| 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 |
| Microsatellite DNA analysis shows that greater sage grouse leks are not kin groups | Gibson, RM | 2005 |
Keywordskinship; lek skew paradox; microsatellite analysis; sage grouse AbstractThe spectacular social courtship displays of lekking birds are thought to evolve via sexual selection, but this view does not easily explain the participation of many males that apparently fail to mate. One of several proposed solutions to this 'lek skew paradox' is that kin selection favours low-ranking males joining leks to increase the fitness of closely related breeders. We investigated the potential for kin selection to operate in leks of the greater sage grouse, Centrocercus urophasianus, by estimating relatedness between lekking males using microsatellite DNA markers. We also calibrated these estimates using data from known families. Mean relatedness within leks was statistically indistinguishable from zero. We also found no evidence for local clustering of kin during lek display, although males tended to range closer to kin when off the lek. These results make kin selection an unlikely solution to the lek skew paradox in sage grouse. Together with other recent studies, they also raise the question of why kin selection apparently promotes social courtship in some lekking species, but not in others. AuthorsGibson, RM; Pires, D; Delaney, KS; Wayne, RK Year Published2005 PublicationMolecular Ecology LocationsDOI10.1111/j.1365-294X.2005.02746.x |
| 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 |
| Normal hematologic and biochemical values for prelaying greater sage grouse (Centrocercus urophasianus) and their influence on chick survival | Dunbar, MR | 2005 |
KeywordsCentrocercus urophasianus, hematology, nutrition, sage grouse, serum AbstractDeclines in greater sage grouse (Centrocercus urophasianus) productivity and population numbers throughout their range demand a better understanding of how nutrition influences sage grouse populations. During March and April 1999-2001, blood samples were collected from 158 female (73 adult, 85 yearling), free-ranging, prelaying, greater sage grouse from an area in northwestern Nevada, USA, and southeastern Oregon, USA. These blood samples were evaluated to establish normal blood values for sage grouse and ascertain if certain blood parameters, as indices of nutrition, are useful for predicting if sage grouse hens would raise at least one chick to 1 August. Results of logistic regression indicated that three of six blood parameters analyzed-glucose, total plasma protein, and calcium phosphorus ratio-affected the probability of a female sage grouse raising at least one chick to late summer. Ranking of the standardized estimates revealed that glucose and total plasma protein had the greatest impact on the likelihood of a female successfully raising chicks. Odds ratios indicated that a 1-unit increase in glucose (1 mg/dl) and plasma protein (0.1 g/dl) would result in a 4% and 113% positive increase, respectively, in the predicted odds of at least one chick surviving until 1 August. Odds ratios for calcium : phosphorus ratio revealed a 70% decline in the predicted odds of at least one chick surviving until 1 August if the level of this parameter increased one unit (e.g., 3:1 to 4:1). Based on these analyses, values of some blood parameters used as indices of nutrition, especially glucose, total plasma protein, and calcium : phosphorus ratio, can be successfully used to predict reproductive success of sage grouse. These parameters are not only indicative of the nutritional status of prelaying hens but may be associated with nutritional quality of the habitat and therefore have important management significance. AuthorsDunbar, MR; Gregg, MA; Crawford, JA; Giordano, MR; Tornquist, SJ Year Published2005 PublicationJournal of Zoo And Wildlife Medicine LocationsDOI10.1638/04-065.1 |
| Spatial distribution of Greater Sage-Grouse nests in relatively contiguous sagebrush habitats | Holloran, MRJ | 2005 |
KeywordsCentrocercus urophasianus, fidelity, Greater Sage-Grouse, lek-to-nest distance, nest distribution, nest spacing, Wyoming AbstractDegradation of nesting habitat has been proposed as a factor contributing to Greater Sage-Grouse (Centrocercus urophasianus) population declines throughout North America. Delineating suitable nesting habitat across landscapes with relatively contiguous sagebrush cover is difficult but important to identify areas for protection. We used radiotelemetry to locate Greater Sage-Grouse nests in relatively contiguous sagebrush habitats in Wyoming to investigate the spatial arrangement of nests relative to lek and other nest locations. Nest distributions were spatially related to lek location within 3 and 5 km of a lek, and a 5-km buffer included 64% of the nests. There was no relationship between lek size and lek-to-nest distance, suggesting that accurate population trend evaluation might require lek surveys in addition to lek counts. Closest known lek-to-nest distance was greater for successfully hatched compared to destroyed nests, and closely spaced nests tended to experience lower success and have higher probabilities of both nests experiencing the same fate compared to isolated nests, suggesting that a mechanism of enhanced prey detection occurred at higher nest densities. A low probability that a given individual's consecutive-year nest spacing occurred randomly suggested nesting site-area fidelity. Although a grouped pattern of nests occurred within 5 km of a lek, the proportion of nesting females located farther than 5 km could be important for population viability. Managers should limit strategies that negatively influence nesting habitat regardless of lek locations, and preserve adequate amounts of unaltered nesting habitat within treatment boundaries to maintain nest dispersion and provide sites for philopatric individuals. AuthorsHolloran, MRJ; Anderson, SH Year Published2005 PublicationThe Condor: Ornithological Applications Locations- Kemmerer, Wyoming (45.883, -110.9)
- Rawlins, Wyoming (44.116, -107.266)
- Pinedale, Wyoming (42.75, -109.916)
- Jonah, Wyoming (42.55, -109.666)
- Lander, Wyoming (42.55, -108.483)
- Casper, Wyoming (42.416, -106.166)
- Farson, Wyoming (42.333, -109.133)
DOI10.1650/7749.1 |
| Population genetics of Gunnison sage-grouse: Implications for management | Oyler-McCance, SJ | 2005 |
KeywordsColorado, Centrocercus minimus, gene flow, genetic diversity, Gunnison sage-grouse, microsatellites, mitochondrial DNA, Utah AbstractThe newly described Gunnison sage-grouse (Centrocercus minimus) is a species of concern for management because of marked declines in distribution and abundance due to the loss and fragmentation of sagebrush habitat. This has caused remaining populations to be unusually small and isolated. We utilized mitochondrial DNA sequence data and data from 8 nuclear microsatellites to assess the extent of population subdivision among Gunnison sage-grouse populations in southwestern Colorado and southeastern Utah, USA. We found a high degree of population structure and low amounts of gene flow among all pairs of populations except the geographically adjacent Gunnison and Curecanti populations. Population structure for Gunnison sage-grouse was significantly higher than has been reported for greater sage-grouse (C. urophasianus). Further, we documented low levels of genetic diversity in some populations (particularly Dove Creek/Monticello and Pinon Mesa with an average of only 3.00 and 2.13 alleles per locus respectively) indicating that translocations from larger, more genetically diverse populations may be warranted. Bayesian analysis identified 3 potential migrants (involving San Miguel, Dove Creek/Monticello, Crawford, and Curecanti). Further, this analysis showed that 4 individuals from Cerro/Cimarron were more closely related to birds from San Miguel than to its geographically closer neighbors Gunnison and Curecanti. This suggests the Cerro/Cimarron area may act as a stepping stone for gene flow between San Miguel and Gunnison and that habitat restoration and protection in areas between these 2 basins should be a priority in an attempt to facilitate natural movement among these populations. Conservation plans should include monitoring and maintaining genetic diversity, preventing future habitat loss and fragmentation, enhancing existing habitat, and restoring converted sagebrush communities. AuthorsOyler-McCance, SJ; St John, J; Taylor, SE; Apa, AD; Quinn, TW Year Published2005 PublicationJournal of Wildlife Management LocationsDOI10.2193/0022-541X(2005)069[0630:PGOGSI]2.0.CO;2 |
| Greater sage-grouse nesting habitat selection and success in Wyoming | Holloran, MJ | 2005 |
KeywordsCentrocercus urophasianus, habitat, nest, residual grass, sage-grouse, sagebrush, Wyoming AbstractNesting habitat degradation and its negative effect on nesting success might contribute to the recent population and distributional declines of greater sage-grouse (Centrocercus urophasianus) throughout North America. We used radiotelemetry to locate greater sage-grouse nests in 7 different areas of central and southwestern Wyoming between 1994 and 2002; we studied each area for 2 to 4 years. Using binary logistic regression, we compared microsite vegetal data collected at nests (n = 457) and random (n = 563) sites and successful (n = 211) and unsuccessful (n = 238) nests to test hypotheses concerning greater sage-grouse nesting habitat selection and vegetal conditions associated with nesting success. We used Akaike's Information Criterion (AIC(c)) and model averaging to make inference about the weighted support for the importance of individual habitat variables through the comparison of sets of competing models. Selected nest sites were located in areas with increased total shrub canopy cover (relative importance [RI] = 1.00), residual grass cover (RI = 0.47), and residual grass height (RI = 0.77) compared to random sites. Successful nests had increased residual grass cover (RI = 0.43) and height (RI = 0.48) relative to unsuccessful nests. Additionally, annual nest success rates (i.e., above vs. below our study's average) were related to the preceding year's spring (Apr-May; RI = 0.44) and winter-early spring (Jan-Jun) precipitation (RI = 0.32). Correct classification rates for weighted average models that we derived through the 3 comparisons were between 60 and 70%, suggesting the variables adequately differentiated between plot types. However, high model selection uncertainty (i.e., the total number of models included in the sets of AIC(c)-selected models) suggested that nest site selection and nesting success may be influenced by factors not considered in the modeling process. Management strategies that protect dense sagebrush stands and enhance residual grass cover and height within those stands should be used to maintain nesting habitat and increase nesting success of greater sage-grouse. AuthorsHolloran, MJ; Heath, BJ; Lyon, AG; Slater, SJ; Kuipers, JL; Anderson, SH Year Published2005 PublicationJournal of Wildlife Management Locations- Kemmerer, Wyoming (45.883, -110.9)
- Rawlins, Wyoming (44.116, -107.266)
- Pinedale, Wyoming (42.75, -109.916)
- Jonah, Wyoming (42.55, -109.666)
- Lander, Wyoming (42.55, -108.483)
- Casper, Wyoming (42.416, -106.166)
- Farson, Wyoming (42.3333, -109.133)
DOI10.2193/0022-541X(2005)069[0638:GSNHSA]2.0.CO;2 |
| Husbandry of wild-caught greater sage-grouse | Oesterle, P | 2005 |
KeywordsArtemisia, Centrocercus urophasianus, husbandry, sage-grouse, West Nile virus AbstractThis study reports the first successful husbandry and breeding in captivity of wild-caught greater sage-grouse (Centrocercus urophasianus). In October 2003, 21 hatch-year greater sage-grouse were trapped in northwestern Nevada and transported to Fort Collins, Colorado. We held grouse in pens at the United States Department of Agriculture's National Wildlife Research Center for 8 months. We offered a varied diet, including native food items such as sagebrush (Artemisia tridentata and A. tripartita) and yarrow (Achillea millefolium). We housed grouse in a large flight pen and allowed to them free-range as one flock. Mortality rate was 16.7%. Several of the grouse exhibited breeding behavior, and 13 eggs were laid. We describe the techniques used to house and feed wild-caught sage-grouse. This study has conservation implications for captive breeding of this species of concern. AuthorsOesterle, P; McLean, R; Dunbar, M; Clark, L Year Published2005 PublicationWildlife Society Bulletin LocationsDOI10.2193/0091-7648(2005)33[1055:HOWGS]2.0.CO;2 |
| West Nile virus and sage-grouse: What more have we learned? | Naugle, DE | 2005 |
KeywordsCentrocercus urophasianus; emerging infectious disease; monitoring; population decline; sage-grouse; survival; West Nile virus AbstractWest Nile virus (WNv) has emerged as a new issue in the conservation of native avifauna in North America. Mortality associated with WNv infection decreased survival of female greater sage-grouse (Centrocercus urophasianus) by 25% across 4 populations in Wyoming and Montana, USA, and Alberta, Canada, in 2003. In 2004 WNv spread to populations in Colorado and California, and female survival in late summer was 10% lower at 4 sites with confirmed WNv mortalities (86% survival) than at 8 sites without (96%). We still have no evidence that sage-grouse show resistance to the virus. The 2004 WNv season was not the catastrophe that many had predicted, and the decrease in prevalence of infection and mortality in sage-grouse, humans, and horses (except in California) has left many wondering if the worst has past. Evidence suggests that risk of infection was low in 2004 because unseasonably cool summer temperatures delayed or reduced mosquito production. Moreover, mortalities occurred 2-3 weeks later in 2004 than in 2003, and the shift to later timing was consistent between years at sites where WNv reduced survival both years. Mosquito surveillance data indicated a sharp decline in prevalence and infection rate of adult C. tarsalis in southeast Alberta, the most northern latitude where WNv reduced survival, in 2003 but not in 2004. A full understanding of the implications of WNv for sage-grouse requires a long-term, coordinated monitoring strategy among researchers and a sensitivity analysis to evaluate the role of WNv in population viability. Epidemiological research examining the prevalence and ecology of the virus among reservoir hosts is crucial. AuthorsNaugle, DE; Aldridge, CL; Walker, BL; Doherty, KE; Matchett, MR; McIntosh, J; Cornish, TE; Boyce, MS Year Published2005 PublicationWildlife Society Bulletin Locations- Alberta, Canada (49.4, -110.702)
- Phillips County, Montana (48.2, -107.933)
- Central Washington (46.779, -119.486)
- Roundup, Montana (46.4453, -108.541)
- Southern Powder River Basin, Wyoming (44.3442, -106.293)
- Lander, Wyoming (42.8331, -108.73)
- Upper Green River Basin, Wyoming (42.742, -109.869)
- Routt County, Colorado (40.5167, -106.983)
- Moffat County, Colorado. Axial Basin 40 km southwest of Craig, Colorado. (40.2602, -107.881)
- Gunnison County Colorado (38.7, -107.067)
- Mono County, California (37.9167, -118.867)
DOI10.2193/0091-7648(2005)33[616:WNVASW]2.0.CO;2 |
| Effect of harvest on sage-grouse Centrocercus urophasianus populations: what can we learn from the current data? | Sedinger, JS | 2005 |
KeywordsCentrocercus urophasianus, exploitation, harvest, population dynamics, sage-grouse AbstractUnderstanding the impact of human harvest is fundamental to the effective management of many wildlife populations. Such understanding has been elusive because harvest mortality may compensate for other sources of mortality when the mortality process is density dependent. This problem is exacerbated by the ubiquitous positive con-elation between harvest regulations and population size: more harvest is allowed when populations are larger. Connelly et al. (2003) studied the impact of harvest regulations on sage-grouse Centrocercus urophasianus using three sets of regulations: closed season, 1 -bird bag and seven-day season, 2-bird bag and 23-day season. Connelly et al. (2003) reported a generally negative correlation between harvest regulations and increase in number of males on leks for harvest regulations that ranged from a hunting closure to a 23-day season with a 2-bird bag. Because lek sizes were smaller where hunting was closed there was confounding between harvest and population density, making it difficult to distinguish harvest effects from those of population density. Based on a simple simulation the apparent effects of harvest on change in population size observed by Connelly et al. (2003) could be produced entirely by density-dependent phenomena. Additionally, lambda (finite rate of population increase) was greater in areas with more restrictive harvest regulations. lambda is a ratio of Nt+1 to N-t, however, and there is a negative sampling covariance between lambda and N-t; we expect lambda to be larger when N-t is smaller based purely on this statistical fact. The study by Connelly et al. (2003) is an important attempt to study effects of harvest on population dynamics of sage-grouse. We do not argue that either additive mechanisms in survival or compensatory mechanisms in survival or reproduction influence the relationship between harvest and population dynamics of sage-grouse, but that correlation between population size and harvest regulations, combined with statistical issues make it impossible to distinguish between these two hypotheses in Connelly et al. (2003). AuthorsSedinger, JS; Rotella, JJ Year Published2005 PublicationWildlife Biology LocationsDOI10.2981/0909-6396(2005)11[371:EOHOSC]2.0.CO;2 |
