Microsatellite analysis of female mating behaviour in lek-breeding sage grouse (vol 10, pg 2043, 2001) | Semple, KE | 2002 |
Microsatellite analysis of female mating behaviour in lek-breeding sage grouse (vol 10, pg 2043, 2001)KeywordsNo keywords available AbstractNo abstract available AuthorsSemple, KE; Wayne, RK; Gibson, RM Year Published2002 PublicationMolecular Ecology Locations |
Microsatellite analysis of female mating behaviour in lek-breeding sage grouse | Semple, K | 2001 |
Keywordslek mating; microsatellite DNA; paternity; sexual selection; sage grouse AbstractWe used microsatellite DNA markers to genotype chicks in 10 broods of lek-breeding sage grouse, Centrocercus urophasianus, whose mothers' behaviour was studied by radiotracking and observing leks. Previous behavioural studies suggested that almost all matings are performed by territorial males on leks and that multiple mating is rare. Two broods (20%) were sired by more than one male. Genetic analyses of the broods of eight females that visited an intensively studied lek were consistent with behavioural observations. Four females observed mating produced singly sired broods and males other than the individual observed copulating were excluded as sires for most or all of their chicks. Territorial males at the study lek were excluded as sires of broods of four other females that visited the lek but were not observed mating there. Radio-tracking suggested that two of these females mated at other leks. Our results confirm the reliability of mating observations at leks, but do not rule out a possible unseen component of the mating system. AuthorsSemple, K; Wayne, RK; Gibson, RM Year Published2001 PublicationMolecular Ecology LocationsDOI10.1046/j.0962-1083.2001.01348.x |
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 |
Assessing Compensatory Versus Additive Harvest Mortality: An Example Using Greater Sage-Grouse. | SEDINGER, JAMES S. | 2010 |
KeywordsCentrocercus urophasianus;compensatory harvest;exploitation;Markov chain Monte Carlo;survival AbstractWe used band-recovery data from 2 populations of greater sage-grouse (Centrocercus urophasianus), one in Colorado, USA, and another in Nevada, USA, to examine the relationship between harvest rates and annual survival. We used a Seber parameterization to estimate parameters for both populations. We estimated the process correlation between reporting rate and annual survival using Markov chain Monte Carlo methods implemented in Program MARK. If hunting mortality is additive to other mortality factors, then the process correlation between reporting and survival rates will be negative. Annual survival estimates for adult and juvenile greater sage-grouse in Nevada were 0.42 ± 0.07 (x ¯ ± SE) for both age classes, whereas estimates of reporting rate were 0.15 ± 0.02 and 0.16 ± 0.03 for the 2 age classes, respectively. For Colorado, average reporting rates were 0.14 ± 0.016, 0.14 ± 0.010, 0.19 ± 0.014, and 0.18 ± 0.014 for adult females, adult males, juvenile females, and juvenile males, respectively. Corresponding mean annual survival estimates were 0.59 ± 0.01, 0.37 ± 0.03, 0.78 ± 0.01, and 0.64 ± 0.03. Estimated process correlation between logit-transformed reporting and survival rates for greater sage-grouse in Colorado was ? = 0.68 ± 0.26, whereas that for Nevada was ? = 0.04 ± 0.58. We found no support for an additive effect of harvest on survival in either population, although the Nevada study likely had low power. This finding will assist mangers in establishing harvest regulations and otherwise managing greater sage-grouse populations. AuthorsSEDINGER, JAMES S., GARY C. WHITE, SHAWN ESPINOSA, ED T. PARTEE and CLAIT E. BRAUN. Year Published2010 PublicationJournal of Wildlife Management LocationsDOI10.2193/2009-071 |
Mating behavior of the Sage Grouse. | Scott, J. W. | 1942 |
Mating behavior of the Sage Grouse.KeywordsNo keywords available AbstractNo abstract available AuthorsScott, J. W. Year Published1942 PublicationThe Auk: Ornithological Advances Locations |
Changes in the distribution and abundance of sage grouse in Washington. | Schroeder, Michael A. | 2000 |
KeywordsSage grouse, Centrocercus urophasianus, abundance, distribution, shrub-steppe, survey, Washington habitat fragementation AbstractSage grouse (Centrocercus urophasianus) historically occurred in shrub-steppe and meadow-steppe communities throughout much of eastern Washington. The decline in distribution has been dramatic; 73% of 67 lek complexes documented since 1960 are currently vacant. Many vacant lek complexes (53%) are in areas where sage grouse have been recently extirpated. The current range is about 8% of the historic range, occurring in 2 relatively isolated areas. Based on changes in number of males counted on lek complexes, the sage grouse population size in Washington declined at least 77% from 1960 to 1999; the 1999 spring population was estimated to be about 1,100 birds. Historic and recent declines of sage grouse are linked to conversion of native habitat for production of crops and degradation of the remaining native habitat. Although declines in populations of sage grouse appear to be slowing, the small size and isolated nature of the 2 remaining populations may be a long-term problem. Management should be directed toward protecting, enhancing, expanding, and connecting the existing populations. AuthorsSchroeder, Michael A.; Hays, David W.; Livingston, Michael F.; Stream, Leray E.; Jacobson, John E.; Pierce, D. John Year Published2000 PublicationNorthwestern Naturalist LocationsDOI10.2307/3536821 |
Unusually High Reproductive Effort by Sage Grouse in a Fragmented Habitat in North-Central Washington | Schroeder, MA | 1997 |
KeywordsCentrocercus urophasianus, clutch size, life history, nesting, productivity, renesting, Sage Grouse AbstractProductivity of Sage Grouse (Centrocercus urophasianus) was studied in north-central Washington during 1992-1996. Nest timing and success, clutch size, probability of nesting and renesting, and variation associated with age and year were examined for 84 females monitored with the aid of radio telemetry. Although date of nest initiation varied annually, yearling females (hatched in previous year) consistently nested later than adults; mean date of initiation of incubation was 22 April overall. The average nest contained 9.1 eggs and was incubated for 27 days. Clutch size was smaller for renests than for first nests; clutch size also varied annually. Although the overall rate of nest success was only 36.7%, all females apparently nested at least once, and at least 87.0% of females renested following predation of their first nests. As a result of renesting, annual breeding success was estimated as 61.3%. Percent of all females that produced a brood at least 50 days old was 49.5%; at least 33.4% of 515 chicks survived greater than or equal to 50 days following hatch. Although the rates of nesting and renesting appear to have been under-estimated in other studied populations, Sage Grouse in north-central Washington display more reproductive effort overall; they lay more eggs and are more likely to nest and renest. AuthorsSchroeder, MA Year Published1997 PublicationThe Condor: Ornithological Applications LocationsDOI10.2307/1370144 |
Fidelity of greater sage-grouse Centrocercus urophasianus to breeding areas in a fragmented landscape | Schroeder, MA | 2003 |
Fidelity of greater sage-grouse Centrocercus urophasianus to breeding areas in a fragmented landscapeKeywordsCentrocercus urophasianus, fidelity, greater sage-grouse, landscape fragmentation, lek visitation, nesting success, Washington AbstractIn this paper, we report on breeding site fidelity for a small, localized population of greater sage-grouse Centrocercus urophasianus inhabiting a highly altered and fragmented landscape in north-central Washington, USA. One hundred sixteen greater sage-grouse were captured, fitted with radio transmitters and monitored during 1992-1998. Of 19 males captured as adults and nine captured as yearlings, one and four, respectively, were observed visiting two different leks. Of 78 females, 24 were observed visiting at least two leks, and eight visited at least three leks. Although the incidence of multiple lek visitation was similar to what has been reported for other regions, the average of 10.2 km distance between neighbouring leks was substantially further in north-central Washington. Average distance between a female's first nest and her renest was higher for yearlings (6.3 km) than for adults (2.0 km). Successful females moved an average of 1.6 km and unsuccessful females moved 5.2 km to nest in subsequent years. Most distances between consecutive nests were < 3.0 km, but some females, including adults, moved > 20 km. These data suggest that fidelity of greater sage-grouse to nesting areas in north-central Washington is substantially lower than has been found for other populations. Although the relationship between behaviour of greater sage-grouse and regional habitat fragmentation is a possible explanation for these observations, we were not able to detect a correlation between fidelity and local habitat availability. AuthorsSchroeder, MA; Robb, LA Year Published2003 PublicationWildlife Biology Locations |
Sarcocystis rileyi in Sage Grouse | SALT, WR | 1958 |
KeywordsNo keywords available AbstractNo abstract available AuthorsSALT, WR Year Published1958 PublicationThe Journal of Parasitology LocationsDOI10.2307/3274418 |
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 |