| Multi-scale assessment of greater sage-grouse fence collision as a function of site and broad scale factors | Stevens, Bryan S. | 2012 |
Keywordsavian collisionCentrocercus urophasianusfence managementgreater sage-grouseIdahoinfrastructure collisionmodeling collision risk AbstractPrevious research in Europe and North America suggested grouse are susceptible to collision with infrastructure, and anecdotal observation suggested greater sage-grouse (Centrocercus urophasianus) fence collision in breeding habitats may be prevalent. However, no previous research systematically studied greater sage-grouse fence collision in any portion of their range. We used data from probability-based sampling of fences in greater sage-grouse breeding habitats of southern Idaho, USA, to model factors associated with collision at microsite and broad spatial scales. Site-scale modeling suggested collision may be influenced by technical attributes of fences, with collisions common at fence segments absent wooden fence posts and with segment widths >4?m. Broad-scale modeling suggested relative probability of collision was influenced by region, a terrain ruggedness index (TRI), and fence density per square km. Conditional on those factors, collision counts were also influenced by distance to nearest active sage-grouse lek. Our models provide a conceptual framework for prioritizing sage-grouse breeding habitats for collision mitigation such as fence marking or moving, and suggest mitigation in breeding habitats should start in areas with moderate-high fence densities (>1?km/km2) within 2?km of active leks. However, TRI attenuated other covariate effects, and mean TRI/km2 >10?m nearly eliminated sage-grouse collision. Thus, our data suggested mitigation should focus on sites with flat to gently rolling terrain. Moreover, site-scale modeling suggested constructing fences with larger and more conspicuous wooden fence posts and segment widths <4?m may reduce collision. (c) 2012 The Wildlife Society. AuthorsStevens, Bryan S.; Connelly, John W.; Reese, Kerry P. Year Published2012 PublicationJournal of Wildlife Management LocationsDOI10.1002/jwmg.397 |
| Disturbance factors influencing greater sage-grouse lek abandonment in north-central Wyoming | Hess, Jennifer E. | 2012 |
Keywordsbig sagebrush, Centrocercus urophasianus, cumulative disturbance factors, energy development, greater sage-grouse, lek, abandonment, shrubs, wildfire AbstractDetecting the disappearance of active leks is the most efficient way to determine large declines in greater sage-grouse (Centrocercus urophasianus) populations; thus, understanding factors that influence lek abandonment is critical. We evaluated factors that may have influenced the probability of sage-grouse lek abandonment in the Bighorn Basin (BHB) of north-central Wyoming from 1980 to 2009. Our objective was to examine lek abandonment based on landscape characteristics that explain differences between occupied and unoccupied leks. We evaluated lek abandonment from 144 occupied and 39 unoccupied leks from the Wyoming Game and Fish Department lek database with sufficient data for our 30-year analysis. We conducted our analysis with binary logistic regression using landscape predictor variables obtained from geographic coverages at 5 scales (1.0-, 3.2-, 4.0-, 5.0-, and 6.4-km radii around leks) to evaluate how these disturbances have influenced lek abandonment. Coverages included anthropogenic characteristics such as agricultural development, oil and gas development, prescribed burned treatments, and roads; and environmental characteristics such as vegetation attributes and wildfire. Our combined model included the number of oil and gas wells in a 1.0-km radius, percent area of wildfire in a 1.0-km radius, and variability in shrub height in a 1.0-km radius around sage-grouse leks. Abandoned (unoccupied) leks had 1.1-times the variability of shrub height in a 1.0-km radius, 3.1-times the percentage of wildfire in a 1.0-km radius, and 10.3-times the number of oil and gas wells in a 1.0-km radius compared to occupied leks. The model-averaged odds of lek persistence with every 1 unit increase in oil and gas wells within a 1.0-km radius was 0.66 (90% CI: 0.370.94), odds with every 1% increase in wildfire in a 1.0-km radius was 0.99 (90% CI: 0.851.12), and odds with every 1 unit increase in the standard deviation of shrub height within a 1.0-km radius around a lek was 0.77 (90% CI: 0.451.08). Because the 90% confidence intervals around the odds ratios of wells did not overlap 1.0, we suggest this predictor variable was most influential in our model-averaged estimates. The BHB has lower developed reserves of oil and gas than many other regions; however, our study supports findings from other studies that demonstrate energy development increases lek abandonment. Our findings indicate conservation efforts should be focused on minimizing well development and implementing wildfire suppression tactics near active sage-grouse leks. (c) 2012 The Wildlife Society. AuthorsHess, Jennifer E.; Beck, Jeffrey L. Year Published2012 PublicationJournal of Wildlife Management LocationsDOI10.1002/jwmg.417 |
| 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 |
| Greater sage-grouse and fences: Does marking reduce collisions? | Stevens, B.S. | 2012 |
Keywordsavian collisionCentrocercus urophasianuscollision mitigationfence managementgreater sage-grouseIdahoinfrastructure markingprairie-grouse AbstractCollision with infrastructure such as fences is widespread and common for many species of grouse. Greater sage-grouse (Centrocercus urophasianus) fence-collision has been documented and fence-marking methods have been recommended for mitigating prairie-grouse collision in rangeland habitats. We tested a marking method in greater sage-grouse breeding habitat and modeled collision as a function of fence marking and control covariates, in Idaho (USA) in 2010. Our results suggested collision risk decreased with fence marking, increased with lek-count indices of local abundance, and decreased with increasing distance from lek. We found an approximate 83% reduction in collision rates at marked fences relative to unmarked fences. Our results also suggested marking may not be necessary on all fences, and mitigation should focus on areas with locally abundant grouse populations and fence segments <500 m from large leks and moving or removing fences may be necessary in some areas if management is to eliminate collision AuthorsSTEVENS, B. S., REESE, K. P., CONNELLY, J. W. & MUSIL, D. D. Year Published2012 PublicationWildlife Society Bulletin Locations- Clark County, Idaho (44.3, -112.45)
- Butte County, Idaho (44.1667, -113.375)
- Jefferson County, Idaho (44.0417, -112.625)
- Blaine County, Idaho (43.2482, -114.04)
- Twin Falls County, Idaho (42.3506, -114.644)
DOI10.1002/wsb.142 |
| Burning and mowing Wyoming big sagebrush: Do treated sites meet minimum guidelines for greater sage‐grouse breeding habitats? | Hess, J.E. | 2012 |
KeywordsArtemisia tridentata; Centrocercus urophasianus; early brood-rearing; greater sage-grouse; habitat management; mowing; nesting; prescribed burning; Wyoming; Wyoming big sagebrush AbstractWyoming big sagebrush (Artemisia tridentata wyomingensis) treatments are often implemented to improve breeding habitat for greater sage-grouse (Centrocercus urophasianus), a species of considerable conservation concern. In 2008 and 2009, we measured vegetation structure available to sage-grouse for breeding at 19 sites that were prescribed burned during 1990–1999 and 2000–2006, 6 sites that were mowed during 2000–2006, and 25 paired, untreated reference sites in the Bighorn Basin of north-central Wyoming, USA. We compared minimum guidelines for canopy cover and height of Wyoming big sagebrush and perennial grass in arid greater sage-grouse breeding habitat (Connelly et al. 2000b) to measurements at our sampling sites. Sagebrush canopy cover and height at reference sites met the minimum guidelines. Sagebrush canopy cover at burned and mowed sites did not meet the minimum guideline, except for sites mowed on aridic soils measured during 2009. Burned and mowed (3 of 4 cases) sagebrush did not meet minimum height for breeding up to 19 yr and 9 yr post-treatment, respectively. Perennial grass canopy cover and height met the minimum guidelines for breeding habitat at reference, burned, and mowed sites. Burning increased grass canopy cover, but not height, compared to reference sites in 2 of 8 instances. Because burning, but not mowing, infrequently enhanced grass cover, but not height, and sagebrush structure was reduced by both practices for long periods, managers should consider how treatments may negatively affect Wyoming big sagebrush communities for sage-grouse and consider other practices, including continued nontreatment and improved livestock grazing, to increase grass cover and height. AuthorsHess, J. E., & Beck, J. L. Year Published2012 PublicationWildlife Society Bulletin LocationsDOI10.1002/wsb.92 |
| Phenotypic divergence of secondary sexual traits among sage grouse, Centrocercus urophasianus, populations | YOUNG, JR | 1994 |
KeywordsNo keywords available AbstractSage grouse, Centrocercus urophasianus, in an isolated montane basin near Gunnison, Colorado differ in several morphological and behavioural traits from conspecifics studied in other areas of the species' range. Both sexes in Gunnison are smaller than sage grouse elsewhere, and males possess differences in feather morphology as well. The mating behaviour of male sage grouse in three populations was examined to determine whether male strut displays of Gunnison sage grouse were behaviourally distinct. Behavioural analyses revealed Gunnison males perform strut displays at a slower rate than males in the two other sage grouse populations sampled. In addition, Gunnison males' strut displays contain unique visual and acoustical aspects. The most distinguishing attributes of Gunnison sage grouse were male secondary sexual characteristics including traits that correlate with mating success in other populations. Thus, phenotypic differences observed in the Gunnison population represent a divergence in expression of traits that are likely to be influenced by sexual selection. Recent models of speciation suggest that species characterized by intense sexual selection, such as those with lek mating systems, have the potential for rapid inter-populational divergence in male traits and female preferences leading to speciation. AuthorsYOUNG, JR; HUPP, JW; BRADBURY, JW; BRAUN, CE Year Published1994 PublicationAnimal Behaviour LocationsDOI10.1006/anbe.1994.1183 |
| A re-evaluation of hotspot settlement in lekking sage grouse | Gibson, RM | 1996 |
KeywordsNo keywords available AbstractRecent analyses of avian leks have come to conflicting conclusions concerning the role of male settlement on female traffic hotspots. This issue was re-examined in the sage grouse, Centrocercus urophasianus, using data on pre-nesting movements of radiotagged females and the dispersion of lekking males collected during a 10-year field study. As expected with hotspot settlement, leks were preferentially located in areas through which females travelled between wintering and nesting ranges before mating. In addition, the distribution of males among leks was related proximately to variation in numbers of females visiting each lek during the mating period and ultimately to numbers that nested within a 2-km radius, within which nesting hens were preferentially attracted. The results show both that hotspot settlement can explain certain coarse scale features of male dispersion, and that female behaviour during different stages of the pre-nesting period may influence particular components of male dispersion to differing extents. (C) 1996 The Association for the Study of Animal Behaviour AuthorsGibson, RM Year Published1996 PublicationAnimal Behaviour LocationsDOI10.1006/anbe.1996.0247 |
| Modeling sage grouse: Progressive computational methods for linking a complex set of local, digital biodiversity and habitat data towards global conservation statements and decision-making systems | Onyeahialam, A | 2005 |
KeywordsNo keywords available AbstractModem conservation management needs to link biological questions with computational approaches. As a global template, here we present such an approach from a local study on sage grouse breeding habitat, leks, in North Natrona County, Wyoming, using remote sensing imagery, digital datasets, spatial statistics, predictive modelling and a Geographic Information System (GIS). Four quantitative models that describe sage grouse breeding habitat selection were developed for multiple scales using logistic regression and multivariate adaptive regression splines (MARS-Salford Systems). Based on candidate models and AIC, important habitat predictor variables were elevation, distance to human development, slope, distance to roads, NDVI and distance to water, but not Sagebrush. Some predictors changed when using different scales and MARS. For the year 2011, a cumulative prediction index approach is presented on how the population viability of sage grouse can be assessed over time and space using Markov chain models for deriving future landscape scenarios and MARS for species predictions. AuthorsOnyeahialam, A; Huettmann, F; Bertazzon, S Year Published2005 PublicationComputational Science And Its Applications - Iccsa 2005, Pt 3 LocationsDOI10.1007/11424857_17 |
| Sexual selection in lekking sage grouse: phenotypic correlates of male mating success | GIBSON, RM | 1985 |
KeywordsNo keywords available AbstractMate choice cues in sage grouse were reinvestigated by analyzing relationships between male mating success and a range of suggested cues. Display cues were implicated by significant relationships between mating status (whether or not a male mated) and lek attendance, display rate (corrected for effects of female proximity and time of day) and an acoustic component related to temporal and frequency measure of a whistle emltted during the strut display. Although display rate and the acoustic component were intercorrelated, both exerted significant partial effects on mating success in mutivariate analyses. These display measures also differed significantly between males. In contrast, mating success was not significantly related to measures of territory characteristics, including size and proximity to the lek center, or to body size. These results resolve discrepancies between previous studies and provide a basis for experimental analysis of the role of female choice in this lek system. AuthorsGIBSON, RM; BRADBURY, JW Year Published1985 PublicationBehavioral Ecology And Sociobiology LocationsDOI10.1007/BF00299040 |
| Dispersion of displaying male sage grouse | BRADBURY, JW | 1989 |
KeywordsNo keywords available AbstractThe degree to which male sage grouse select lek sites and females select nesting sites to maximize proximity to the other sex was examined by contrasting male dispersions with the dispersions and movements of females in the months preceeding incubation. Wintering females exhibit highly overlapping ranges due to shared use of central refuging areas. In late winter and early spring, females move an average 9 km from wintering areas to select nest sites and males begin occupying leks. Pooled evidence suggests that females select nest sites independently of male dispersion whereas males adjust lek occupation so as to maximize proximity to females. Relevant observations include females visiting nest sites before leks, moving further to select a nest site than to select a lek, and increasing their distance to leks as a result of selecting nest sites. In addition, males avoid leks until females have moved to within 5 km of the arenas, abandon early season leks as local female densities drop, and exhibit dispersions in which mean ratios of females/male are similar across leks. Contrasts between predicted and observed dispersions of males showed that hotspot settlement models are adequate to explain male dispersions on very coarse scales (2 km or greater); on finer scales, habitat preferences of males and tendencies for males to cluster tightly must be invoked in addition to hotspots to explain specific lek sitings. AuthorsBRADBURY, JW; GIBSON, RM; MCCARTHY, CE; VEHRENCAMP, SL Year Published1989 PublicationBehavioral Ecology And Sociobiology LocationsDOI10.1007/BF00300113 |
