| Experimental Evidence for the Effects of Chronic Anthropogenic Noise on Abundance of Greater Sage-Grouse at Leks | Blickley, Jessica L. | 2012 |
Keywordschronic noise, energy development, Centrocercus urophasianus roads AbstractIncreasing evidence suggests that chronic noise from human activities negatively affects wild animals, but most studies have failed to separate the effects of chronic noise from confounding factors, such as habitat fragmentation. We played back recorded continuous and intermittent anthropogenic sounds associated with natural gas drilling and roads at leks of Greater Sage-Grouse (Centrocercus urophasianus). For 3 breeding seasons, we monitored sage grouse abundance at leks with and without noise. Peak male attendance (i.e., abundance) at leks experimentally treated with noise from natural gas drilling and roads decreased 29% and 73%, respectively, relative to paired controls. Decreases in abundance at leks treated with noise occurred in the first year of the study and continued throughout the experiment. Noise playback did not have a cumulative effect over time on peak male attendance. There was limited evidence for an effect of noise playback on peak female attendance at leks or male attendance the year after the experiment ended. Our results suggest that sage-grouse avoid leks with anthropogenic noise and that intermittent noise has a greater effect on attendance than continuous noise. Our results highlight the threat of anthropogenic noise to population viability for this and other sensitive species. AuthorsBlickley, Jessica L.; Blackwood, Diane; Patricelli, Gail L. Year Published2012 PublicationConservation Biology LocationsDOI10.1111/j.1523-1739.2012.01840.x |
| Seasonal reproductive costs contribute to reduced survival of female greater sage-grouse | Blomberg, Erik J. | 2013 |
KeywordsNo keywords available AbstractTradeoffs among demographic traits are a central component of life history theory. We investigated tradeoffs between reproductive effort and survival in female greater sage-grouse breeding in the American Great Basin, while also considering reproductive heterogeneity by examining covariance among current and future reproductive success. We analyzed survival and reproductive histories from 328 individual female greater sage-grouse captured between 2003 and 2011, and examined the effect of reproductive effort on survival and future reproduction. Monthly survival of females was variable within years, and this within-year variation was associated with distinct biological seasons. Monthly survival was greatest during the winter (NovemberMarch; phi W= 0.99 +/- 0.001 SE), and summer (JuneJuly; phi S= 0.98 +/- 0.01 SE), and lower during nesting (AprilMay; phi N= 0.93 +/- 0.02 SE) and fall (AugustOctober; phi F= 0.92 +/- 0.02 SE). Successful reproduction was associated with reduced monthly survival during summer and fall, and this effect was greatest during fall. Females that successfully fledged chicks had lower annual survival (0.47 +/- 0.05 SE) than females who were not successful (0.64 +/- 0.04 SE). Annual survival did not vary across years, consistent with a slow-paced life history strategy in greater sage-grouse. In contrast, reproductive success varied widely, and was positively correlated with annual rainfall. We found evidence for heterogeneity among females with respect to reproductive success; compared with unsuccessful females, females that raised a brood successfully in year t were more than twice as likely to be successful in year t+ 1. Female greater sage-grouse incur costs to survival associated with reproduction, however, variation in quality among females may override costs to subsequent reproductive output. AuthorsBlomberg, Erik J.; Sedinger, James S.; Nonne, Daniel V.; Atamian, Michael T. Year Published2013 PublicationJournal of Avian Biology LocationsDOI10.1111/j.1600-048X.2012.00013.x |
| A Landscape Approach for Ecologically Based Management of Great Basin Shrublands | Wisdom, Michael J. | 2009 |
Keywordscheatgrass; disturbance; resistance; sagebrush; Sage-grouse; woodlands AbstractNative shrublands dominate the Great Basin of western of North America, and most of these communities are at moderate or high risk of loss from non-native grass invasion and woodland expansion. Landscape-scale management based on differences in ecological resistance and resilience of shrublands can reduce these risks. We demonstrate this approach with an example that focuses on maintenance of sagebrush (Artemisia spp.) habitats for Greater Sage-grouse (Centrocercus urophasianus), a bird species threatened by habitat loss. The approach involves five steps: (1) identify the undesired disturbance processes affecting each shrubland community type; (2) characterize the resistance and resilience of each shrubland type in relation to the undesired processes; (3) assess potential losses of shrublands based on their resistance, resilience, and associated risk; (4) use knowledge from these steps to design a landscape strategy to mitigate the risk of shrubland loss; and (5) implement the strategy with a comprehensive set of active and passive management prescriptions. Results indicate that large areas of the Great Basin currently provide Sage-grouse habitats, but many areas of sagebrush with low resistance and resilience may be lost to continued woodland expansion or invasion by non-native annual grasses. Preventing these losses will require landscape strategies that prioritize management areas based on efficient use of limited resources to maintain the largest shrubland areas over time. Landscape-scale approaches, based on concepts of resistance and resilience, provide an essential framework for successful management of arid and semiarid shrublands and their native species. AuthorsWisdom, Michael J.; Chambers, Jeanne C. Year Published2009 PublicationRestoration Ecology LocationsDOI10.1111/j.1526-100X.2009.00591.x |
| A pressure-operated drop net for capturing Greater Sage-Grouse | Bush, Krista L. | 2008 |
Keywordscapture; drop net; greater Sage-Grouse; pressure operated; Sage-Grouse AbstractA pressure-operated drop net was developed to capture endangered Greater Sage-Grouse (Centrocercus urophasianus) in Alberta, Canada. A drop net was developed because other capture methods, such as night lighting and walk-in traps, have largely been unsuccessful in Alberta, and rocket netting was too dangerous to be used with an endangered population. Nets (one black and one gray) were used to capture 13 birds (12 males and 1 female) in six attempts. Nets dropped quickly (about 1 s) and quietly and captured all birds under the net. More birds (N = 12) were captured using a gray net than a black net, probably because it was less conspicuous. The presence of a drop net on the lek did not alter the behavior of the birds at the lek or influence lek attendance. The cost of a net, including all supplies, tools, and equipment needed, was $790 US ($900 CAN). This pressure-operated drop net system should prove effective for capturing other lekking species and other ground-dwelling birds that will respond to baiting. AuthorsBush, Krista L. Year Published2008 PublicationJournal of Field Ornithology LocationsDOI10.1111/j.1557-9263.2008.00146.x |
| Predators of Greater Sage-Grouse nests identified by video monitoring | Coates, Peter S. | 2008 |
KeywordsAmerican badger;
camera;
Centrocercus urophasianus;
Common Raven;
Greater Sage-Grouse;
ground squirrel;
nest predation;
Nevada;
video monitoring AbstractNest predation is the primary cause of nest failure for Greater Sage-Grouse (Centrocercus urophasianus), but the identity of their nest predators is often uncertain. Confirming the identity of these predators may be useful in enhancing management strategies designed to increase nest success. From 2002 to 2005, we monitored 87 Greater Sage-Grouse nests (camera, N = 55; no camera, N = 32) in northeastern Nevada and south-central Idaho and identified predators at 17 nests, with Common Ravens (Corvus corax) preying on eggs at 10 nests and American badgers (Taxidea taxis) at seven. Rodents were frequently observed at grouse nests, but did not prey on grouse eggs. Because sign left by ravens and badgers was often indistinguishable following nest predation, identifying nest predators based on egg removal, the presence of egg shells, or other sign was not possible. Most predation occurred when females were on nests. Active nest defense by grouse was rare and always unsuccessful. Continuous video monitoring of Sage-Grouse nests permitted unambiguous identification of nest predators. Additional monitoring studies could help improve our understanding of the causes of Sage-Grouse nest failure in the face of land-use changes in the Intermountain West. AuthorsCoates, Peter S.; Connelly, John W.; Delehanty, David J. Year Published2008 PublicationJournal of Field Ornithology LocationsDOI10.1111/j.1557-9263.2008.00189.x |
| Linking occurrence and fitness to persistence: Habitat-based approach for endangered Greater Sage-Grouse | Aldridge, Cameron L. | 2007 |
KeywordsAlberta, Canada; Centrocercus urophasianus; Cox proportional hazard; fitness; GreaterSage-Grouse; habitat; logistic regression; occurrence; persistence; population viability; sagebrush AbstractDetailed empirical models predicting both species occurrence and fitness across a landscape are necessary to understand processes related to population persistence. Failure to consider both occurrence and fitness may result in incorrect assessments of habitat importance leading to inappropriate management strategies. We took a two-stage approach to identifying critical nesting and brood-rearing habitat for the endangered Greater Sage-Grouse ( Centrocercus urophasianus) in Alberta at a landscape scale. First, we used logistic regression to develop spatial models predicting the relative probability of use ( occurrence) for Sage-Grouse nests and broods. Secondly, we used Cox proportional hazards survival models to identify the most risky habitats across the landscape. We combined these two approaches to identify Sage- Grouse habitats that pose minimal risk of failure ( source habitats) and attractive sink habitats that pose increased risk ( ecological traps). Our models showed that Sage- Grouse select for heterogeneous patches of moderate sagebrush cover ( quadratic relationship) and avoid anthropogenic edge habitat for nesting. Nests were more successful in heterogeneous habitats, but nest success was independent of anthropogenic features. Similarly, broods selected heterogeneous high- productivity habitats with sagebrush while avoiding human developments, cultivated cropland, and high densities of oil wells. Chick mortalities tended to occur in proximity to oil and gas developments and along riparian habitats. For nests and broods, respectively, approximately 10% and 5% of the study area was considered source habitat, whereas 19% and 15% of habitat was attractive sink habitat. Limited source habitats appear to be the main reason for poor nest success ( 39%) and low chick survival ( 12%). Our habitat models identify areas of protection priority and areas that require immediate management attention to enhance recruitment to secure the viability of this population. This novel approach to habitat- based population viability modeling has merit for many species of concern. AuthorsAldridge, Cameron L.; Boyce, Mark S. Year Published2007 PublicationEcological Applications LocationsDOI10.1890/05-1871 This article contributed by:Ecological Society of America |
| Limits on egg predation by Richardson's ground squirrels | Michener, GR | 2005 |
KeywordsNo keywords available AbstractTo test the inference, arising from circumstantial evidence, that Richardson's ground squirrels (Spermophilus richardsonii (Sabine, 1822)) frequently depredate eggs of greater sage-grouse (Centrocercus urophasianus (Bonaparte, 1827)), gape size was measured and the response of free-living squirrels to three sizes of eggs was observed. Maximum gape measured on carcasses was 26 mm and functional gape assessed from tooth imprints in artificial clay eggs was 17 mm. Squirrels left imprints in 46 of 110 clay eggs, but whether tested with domestic fowl (Gallus gallus (L., 1758)) or ring-necked pheasant (Phasianus colchicus L., 1758) eggs that approximated the maximum width of sage-grouse eggs or with much smaller Japanese quail (Coturnix japonica Temminck and Schlegel, 1849) eggs that approximated maximum gape, no squirrels (28 adults and at least 28 juveniles) spontaneously depredated eggs, even after multiple exposures. When re-tested with damaged eggs, 15 of 16 adult females scavenged contents, though usually not on their first exposure. After scavenging damaged eggs, 2 of 12 squirrels opened a few intact eggs, but only quail eggs and usually only if the shell was rough. Although Richardson's ground squirrels are potential scavengers of large damaged eggs and likely they could depredate small eggs, the inference from circumstantial evidence that they are major predators of greater sage-grouse eggs remains unsubstantiated. AuthorsMichener, GR Year Published2005 PublicationCanadian Journal of Zoology LocationsDOI10.1139/Z05-094 |
| Influence of wind speed on sage grouse metabolism | SHERFY, MH | 1995 |
KeywordsNo keywords available AbstractWe measured the effect of wind speed on the metabolic rate of six adult sage grouse (Centrocercus urophasianus) with indirect respiration calorimetry at ambient temperatures above, near, and below the lower critical temperature. There was a significant effect (P < 0.05) of temperature on metabolic rate at all wind speeds, and a significant effect (P < 0.05) of wind speed on metabolic rate for temperatures less than or equal to 0 degrees C. Wind speed had a more pronounced effect on metabolism at temperatures below the lower critical temperature for sage grouse. Metabolic rates measured at wind speeds of greater than or equal to 1.5 m/s were significantly higher than those measured at wind speeds < 1.5 m/s. Multiple regression analysis of wind speed (u; m/s) and temperature (T-a; degrees C) on metabolism (MR; mL O-2 . g(-1). h(-1)) yielded the equation MR = 0.0837 (u) - 0.0248 (T-a) + 0.5444. The predicted cost of thermoregulation at conditions of -5 degrees C and u = 1.5 mis was about 1.5 x standard metabolic rate; half the increase was due to wind. Measurements of wind speed in sagebrush (Artemisia spp.) stands indicate that such habitat effectively reduces wind speed to < 1.5 m/s. Microhabitat value should be recognized in the management of sagebrush stands. AuthorsSHERFY, MH; PEKINS, PJ Year Published1995 PublicationCanadian Journal of Zoology LocationsDOI10.1139/z95-088 |
| Spatial and temporal patterns of predation of simulated sage grouse nests at high and low nest densities: an experimental study | NIEMUTH, ND | 1995 |
KeywordsNo keywords available AbstractWe examined patterns of predation on 252 simulated sage grouse (Centrocercus urophasianus) nests placed at two densities around six active leks in southeastern Wyoming, U.S.A. Predation intensity, as measured by the frequency of multiple-nest predation events, was significantly greater at high-density sites, implying enhanced prey capture (functional and (or) numerical response) by predators. Significant spatial aggregation of nest predation further implies enhanced prey capture by predators at high prey densities. Predation varied significantly among sites, but there were no significant first-order differences in predation between densities. Predation was also significantly affected by year-density and site-year-density interactions. Several factors, including nest cover, prey defense mechanisms, study site location, nest location, year, search methods of predators, number of predators, and random encounter may inhibit or confound density-dependent nest predation. Enhanced prey capture provides a mechanism for density-dependent population regulation. AuthorsNIEMUTH, ND; BOYCE, MS Year Published1995 PublicationCanadian Journal of Zoology LocationsDOI10.1139/z95-096 |
| Landscape features and weather influence nest survival of a ground-nesting bird of conservation concern, the greater sage-grouse, in human-altered environments. | Webb, Stephen L. | 2012 |
Keywordsbehavior, Centrocercus urophasianus, conservation, greater sage-grouse, depredation, generalized linear mixed model, management, nest survival, weather AbstractIntroduction: Ground-nesting birds experience high levels of nest predation. However, birds can make selection decisions related to nest site location and characteristics that may result in physical, visual, and olfactory impediments to predators. Methods: We studied daily survival rate (DSR) of greater sage-grouse (Centrocercus urophasianus) from 2008 to 2010 in an area in Wyoming experiencing large-scale alterations to the landscape. We used generalized linear mixed models to model fixed and random effects, and a correlation within nesting attempts, individual birds, and years. Results: Predation of the nest was the most common source of nest failure (84.7%) followed by direct predation of the female (13.6%). Generally, landscape variables at the nest site (= 30 m) were more influential on DSR of nests than features at larger spatial scales. Percentage of shrub canopy cover at the nest site (15-m scale) and distances to natural gas wells and mesic areas had a positive relationship with DSR of nests, whereas distance to roads had a negative relationship with DSR of nests. When added to the vegetation model, maximum wind speed on the day of nest failure and a 1-day lag in precipitation (i.e., precipitation the day before failure) improved model fit whereby both variables negatively influenced DSR of nests. Conclusions: Nest site characteristics that reduce visibility (i.e., shrub canopy cover) have the potential to reduce depredation, whereas anthropogenic (i.e., distance to wells) and mesic landscape features appear to facilitate depredation. Last, predators may be more efficient at locating nests under certain weather conditions (i.e., high winds and moisture). AuthorsWebb, Stephen L.; Olson, Chad V.; Dzialak, Matthew R.; Harju, Seth M.; Winstead, Jeffrey B.; Lockman, Dusty Year Published2012 PublicationEcological Processes LocationsDOI10.1186/2192-1709-1-4 |
