| Vegetation Characteristics of Mountain and Wyoming Big Sagebrush Plant Communities in the Northern Great Basin | Davies, Kirk W. | 2010 |
KeywordsArtemisia tridentata, diversity, habitat, herbaceous cover, sage-grouse AbstractDominant plant species are often used as indicators of site potential in forest and rangelands. However, subspecies of dominant vegetation often indicate different site characteristics and, therefore, may be more useful indicators of plant community potential and provide more precise information for management. Big sagebrush (Artemisia tridentata Nutt.) occurs across large expanses of the western United States. Common subspecies of big sagebrush have considerable variation in the types of sites they occupy, but information that quantifies differences in their vegetation characteristics is lacking. Consequently, wildlife and land management guidelines frequently do not differentiate between subspecies of big sagebrush. To quantify vegetation characteristics between two common subspecies of big sagebrush, we sampled 106 intact big sagebrush plant communities. Half of the sampled plant communities were Wyoming big sagebrush (A. tridentata subsp. wyomingensis [Beetle & A. Young] S. L. Welsh) plant communities, and the other half were mountain big sagebrush (A. tridentata subsp. vaseyana [Rydb.] Beetle) plant communities. In general, mountain big sagebrush plant communities were more diverse and had greater vegetation cover, density, and biomass production than Wyoming big sagebrush plant communities. Sagebrush cover was, on average, 2.4-fold higher in mountain big sagebrush plant communities. Perennial forb density and cover were 3.8- and 5.6-fold greater in mountain compared to Wyoming big sagebrush plant communities. Total herbaceous biomass production was approximately twofold greater in mountain than Wyoming big sagebrush plant communities. The results of this study suggest that management guidelines for grazing, wildlife habitat, and other uses should recognize widespread subspecies as indicators of differences in site potentials. AuthorsDavies, Kirk W.; Bates, Jon D. Year Published2010 PublicationRangeland Ecology & Management LocationsDOI10.2111/REM-D-09-00055.1 |
| Vegetation characteristics across part of the Wyoming big sagebrush alliance | Davies, Kirk W. | 2006 |
KeywordsArtemisia tridentata spp. wyomingensis, cover potential, plant associations, vegetation cover, sage-grouse AbstractThe Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) alliance is the most extensive of the big sagebrush complex in the Intermountain West. This alliance provides critical habitat for many sagebrush obligate and facultative wildlife species and serves as a forage base for livestock production. There is a lack of information that describes vegetation cover values, characteristics, diversity, and heterogeneity of the Wyoming big sagebrush alliance. This study describes vegetation cover values and defines distinct associations for intact, late-seral Wyoming big sagebrush plant communities across part of its northwestern range. We sampled 107 Wyoming big sagebrush plant communities. Total herbaceous cover values were variable among sites with differences between sites exceeding 700%. Mean sagebrush cover was 12.3% with 90% of the sites producing 6% to 20% cover. Tall forb (> 18 cm) cover averaged 1.9% and 90% of the sites varied between 0.2% and 5.6% cover. Five associations delineated by dominant perennial bunchgrass species were identified: ARTRW8 (Wyoming big sagebrush)[PSSP6 (Pseudoroegneria spicata [Pursh] A. Love, bluebunch wheatgrass), ARTRW8/ACTH7 (Achnatherum thurberianum [Piper] Barkworth, Thurber's needlegrass), ARTRW8/FEID (Festuca idahoensis Elmer, Idaho fescue), ARTRW8/HECO26 (Hesperostipa comata [Trin. & Rupr.] Barkworth, needle-and-thread), and ARTRW8/PSSP6ACTH7 (a codominance of bluebunch wheatgrass and Thurber's needlegrass). Our results suggest when the vegetation cover values proposed for sage-grouse are applied as requirements at or above the stand level, they exceed the ecological potential of many of the sites sampled. AuthorsDavies, Kirk W.; Bates, Jonatban D.; Miller, Ricbard E. Year Published2006 PublicationRangeland Ecology & Management LocationsDOI10.2111/06-004R2.1 |
| Using Statistical Population Reconstruction to Estimate Demographic Trends in Small Game Populations | Broms, Kristin | 2010 |
Keywordsage-at-harvest, Centrocercus urophasianus, hunter survey, lek count, population reconstruction, sage-grouse, wing-bee AbstractStatistical population reconstruction offers a robust approach to demographic assessment for harvested populations, but current methods are restricted to big-game species with multiple age classes. We extended this approach to small game and analyzed 14 years of age-at-harvest data for greater sage-grouse (Centrocercus urophasianus) in Oregon, USA, in conjunction with radiotelemetry data to reconstruct annual abundance levels, recruitment, and natural survival probabilities. Abundance estimates ranged from a low of 26,236 in 1995 to a high of 39,492 in 2004. Annual abundance estimates for adult males were correlated with a spring lek count index (r = 0.849, P < 0.029). We estimated the average annual harvest mortality for the population to be 0.028, ranging from 0.021 to 0.031 across years. We estimated the probability of natural survival of adult females to be 0.818 ( = 0.052), somewhat higher than that of adult males ((S) over cap = 0.609, (SE) over cap = 0.163). Our precision in reconstructing the population was hampered by low harvest rates and the few birds tagged in the radiotelemetry investigations. Despite these issues, our analysis illustrates how modern statistical reconstruction procedures offer a flexible framework for demographic assessment using commonly collected data. This approach offers a useful alternative to small-game indices and would be most appropriate for species with 5 or more years of age-at-harvest data and moderate-to-heavy harvest rates. AuthorsBroms, Kristin; Skalski, John R.; Millspaugh, Joshua J.; Hagen, Christian A.; Schulz, John H. Year Published2010 PublicationJournal of Wildlife Management LocationsDOI10.2193/2008-469 |
| Using spatial statistics and point-pattern simulations to assess the spatial dependency between greater sage-grouse and anthropogenic features | Gillan, Jeffrey K. | 2013 |
KeywordsCentrocercus urophasianus, Monte Carlo, pair correlation function, point pattern, Ripley’s K, sage-grouse, spatial statistics AbstractThe greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse), a candidate species
for listing under the Endangered Species Act, has experienced population declines across its range in the
sagebrush (Artemisia spp.) steppe ecosystems of western North America. One factor contributing to the loss
of habitat is the expanding human population with associated development and infrastructure. Our objective
was to use a spatial-statistical approach to assess the effect of roads, power transmission lines, and rural
buildings on sage-grouse habitat use. We used the pair correlation function (PCF) spatial statistic to compare
sage-grouse radiotelemetry locations in west-central Idaho, USA, to the locations of anthropogenic features
to determine whether sage-grouse avoided these features, thus reducing available habitat. To determine
significance, we compared empirical PCFs with Monte Carlo simulations that replicated the spatial
autocorrelation of the sampled sage-grouse locations. We demonstrate the implications of selecting an
appropriate null model for the spatial statistical analysis by comparing results using a spatially random and a
clustered null model. Results indicated that sage-grouse avoided buildings by 150 m and power transmission
lines by 600 m, because their PCFs were outside the bounds of a 95% significance envelope constructed from
1,000 iterations of a null model. Sage-grouse exhibited no detectable avoidance of major and minor roads.
The methods used here are broadly applicable in conservation biology and wildlife management to evaluate
spatial relationships between species occurrence and landscape features. Our results can directly inform
planning of infrastructure and other development projects in or near sage-grouse habitat. AuthorsGillan, Jeffrey K., Strand, Eva K., Karl, Jason W., Reese, Kerry P. and Laninga, Tamara Year Published2013 PublicationWildlife Society Bulletin LocationsDOI10.1002/wsb.272 |
| Using human-imprinted chicks to evaluate the importance of forbs to sage-grouse | Huwer, Sherri L. | 2008 |
Keywordsbrood habitat; Centrocercus urophasianus; Colorado; forb; growth; habitat; imprinting; sage-grouse AbstractAlthough several studies have indicated the importance of forbs in brood habitats, no studies have quantified direct effects of the amount of forb cover on sage-grouse (Centrocercus urophasianus) chicks. In 2002 and 2003, we conducted field experiments in Middle Park and Moffat County, Colorado, USA, respectively. Our objective was to quantify effects of 3 levels of forb cover in brood habitat on mass gain and feather growth of human-imprinted sage-grouse chicks. The results indicate that increasing forb cover in brood areas with <20% forb cover may lead to increased chick survival and grouse productivity. AuthorsHuwer, Sherri L.; Anderson, David R.; Remington, Thomas E.; White, Gary C. Year Published2008 PublicationJournal of Wildlife Management LocationsDOI10.2193/2004-340 |
| Using gas chromatography to determine winter diets of greater sage-grouse in Utah | Thacker, Eric T. | 2012 |
KeywordsArtemisia; black sagebrush; Centrocercus urophasianus; gas chromatography; Utah; winter diet; Wyoming sagebrush AbstractSagebrush (Artemisia spp.) constitutes the majority (>99%) of sage-grouse (Centrocercus spp.) winter diets. Thus, identification and protection of important winter habitats is a conservation priority. However, not all sagebrush may be alike. More information is needed regarding sage-grouse sagebrush winter dietary preferences for application to management. The objective of our research was to determine if chemical analysis of fecal pellets could be used to characterize winter sage-grouse diets as a substitute for more invasive methods. We collected and analyzed fecal pellets and sagebrush samples from 29 different sage-grouse flock locations in northwestern and southcentral Utah. Using gas chromatography, we were able to identify crude terpene profiles that were unique to Wyoming sagebrush (A. tridentata wyomingensis) and black sagebrush (A. nova). We subsequently used the profiles to determine sagebrush composition of sage-grouse fecal pellets, thus reflecting sage-grouse winter diets. This technique provides managers with a tool to determine which species or subspecies of sagebrush may be important in the winter diets of sage-grouse populations. (c) 2011 The Wildlife Society. AuthorsThacker, Eric T.; Gardner, Dale R.; Messmer, Terry A.; Guttery, Michael R.; Dahlgren, Dave K. Year Published2012 PublicationJournal of Wildlife Management LocationsDOI10.1002/jwmg.273 |
| Use of Remote Sensing Methods in Modelling Sage Grouse Winter Habitat | HOMER, CG | 1993 |
KeywordsNo keywords available AbstractPopulations of Rich County, Utah sage grouse (Centrocercus urophasianus) have been declining in recent years. Because loss of winter habitat is a suspected factor, we used Landsat Thematic Mapper data to model structural and compositional attributes of sage grouse winter habitat over a 2,548-km2 area in Rich County, 1989-90. Of the 7 shrub and 1 no-shrub classes delineated from the Thematic Mapper, sage grouse preferred 3, avoided 3, and demonstrated no preference for the remaining 2. To determine if the model could be extrapolated to other unsampled areas, we tested model validity with 2 independent data sets from the northern and southern ends of the county. Model fit was excellent (P = 0.984). The successful development of this Geographic Information System model demonstrates the future capability of remote sensing/Geographic Information System applications to model structural and compositional attributes of wildlife habitat over large spatial scales. AuthorsHOMER, CG; EDWARDS, TC; RAMSEY, RD; PRICE, KP Year Published1993 PublicationThe Journal of Wildlife Management LocationsDOI10.2307/3809003 |
| Use of implanted radiotransmitters to estimate survival of greater sage-grouse chicks | Gregg, Michael A. | 2007 |
KeywordsCentrocercus urophasianus; chick; hatchling; mortality; radiotransmitter; sage-grouse; subcutaneous implant; survival; telemetry AbstractReduced chick survival has been implicated in declines of greater sage-grouse (Centrocercus urophasianus) populations. Because monitoring survival of unmarked sage-grouse chicks is difficult, radiotelemetry may be an effective technique to estimate survival rates, identify causes of mortality, and collect ecological data. Previous studies have used subcutaneous implants to attach radiotransmitters to hatchlings of several species of birds with precocial young. Previous researchers who used subcutaneous implants in free-ranging populations removed chicks from the capture location and implanted transmitters at an alternate site. Because logistics precluded removing newly hatched greater sage-grouse chicks from the field, we evaluated a method for implanting transmitters at capture locations. We captured 288 chicks from 52 broods and monitored 296 radiomarked chicks daily for 28 days following capture during May and June 2001-2002. Two (<= 21 days posthatch and predation (82%, 174/212) was the primary cause of death. Necropsies of 22 radiomarked chicks did not indicate inflammation or infection from implants, and they were not implicated in the death of any chicks. Fate of 49 chicks was unknown because of transmitter loss (n = 16), radio failure (n = 29), and brood mixing (n = 3). Overall, the 28-day chick survival rate was 0.220 (SE = 0.028). We found that mortalities related to the implant procedure and transmitter loss were similar to rates reported by previous researchers who removed chicks from capture sites and implanted transmitters at an alternate location. Subcutaneous implants may be a useful method for attaching transmitters to newly hatched sage-grouse chicks to estimate survival rates, identify causes of mortality, and collect ecological data. AuthorsGregg, Michael A.; Dunbar, Mike R.; Crawford, John A. Year Published2007 PublicationJournal of Wildlife Management LocationsDOI10.2193/2006-353 |
| 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 |
| 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 |
