| 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 |
| A comparison of sample types varying in invasiveness for use in DNA sex determination in an endangered population of greater Sage-Grouse (Centrocercus uropihasianus) | Bush, KL | 2005 |
KeywordsDNA extraction, endangered species, noninvasive samples, Sage-Grouse, sex determination AbstractNo abstract available AuthorsBush, KL; Vinsky, MD; Aldridge, CL; Paszkowski, CA Year Published2005 PublicationConservation Genetics LocationsDOI10.1007/s10592-005-9040-6 |
| 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 |
| 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 |
| 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 |
| Long-range visibility of greater sage grouse leks: a GIS-based analysis | Aspbury, A | 2004 |
KeywordsNo keywords available AbstractWe investigated whether male greater sage grouse, Centrocercus urophasianus, select lek locations on the basis of topographic features that affect their visibility to both conspecific females and a major avian predator, the golden eagle, Aquila chrysaetos. We mapped locations of displaying males at all leks in a local population and used a Geographic Information System (GIS) and digital elevation model (DEM) to generate 'viewsheds' around male locations within a boundary set by the estimated maximal visual acuity of the viewer. Areas visible around leks were compared to those visible around random sites with the same conformation of displaying males. Male sage grouse displayed at sites where surrounding topography both diminished long-range visibility (>1000 m) and enhanced short-range visibility (<500 m) to ground observers. These characteristics could (1) force eagles to monitor lek activity from the air, where they may be more visible to their prey, (2) make displaying males more visible to females and (3) allow males to monitor predators approaching the lek more easily. These results suggest that, in open habitats, visually signalling animals may exploit local topography to control both their visibility to receivers and the visibility of their immediate surroundings. (C) 2004 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. AuthorsAspbury, A; Gibson, RM Year Published2004 PublicationAnimal Behaviour LocationsDOI10.1016/j.anbehav.2003.06.021 |
| Greater sage-grouse as an umbrella species for sagebrush-associated vertebrates | Rowland, MM | 2006 |
KeywordsConservation planning; Great Basin; Habitat risk; Greater sage-grouse; Sagebrush ecosystem; Umbrella species AbstractWidespread degradation of the sagebrush ecosystem in the western United States, including the invasion of cheatgrass, has prompted resource managers to consider a variety of approaches to restore and conserve habitats for sagebrush-associated species. One such approach involves the use of greater sage-grouse, a species of prominent conservation interest, as an umbrella species. This shortcut approach assumes that managing habitats to conserve sage-grouse will simultaneously benefit other species of conservation concern. The efficacy of using sage-grouse as an umbrella species for conservation management, however, has not been fully evaluated. We tested that concept by comparing: (1) commonality in land-cover associations, and (2) spatial overlap in habitats between sage-grouse and 39 other sagebrush-associated vertebrate species of conservation concern in the Great Basin ecoregion. Overlap in species' land-cover associations with those of sage-grouse, based on the p (phi) correlation coefficient, was substantially greater for sagebrush obligates ((x) over bar = 0.40) than non-obligates ((x) over bar = 0.21). Spatial overlap between habitats of target species and those associated with sage-grouse was low (mean phi = 0.23), but somewhat greater for habitats at high risk of displacement by cheatgrass (mean phi = 0.33). Based on our criteria, management of sage-grouse habitats likely would offer relatively high conservation coverage for sagebrush obligates such as pygmy rabbit (mean phi = 0.84), but far less for other species we addressed, such as lark sparrow (mean phi = 0.09), largely due to lack of commonality in land-cover affinity and geographic ranges of these species and sage-grouse. Published by Elsevier Ltd. AuthorsRowland, MM; Wisdom, MJ; Suring, LH; Meinke, CW Year Published2006 PublicationBiological Conservation LocationsDOI10.1016/j.biocon.2005.10.048 |
| Polygyny and female breeding failure reduce effective population size in the lekking Gunnison sage-grouse | Stiver, Julie R. | 2008 |
KeywordsLek; Reproductive success; Variance; Mating system; Centrocercus AbstractPopulations with small effective sizes are at risk for inbreeding depression and loss of adaptive potential. Variance in reproductive success is one of several factors reducing effective population size (N-e) below the actual population size (N). Here, we investigate the effects of polygynous (skewed) mating and variation in female breeding success on the effective size of a small population of the Gunnison sage-grouse (Centrocercus minimus), a ground nesting bird with a lek mating system. During a two-year field study, we recorded attendance of marked birds at leks, male mating success, the reproductive success of radio-tagged females, and annual survival. We developed simulations to estimate the distribution of male reproductive success. Using these data, we estimated population size ((N) over cap) and effective population size N-e for the study population. We also simulated the effects of population size, skewed vs. random mating, and female breeding failure on N-e. In our study population, the standardized variance in seasonal reproductive success was almost as high in females as in males, primarily due to a high rate of nest failure (73%). Estimated N-e (42) was 19% of (N) over cap in our population, below the level at which inbreeding depression is observed in captive breeding studies. A high hatching failure rate (28%) was also consistent with ongoing inbreeding depression. In the simulations, N-e was reduced by skewed male mating success, especially at larger population sizes, and by female breeding failure. Extrapolation of our results suggests that six of the seven extant populations of this species may have effective sizes low enough to induce inbreeding depression and hence that translocations may be needed to supplement genetic diversity. (C) 2007 Elsevier Ltd. All rights reserved. AuthorsStiver, Julie R.; Apa, Anthony D.; Remington, Thomas E.; Gibson, Robert M. Year Published2008 PublicationBiological Conservation LocationsDOI10.1016/j.biocon.2007.10.018 |
| Predictive modeling and mapping sage grouse (Centrocercus urophasianus) nesting habitat using Maximum Entropy and a long-term dataset from Southern Oregon | Yost, Andrew C. | 2008 |
KeywordsSage grouse; Predictive modeling and mapping; Maximum Entropy; Hart Mountain National Antelope Refuge AbstractPredictive modeling and mapping based on the quantitative relationships between a species and the biophysical features (predictor variables) of the ecosystem in which it occurs can provide fundamental information for developing sustainable resource management policies for species and ecosystems. To create management strategies with the goal of sustaining a species such as sage grouse (Centrocercus urophasianus), whose distribution throughout North America has declined by approximately 50%, land management agencies need to know what attributes of the range they now inhabit will keep populations sustainable and which attributes attract disproportionate levels of use within a home range. The objectives of this study were to 1) quantify the relationships between sage grouse nest-site locations and a set of associated biophysical attributes using Maximum Entropy, 2) find the best subset of predictor variables that explain the data adequately, 3) create quantitative sage grouse distribution maps representing the relative likelihood of nest-site habitat based on those relationships, and 3) evaluate the implications of the results for future management of sage grouse. Nest-site location data from 1995 to 2003 were collected as part of a long-term research program on sage grouse reproductive ecology at Hart Mountain National Antelope Refuge. Two types of models were created: 1) with a set of predictor variables derived from digital elevation models, a field-validated vegetation classification, and UTM coordinates and 2) with the same predictors and UTM coordinates excluded. East UTM emerged as the most important predictor variable in the first type of model followed by the vegetation classification which was the most important predictor in the second type of model. The average training gain from ten modeling runs using all presence records and randomized background points was used to select the best subset of predictors. A predictive map of sage grouse nest-site habitat created from the application of the model to the study area showed strong overlap between model predictions and nest-site locations. (C) 2008 Elsevier B.V. All rights reserved. AuthorsYost, Andrew C.; Petersen, Steven L.; Gregg, Michael; Miller, Richard Year Published2008 PublicationEcological Informatics LocationsDOI10.1016/j.ecoinf.2008.08.004 |
| Participatory modeling of endangered wildlife systems: Simulating the sage-grouse and land use in Central Washington | Beall, Allyson | 2008 |
KeywordsParticipatory modeling; Wildlife modeling; Sage-grouse; System dynamics; Endangered species AbstractThe Greater sage-grouse (Centrocercus urophasianus) occupies the sage brush habitats of Western North America. Large population declines in the last several decades have made it a candidate for possible listing under the Endangered Species Act. Listing was recently avoided in part because local working groups are developing long-range management plans in conjunction with federal and local agencies. The Foster Creek Conservation District, a working group in Douglas County, Washington, saw the potential for system dynamics to synthesize known sage-grouse dynamics and local land use patterns to support development of their Habitat Conservation Plan and subsequent land management decisions. This case study highlights the integration of science, local knowledge and social concerns into a participatory process that uses system dynamics as a forum for the exploration of the impacts of land management decisions upon the sage-grouse population and the landowners of Douglas County, Washington. (C) 2008 Elsevier B.V. All rights reserved. AuthorsBeall, Allyson; Zeoli, Len Year Published2008 PublicationEcological Economics LocationsDOI10.1016/j.ecolecon.2008.08.019 |
