| Sage-Grouse Habitat Selection During Winter in Alberta. | Carpenter, Jennifer | 2010 |
KeywordsCentrocercus urophasianus;critical habitat;energy development;greater sage-grouse;resource selection functions;winter habitats AbstractGreater sage-grouse (Centrocercus urophasianus) are dependent on sagebrush (Artemisia spp.) for food and shelter during winter, yet few studies have assessed winter habitat selection, particularly at scales applicable to conservation planning. Small changes to availability of winter habitats have caused drastic reductions in some sage-grouse populations. We modeled winter habitat selection by sage-grouse in Alberta, Canada, by using a resource selection function. Our purpose was to 1) generate a robust winter habitat-selection model for Alberta sage-grouse; 2) spatially depict habitat suitability in a Geographic Information System to identify areas with a high probability of selection and thus, conservation importance; and 3) assess the relative influence of human development, including oil and gas wells, in landscape models of winter habitat selection. Terrain and vegetation characteristics, sagebrush cover, anthropogenic landscape features, and energy development were important in top Akaike's Information Criterion-selected models. During winter, sage-grouse selected dense sagebrush cover and homogenous less rugged areas, and avoided energy development and 2-track truck trails. Sage-grouse avoidance of energy development highlights the need for comprehensive management strategies that maintain suitable habitats across all seasons. AuthorsCarpenter, Jennifer, Cameron Aldridge and Mark S. Boyce. Year Published2010 PublicationJournal of Wildlife Management LocationsDOI10.2193/2009-368 |
| 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 |
| Tactical allocation of effort among multiple signals in sage grouse: an experiment with a robotic female | Patricelli, Gail L. | 2010 |
Keywordsacoustic localization communication greater sage grouse multiple traits plasticity sexual selection trade-off AbstractMales in many species have complex, multicomponent sexual signals, and there may be trade-offs between different signal components. By adjusting their signaling behaviors, males may be able to produce more attractive courtship displays in the face of these trade-offs, but this possibility has rarely been tested. In this study, we examined adaptive adjustment of display behaviors during courtship in a lek-breeding bird, the greater sage grouse (Centrocercus urophasianus). We measured the potential trade-off between display quantity (display rate) and quality (a temporal feature of displays) in a wild population of sage grouse using controlled approaches of a robotic female to experimentally induce changes in male display rate. We found that males who are more successful in mating can increase quantity without a decline in quality, with only unsuccessful males expressing an apparent trade-off. Male mating success was also positively correlated with responsiveness to changes in receiver distance, suggesting that successful males may avoid a trade-off by tactically adjusting their display rate-saving energy by displaying at low levels when females are farther away and at higher levels as females approach. Alternative explanations for this differential response to female proximity are discussed. Our results suggest that to be successful, males may need both the ability to produce attractive signals and the ability to effectively allocate their display effort by responding to female behaviors. AuthorsPatricelli, Gail L.; Krakauer, Alan H. Year Published2010 PublicationBehavioral Ecology LocationsDOI10.1093/beheco/arp155 |
| A Currency for Offsetting Energy Development Impacts: Horse-Trading Sage-Grouse on the Open Market | Doherty, Kevin E. | 2010 |
KeywordsNo keywords available AbstractBackground: Biodiversity offsets provide a mechanism to compensate for unavoidable damages from new energy development as the U. S. increases its domestic production. Proponents argue that offsets provide a partial solution for funding conservation while opponents contend the practice is flawed because offsets are negotiated without the science necessary to backup resulting decisions. Missing in negotiations is a biologically-based currency for estimating sufficiency of offsets and a framework for applying proceeds to maximize conservation benefits.Methodology/Principal Findings: Here we quantify a common currency for offsets for greater sage-grouse (Centrocercus urophasianus) by estimating number of impacted birds at 4 levels of development commonly permitted. Impacts were indiscernible at 1-12 wells per 32.2 km(2). Above this threshold lek losses were 2-5 times greater inside than outside of development and bird abundance at remaining leks declined by -32 to -77%. Findings reiterated the importance of time-lags as evidenced by greater impacts 4 years after initial development. Clustering well locations enabled a few small leks to remain active inside of developments.Conclusions/Significance: Documented impacts relative to development intensity can be used to forecast biological tradeoffs of newly proposed or ongoing developments, and when drilling is approved, anticipated bird declines form the biological currency for negotiating offsets. Monetary costs for offsets will be determined by true conservation cost to mitigate risks such as sagebrush tillage to other populations of equal or greater number. If this information is blended with landscape level conservation planning, the mitigation hierarchy can be improved by steering planned developments away from conservation priorities, ensuring compensatory mitigation projects deliver a higher return for conservation that equate to an equal number of birds in the highest priority areas, provide on-site mitigation recommendations, and provide a biologically based cost for mitigating unavoidable impacts. AuthorsDoherty, Kevin E.; Naugle, David E.; Evans, Jeffrey S. Year Published2010 PublicationPLOS One LocationsDOI10.1371/journal.pone.0010339 |
| BIRDS OF A FEATHER DO NOT ALWAYS LEK TOGETHER: GENETIC DIVERSITY AND KINSHIP STRUCTURE OF GREATER SAGE-GROUSE (CENTROCERCUS UROPHASIANUS) IN ALBERTA | Bush, Krista L. | 2010 |
KeywordsCentrocercus urophasianus, dispersal, genetic diversity, Greater Sage-Grouse, kin selection, population genetics, relatedness AbstractAcr Endangered species are sensitive to the genetic effects of fragmentation, small population size, and inbreeding, so effective management requires a thorough understanding of their breeding systems and genetic diversity. The Greater Sage-Grouse (Centrocercus urophasianus) is a lekking species that has declined by 66-92% during the past 35 years in Alberta. Our goals were to assess the genetic diversity of Greater Sage-Grouse in Alberta and to determine the degree of sex-specific relatedness within and among leks. Six hundred and four individuals sampled in 1998-2007 were genotyped at 13 microsatellite loci. Levels of genetic diversity were high, with the exception of one recently founded lek, and did not change over time. Overall, we did not observe isolation-by-distance among leks, and most leks were not differentiated from one another, which suggests that gene flow occurs across the study area. Males and females exhibited similar patterns of isolation-by-distance, so dispersal was not sex-specific. Overall relatedness was close to zero for both sexes at the level of the province, lek, and year, which suggests that neither sex forms strong kin associations. However, we found relatedness within leks at the year level to be greater than zero, which indicates interannual variation. We also found no evidence that Greater Sage-Grouse follow the typical avian pattern of male philopatry. Although the species is endangered in Alberta and occurs in fragmented habitat, it has maintained genetic diversity and connectivity. Received 8 September 2008, accepted 22 September 2009. AuthorsBush, Krista L.; Aldridge, Cameron L.; Carpenter, Jennifer E.; Paszkowski, Cynthia A.; Boyce, Mark S.; Coltman, David W. Year Published2010 PublicationThe Auk: Ornithological Advances LocationsDOI10.1525/auk.2009.09035 |
| BALANCED SEX RATIO AT HATCH IN A GREATER SAGE-GROUSE (CENTROCERCUS UROPHASIANUS) POPULATION | Atamian, Michael T. | 2010 |
KeywordsCentrocercus urophasianus, CHD-gene, genetic sexing, Greater Sage-Grouse, parental investment, sex ratio. AbstractOnly one estimate of sex ratio at hatch exists for Greater Sage-Grouse (Centrocercus urophasianus). Managers typically assume a ratio at the population level of approximately 2:1 (female:male), primarily on the basis of sex ratio in the harvest. We determined the sex of newly hatched young and unhatched Greater Sage-Grouse by amplifying a portion of the sex-linked CHD gene. Sex ratio for Greater Sage-Grouse in east-central Nevada was 0.51 +/- 0.03 (SE; n = 272). We found no substantial difference in size between eggs that produced male chicks and those that produced females (44.5 + 0.2 mm(3) vs. 44.3 +/- 0.3 mm(3)) or between the masses of male and female chicks (25.8 +/- 0.3 g vs. 26.3 +/- 0.3 g), which suggests that energetic cost investments by females were similar between offspring of different sexes. We also found no effect of female condition oil differential investment in male versus female offspring. Given that adult survival does not differ Substantially between the sexes in our study Population (J. S. Sedinger unpubl. data), we suggest that this Population may not contain 2 adult females to I adult male and that any bias in adult sex ratio is likely attributable to differential survival from hatch to first breeding. Received 10 February 2009, accepted 1 june 2009. AuthorsAtamian, Michael T.; Sedingeir, James S. Year Published2010 PublicationThe Auk: Ornithological Advances LocationsDOI10.1525/auk.2009.09136 |
| 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 |
| GREATER SAGE-GROUSE SELECT NEST SITES TO AVOID VISUAL PREDATORS BUT NOT OLFACTORY PREDATORS | Conover, Michael R. | 2010 |
KeywordsCentrocercus urophasianus, nest depredation, nest-site characteristics, olfactory predators, sage-grouse, visual predators. AbstractBirds can hide from visual predators by locating nests where there is cover and from olfactory predators where habitat features create updrafts, high winds, and atmospheric turbulence, but sites optimal for hiding from visual and olfactory predators often differ. We examined how Greater Sage-Grouse (Centrocercus urophasianus) balance the dual needs of hiding from both visual and olfactory predators on Parker Mountain, Utah, where the Common Raven (Corvus corax) is the main visual predator and the striped skunk (Mephitis mephitis) and American badger (Taxidea taxus) are the main olfactory predators. By comparing nest sites to random sites during 2005 and 2006, we found that sage-grouse nest at sites where their nests were obscured from visual predators but were exposed to olfactory predators. To validate these findings, we replicated the study in southwest Wyoming during 2008. Again, we found that visual obscurity at nest sites was greater than at control sites but olfactory obscurity was less. Our results indicate that Greater Sage-Grouse select nest sites where they will be concealed from visual predators but at the cost of locating nests where they are exposed to olfactory predators. In southwest Wyoming, we found that olfactory predators (mammals) and visual predators (birds) depredated an equal number of nests. By selecting nest sites with visual obscurity, Greater Sage-Grouse have reduced the threat from visual predators to where it was similar to the threat posed by olfactory predators. AuthorsConover, Michael R.; Borgo, Jennifer S.; Dritz, Rebekah E.; Dinkins, Jonathan B.; Dahlgren, David K. Year Published2010 PublicationThe Condor: Ornithological Applications LocationsDOI10.1525/cond.2010.090172 |
| Vegetation Characteristics of Mountain and Wyoming Big Sagebrush Plant Communities in the Northern Great Basin | Davies, Kirk W. | 2010 |
KeywordsArtemisia tridentata, diversity, habitat, herbaceous cover, sage-grouse AbstractDominant plant species are often used as indicators of site potential in forest and rangelands. However, subspecies of dominant vegetation often indicate different site characteristics and, therefore, may be more useful indicators of plant community potential and provide more precise information for management. Big sagebrush (Artemisia tridentata Nutt.) occurs across large expanses of the western United States. Common subspecies of big sagebrush have considerable variation in the types of sites they occupy, but information that quantifies differences in their vegetation characteristics is lacking. Consequently, wildlife and land management guidelines frequently do not differentiate between subspecies of big sagebrush. To quantify vegetation characteristics between two common subspecies of big sagebrush, we sampled 106 intact big sagebrush plant communities. Half of the sampled plant communities were Wyoming big sagebrush (A. tridentata subsp. wyomingensis [Beetle & A. Young] S. L. Welsh) plant communities, and the other half were mountain big sagebrush (A. tridentata subsp. vaseyana [Rydb.] Beetle) plant communities. In general, mountain big sagebrush plant communities were more diverse and had greater vegetation cover, density, and biomass production than Wyoming big sagebrush plant communities. Sagebrush cover was, on average, 2.4-fold higher in mountain big sagebrush plant communities. Perennial forb density and cover were 3.8- and 5.6-fold greater in mountain compared to Wyoming big sagebrush plant communities. Total herbaceous biomass production was approximately twofold greater in mountain than Wyoming big sagebrush plant communities. The results of this study suggest that management guidelines for grazing, wildlife habitat, and other uses should recognize widespread subspecies as indicators of differences in site potentials. AuthorsDavies, Kirk W.; Bates, Jon D. Year Published2010 PublicationRangeland Ecology & Management LocationsDOI10.2111/REM-D-09-00055.1 |
| Thresholds and Time Lags in Effects of Energy Development on Greater Sage-Grouse Populations | Harju, Seth M. | 2010 |
KeywordsCentrocercus urophasianus, energy development, greater sage-grouse, lek count, threshold AbstractRapid expansion of energy development in some portions of the Intermountain West, USA, has prompted concern regarding impacts to declining greater sage-grouse (Centrocercus urophasianus) populations. We used retrospective analyses of public data to explicitly investigate potential thresholds in the relationship between lek attendance by male greater sage-grouse, the presence of oil or gas wells near leks (surface occupancy), and landscape-level density of well pads. We used generalized linear models and generalized estimating equations to analyze data on peak male attendance at 704 leks over 12 years in Wyoming, USA. Within this framework we also tested for time-lag effects between development activity and changes in lek attendance. Surface occupancy of oil or gas wells adjacent to leks was negatively associated with male lek attendance in 5 of 7 study areas. For example, leks that had >= 1 oil or gas well within a 0.4-km (0.25-mile) radius encircling the lek had 35-91% fewer attending males than leks with no well within this radius. In 2 of these 5 study areas, negative effects of well surface occupancy were present out to 4.8 km, the largest radius we investigated. Declining lek attendance was also associated with a higher landscape-level density of well pads; lek attendance at well-pad densities of 1.54 well pads/km(2) (4 well pads/mile(2)) ranged from 13% to 74% lower than attendance at unimpacted leks (leks with zero well pads within 8.5 km). Lek attendance at a well-pad density of 3.09 well pads/km(2) (8 well pads/mile(2)) ranged from 77% to 79% lower than attendance at leks with no well pad within 8.5 km. Further, our analysis of time-lag effects suggested that there is a delay of 2-10 years between activity associated with energy development and its measurable effects on lek attendance. These results offer new information for consideration by land managers on spatial and temporal associations between human activity and lek attendance in sage-grouse, and suggest that regional variation is an important consideration in refining existing management strategies. AuthorsHarju, Seth M.; Dzialak, Matthew R.; Taylor, Renee C.; Hayden-Wing, Larry D.; Winstead, Jeffrey B. Year Published2010 PublicationJournal of Wildlife Management LocationsDOI10.2193/2008-289 |
