Nesting and summer habitat use by translocated Sage Grouse ( Centrocercus Urophasianus ) in central Idaho

We translocated 196 Sage Grouse ( Centrocercus urophasianus into Sawtooth Valley, Idaho, during March-April 1986-87 to augment a small resident population. Forty-four grouse equipped with radio transmitters were monitored through spring and summer. Nest sites ( n = 6) had greater ( P = .032) horizontal cover than did independent random plots ( n = 7). During summer, grouse used sites ( n = 50) with taller live and dead shrub heights, greater shrub canopy cover, and more ground litter ( P n = 50) 50-300 m from use sites. Distance to edge and mountain sagebrush ( Artemisia tridentata vaseyana ) density best separated use sites from independent random plots in logistic regression analysis and correctly classified 64% of the use sites and 78% of the independent random plots. Sage Grouse used sties that had narrower frequency distributions for many variables than did independent plots ( P < .04), suggesting selection for uniform habitat.     

Reproductive ecology of bison on Antelope Island, Utah

Autumn musters of bison ( Bison bison ) on Antelope Island State Park, Utah, conducted annually since 1987, provided data on temporal and age-specific reproductive patterns and a basis to evaluate the efficacy of management measures implemented to elevate reproductive performance in the herd. Pregnancy rates were variable and low ( x = 46.2%) in comparison to other free-ranging, noncommercial bison herds in North America. Cows in the 3- and > 6-yr range age classes exhibited lower-than-expected pregnancy rates ( P r = 0.64, P = 0.047) linear decline of 2.5% per annum. Variance in distribution of fetal ages observed in 6 yr indicates substantial temporal fluctuation. Long-term reproductive performance of cohorts born prior to implementation of management measures did not differ from that of cohorts born subsequent to these changes.     

Model of breeding habitat of the Mountain Plover ( Charadrius montanus ) in western Wyoming

To aid the conservation and management of Mountain Plovers ( Charadrius montanus ), we developed a spatially explicit model of breeding habitat for the shrub-steppe of western Wyoming. Points of Mountain Plover presence and absence were determined by field surveys conducted May through June 1999. At each point we measured topographic slope and a cover type suitability index related to vegetation height and density. Logistic regression revealed a strong negative relationship between presence and slope, and a weaker and positive relationship between presence and cover index. A multiple logistic regression model using slope and cover index to predict presence successfully classified 87% of the points in an independent data set covering much of western Wyoming. The spatial expression of this model will help managers target future surveys and identify currently unsuitable habitat that could be improved via vegetation management. Patches of suitable breeding habitat of the Mountain Plover in western Wyoming are probably functions of poor soil, low precipitation, and wind scour, and thus are likely rather persistent in space and time. Combined with the relatively large proportion of publicly owned land here, this may make conservation and recovery of the Mountain Plover easier in western Wyoming than in the more dynamic and privately controlled Great Plains.     

Site and stand characteristics related to white pine blister rust in high-elevation forests of southern Idaho and western Wyoming

Successful infection of white pine species by white pine blister rust (WPBR) is contingent upon environmental conditions that are favorable to the spread and development of Cronartium ribicola . Site and stand factors related to this process have been studied elsewhere within the distribution of the disease, but few studies have concentrated on the high-elevation white pine forests of southern Idaho and western Wyoming. We found that mean summer precipitation, average tree diameter, and elevation were the most important variables in 3 logistic regression models of WPBR presence and intensity. The models were tested on a randomly chosen portion of our data set. The model with 9 variables correctly predicted categories of low-, moderate-, and high-disease incidence in 79% of cases. The 2 models with fewer variables had lower predictive efficiencies but were more parsimonious and generally easy to measure. The ability to use easily measured or remotely sensed site and stand characteristics to predict WPBR spread or intensification could be an important asset to land managers who need to decide where to focus disease mitigation efforts and predict disease effects on water quality, wildlife habitat, recreation potential, and other land-management activities.     

Distributional information on birds from egg sets collected by Henry Rogers Durkee in 1870 in southwestern Wyoming

Henry Rogers Durkee collected 74 egg sets of 27 avian species in 1870 at Gilmer, Uinta County, in southwestern Wyoming. Despite the paucity of documented breeding evidence from this region during the late 19th and early 20th centuries, his material at the Smithsonian Institution was generally overlooked and has never been critically examined. Durkee's egg sets included 5 species (Sandhill Crane, Grus candensis ; Northern Rough-winged Swallow, Stelgidoteryx serripennis ; Grasshopper Sparrow, Ammodramus savannarum ; Fox Sparrow, Passerella iliaca ; Cassin's Finch, Carpodacus cassinii ) whose breeding distribution was then poorly known, 25 to more than 70 years before nests and eggs were otherwise documented in Wyoming. Durkee also collected complete egg sets of Lark Bunting ( Calamospiza melanocorys ) over 70 years before breeding was confirmed at other peripheral locations in Wyoming. In addition, Durkee's incomplete egg sets of Grasshopper Sparrow were the 1st western subspecies ( A. s. perpallidus ); his complete egg set and nest of the Fox Sparrow collected at Gilmer constituted the 2nd locality for the species or species group ( P. i. schistacea ). Although the number of egg sets Durkee collected is modest, he made a meaningful contribution to the early history of avifaunal exploration in Wyoming.     

Indicators of red squirrel (Tamiasciurus hudsonicus) abundance in the whitebark pine zone

We investigated occupied squirrel middens and squirrel sightings and vocalizations as indicators of red squirrel ( Tamiasciurus hudsonicus ) abundance in high-elevation whitebark pine ( Pinus albicaulis ) zone. Data were collected 1984-1989 from line transects located on 2 study sites in the Yellowstone ecosystem. We evaluated the performance of each measure on the basis of precision and biological considerations. We concluded that, of the 3 measures, active middens were the best indicator of red squirrel abundance. We also observed that the density of active middens dropped by 48%-66% between 1987 and 1989, following a severe drought and extensive wildfires that burned one of the study sites during 1988.     

GABAergic inhibition of neurons in the ventral tegmental area.

Stimulation of the nucleus accumbens evokes a potent inhibition in neurons of the ventral tegmental area. GABA is likely to act as a transmitter in this descending inhibitory system.     

Isoelectric focusing study of radiation damage to dry conalbumin.

The effect of gamma-rays on iron-free conalbumin was studied by isoelectric focusing technique. The results obtained can be interpreted on the basis of radiation-induced conformational changes of the macromolecules through a cleavage of disulphide bridges. Treatments with reagents acting on disulphide bridges lead to isoelectric focusing patterns that confirm this hypothesis.