wind turbines under construction in both spring and fall. For example, an increase in distance to turbine from 0 to 1 km translated to a 33% and 300% increase in the relative probability of selection for stopover sites in spring and winter, respectively. The behavioral adjustments pronghorn made relative to wind turbines could reduce the functional benefits of their migration, such as foraging success or the availability of specific routes, over the long term.

14 Effect of Pulmonary Arterial Pressure and Precipitation Interaction on Reproductive Performance in Angus Heifers in South Central Wyoming

Abstract Variable precipitation in the western United States impacts forage availability, potentially influencing fertility. Furthermore, producers located above 1,500 meters contend with high altitude disease (HAD) due to reduced atmospheric oxygen, potentially resulting in right sided heart failure. Pulmonary arterial pressure (PAP) score is an indicator trait of HAD. The physiological stress of elevated PAP score could compound environmental stress, such as variable precipitation. Thus, the objective of this study was to investigate the interaction of precipitation and PAP score on beef heifer fertility. Data for this study were sourced from the Colorado State University Beef Improvement Center (CSU-BIC; 1993-2019; n = 3,834; 2,150 to 2,411 m elevation) near Saratoga, Wyoming. Records included identification, birth year, yearling year, yearling weight (YW), PAP, first service conception (FSC), overall heifer pregnancy (HPG) and sire. Precipitation data were sourced from the National Oceanic and Atmospheric Administration. Three classifications were created: cumulative precipitation from birth to breeding, precipitation from heifer birth to weaning, and precipitation from heifer weaning to breeding. Initial models contained sources of variation of precipitation classification, PAP, YW and a PAP by precipitation classification interaction for the response of HPG and FSC. Logistical regression was executed followed by analysis of variance. Yearling weight was a predictor of FSC (P < 0.01) while weaning to breeding precipitation was a predictor for HPG (P < 0.05). In general, the PAP by precipitation interaction was not detected; however, PAP by weaning to breeding precipitation tended to predict HPG (P < 0.10). A favorable, positive relationship was detected between YW and FSC (bi=0.00120 to 00120 to 0.00124; P < 0.01). A favorable, positive relationship also existed between weaning to breeding precipitation and HPG (bi=0.2528, P < 0.05). Those results suggested that increased precipitation during the development period from weaning to breeding was advantageous to HPG. The results also provided evidence to suggest that precipitation and PAP may interact to influence breeding success. Thus, we conclude that increased precipitation during the weaning to breeding period appears advantageous to overall breeding success of Angus heifers in a high-altitude production system.

Effect of pulmonary arterial pressure and annual precipitation on reproductive performance of Angus heifers in south central Wyoming

Effect of pulmonary arterial pressure and annual precipitation on reproductive performance of Angus heifers in south central Wyoming

Magnetostratigraphy of lower Paleocene strata in the Ferris Formation, Hanna Basin, Wyoming, with refined resolution of the Pu1–Pu2 interval-zone boundary of the Puercan North American Land Mammal Age

ABSTRACT Recent studies of early Paleocene stratigraphic sections across the U.S. Western Interior are refining our understanding of the biotic recovery in the aftermath of the Cretaceous–Paleogene (K–Pg) mass extinction event. Herein we present magnetostratigraphic data from an approximately 600-m-thick section of strata of the Ferris Formation in the Hanna Basin, south-central Wyoming, that spans the K–Pg boundary and includes in conformable superposition the three subdivisions of the earliest Paleocene Puercan North American Land Mammal Age: interval zones Pu1, Pu2, and Pu3. Prior studies on early Paleocene stratigraphic sections in Montana to the north of Hanna Basin and in Colorado and New Mexico to the south have been only marginally successful in defining the temporal boundaries of these divisions. This earlier work typically restricted Pu1 entirely within reversed magnetochron C29r, Pu2 entirely within normal magnetochron C29n, and at least the early part of Pu3 in C29n, as well. Results of the present study confirm what has been only tentatively suggested previously: that interval zone Pu2 begins in the youngest part of C29r, with later Pu2 fauna extending into C29n. Although Pu3 is known to begin in C29n, its younger limit remains unknown in our Hanna Basin section, because the top of the local Puercan is well above the stratigraphic level of our sampling for this project. We estimate a date for the Pu1–Pu2 boundary in the Hanna Basin section of approximately 65.82 Ma—nearly 70 k.y. earlier than prior estimates. This boundary marks the transition from the Pu1 survival fauna to later phases of the mammalian recovery characterized by a significant increase in diversity, appearance of considerably larger-bodied mammals, and greater dental and dietary specializations.

Variation in sage-grouse habitat quality metrics across a gradient of feral horse use

Feral horse (Equus ferus caballus) grazing can alter arid shrubland habitat in the western United States to the detriment of sympatric wildlife species, including the greater sage-grouse (Centrocercus urophasianus). To date, studies of horse-influenced habitat alteration have only occurred in a few locations and have infrequently represented gradients of horse use. We investigated whether greater sage-grouse habitat quality metrics were negatively associated with feral horse use in southcentral Wyoming, USA. We also tested whether utilization distributions generated from feral horses tracked with global position system transmitters were correlated with dung pile density, our index of horse use. Dung pile density did not vary among utilization distribution levels, indicating utilization distributions were a poor predictor of cumulative horse use. Bare ground increased with dung pile density (β = 0.06, 85% CI = 0.04–0.18), and grass height exhibited a threshold response and began to decline after 638 piles/ha. Other habitat metrics including percent shrub cover, native perennial grass cover, and visual obstruction were better explained by topographic and temporal variation. Our results suggest that herd size reduction may limit soil erosion potential and improve desired herbaceous structure, though additional management actions regarding feral horse use are needed to sustain high-quality greater sage-grouse habitat.

PSI-32 Effect of pulmonary arterial pressure on reproductive performance in Angus heifers located in south central Wyoming

Abstract Pulmonary hypertension (i.e., high altitude disease) occurs in locations above 1,600 m in elevation and causes heart failure and death. Pulmonary arterial pressure scoring is an effective indicator of pulmonary hypertension and high-altitude disease. The objective of this study was to look at the effect of pulmonary arterial pressure (PAP) scoring on reproductive performance in Angus heifers. First service conception (FSC), pregnancy rate, and pulmonary arterial pressure scores were obtained from the Colorado State University Beef Improvement Center for 2,503 Angus heifers between 1995 and 2016. All spring-calving females were exposed to estrous synchronization and one-round of artificial insemination. After a 10-d holding period heifers were exposed to natural service sires for 60 days. First service conception and pregnancy rate traits were determined using ultrasonography via rectal palpation at 30 and 60 days post artificial insemination. Pulmonary arterial pressure scores were collected at ~12 mos of age. Data were analyzed with ANOVA as a completely randomized block design, blocking by birth year. Fixed effect was pulmonary arterial pressure group [high (>42mm Hg) vs. low (<42 mmHg)]. Logistic regression was used to further investigate fertility traits with PAP scores. Nodifferences were detected among pulmonary arterial pressure group for first service conception (P > 0.05); however, high pulmonary arterial pressure heifers had lower pregnancy rates compared to low PAP heifers (0.86 vs. 0.91 ± 0.01; P = 0.03). Logistic regression supported these findings, identifying PAP score as a significant predictor of breeding season pregnancy rate (P < 0.05), indicating an inverse relationship between PAP score and pregnancy rate. Cumulatively, results show an unfavorable relationship between heifers with high pulmonary arterial pressure scores and overall pregnancy rate.

Large Scaphitid Ammonites (Hoploscaphites) from the Upper Cretaceous (Upper Campanian–Lower Maastrichtian) of North America: Endless Variation on a Single Theme

We describe three species of large scaphitid ammonites (Ammonoidea: Ancyloceratina) from the Upper Cretaceous (upper Campanian–lower Maastrichtian) of the Western Interior of North America. Each species occurs as two dimorphs, referred to as macroconch and microconch. All three species share a similar pattern of ornamentation consisting of long, thin, nonbifurcating ribs on the adoral part of the phragmocone, suggesting that they constitute a single monophyletic clade. Macroconchs of Hoploscaphites crassus (Coryell and Salmon, 1934) are characterized by a globose whorl section, with closely spaced ventrolateral tubercles on the body chamber, usually persisting to the aperture. Macroconchs of Hoploscaphites plenus (Meek and Hayden, 1860) differ from those of H. crassus in having a more subquadrate whorl section with flatter flanks, and fewer, larger, and more widely spaced ventrolateral tubercles. Macroconchs of Hoploscaphites peterseni, n. sp., closely resemble those of H. crassus, but differ in being nearly circular in side view with a more compressed whorl section. All three species lived at approximately the same time in the same general area and depositional environment. They are abundant in the Baculites baculus Zone but also occasionally occur in the B. eliasi Zone and possibly lower part of the B. grandis Zone. They are present in the Pierre Shale of east-central Montana and east-central Wyoming, the Lewis Shale of south-central Wyoming, and the Bearpaw Shale of northeast Montana. It is possible that these three species represent subspecies within a single species or a “flock” of very closely related species, similar to the “species flocks” observed in modern cichlid fishes.

A New Sciuravid Rodent (Mammalia) from the Early Eocene (Bridgerian) and the Sciuravid-Eomyid Transition

A new genus and species of sciuravid rodent, Perasciuravus mcintoshi, is named from the late Bridgerian (early Eocene) of the Washakie Formation, southcentral Wyoming. The most distinguishing characters of the species (and genus) are that it retains the primitive condition of the zygomasseteric structure for rodents, characteristic of sciuravids, but has a more specialized dental morphology of the cheek teeth (complete ectolophids and hypolophids on the lower molars; complete metalophs and protolophs on the upper molars) typical of the later-occurring family of geomyoid rodents, the Eomyidae. Perasciuravus is viewed as morphologically transitional between the Sciuravidae and the Eomyidae. Its occurrence also overlaps the temporal range of the Sciuravidae (Wasatchian [early Eocene] to Duchesnean [early-late Eocene]) and predates the first occurrence of the Eomyidae (Uintan [middle Eocene]).

New material of fossil rodents (Mammalia) from the Eocene (Bridgerian-Uintan) Washakie Formation, southcentral Wyoming

Eight species of rodents are described based on previously unreported fossil material from the early Eocene Adobe Town Member of the Washakie Formation of Wyoming. Among these are two new species: the sciuravid Pauromys turnbulli and the cylindrodont Pareumys flynni. The overall rodent fauna consists of twelve species. The greatest change in the rodent fauna is between the lower and middle units of the Adobe Town Member; six species having their last occurrence in the lower unit and three species having their first occurrence in the middle unit. This coincides with the boundary of the Bridgerian and Uintan North American Land Mammal Ages.

Pronghorn Winter Resource Selection Before and After Wind Energy Development in South-Central Wyoming

Few studies have evaluated the response of ungulate populations to wind energy development. Recent demand for wind-generated electricity coupled with a tendency for wind-energy facilities to be sited within suitable pronghorn (Antilocapra americana) winter range make this a critical issue for conservation of this icon of western North America. We evaluated pronghorn response to wind energy development at the winter home range scale, as well as within individual winter home ranges using data collected from 47 adult female pronghorn equipped with Global Positioning System transmitters. At both scales, we developed separate resource selection models for pronghorn before (winter 2010) and after (winters 2011 and 2012) development of the Dunlap Ranch wind energy facility in south-central Wyoming to evaluate the potential impacts of wind energy infrastructure on pronghorn winter resource selection. In general, pronghorn winter resource selection was correlated with greater sagebrush (Artemisia spp.) cover, lower snow depth, and lower slopes before and after wind energy development at both scales. At the larger scale, pronghorn selected home ranges closer to wind turbines during all winters. Within home ranges, pronghorn selected areas closer to future locations of wind turbines at Dunlap Ranch during 2010 before turbine erection. However, we found evidence that pronghorn avoided wind turbines in winters after development within their winter home ranges. This relationship was most evident during winter 2011, which coincided with the most severe winter of our study. Long-term replicated studies will be necessary to make inferences for pronghorn populations exposed to wind energy development in different environments and scales than we evaluated. Nonetheless, in the absence of additional information on how ungulates respond to wind energy development, our finding that pronghorn avoided wind turbines within their winter home ranges has important implications for future wind development projects, particularly in areas known to fulfill important seasonal requirements of pronghorn populations.

Go West Young Mensch! The Rise and Decline of the Jewish Community of Carbon County, Wyoming (U.S.A.)

Carbon County is a remote, sparsely-populated region of high desert located in south-central Wyoming, U.S.A. Bifurcated by the Union Pacific railway, the county’s economy has long relied upon attracting a labor force from near and far in order to prosper. For a brief period from about 1880-1980, a small yet significant part of that population was comprised of Jewish immigrants from Russia and Eastern Europe.This study discusses the unique history of the Jewish migration to the Wyoming Territory that occurred just prior to and following statehood (1890). Using primary documentation including census logs, military records, and genealogical data, several case studies are presented of individual Jewish immigrants as well as entire families that left their homes in Europe only to eventually make their homes in Rawlins and neighboring communities of Carbon County. It is seen that, by and large, the randomly-chosen life experiences discussed largely parallel those of the county at large, both shaping and being shaped by broader communal developments. The study concludes by addressing the question of why, after 100 years of successful participation in the life of the county’s economic growth, the Jews departed wholesale, leaving barely a trace behind.

Gypsum, langbeinite, sulfur, and compost for reclamation of drastically disturbed calcareous saline–sodic soils

Soil disturbance during arid region energy development often redistributes subsurface salts, including sodium (Na), to the surface. Elevated Na degrades soil structure and inhibits germination and establishment of native plants important for ecosystem functions. Strategies for rapid reclamation of thin surface horizons are needed. Study objectives were to evaluate chemical amendments and compost for remediation of saline–sodic soils on a well pad that had electrical conductivity (EC) of 8.7 dS m−1 and exchangeable sodium percentage of 38.6% following reclamation practices in south-central Wyoming. Eight treatments applied in October 2012 included gypsum, langbeinite, and elemental sulfur (S) with and without compost, plus compost alone, and an untreated control. Plots were sampled four times over 1 year at depths of 0–3, 3–8, and 8–15 cm. Samples were analyzed for exchangeable plus solution concentrations of Na, calcium (Ca), magnesium (Mg), and potassium (K). Results indicate that Na was leached from surface soils in all the treatments and the untreated control. Langbeinite most effectively enhanced movement of Na and caused initial increases in salinity that abated within 1 year. Gypsum enhanced movement of Na to lesser degree, and movement under S and compost was equivalent to untreated controls. Added compost did not affect activity of langbeinite, gypsum, or S. Langbeinite effectively reduced sodicity, but high cost and initial increases in soil salinity warrant additional investigation of appropriate application rates and alternative management practices, such as delaying planting until high-salinity abates.

Stock raising and winter sheep camps in south-central Wyoming (1880–1957): An ethnoarchaeological example

Winter sheep camp locations on one ranch in south-central Wyoming are strongly influenced by particular landscape and topographic attributes. A patterned distribution of camps is suggested from both archaeological and ethnohistoric evidence. Sheep camps are one of the most ubiquitous archaeological sites in the region and offer valuable insights into the transhumant settlement pattern of the nineteenth and early twentieth century sheep industry. Our knowledge of this site type owes much to the growth of Cultural Resource Management over the last 40 years. The present study incorporates both participant interviews and Cultural Resource Management archaeology to offer a testable model for site location and content on sheep range in Carbon County, Wyoming.

Seed bank dynamics of blowout penstemon in relation to local patterns of sand movement on the Ferris Dunes, south-central Wyoming

Plants restricted to active sand dunes possess traits that enable both survival in a harsh environment and local migration in response to a shifting habitat mosaic. We examined seed bank dynamics of Penstemon haydenii S. Watson (blowout penstemon) in relation to local sand movement. We measured within-year sand movement along a 400 m transect and examined plant density, seed production, and seed density in relation to this movement. Plant densities were highest in areas of moderate sand movement. Annual seed rain averaged 13 seeds·m−2, whereas persistent seed bank density (0–10 cm depth) averaged only 0.1 seeds·m−2. A laboratory burial experiment with nondormant (chilled) seeds showed that most deeply buried seeds (>6 cm) were held in enforced dormancy under spring conditions, while seeds at intermediate depths (4–6 cm) were induced into secondary dormancy that was broken by subsequent drying and re-chilling, thus promoting seed carryover until the following spring. Most near-surface seeds produced seedlings. Enforced and secondary dormancy provide mechanisms for maintaining a persistent seed bank of more deeply buried seeds that could become part of the active seed bank as sand movement re-exposes them near the surface. This could facilitate both population persistence and migration as previously occupied habitat becomes unsuitable.

Winter Habitat Associations for Spotted Skunks (Spilogale spp) in South-Central Wyoming

Abstract Long-term trends suggest the eastern spotted skunk (Spilogale putorius) experienced a significant decrease in populations throughout the distribution of the species, necessitating development of range-wide management and conservation strategies. However, information on the basic ecology for both S. putorius and the western spotted skunk (S. gracilis) is lacking especially in regions where the distribution of these two species is predicted to converge. We evaluated habitat associations for spotted skunks in an occupancy modeling framework within the foothill transitional habitat of south-central Wyoming during–December 2014. We found occurrence of spotted skunks was positively associated with rocky outcroppings (β = 2.51, se = 1.11, 95% ci = 0.34–4.68, P-value = 0.02). During late-fall and winter, rocky outcropping may represent an important habitat requirement of spotted skunks in this region.

A Reassessment of the Distribution of Virginia’s Warbler in the Black Hills of South Dakota

virginia’s Warbler (Oreothlypis virginiae) reaches the northeastern limit of its breeding range in the southern Black Hills of South Dakota, where it is considered a species of conservation concern. this population occurs in pine–juniper–shrub habitat in several canyons in extreme western Custer County. additional such habitat occurs in the southern Black Hills south and east of the documented breeding populations, but these areas have received few systematic surveys, and whether virginia’s Warbler occupies them was uncertain. therefore, to define the species’ distribution in the South Dakota Black Hills more precisely, we surveyed with the aid of broadcast song and reviewed other reports. virginia’s Warblers occurred in appropriate habitats all along the southwestern front (approximately 30 km total) of the Black Hills in Custer County but did not occur in similar habitat along the southeastern front, approximately 25 km distant. the species’ relative abundance in previously and newly identified pine–juniper–shrub habitats was similar. virginia’s Warbler occurrence was positively associated with shrub cover (primarily mountain-mahogany, Cercocarpus montanus), pine overstory, and slopes of >15°. its association with the Spotted towhee (Pipilo maculatus) was negative, with the yellow-rumped Warbler (Setophaga coronata) tended toward positive, and with the Dusky flycatcher (Empidonax oberholseri) was variable (negative along the southwestern front but weakly positive across all sites). these data extend the documented breeding range of virginia’s Warbler in South Dakota by more than 20 km to the southeast. to clarify conservation priorities for this species at the northeastern limit of its range, future studies should delineate local and landscape-level characteristics of this population’s habitat more precisely and address its source–sink population dynamics. virginia’s Warbler (Oreothlypis virginiae) nests widely in mountainous regions of southwestern north america from southeastern idaho and southwestern Wyoming into southern arizona, new Mexico, and western texas (olson and Martin 1999). the species’ northeasternmost population is isolated in the southwestern Black Hills of South Dakota, separated by over 200 km from the next nearest breeding population in south-central Wyoming (Swanson et al. 2000). Breeding habitat occurs on mountain slopes and consists of dense, shrubby vegetation with taller plants interspersed or nearby (olson and Martin 1999). in various portions of the breeding range the shrubby vegetation may include chokecherry (Prunus virginiana), snowberry (Symphoricarpos spp.), currant (Ribes spp.), serviceberry (Amelanchier spp.), manzanita (Arctostaphylos spp.), scrub oak (Quercus gambelii), or mountain-mahogany (Cercocarpus montanus) (olson and Martin 1999). the taller vegetation may consist of pinyon pine (Pinus spp.), juniper (Juniperus spp.), ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii), taller scrub oak, or aspen (Populus tremuloides) (olson and Martin 1999). virginia’s Warbler was first definitively recorded in South Dakota in 1997,

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.

Identification of Columbian Sharp-Tailed Grouse Lek Sites in South Central Wyoming

The Columbian Sharp-tailed Grouse (Tympanuchus phasianellus columbianus; hereafter CSTG) occupies approximately 10% of its historic range and is a species of conservation concern in 7 U.S. states and British Columbia. Because little is known about the status of CSTG in Wyoming, we sought to model the relative probability of lek site occurrence within the known distribution of CSTG in the state to identify areas that contained previously undocumented lek sites. The proximity of nesting and brood-rearing habitats to leks advocates their use as a focus of conservation for prairie grouse, including CSTG. We modeled a resource selection function (RSF) to identify areas that were predicted to have a high probability of lek occurrence. In areas identified by the RSF, we searched for leks by conducting ground surveys and surveys from a fixed-wing airplane using aerial infrared (AIR) technology. We identified 6 previously undocumented CSTG leks through ground searches and 4 previously undocumented Greater Sage-Grouse (Centrocercus urophasianus) leks through AIR searches. Newly identified leks represented a 22% increase in the number of known CSTG leks in south central Wyoming. Our method not only improved knowledge of CSTG status in Wyoming, but may also improve identification of unknown lek sites and conservation of lekking habitat and additional reproductive habitats for prairie grouse species in other western states and provinces.