| Chapter 3: Potential acoustic masking of Greater Sage-Grouse (Centrocercus urophasianus) display components by chronic industrial noise | Blickley, J.L. | 2012 |
KeywordsNo keywords available AbstractAnthropogenic noise can limit the ability of birds to communicate by masking their acoustic signals. Masking, which reduces the distance over which the signal can be perceived by a receiver, is frequency dependent, so the different notes of a single song may be masked to different degrees. We analyzed the individual notes of mating vocalizations produced by Greater Sage-Grouse ( Centrocercus urophasianus ) and noise from natural gas infrastructure to quantify the potential for such noise to mask Greater Sage-Grouse vocalizations over both long and short distances. We found that noise produced by natural gas infrastructure was dominated by low frequencies, with substantial overlap in frequency with Greater Sage-Grouse acoustic displays. Such overlap predicted substantial masking, reducing the active space of detection and discrimination of all vocalization components, and particularly affecting low-frequency and low-amplitude notes. Such masking could increase the difficulty of mate assessment for lekking Greater Sage-Grouse. We discuss these results in relation to current stipulations that limit the proximity of natural gas infrastructure to leks of this species on some federal lands in the United States. Significant impacts to Greater Sage-Grouse populations have been measured at noise levels that predict little or no masking. Thus, masking is not likely to be the only mechanism of noise impact on this species, and masking analyses should therefore be used in combination with other methods to evaluate stipulations and predict the effects of noise exposure. AuthorsBlickley, J.L. & Patricelli, G.L. Year Published2012 PublicationOrnithological Monographs LocationsDOI10.1525/om.2012.74.1.23 |
| Temporal and hierarchical spatial components of animal occurrence: conserving seasonal habitat for greater sage-grouse | Dzialak, M.R. | 2012 |
Keywordsdiel cycle; energy development; GPS; greater sage-grouse, hierarchical process, individual variation;random effects; resource selection function; spatial modeling; sustainable landscape management; winter. AbstractDeveloping strategies for sustainable management of landscapes requires research that bridges
regionally important ecological and socioeconomic issues, and that aims to provide solutions to
sustainability problems.We integrated Global Positioning Systems (GPS) telemetry and statistical modeling
to quantify hierarchical spatial and temporal components of occurrence among greater sage-grouse
(Centrocercus urophasianus; n ¼ 87), a species of conservation concern, with the larger goal of developing
spatially-explicit guidance for conservation of important winter habitat in a Wyoming, USA landscape
undergoing development for energy resources. The pattern of occurrence at the landscape level (secondorder)
and within seasonal use areas (third-order) included selection for shrub vegetation with a prominent
sagebrush (Artemisia spp.) component, and avoidance of rough terrain, mesic areas, and human activity. A
change in resource selection behavior across the diel cycle was not an apparent component of the higherorder
selection process; however, at the finer scale of investigation sage-grouse shifted behavior across the
diel cycle in ways likely related to risk aversion or maintaining a favorable thermal environment (i.e., daytime-
only avoidance of natural gas wells and night-time-only selection for taller shrubs). At both spatial
scales there was considerably more variation among individuals in the sign of their association with
anthropogenic features than with vegetation and terrain. The final spatially-explicit model, which depicted
lower-order selection (local, patch-level, and seasonal use area) across the diel cycle constrained by selection
processes at a higher order (second-order), validated well, offering specific guidance for managing human
activity and sage-grouse conservation in the study area, and general guidance in developing sustainable
landscape management strategies when animal occurrence reflects multiple spatial and temporal processes. AuthorsDzialak, M. R., C. V. Olson, S. M. Harju, S. L. Webb, and J. B. Winstead Year Published2012 PublicationEcosphere LocationsDOI10.1890/ES11-00315.1 This article contributed by:Ecological Society of America |
| Survival of Translocated Greater Sage-Grouse Hens in Northeastern California | Bell, Chad B. | 2012 |
KeywordsNo keywords available AbstractTranslocation success of Greater Sage-Grouse (Centrocercus urophasianus) is generally measured by documenting whether translocated individuals survive and reproduce at the release site. However. demographic parameters, such as annual survival of translocated individuals, provide a more accurate measure of translocation success. We translocated 60 female sage-grouse from Oregon and Nevada to Clear Lake National Wildlife Refuge, California, during 2005-2010 to augment a small population of resident grouse. We radio-marked each translocated female and a sample of resident female sage-grouse, recorded their locations, and monitored their survival at monthly intervals over the study period. We observed most (55/60) translocated birds near (<2 Delta AlCc) with the top model. However, the 1 coefficient distinguishing breeding from nonbreeding season survival was the only coefficient whose 95% confidence interval did not overlap zero; monthly survival during the breeding season (0.952 +/- 0.014) was lower than during the nonbreeding season (0.960 +/- 0.008). The model average estimate of annual survival for female sage-grouse in our study area was 59.6% (95% CI 47.9-70.1). Our analyses provide little support for a difference in survival between translocated and resident sage-grouse, :mud our annual survival estimates were comparable to annual survival estimates of resident sage-grouse in other locations. Our results suggest that when current recommendations for translocation protocols are followed, translocated female sage-grouse survive just as well as resident individuals and quickly integrate into the local population. AuthorsBell, Chad B.; George, T. Luke Year Published2012 PublicationWestern North American Naturalist LocationsDOI10.3398/064.072.0311 |
| Energy development affects populations of sagebrush songbirds in Wyoming. | Gilbert, Michelle M. | 2011 |
Keywordsavian abundance;Brewer's sparrow;natural gas;oil;sage sparrow;sage thrasher;shrubsteppe;species richness AbstractOil and natural gas development in the Intermountain West region of North America has expanded over the last 2 decades, primarily within sagebrush dominated landscapes. Although the effects of energy development on high-profile game species such as the greater sage-grouse (Centrocercus urophasianus) have been documented, studies examining responses of non-game birds are lacking. Simultaneously, many songbirds that breed within sagebrush steppe habitats have shown range-wide population declines that are likely due to widespread habitat loss and alteration. We evaluated songbird abundance and species richness across gradients of oil and natural gas development intensity, as indexed by well density, at 3 energy fields (2 natural gas and 1 oil) in the Upper Green River Basin, Wyoming, USA during 2008-2009. While simultaneously accounting for important habitat attributes, increased well density was associated with significant decreases in Brewer's sparrow (Spizella breweri) and sage sparrow (Amphispiza belli) abundance, particularly in the Jonah natural gas field. Vesper sparrows (Pooecetes gramineus) were also negatively influenced by increased well density. Horned larks (Eremophila alpestris) increased with well density in the Pinedale Anticline natural gas field, and sage thrashers (Oreoscoptes montanus) showed no response to energy development. Species richness was not significantly affected by well density. Results suggest that regional declines of some songbird species, especially sagebrush-obligates, may be exacerbated by increased energy development. Understanding the specific mechanisms underlying responses to energy development is an important next step and will aid land managers in the development of effective mitigation and management strategies for the maintenance of stable bird communities in sagebrush habitat. © 2011 The Wildlife Society. AuthorsGilbert, Michelle M. and Anna D. Chalfoun. Year Published2011 PublicationJournal of Wildlife Management LocationsDOI10.1002/jwmg.123 |
| Are There Benefits to Mowing Wyoming Big Sagebrush Plant Communities? An Evaluation in Southeastern Oregon | Davies, Kirk W. | 2011 |
KeywordsAnnual grass Artemisia tridentata Bromus tectorum Brush control Brush management Sage-grouse AbstractWyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle & Young) communities frequently are mowed in an attempt to increase perennial herbaceous vegetation. However, there is limited information as to whether expected benefits of mowing are realized when applied to Wyoming big sagebrush communities with intact understory vegetation. We compared vegetation and soil nutrient concentrations in mowed and undisturbed reference plots in Wyoming big sagebrush plant communities at eight sites for three years post-treatment. Mowing generally did not increase perennial herbaceous vegetation cover, density, or biomass production (P > 0.05). Annual forbs and exotic annual grasses were generally greater in the mowed compared to the reference treatment (P < 0.05). By the third year post-treatment annual forb and annual grass biomass production was more than nine and sevenfold higher in the mowed than reference treatment, respectively. Our results imply that the application of mowing treatments in Wyoming big sagebrush plant communities does not increase perennial herbaceous vegetation, but may increase the risk that exotic annual grasses will dominate the herbaceous vegetation. We suggest that mowing Wyoming big sagebrush communities with intact understories does not produce the expected benefits. However, the applicability of our results to Wyoming big sagebrush communities with greater sagebrush cover and/or degraded understories needs to be evaluated. AuthorsDavies, Kirk W.; Bates, Jon D.; Nafus, Aleta M. Year Published2011 PublicationEnvironmental Management LocationsDOI10.1007/s00267-011-9715-3 |
| The Importance of Within-Year Repeated Counts and the Influence of Scale on Long-Term Monitoring of Sage-Grouse | Fedy, Bradley C. | 2011 |
KeywordsCentrocercus urophasianus; generalized additive models; greater sage-grouse; lek; monitoring; population trends; Wyoming AbstractLong-term population monitoring is the cornerstone of animal conservation and management. The accuracy and precision of models developed using monitoring data can be influenced by the protocols guiding data collection. The greater sage-grouse (Centrocercus urophasianus) is a species of concern that has been monitored over decades, primarily, by counting the number of males that attend lek (breeding) sites. These lek count data have been used to assess long-term population trends and for multiple mechanistic studies. However, some studies have questioned the efficacy of lek counts to accurately identify population trends. In response, monitoring protocols were changed to have a goal of counting lek sites multiple times within a season. We assessed the influence of this change in monitoring protocols on model accuracy and precision applying generalized additive models to describe trends over time. We found that at large spatial scales including > 50 leks, the absence of repeated counts within a year did not significantly alter population trend estimates or interpretation. Increasing sample size decreased the model confidence intervals. We developed a population trend model for Wyoming greater sage-grouse from 1965 to 2008, identifying significant changes in the population indices and capturing the cyclic nature of this species. Most sage-grouse declines in Wyoming occurred between 1965 and the 1990s and lek count numbers generally increased from the mid-1990s to 2008. Our results validate the combination of monitoring data collected under different protocols in past and future studies-provided those studies are addressing large-scale questions. We suggest that a larger sample of individual leks is preferable to multiple counts of a smaller sample of leks. (C) 2011 The Wildlife Society. AuthorsFedy, Bradley C.; Aldridge, Cameron L. Year Published2011 PublicationJournal of Wildlife Management LocationsDOI10.1002/jwmg.155 |
| Survival and Detectability Bias of Avian Fence Collision Surveys in Sagebrush Steppe | Stevens, Bryan S. | 2011 |
Keywordscarcass survival; Centrocercus urophasianus; detectability; fence collisions; Idaho; sagebrush; sage-grouse; scavenging AbstractWe used female ring-necked pheasant (Phasianus colchicus) carcasses as surrogates for greater sage-grouse (Centrocercus urophasianus) to study factors influencing survival and detection bias associated with avian fence collision surveys in southern Idaho, USA, during spring 2009. We randomly placed 50 pheasant carcasses on each of 2 study areas, estimated detection probability during fence-line surveys, and monitored survival and retention of carcasses and their associated sign over a 31-day period. Survival modeling suggested site and habitat features had little impact on carcass survival, and constant survival models were most supported by the data. Model averaged carcass daily survival probability was low on both study areas and ranged from 0.776 to 0.812. Survival of all carcass sign varied strongly by location, and the top sign survival model included a site effect parameter. Model averaged daily survival probability for collision sign on the 2 study sites ranged from 0.863 to 0.988 and varied between sites. Logistic regression modeling indicated detection probability of carcasses during fence-line surveys for avian collision victims was influenced by habitat type and microsite shrub height at the carcass location. Carcasses located in big sagebrush (Artemisia tridentata) habitats were detected at a lower rate (0.36) than carcasses in little (A. arbuscula) and black sagebrush (A. nova) habitats (0.71). Increasing shrub height at the carcass location from the little sagebrush mean of 16.5 cm to the big sagebrush mean of 36.0 cm reduced detection probability by approximately 30%. Avian fence collision surveys in sagebrush-steppe habitats should be conducted at <= 2-week sampling intervals to reduce the impact of survival bias on collision rate estimates. Two-week sampling intervals may be too long in areas with low carcass and sign survival, therefore survival rates should be estimated on all study areas to determine the appropriate sampling interval duration. Researchers should be aware of the effects of local vegetation on detection probabilities, and methods to correct detection probabilities based on collision site attributes should be applied to ensure more accurate collision rate estimates. Additionally, caution should be used when aggregating or comparing uncorrected collision data from areas with differing vegetation, as detection probabilities are likely different between sites. (C) 2011 The Wildlife Society. AuthorsStevens, Bryan S.; Reese, Kerry P.; Connelly, John W. Year Published2011 PublicationJournal of Wildlife Management LocationsDOI10.1002/jwmg.53 |
| Population cycles are highly correlated over long time series and large spatial scales in two unrelated species: greater sage-grouse and cottontail rabbits | Fedy, Bradley C. | 2011 |
KeywordsCentrocercus urophasianus – Sylvilagus sp. – Indices – Generalized additive models – Conservation AbstractAnimal species across multiple taxa demonstrate multi-annual population cycles, which have long been of interest to ecologists. Correlated population cycles between species that do not share a predator-prey relationship are particularly intriguing and challenging to explain. We investigated annual population trends of greater sage-grouse (Centrocercus urophasianus) and cottontail rabbits (Sylvilagus sp.) across Wyoming to explore the possibility of correlations between unrelated species, over multiple cycles, very large spatial areas, and relatively southern latitudes in terms of cycling species. We analyzed sage-grouse lek counts and annual hunter harvest indices from 1982 to 2007. We show that greater sage-grouse, currently listed as warranted but precluded under the US Endangered Species Act, and cottontails have highly correlated cycles (r = 0.77). We explore possible mechanistic hypotheses to explain the synchronous population cycles. Our research highlights the importance of control populations in both adaptive management and impact studies. Furthermore, we demonstrate the functional value of these indices (lek counts and hunter harvest) for tracking broad-scale fluctuations in the species. This level of highly correlated long-term cycling has not previously been documented between two non-related species, over a long time-series, very large spatial scale, and within more southern latitudes. AuthorsFedy, Bradley C.; Doherty, Kevin E. Year Published2011 PublicationOecologia LocationsDOI10.1007/s00442-010-1768-0 |
| Population structure and genetic diversity of greater sage-grouse (Centrocercus urophasianus) in fragmented landscapes at the northern edge of their range | Bush, Krista L. | 2011 |
KeywordsSage-grouse Genetic structure Decliningpopulation Genetic diversity Periphery AbstractRange-edge dynamics and anthropogenic fragmentation are expected to impact patterns of genetic diversity, and understanding the influence of both factors is important for effective conservation of threatened wildlife species. To examine these factors, we sampled greater sage-grouse (Centrocercus urophasianus) from a declining, fragmented region at the northern periphery of the species' range and from a stable, contiguous core region. We genotyped 2,519 individuals at 13 microsatellite loci from 104 leks in Alberta, Saskatchewan, Montana, and Wyoming. Birds from northern Montana, Alberta, and Saskatchewan were identified as a single population that exhibited significant isolation by distance, with the Milk River demarcating two subpopulations. Both subpopulations exhibited high genetic diversity with no evidence that peripheral regions were genetically depauperate or highly structured. However, river valleys and a large agricultural region were significant barriers to dispersal. Leks were also composed primarily of non-kin, rejecting the idea that leks form because of male kin association. Northern Montana sage-grouse are maintaining genetic connectivity in fragmented and northern peripheral habitats via dispersal through and around various forms of fragmentation. AuthorsBush, Krista L.; Dyte, Christopher K.; Moynahan, Brendan J.; Aldridge, Cameron L.; Sauls, Heather S.; Battazzo, Angela M.; Walker, Brett L.; Doherty, Kevin E.; Tack, Jason; Carlson, John; Eslinger, Dale; Nicholson, Joel; Boyce, Mark S.; Naugle, David E.; Paszkowski, Cynthia A.; Coltman, David W. Year Published2011 PublicationConservation Genetics LocationsDOI10.1007/s10592-010-0159-8 |
| Identifying and Prioritizing Greater Sage-Grouse Nesting and Brood-Rearing Habitat for Conservation in Human-Modified Landscapes | Dzialak, Matthew R. | 2011 |
KeywordsNo keywords available AbstractBackground: Balancing animal conservation and human use of the landscape is an ongoing scientific and practical challenge throughout the world. We investigated reproductive success in female greater sage-grouse (Centrocercus urophasianus) relative to seasonal patterns of resource selection, with the larger goal of developing a spatially-explicit framework for managing human activity and sage-grouse conservation at the landscape level.Methodology/Principal Findings: We integrated field-observation, Global Positioning Systems telemetry, and statistical modeling to quantify the spatial pattern of occurrence and risk during nesting and brood-rearing. We linked occurrence and risk models to provide spatially-explicit indices of habitat-performance relationships. As part of the analysis, we offer novel biological information on resource selection during egg-laying, incubation, and night. The spatial pattern of occurrence during all reproductive phases was driven largely by selection or avoidance of terrain features and vegetation, with little variation explained by anthropogenic features. Specifically, sage-grouse consistently avoided rough terrain, selected for moderate shrub cover at the patch level (within 90 m(2)), and selected for mesic habitat in mid and late brood-rearing phases. In contrast, risk of nest and brood failure was structured by proximity to anthropogenic features including natural gas wells and human-created mesic areas, as well as vegetation features such as shrub cover.Conclusions/Significance: Risk in this and perhaps other human-modified landscapes is a top-down (i.e., human-mediated) process that would most effectively be minimized by developing a better understanding of specific mechanisms (e.g., predator subsidization) driving observed patterns, and using habitat-performance indices such as those developed herein for spatially-explicit guidance of conservation intervention. Working under the hypothesis that industrial activity structures risk by enhancing predator abundance or effectiveness, we offer specific recommendations for maintaining high-performance habitat and reducing low-performance habitat, particularly relative to the nesting phase, by managing key high-risk anthropogenic features such as industrial infrastructure and water developments. AuthorsDzialak, Matthew R.; Olson, Chad V.; Harju, Seth M.; Webb, Stephen L.; Mudd, James P.; Winstead, Jeffrey B.; Hayden-Wing, L. D. Year Published2011 PublicationPLOS One LocationsDOI10.1371/journal.pone.0026273 |
