| 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 |
| Effects of prescribed fire on movements of female Sage Grouse from breeding to summer ranges | Fischer, RA | 1997 |
Effects of prescribed fire on movements of female Sage Grouse from breeding to summer rangesKeywordsNo keywords available AbstractWe compared summer movement patterns of female Sage Grouse (Centrocercus urophasianus) in southeastern Idaho before (1987-1989) and after (1990-1992) a prescribed fire which removed vegetation cover, primarily Wyoming big sagebrush (Artemisia tridentata wyomingensis), from approximately 57% of a 5800 ha area. Grouse moved 1-69 km ((x) over bar = 17.8 +/- 2.0 km [SE]; N = 81) from breeding and nesting areas to summer ranges, predominantly in northwest or southwest directions during the 6-year period. There was no difference in timing, distance, or direction moved between birds captured in burned and unburned habitats. The data provided further evidence of traditional migration routes for Sage Grouse breeding and nesting in the Big Desert. AuthorsFischer, RA; Wakkinen, WL; Reese, KP; Connelly, JW Year Published1997 PublicationWilson Bulletin Locations |
| Nesting Habitat Selection by Sage Grouse in South-Central Washington | Sveum, CM | 1998 |
KeywordsNo keywords available AbstractTo characterize western sage grouse (Centrocercus urophasianus phaios Bonaparte) nesting habitat in sagebrush-steppe habitat in Washington, we initiated a study on the Yakima Training Center to determine nesting habitat characteristics and whether these characteristics differed between successful and depredated nests. Most nests (71%) were in big sagebrush (Artemesia tridentata Nutt.)/bunchgrass communities. Nest habitat was characterized by greater shrub cover, shrub height, vertical cover height, residual cover, and litter than at random locations, Successful 1-m(2) nest sites within big sagebrush/bunchgrass in 1992 had less shrub cover (51%) and shrub height (64 cm) than depredated nest sites (70% and 90 cm, respectively). Successful 77-m(2) nest areas in big sagebrush/bunchgrass in 1993 had more tall grass (greater than or equal to 18 cm) than depredated nest areas. Management that protects the big sagebrush/bunchgrass community is essential for maintaining nesting habitat for sage grouse. AuthorsSveum, CM; Edge, WD; Crawford, JA Year Published1998 PublicationJournal of Range Management LocationsDOI10.2307/4003409 |
| Use and selection of brood-rearing habitat by Sage Grouse in south central Washington | Sveum, CM | 1998 |
Use and selection of brood-rearing habitat by Sage Grouse in south central WashingtonKeywordsNo keywords available AbstractSage Grouse (Centrocercus urophasianus) brood-habitat use was examined during 1992 and 1993 at the Yakima Training Center in Yakima and Kittitas counties, Washington. During the 2 yr we followed 38 broods, of which 12 persisted to 1 August ((x) over bar = approximately 1.5 chicks/brood). Food forb cover was greater at all brood locations than at random locations. Hens with broods in big sagebrush/bunchgrass habitat (Artemisia tridentata/Agropyron spicatum) selected for greater food forb cover, total forb cover, and lower shrub heights; broods in altered big sagebrush/bunchgrass habitats selected greater tall grass cover and vertical cover height; broods in grassland showed no preference for any measured vegetation characteristics. During the early rearing period (post-hatching-6 wk) each year, broods selected sagebrush/bunchgrass. Broods in 1993 made greater use of grasslands than in 1992 and selected grassland during the late brood-rearing period (7-12 wk). Broods selected for sagebrush/bunchgrass during midday, but 52% of brood locations in the afternoon were in grassland. Tall grass cover was greater at morning (0500-1000 h) and afternoon (1501-2000 h) brood locations than at midday (1001-1500 h) and random locations. Midday brood locations had greater shrub cover and height than morning and afternoon locations. Selection of habitat components was similar to the results of other studies, but habitat conditions coupled with a possible lack of alternate brood-rearing cover types resulted in low survival of chicks. AuthorsSveum, CM; Crawford, JA; Edge, WD Year Published1998 PublicationGreat Basin Naturalist Locations |
| A population genetic comparison of large- and small-bodied sage grouse in Colorado using microsatellite and mitochondrial DNA markers | Oyler-McCance, SJ | 1999 |
KeywordsColorado;gene flow;microsatellites;mtDNA;sage grouse;speciation AbstractSage grouse (Centrocercus urophasianus) from southwestern Colorado and southeastern Utah (United States) are 33% smaller than all other sage grouse and have obvious plumage and behavioural differences. Because of these differences, they have been tentatively recognized as a separate 'small-bodied' species. We collected genetic evidence to further test this proposal, using mitochondrial sequence data and microsatellite markers to determine whether there was gene flow between the two proposed species. Significant differences in the distribution of alleles between the large- and small-bodied birds were found in both data sets. Analysis of molecular variance (AMOVA) revealed that 65% of the variation in mitochondrial DNA (mtDNA) haplotypes could be explained by the large- vs, small-bodied distinction. Genetic distances and neighbour-joining trees based on allelic frequency data showed a distinct separation between the proposed species, although cladistic analysis of the phylogenetic history of the mitochondrial sequence haplotypes has shown a lack of reciprocal monophyly. These results further support the recognition of the small-bodied sage grouse as a distinct species based on the biological species concept, providing additional genetic evidence to augment the morphological and behavioural data. Furthermore, small-bodied sage grouse had much less genetic variation than large-bodied sage grouse, which may have implications for conservation issues. AuthorsOyler-McCance, SJ; Kahn, NW; Burnham, KP; Braun, CE; Quinn, TW Year Published1999 PublicationMolecular Ecology Locations- Cold Springs, Colorado (40.8672, -108.827)
- North Park, Colorado (40.7835, -106.176)
- Blue Mountain Colorado (40.2483, -108.861)
- Middle Park, Colorado (40.0867, -106.217)
- Eagle Colorado (39.6553, -106.828)
- Crawford, Colorado (38.7039, -107.608)
- Gunnison Basin, Colorado (38.5458, -106.925)
- Dry Creek, Colorado (38.0459, -108.554)
- Dove Creek, Colorado (37.6331, -108.915)
DOI10.1046/j.1365-294x.1999.00716.x |
| Viability and Conservation of an Exploited Sage Grouse Population | Johnson, KH | 1999 |
KeywordsNo keywords available AbstractWe analyzed the viability of the Sage Grouse (Centrocercus urophasianus) population of North Park, Colorado, to evaluate its supposed decline due to hunting pressure and habitat degradation. Demographic data from 23 years of surveys were used to parameterize a post-breeding, female-based projection matrix with three life stages:juveniles, yearlings, and adults The population was found to be approximately stable or in decline only if immigration and apparent surveying errors were factored from the data set. Adult and juvenile survival and adult and juvenile reproduction, respectively, were identified as the most limiting demographic factors. Empirical evidence from designed experiments with Sage Grouse has shown that these demographic factors respond markedly to habitat manipulations, especially brush manipulation. Several plausible management scenarios were evaluated with 100-year population projections generated through Monte Carlo simulation (1000 iterations), sampling from a normal probability distribution entraining the observed variability in each demographic parameter (95% confidence limits). Habitat manipulations to achieve moderate levels (similar to 15% canopy cover) of sagebrush (Artemisia tridentata) are recommended Regression analyses with power tests showed correspondence between hunting mortality and total mortality for juveniles and adults. Provided that habitat manipulations improve the survival of juveniles and adults, population viability may be conserved without reducing harvest by hunters. AuthorsJohnson, KH; Braun, CE Year Published1999 PublicationConservation Biology LocationsDOI10.1046/j.1523-1739.1999.97284.x |
| Directional acoustic radiation in the strut display of male sage grouse Centrocercus urophasianus | Dantzker, MS | 1999 |
Directional acoustic radiation in the strut display of male sage grouse Centrocercus urophasianusKeywordsNo keywords available AbstractWe present evidence that the acoustic component of the strut display of male sage grouse Centrocercus urophasianus is highly directional and that the nature of this directionality is unique among measured vertebrates. Where vertebrate acoustic signals have been found to be directional, they rare most intense anteriorly and are bilaterally symmetrical. Our results show that sage grouse acoustic radiation (beam) patterns are often asymmetric about the birds' anterior-posterior axis. The beam pattern of the 'whistle' note is actually strikingly bilobate with a deep null directly in front of the displaying bird. While the sage grouse display serves to attract potential mates, male sage grouse rarely face females head on when they call. The results of this study suggest that males may reach females with a high-intensity signal despite their preference for an oblique display posture relative to those females. We characterized these patterns using a novel technique that allowed us to map acoustic radiation patterns of unrestrained animals calling in the wild. Using an eight-microphone array, our technique integrates acoustic localization with synchronous pressure-field measurements while controlling for small-scale environmental variation in sound propagation. AuthorsDantzker, MS; Deane, GB; Bradbury, JW Year Published1999 PublicationJournal of Experimental Biology Locations |
| Molecular analysis of genetic variation among large- and small-bodied sage grouse using mitochondrial control-region sequences | Kahn, NW | 1999 |
Molecular analysis of genetic variation among large- and small-bodied sage grouse using mitochondrial control-region sequencesKeywordsNo keywords available AbstractNo abstract available AuthorsKahn, NW; Braun, CE; Young, JR; Wood, S; Mata, DR; Quinn, TW Year Published1999 PublicationThe Auk: Ornithological Advances Locations- Cold Springs, Colorado (40.8672, -108.827)
- Blue Mountain Colorado (40.2483, -108.861)
- Eagle Colorado (39.6553, -106.828)
- Middle Park, Colorado (40.0867, -106.217)
- North Park, Colorado (40.7835, -106.176)
- Rich County, Utah (41.6256, -111.249)
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| A NEW SPECIES OF SAGE-GROUSE (PHASIANIDAE: CENTROCERCUS ) FROM SOUTHWESTERN COLORADO | Young, JR | 2000 |
KeywordsNo keywords available AbstractThe Gunnison Sage-Grouse (Centrocercus minimus) is described as a new species from southwestern Colorado and contrasted with the Sage-Grouse (Centrocercus urophasianus) from northern Colorado and western North America. Gunnison Sage-Grouse differ from all other described sage-grouse (C. u. urophasianus. C. u. phaios) in morphological measurements, plumage, courtship display, and generics. The species currently is limited to 8 isolated populations in southwestern Colorado and adjacent San Juan County, Utah. Total estimated spring breeding population is fewer than 5000 individuals with the largest population (<3000) in the Gunnison Basin (Gunnison and Saguache counties), Colorado. AuthorsYoung, JR; Braun, CE; Oyler-McCance, SJ; Hupp, JW; Quinn, TW Year Published2000 PublicationThe Wilson Bulletin LocationsDOI10.1676/0043-5643(2000)112[0445:ANSOSG]2.0.CO;2 |
| 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 |
