| Survival Rates of Female Greater Sage-Grouse in Autumn and Winter in Southeastern Oregon | Anthony, Robert G. | 2009 |
KeywordsCentrocercus urophasianus; fall—winter survival rates; known-fate models; Oregon; sage-grouse; weather effects AbstractWe estimated survival rates of 135 female greater sage-grouse (Centrocercus urophasianus) on 3 study areas in southeastern Oregon, USA during autumn and winter for 3 years. We used known-fate models in Program MARK to test for differences among study areas and years, investigate the potential influence of weather, and compute estimates of overwinter survival. We found no evidence for differences in survival rates among study areas, which was contrary to our original hypothesis. There also were no declines in survival rates during fall-winter, but survival rates varied among years and time within years. Average survival rate from October through February was 0.456 (SE = 0.062). The coefficient of variation for this estimate was 13.6% indicating good precision in our estimates of survival. We found strong evidence for an effect of weather (i.e., mean daily min. temp, extreme min. temp, snow depth) on bi-weekly survival rates of sage-grouse for 2 of the study areas in one year. Extremely low ( 1,500 m) elevations. In contrast, we found no evidence for an influence of weather on the low-elevation study area or during the winters of 1989-1990 and 1991-1992. Extreme weather during winter can cause lower survival of adult female sage-grouse, so managers should be aware of these potential effects and reduce harvest rates accordingly. (JOURNAL OF WILDLIFE MANAGEMENT 73(4): 538-545; 2009) AuthorsAnthony, Robert G.; Willis, Mitchell J. Year Published2009 PublicationJournal of Wildlife Management LocationsDOI10.2193/2008-177 |
| 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 |
| 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 |
| Landscape-Level Assessment of Brood Rearing Habitat for Greater Sage-Grouse in Nevada | Atamian, Michael T. | 2010 |
Keywordsbrood rearing habitat; Centrocercus urophasianus; ecological niche factor analysis; greater sage-grouse; habitat suitability; landscape management; Nevada AbstractLoss of quality brood rearing habitat, resulting in reduced chick growth and poor recruitment, is one mechanism associated with decline of greater sage-grouse (Centrocercus urophasianus) populations. Low chick survival rates are typically attributed to poor-quality brood rearing habitat. Models that delineate suitability of sage-grouse nesting or brood rearing habitat at the landscape scale can provide key insights into the relationship between sage-grouse and the environment, allowing managers to identify and prioritize habitats for protection or restoration. We used Southwest Regional Gap landcover types to identify early and late greater sage-grouse brood rearing in east-central Nevada. We conducted an Ecological Niche Factor Analysis to 1) examine the effect these landcover types and other ecogeographical variables have on sage-grouse selection of brood rearing habitat, and 2) generate landscape-scale suitability maps. We also evaluated if incorporating a fitness component (brood survival) in landscape spatial analyses of habitat quality influenced our assessment of habitat suitability. Because 36% of our 6,500-km(2) study area was identified as early brood rearing habitat, we believe this habitat may not be limiting greater sage-grouse populations in east-central Nevada, USA, at least in wet years. We found strong selection for particular landcover types (e. g., higher elevation, moist sites with riparian shrubs or montane sagebrush) during late brood rearing. Late brood rearing habitat on which broods were successfully reared represented only 2.8% of the study area and had a restricted distribution, suggesting the potential that such habitat could limit sage-grouse populations in east-central Nevada. AuthorsAtamian, Michael T.; Sedinger, James S.; Heaton, Jill S.; Blomberg, Erik J. Year Published2010 PublicationJournal of Wildlife Management LocationsDOI10.2193/2009-226 |
| SAGE GROUSE USE OF SNOW BURROWS IN NORTHEASTERN NEVADA | BACK, GN | 1987 |
SAGE GROUSE USE OF SNOW BURROWS IN NORTHEASTERN NEVADAKeywordsNo keywords available AbstractNo abstract available AuthorsBACK, GN; BARRINGTON, MR; MCADOO, JK Year Published1987 PublicationWilson Bulletin Locations |
| Effect of Imazapic on Cheatgrass and Native Plants in Wyoming Big Sagebrush Restoration for Gunnison Sage-grouse | Baker, William L. | 2009 |
Keywordsforbs, Gunnison sage-grouse, native plants, restoration AbstractImazapic has shown potential to control invasive weeds, such as cheatgrass (Bromus tectorum L.), during ecological restoration, but effects on non-target native plants are poorly known. In a replicated field experiment, as part of restoration for Gunnison sage-grouse (Centrocercus minimus) in Colorado, imazapic was applied in the fall at a high rate (175 g/ha) to control cheatgrass in mowed Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young). Cheatgrass was reduced, but only by 67%. and non-native forbs were reduced by 80% by the following summer. However, native forbs also declined (by 84%). Two native grasses declined, but others were not affected. Damage to native forbs would likely be detrimental to sage-grouse and other wildlife if it occurred over large areas. Perhaps application of imazapic just to cheatgrass plants or patches and application earlier in restoration would allow control with less adverse effects on native forbs. AuthorsBaker, William L.; Garner, Jim; Lyon, Peggy Year Published2009 PublicationNatural Areas Journal LocationsDOI10.3375/043.029.0301 |
| Pre-Laying Nutrition of Sage Grouse Hens in Oregon | BARNETT, JK | 1994 |
KeywordsNo keywords available AbstractDiet, dietary selection, and nutritional composition of the foods of sage grouse (Centrocercus urophasianus) hens were determined during the pre-laying period in southeastern Oregon in 1990 and 1991. We collected 42 female sage grouse during a 5-week period preceding incubation (4 March-8 April). Sagebrush (Artemisia spp.) was the most common among 21 foods consumed but forbs composed 18 to 50% of the diet by weight. Desert-parsley (Lomatium spp.), hawksbeard (Crepis spp.), long-leaf phlox (Phlox longifolia Nutt.), everlasting (Antennaria spp.), mountain-dandelion (Agoseris spp.), clover (Trifolium spp.), Pursh's milk-vetch (Astragalus purshii Dougl.), buckwheat (Eriogonum spp.), and obscure milk-vetch (A. obscurus) were the primary (greater-than-or-equal-to 1% of the diet by weight) forbs consumed. Forbs were used selectively over sagebrush in both low and big sagebrush cover types. All forbs were higher in crude protein and phosphorus and many were higher in calcium than sagebrush. Consumption of forbs increased nutrient content of the composite diet. Substantially fewer forbs were present in the diet in 1991 than in 1990, which coincided with reduced sage grouse productivity on the study area. These results suggest that consumption of forbs during the pre-laying period may effect reproductive success by improving nutritional status of hens. AuthorsBARNETT, JK; CRAWFORD, JA Year Published1994 PublicationJournal of Range Management LocationsDOI10.2307/4002817 |
| Saving sage-grouse from the trees: A proactive solution to reducing a key threat to a candidate species | Baruch-Mordo, Sharon | 2013 |
KeywordsConifer encroachment; Ecological economics; Juniperus occidentalis; Proactive management; Random forest models; Sage-Grouse Initiative; Spatial wavelet analysis AbstractConservation investment in management of at-risk species can be less costly than a delay-and-repair approach implemented after species receive legal protection. The United States Endangered Species Act candidate species designation represents an opportunity to implement proactive management to avoid future listing. Such efforts require substantial investments, and the challenge becomes one of optimization of limited conservation funds to maximize return. Focusing on conifer encroachment threats to greater sage-grouse (Centrocercus urophasianus), we demonstrated an approach that links species demographics with attributes of conservation threats to inform targeting of investments. We mapped conifer stand characteristics using spatial wavelet analysis, and modeled lek activity as a function of conifer-related and additional lek site covariates using random forests. We applied modeling results to identify leks of high management potential and to estimate management costs. Results suggest sage-grouse incur population-level impacts at very low levels of encroachment, and leks were less likely to be active where smaller trees were dispersed. We estimated costs of prevention (treating active leks in jeopardy) and restoration (treating inactive leks with recolonization potential) management across the study area (2.5 million ha) at a total of US$17.5 million, which is within the scope of landscape-level conservation already implemented. An annual investment of US$8.75 million can potentially address encroachment issues near all known Oregon leks within the next decade. Investments in proactive conservation with public and private landowners can increase ecosystem health to benefit species conservation and sustainable land uses, replace top-down regulatory approaches, and prevent conservation reliance of at-risk species. AuthorsReese, Kerry P., Naugle, David E., Evans, Jeffrey S., Hagen, Christian A., Baruch-Mordo, Sharon, Severson, John P., Maestas, Jeremy D., Kiesecker, Joseph M. and Falkowski, Michael J. Year Published2013 PublicationBiological Conservation LocationsDOI10.1016/j.biocon.2013.08.017 |
| Factors affecting nest-site selection and nest success of translocated greater sage grouse | Baxter, Rick J. | 2009 |
KeywordsNo keywords available AbstractTranslocations have been used for decades to restore or augment wildlife populations, yet more often than not, little to no data and/or arbitrary means are used for determining translocation success. The objectives of our study were to describe nesting habitat utilised by the greater sage grouse translocated into an extant population and to identify factors related to nest success, thereby demonstrating the adaptability of the birds to their new environment and producing one measure of long-term translocation success. We trapped female grouse individuals during the spring on and near leks of source populations, fitted them with radio-transmitters, and released them in the morning onto an active lek in an extant population in Strawberry Valley, Utah. We monitored translocated females for nesting activity and documented nesting attempts, nest success, clutch size and embryo viability. Data were recorded on habitat variables associated with nest sites and paired-random sites, including factors known to be important for resident females that nested successfully. We used logistic regression and an a priori information-theoretic approach for modelling nest v. paired-random sites and successful v. unsuccessful nest sites. Our analyses suggested that crown area of the nest shrub and percentage grass cover were the two variables that discriminated between nest and paired-random sites. Females that nested successfully selected sites with more total shrub canopy cover, intermediate size-shrub crown area, aspects other than NW and SE, and steeper slopes than for unsuccessful nests. After being translocated from distant sites with differing habitat characteristics, these birds were able to initiate a nest, nest successfully, and select micro-habitat features similar to those selected by resident sage grouse across the species range. Our results demonstrate the adaptability of the translocated female sage grouse individuals and produce one tangible measure of long-term translocation success. AuthorsBaxter, Rick J.; Flinders, Jerran T.; Whiting, David G.; Mitchell, Dean L. Year Published2009 PublicationWildlife Research LocationsDOI10.1071/WR07185 |
| Survival, movements, and reproduction of translocated greater sage-grouse in Strawberry Valley, Utah | Baxter, Rick J. | 2008 |
KeywordsCentrocercus urophasianus; clutch size; dispersal; flocking; greater sage-grouse; nest success; reproductive output; survival; translocation AbstractTranslocations of greater sage-grouse (Centrocercus urophasianus) have been attempted in 7 states and one Canadian province with very little success. To recover a small remnant population and test the efficacy of sage-grouse translocations, we captured and transported 137 adult female sage-grouse from 2 source populations to a release site in Strawberry Valley, Utah, USA, during March-April 2003-2005. The resident population of sage-grouse in Strawberry Valey was approximately 150 breeding birds prior to the release. We radiomarked each female and documented survival, movements, reproductive effort, flocking with resident grouse, and lek attendance. We used Program MARK to calculate annual survival of translocated females in the first year after release, which averaged 0.60 (95% CI = 0.515-0.681). Movements of translocated females were within current and historic sage-grouse habitat in Strawberry Valley, and we detected no grouse outside of the study area. Nesting propensity for first (newly translocated) and second (surviving) year females was 39% and 73%, respectively. Observed nest success of all translocated females during the study was 67%. By the end of their first year in Strawberry Valley, 100% of the living translocated sage-grouse were in flocks with resident sage-grouse. The translocated grouse attended the same lek as the birds with which they were grouped. In 2006, the peak male count for the only remaining active lek in Strawberry Valley was almost 4 times (135 M) the 6-year pretranslocation (1998-2003) average peak attendance of 36 males (range 24-50 M). Translocations can be an effective management tool to increase small populations of greater sage-grouse when conducted during the breeding season and before target populations have been extirpated. AuthorsBaxter, Rick J.; Flinders, Jerran T.; Mitchell, Dean L. Year Published2008 PublicationJournal of Wildlife Management LocationsDOI10.2193/2006-402 |
