| THE INFLUENCE OF SEASON, TEMPERATURE, AND ABSORPTIVE STATE ON SAGE GROUSE METABOLISM | SHERFY, MH | 1994 |
THE INFLUENCE OF SEASON, TEMPERATURE, AND ABSORPTIVE STATE ON SAGE GROUSE METABOLISMKeywordsNo keywords available AbstractWe used indirect respiration calorimetry to measure the metabolism of six adult sage grouse (Centrocercus urophasianus) during winter, spring, and summer. During winter the metabolic rate of fed birds was higher (P < 0.05) than that of fasted birds. The standard metabolic rate (SMR) of females (0.692 mL O-2.g(-1).h(-1)) was higher than of males (0.583 mL O-2.g(-1).h(-1)) in winter; in both sexes SMR was higher in winter than in summer. Females' SMR was lower (P = 0.0001) in spring than in winter. Lower critical temperatures of both males and females were substantially lower in winter (-0.6 degrees C, -4.8 degrees C) than in summer (14.9 degrees C, 14.8 degrees C). Although seasonally elevated, the SMR of sage grouse in winter is low in comparison with that of other galliforms with northern distributions. Thermoregulation during a winter night at -10 degrees C would result in minimal (<5%) expenditure of endogenous reserves by either sex. Thermoregulation and SMR in winter are more energetically costly to female sage grouse than to males, and may necessitate increased behavioral thermoregulation by females. Seasonal change in SMR differs between the sexes, and is probably influenced by the energetic demands of the breeding season. AuthorsSHERFY, MH; PEKINS, PJ Year Published1994 PublicationCanadian Journal of Zoology-Revue Canadienne De Zoologie Locations |
| The influence of gap size on sagebrush cover estimates with the use of line intercept technique | Boyd, Chad S. | 2007 |
KeywordsVegetation inventory, wildlife habitat, sage-grouse, sagebrush obligate AbstractSagebrush cover is often estimated with the use of the line intercept method. However, a lack of standardized protocols may lead to variable estimates of sagebrush canopy cover. Our objectives were to determine the influence of gap size on 1) sagebrush canopy cover estimates, 2) time needed to read a transect, and 3) among-observer variability in sagebrush canopy cover estimates. We utilized 5-, 10-, and 15-cm gaps, and defined a gap as a lack of continuous live or dead shrub canopy. In instances where a segment of dead cover was less than the gap size and adjoined live cover, the dead cover was measured as live. We evaluated canopy cover at 6 Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. Wyomingensis Beetle & A. Young) sites in southeast Oregon. At each site, four 2-person teams measured sagebrush canopy intercept along 50-m transects. Each transect was read by multiple teams to allow for assessment of among-observer variability. Intercept values were converted to percent canopy cover and we used analysis of variance to determine the influence of site and gap size on measurement time and cover estimates. Observer variability was highest at the intermediate gap size (i.e., 10 cm). Transect measurement time was longest with the use of a 5-cm gap (P < 0.001). Total cover estimates were not related to gap size (P = 0.270). Live canopy cover estimates increased (P < 0.001) from 12.1% to 14.5% with increasing gap size, and cover of dead material decreased (P = 0.015) from 4.4% to 3.2%. These differences are small in magnitude and would not likely change a gross assessment of vegetation status. However, use of a standardized gap size will enhance comparability of canopy cover estimates among studies and will decrease between-year sampling error for repeat monitoring. AuthorsBoyd, Chad S.; Bates, Jon D.; Miller, Rick F. Year Published2007 PublicationRangeland Ecology & Management LocationsDOI10.2111/05-226R2.1 |
| The Importance of Within-Year Repeated Counts and the Influence of Scale on Long-Term Monitoring of Sage-Grouse | Fedy, Bradley C. | 2011 |
KeywordsCentrocercus urophasianus; generalized additive models; greater sage-grouse; lek; monitoring; population trends; Wyoming AbstractLong-term population monitoring is the cornerstone of animal conservation and management. The accuracy and precision of models developed using monitoring data can be influenced by the protocols guiding data collection. The greater sage-grouse (Centrocercus urophasianus) is a species of concern that has been monitored over decades, primarily, by counting the number of males that attend lek (breeding) sites. These lek count data have been used to assess long-term population trends and for multiple mechanistic studies. However, some studies have questioned the efficacy of lek counts to accurately identify population trends. In response, monitoring protocols were changed to have a goal of counting lek sites multiple times within a season. We assessed the influence of this change in monitoring protocols on model accuracy and precision applying generalized additive models to describe trends over time. We found that at large spatial scales including > 50 leks, the absence of repeated counts within a year did not significantly alter population trend estimates or interpretation. Increasing sample size decreased the model confidence intervals. We developed a population trend model for Wyoming greater sage-grouse from 1965 to 2008, identifying significant changes in the population indices and capturing the cyclic nature of this species. Most sage-grouse declines in Wyoming occurred between 1965 and the 1990s and lek count numbers generally increased from the mid-1990s to 2008. Our results validate the combination of monitoring data collected under different protocols in past and future studies-provided those studies are addressing large-scale questions. We suggest that a larger sample of individual leks is preferable to multiple counts of a smaller sample of leks. (C) 2011 The Wildlife Society. AuthorsFedy, Bradley C.; Aldridge, Cameron L. Year Published2011 PublicationJournal of Wildlife Management LocationsDOI10.1002/jwmg.155 |
| THE FOOD HABITS AND SUMMER DISTRIBUTION OF JUVENILE SAGE GROUSE IN CENTRAL MONTANA | PETERSON J G | 1970 |
KeywordsNo keywords available AbstractThe food habits of juvenile sage grouse (Centrocercus urophasianus) were studied in central Montana during the summers of 1966 and 1968. Forbs averaged 75 percent of the diet of 127 juveniles through 12 weeks of age. The flower buds and leaves of common dandelion (Taraxacum officinale) and common salsify (Tragopogon dubius) were the most highly preferred and utilized forbs, comprising 25 and 15 percent of the diets, respectively. Other forbs commonly utilized were prairie pepperweed (Lepidium densiflorum), prickly lettuce (Lactuca serriola), alfalfa (Medicago sativa), curlcup gumweed (Grindelia squarrosa), and fringed sagewort (Artemisia frigida). Big sagebrush (A. tridentata) received little use until the birds were 11 weeks old. Insect use declined steadily from a high of 60 percent of the diet in 1-week chicks to 5 percent in 12-week-old juveniles. Observed brood locations, after chicks were 2-3 weeks old, were less frequent on the sagebrush-grassland benches and more frequent on lower areas until, by September, the majority of broods were located on bottomlands. Sagebrush, 6-18 inches high, was most prevalent at brood sites used during morning and evening activity periods. Important components of juvenile sage grouse habitat in this area appear to be an abundance and diversity of forbs and densities of sagebrush ranging from 1-20 percent. AuthorsPETERSON J G Year Published1970 PublicationJournal of Wildlife Management LocationsDOI10.2307/3799502 |
| THE ENERGETIC COST OF DISPLAY IN MALE SAGE GROUSE | VEHRENCAMP, SL | 1989 |
THE ENERGETIC COST OF DISPLAY IN MALE SAGE GROUSEKeywordsNo keywords available AbstractNo abstract available AuthorsVEHRENCAMP, SL; BRADBURY, JW; GIBSON, RM Year Published1989 PublicationAnimal Behaviour Locations |
| The effects of raven removal on sage grouse nest success. | Coates, Peter S. | 2004 |
The effects of raven removal on sage grouse nest success.KeywordsCentrocercus urophasianus, nest success, predator control, raven damage management, sage grouse, video nest monitoring AbstractNo abstract available AuthorsCoates, Peter S.; Delehanty, David J. Year Published2004 PublicationProceedings of The Vertebrate Pest Conference Locations |
| The effect of vegetation structure on predation of artificial Greater Sage-Grouse nests | Watters, ME | 2002 |
The effect of vegetation structure on predation of artificial Greater Sage-Grouse nestsKeywordsNo keywords available AbstractIn Canada, Greater Sage-Grouse (Centrocercus urophasianus) are considered an endangered species by the Committee On the Status of Endangered Wildlife In Canada (COSEWIC), due to declining population numbers and distribution. Encroachment of agriculture and subsequent destruction of suitable sagebrush (Artemisia spp.) habitat is thought to be responsible for historical population declines However, subtle changes in habitat quality may also result in reduced escape and nesting cover, which may lead to increased levels of predation. We examined the influence of vegetation cover and height on the fate of artificial Greater Sage-Grouse nests Because most natural sage-grouse nests are associated with sagebrush, we predicted that sagebrush height and cover would be crucial to the success of nests. Lateral cover is important in protecting nests from detection by predators, and thus we predicted that nests surrounded by shorter grass would suffer greater predation rates than nests with taller grass. To experimentally test this hypothesis, we trimmed grass surrounding some artificial nests Richardson's ground squirrels (Spermophilus richardsonii) were the primary predators of artificial nests, with some predation by corvids and badgers (Taxidea taxus). Successful nests tended to be surrounded by shorter sagebrush, taller grasses, and taller, denser forbs than predated nests. Trimming grass around nests did not affect nest fate However, ground squirrels typically attacked nests with less forb cover and fewer sagebrush, and avian predators tended to destroy nests at inactive leks with greater lateral cover. Thus, lateral cover provided by forbs and sagebrush appeared to be important for protecting nests from mammalian predators. These results suggest implementing management strategies that improve sagebrush habitat by providing tall, dense forbs and sagebrush, which could increase Greater Sage-Grouse nest success and recruitment. AuthorsWatters, ME; McLash, TL; Aldridge, CL; Brigham, RM Year Published2002 PublicationEcoscience Locations |
| Testing sagebrush allometric relationships across three fire chronosequences in Wyoming, USA | Cleary, M. B. | 2008 |
Keywordsaboveground biomass; Artemisia tridentate; plant allometry; root biomass; universal scaling AbstractAboveground and coarse root allometric relationships were tested across three mountain big sagebrush (Artemisia tridentata var. vaseyana (Rydb.) chronosequences at three stages of recovery from fire (establishment, expansion, and mature) in Wyoming, USA. Big sagebrush shrubs dominate North American rangelands and are critical components of habitat for threatened species such as sage grouse. There were no differences in regression relationships estimating biomass over space and time, which reduces the need to destructively sample sagebrush for local studies and supports regional carbon modeling and biomass estimates. Crown volume (CV) explained the most variability (R-2 > 0.75) in aboveground biomass, and crown area (CA) explained the most variability for coarse roots (R-2 >0.87). Analyses supported both the 2/3 power universal scaling rules between leaf and stem biomass, but did not support global models of seed plant and reproductive part biomass. This study provides compelling evidence that simple field measurements may be used to estimate biomass over large regions and that universal scaling rules are valid for semiarid shrubs. (c) 2007 Elsevier Ltd. All rights reserved. AuthorsCleary, M. B.; Pendall, E.; Ewers, B. E. Year Published2008 PublicationJournal of Arid Environments LocationsDOI10.1016/j.jaridenv.2007.07.013 |
| Territoriality and non-random mating in sage grouse, Centrocercus urophaslanus. | Wiley, R.H. | 1973 |
Territoriality and non-random mating in sage grouse, Centrocercus urophaslanus.KeywordsNo keywords available AbstractNo abstract available AuthorsWiley, R.H. Year Published1973 PublicationAnimal Behav Monogr Locations |
| Temporal variation in diet and nutrition of preincubating greater sage-grouse | Gregg, Michael A. | 2008 |
Keywordscalcium, Centrocercus urophasianus, crude protein, forb, phosphorus, reproduction AbstractGreater sage-grouse (Centrocercus urophasianus) habitat management involves vegetation manipulations to increase or decrease specific habitat components. For sage-grouse habitat management to be most effective, all understanding of the functional response of sage-grouse to changes in resource availability is critical. We investigated temporal variation in diet composition and nutrient content (crude protein, calcium, and phosphorus) of foods consumed by preincubating female sage-grouse relative to food supply and age of hen. We collected 86 preincubating female greater sage-grouse at foraging areas during early (18-31 March) and late (1-12 April) preincubation periods during 2002-2003. Females consumed 22 food types including low sagebrush (Artemisia arbuscula Nutt.), big sagebrush (Artemisia tridentata Nutt.), 15 forb species, 2 insect taxa, sagebrush galls, moss, and a trace amount of unidentified grasses. Low sagebrush was the most common food item, but forbs were found in 89% of the crops and composed 30.1% aggregate dry mass (ADM) of the diet. ADM and species composition of female diets were highly variable between collection periods and years, and coincided with temporal variation in forb availability. Adult females consumed more forbs and less low sagebrush compared to yearling females. Because of higher levels of crude protein, calcium, and phosphorus, forbs were important diet components in comparison with low sagebrush, which had the lowest nutrient content of all foods consumed. Our results indicate that increased forb abundance in areas used by female sage-grouse prior to nesting would increase their forb consumption and nutritional status for reproduction. We recommend that managers should emphasize delineation of habitats used by preincubating sage-grouse and evaluate the need for enhancing forb abundance and diversity. AuthorsGregg, Michael A.; Barnett, Jenny K.; Crawford, John A. Year Published2008 PublicationRangeland Ecology & Management LocationsDOI10.2111/08-037.1 |
