| Characterization of small microsatellite loci for use in non invasive sampling studies of Gunnison Sage-grouse (Centrocercus minimus) | Oyler-McCance, Sara J. | 2010 |
KeywordsCentrocercus minimus, Gunnison sage-grouse, microsatellite, non invasive sampling AbstractPrimers for 10 microsatellite loci were developed specifically to amplify low quantity and quality DNA for Gunnison Sage-grouse (Centrocercus minimus), a species that has been petitioned for listing under the US Endangered Species Act. In a screen of 20 individuals from the largest population in the Gunnison Basin, Colorado, the 10 loci were found to have levels of variability ranging from two to seven alleles. No loci were found to be linked, although one locus revealed significant departures from Hardy-Weinberg equilibrium. These microsatellite loci will be applicable for population genetic analyses and for use in mark recapture studies that utilize DNA collected non invasively from feathers and fecal pellets, which will ultimately aid in management efforts. AuthorsOyler-McCance, Sara J.; St John, Judy Year Published2010 PublicationConservation Genetics Resources LocationsDOI10.1007/s12686-009-9122-8 |
| Cheilospirura centrocerci, a New Nematode from the Sage Grouse Centrocercus urophasianus | SIMON, FELIX | 1939 |
KeywordsNo keywords available AbstractNo abstract available AuthorsSIMON, FELIX Year Published1939 PublicationTransactions of The American Microscopical Society LocationsDOI10.2307/3222651 |
| Collection and comparison of natural ejaculates and sperm morphometrics of greater (Centrocercus urophasianus) and gunnison sage-grouse (C. minimus). | Hicks, Tyler L. | 2011 |
Collection and comparison of natural ejaculates and sperm morphometrics of greater (Centrocercus urophasianus) and gunnison sage-grouse (C. minimus).KeywordsNo keywords available AbstractIn spring 2008, we collected four natural ejaculates from strutting male Greater (Galliformes: Centrocercus urophasianus) and Gunnison Sage-Grouse (C. minimus) in Colorado, USA by placing freeze-dried female Greater Sage-Grouse on leks in the soliciting pre-copulatory position and fitting them with false cloacas. We compared between species the sperm concentrations, the percentage of viable sperm, the types and predominance of normal and abnormal sperm in ejaculate samples, and sperm morphometric traits. In addition, we compared sperm concentration and morphometry of both species with other species of Galliformes. Notwithstanding our small sample size, ejaculate characteristics were similar among individuals and between the two grouse species. Total length did not differ substantially between the two species. However, we found that Greater Sage-Grouse possess sperm heads that averaged 10% longer than those of Gunnison Sage-Grouse and Gunnison Sage-Grouse possess sperm tails that averaged 10% longer than those of Greater Sage-Grouse. Total sperm length in both species is among the smallest known for Galliformes. Compared to other Galliformes, sperm concentration was low for Gunnison Sage-Grouse and average for Greater Sage-Grouse. AuthorsHicks, Tyler L.; Magee, Patrick A. Year Published2011 PublicationColorado Birds Locations |
| COMMON RAVEN ACTIVITY IN RELATION TO LAND USE IN WESTERN WYOMING: IMPLICATIONS FOR GREATER SAGE-GROUSE REPRODUCTIVE SUCCESS | Bui, Thuy-Vy D. | 2010 |
Keywordsanthropogenic subsidies, Centrocercus urophasianus, Common Raven, Corvus corax, density and occupancy modeling, Greater Sage-Grouse, nest and brood predation. AbstractAnthropogenic changes in landscapes can favor generalist species adapted to human settlement, such as the Common Raven (Corvus corax), by providing new resources. Increased densities of predators can then negatively affect prey, especially rare or sensitive species. Jackson Hole and the upper Green River valley in western Wyoming are experiencing accelerated rates of human development due to tourism and natural gas development, respectively. Increased raven populations in these areas may negatively influence the Greater Sage-Grouse (Centrocercus urophasianus), a sensitive sagebrush specialist. We investigated landscape-level patterns in raven behavior and distribution and the correlation of the raven data with the grouse's reproductive success in western Wyoming. In our study areas towns provide ravens with supplemental food, water, and nest sites, leading to locally increased density but with apparently limited (< 3 km) movement by ravens from towns to adjacent areas of undeveloped sagebrush. Raven density and occupancy were greatest in land covers with frequent human activity. In sagebrush with little human activity, raven density near incubating and brooding sage-grouse was elevated slightly relative to that expected and observed in sagebrush not known to hold grouse. Raven occupancy near sage-grouse nests and broods was more highly correlated with sage-grouse success than were raven density and behavior, suggesting that the majority of nest predation by ravens is most likely carried out by resident territorial individuals. Integrated region-wide improvement of sagebrush habitat, removal of anthropogenic subsidies, and perhaps removal or aversive conditioning of offending ravens might benefit sage-grouse populations in our study area. AuthorsBui, Thuy-Vy D.; Marzluff, John M.; Bedrosian, Bryan Year Published2010 PublicationThe Condor: Ornithological Applications LocationsDOI10.1525/cond.2010.090132 |
| Comparing Ecological Site Descriptions to Habitat Characteristics Influencing Greater Sage-Grouse Nest Site Occurrence and Success | Doherty, Kevin E. | 2011 |
KeywordsCentrocercus urophasianus, landscape-scale habitat characteristics, local-scale habitat characteristics, nesting AbstractWe used 119 greater sage-grouse (Centrocercus urophasianus) nests located in the Powder River Basin of northeastern Wyoming during 2004-2007 to assess the ability of US Department of Agriculture Natural Resource Conservation Service (USDA-NRCS) ecological site descriptions (ESDs) to predict nest occurrence and success. We used nesting data from a regional study in the Powder River Basin that documented effects of local and landscape scale habitat characteristics on nest occurrence and success. We compared ESD metrics to these predictive local and landscape habitat variables where NRCS ESD field surveys overlapped our regional nest data set. We specifically asked three questions: 1) Are ESDs useful in predicting sage-grouse nest site occurrence and success as a univariate explanatory variable? 2) Can ESD information refine predictions of local scale nest site occurrence and success models? 3) Can ESD information refine landscape scale nest site occurrence models by serving as a surrogate for local scale information that cannot be mapped in a geographic information system (GIS)? Our results demonstrated that all models using ESD information were within +/- 2 Akaike's Information Criterion points of a constant only model (i.e., null model) for local-scale data, or a baseline model where local- and landscape-scale habitat metrics were held constant while allowing ESD models to compete for remaining variation. No ESD metrics were statistically significant at the 95% level (P < 0.05), although some were significant at the 80-90% level (P = 0.09-0.14). Our study does not support the use of ESDs to predict habitat use or base sage-grouse management decisions in the Powder River Basin, but in some instances the refutation was weak. Local and landscape based habitat metrics showed high discrimination between null models with highly significant relationships on the subset data. AuthorsDoherty, Kevin E.; Beck, Jeffrey L.; Naugle, David E. Year Published2011 PublicationRangeland Ecology & Management LocationsDOI10.2111/REM-D-10-00120.1 |
| COMPARISON OF SAGE AND SHARP-TAILED GROUSE LEKS IN SOUTH CENTRAL WYOMING | KLOTT, JH | 1989 |
COMPARISON OF SAGE AND SHARP-TAILED GROUSE LEKS IN SOUTH CENTRAL WYOMINGKeywordsNo keywords available AbstractNo abstract available AuthorsKLOTT, JH; LINDZEY, FG Year Published1989 PublicationGreat Basin Naturalist Locations |
| Comparison of Unmanned Aerial Vehicle Platforms for Assessing Vegetation Cover in Sagebrush Steppe Ecosystems | Breckenridge, Robert P. | 2011 |
Keywordsbare ground, fixed-wing, helicopter, landscape, monitoring, remote sensing AbstractIn this study, the use of unmanned aerial vehicles (UAVs) as a quick and safe method for monitoring biotic resources was evaluated. Vegetation cover and the amount of bare ground are important factors in understanding the sustainability of many ecosystems. Methods that improve speed and cost efficiency could greatly improve how biotic resources are monitored on western lands. Sagebrush steppe ecosystems provide important habitat for a variety of species including sage grouse and pygmy rabbit. Improved methods of monitoring these habitats are needed because not enough resource specialists or funds are available for comprehensive on-the-ground evaluations. In this project, two UAV platforms, fixed-wing and helicopter, were used to collect still-frame imagery to assess vegetation cover in sagebrush steppe ecosystems. This paper discusses the process for collecting and analyzing imagery from the UAVs to 1) estimate percentage of cover for six different vegetation types (shrub, dead shrub, grass, forb, litter, and bare ground) and 2) locate sage grouse using representative decoys. The field plots were located on the Idaho National Laboratory site west of Idaho Falls, Idaho, in areas with varying amounts and types of vegetation cover. A software program called SamplePoint was used along with visual inspection to evaluate percentage of cover for the six cover types. Results were compared against standard field measurements to assess accuracy. The comparison of fixed-wing and helicopter UAV technology against field estimates shows good agreement for the measurement of bare ground. This study shows that if a high degree of detail and data accuracy is desired, then a helicopter UAV may be a good platform to use. If the data collection objective is to assess broad-scale landscape level changes, then the collection of imagery with a fixed-wing system is probably more appropriate. AuthorsBreckenridge, Robert P.; Dakins, Maxine; Bunting, Stephen; Harbour, Jerry L.; White, Sera Year Published2011 PublicationRangeland Ecology & Management LocationsDOI10.2111/REM-D-10-00030.1 |
| Crucial nesting habitat for gunnison sage-grouse: A spatially explicit hierarchical approach | Aldridge, Cameron L. | 2012 |
KeywordsCentrocercus minimus; Colorado; extrapolation; Gunnison sage-grouse; habitat; hierarchical model; nesting; resource selection; sagebrush AbstractGunnison sage-grouse (Centrocercus minimus) is a species of special concern and is currently considered a candidate species under Endangered Species Act. Careful management is therefore required to ensure that suitable habitat is maintained, particularly because much of the species' current distribution is faced with exurban development pressures. We assessed hierarchical nest site selection patterns of Gunnison sage-grouse inhabiting the western portion of the Gunnison Basin, Colorado, USA, at multiple spatial scales, using logistic regression-based resource selection functions. Models were selected using Akaike Information Criterion corrected for small sample sizes (AICc) and predictive surfaces were generated using model averaged relative probabilities. Landscape-scale factors that had the most influence on nest site selection included the proportion of sagebrush cover >5%, mean productivity, and density of 2 wheel-drive roads. The landscape-scale predictive surface captured 97% of known Gunnison sage-grouse nests within the top 5 of 10 prediction bins, implicating 57% of the basin as crucial nesting habitat. Crucial habitat identified by the landscape model was used to define the extent for patch-scale modeling efforts. Patch-scale variables that had the greatest influence on nest site selection were the proportion of big sagebrush cover >10%, distance to residential development, distance to high volume paved roads, and mean productivity. This model accurately predicted independent nest locations. The unique hierarchical structure of our models more accurately captures the nested nature of habitat selection, and allowed for increased discrimination within larger landscapes of suitable habitat. We extrapolated the landscape-scale model to the entire Gunnison Basin because of conservation concerns for this species. We believe this predictive surface is a valuable tool which can be incorporated into land use and conservation planning as well the assessment of future land-use scenarios. (C) 2011 The Wildlife Society. AuthorsAldridge, Cameron L.; Saher, D. Joanne; Childers, Theresa M.; Stahlnecker, Kenneth E.; Bowen, Zachary H. Year Published2012 PublicationJournal of Wildlife Management LocationsDOI10.1002/jwmg.268 |
| Decrease of sage grouse Centrocerus urophasianus after ploughing of sagebrush steppe | SWENSON, JE | 1987 |
KeywordsNo keywords available AbstractThe effects on wildlife of ploughing sagebrush Artemisia spp. steppe have been little studied. From 1973 to 1984, numbers of lekking male sage grouse Centrocerus urophasianus declined by 73% in a study area of south central Montana, 16% of which was ploughed by 1984. The proportion of ploughed wintering areas increased from 10% in 1975 to 30% in 1984. In contrast, numbers of lekking male sage grouse on a nearby unploughed control area showed no clear long-term trend. Ploughing even small areas of sagebrush steppe to produce cereal grains appears more detrimental to sage grouse than chemical control of sagebrush. AuthorsSWENSON, JE; SIMMONS, CA; EUSTACE, CD Year Published1987 PublicationBiological Conservation LocationsDOI10.1016/0006-3207(87)90115-7 |
| Determinants of threatened sage grouse in northeastern Nevada. | van Kooten, G. Cornelis | 2007 |
Keywordspopulation viability analysis, endangered species, sage grouse AbstractWe examined potential human determinants of observed declines in greater sage grouse (Centrocercus urophasianus) populations in Elko County, Nevada. Although monitoring of sage grouse has occurred for decades, monitoring levels have not been consistent. This article contributes to the literature by normalizing grouse counts by the annual effort to count them, performing regression analyses to explain the resulting normalized data, and correcting for sample selectivity bias that arises from years when counts were not taken. Our findings provide some evidence that cattle-grazing contributes to a reduction in sage grouse populations, but this result should be interpreted with caution because our data do not include indications about the timing and precise nature of grazing practices. Annual variations in weather appear to be a major determinant after statistically controlling for human interactions with the landscape, suggesting that climate change is a key potential long-run threat to this species. Authorsvan Kooten, G. Cornelis; Eagle, Alison J.; Eiswerth, Mark E. Year Published2007 PublicationHuman Dimensions of Wildlife LocationsDOI10.1080/10871200601107908 |
