Comparison of Sage and Sharp-tailed Grouse leks in south central Wyoming

Columbian Sharp-tailed Grouse ( Tympanuchus Phasianellus columnianus ) and Sage Grouse ( Centro-cercus urophasianus ) leks were compared in an area of sympatry in south central Wyoming. Sharp-tailed Grouse leks had more (P < .05 shrub cover, taller shrubs, more forb, grass, and shrub species, and less visibility than did Sage Grouse leks. Reduction in shrub cover or the diversity of herbaceous species could potentially have greater influence on the use of lek sites by Columbian Sharp-tailed Grouse than by Sage Grouse in areas of sympatry in Wyoming.     

Summer habitat use by Columbian Sharp-tailed Grouse in western Idaho

We studied summer habitat use by Columbian Sharp-tailed Grouse ( Tympanuchus phasianellus columbianus ) in western Idaho during 1983-85. Vegetative and topographic measurements were recorded at 716 locations of 15 radio-tagged grouse and at 180 random sites within the major vegetation/cover types in the study area. The mean size of summer home ranges was 1.87 ± 1.14 km 2 . Of eight cover types identified in the study area, individual grouse used the big sagebrush Artemisia tridentata ) cover type more than or in proportion to availability, the low sagebrush ( A. arbuscula ) in proportion to availability, and avoided the shrubby eriogonum ( Eriogonum spp.) type. Characteristics of the big sagebrush cover type that Sharp-tailed Grouse preferred include moderate vegetative cover, high plant species diversity, and high structural diversity. Grouse used areas of dense cover (i.e., mountain shrub and riparian cover types) primarily for escape cover. Compared with random sites, grouse selected areas with (1) greater horizontal and vertical cover, (2) greater canopy coverage of forbs typically decreased by livestock grazing, (3) greater density and canopy coverage of arrowleaf balsamroot ( Balsamorhiza sagittata ), and (4) greater canopy coverage of bluebunch wheatgrass ( Agropyron spicatum ) in the big sagebrush cover type in 1984 and the low sagebrush cover type in 1985. The importance of the native perennials arrowleaf balsamroot and bluebunch wheatgrass became apparent during a drought year when many exotic annuals dried up and provided no cover. Overall, grouse selected vegetative communities that were least modified by livestock grazing.     

Summer habitat use and selection by female Sage Grouse ( Centrocercus urophasianus ) in Oregon

Cover types and vegetative characteristics (e.g., grasses, forbs, shrubs) used by female Sage Grouse ( Centrocercus urophasianus ) during summer were compared with available habitat on two study areas in southeastern Oregon. Broodless hens, which constituted 114 of the 125 (91%) radio-marked hens studied, selected big ( Artemisia tridentata ) subspp.) and low sagebrush ( A. arbuscular ) cover types at both study areas. At Hart Mountain, broodless hens did not select specific vegetative characteristics within cover types. However, at Jackass Creek, forb cover was greater ( P = .004) at broodless hen sites than at random locations. Differences in habitat use by broodless hens between study areas were associated with differences in forb availability. Broodless hens used a greater diversity of cover types than hens with broods. Broodless hens gathered in flocks and remained separate from but near hens with broods during early summer. By early July broodless hens moved to meadows while hens with broods remained in upland habitats.     

Brood habitat use by Sage Grouse in Oregon

Habitat use by Sage Grouse ( Centrocercus urophasianus hens with broods was examined at Jackass Creek and Hart Mountain, Oregon, from 1989 through 1991. Sage Grouse hens initially selected low sagebrush ( Artemisia spp.) cover types during early brood-rearing, big sagebrush cover types later in the brood-rearing period, and ultimately concentrated use in and near lakebeds and meadows. Areas used by Sage Grouse broods typically had greater forb frequency than did random sites. Hens at Jackass Creek selected sites with forb cover similar to that generally available at Hart Mountain, but home ranges were larger at Jackass Creek because of lower availability of suitable brood-rearing habitat. Differences in habitat use by broods on the two areas were reflected in dietary differences; at Hart Mountain, chicks primarily ate forbs and insects, whereas at Jackass Creek most of the diet was sagebrush. Larger home ranges, differences in diets, and differences in availability of forb-rich habitats possibly were related to differences in abundance and productivity between areas.     

Use and selection of brood-rearing habitat by Sage Grouse in south central Washington

Sage 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 30 broods, of which 12 persisted to 1 August (￣ x = 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 the 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.     

Home range and seasonal movements of Columbian Sharp-tailed Grouse associated with Conservation Reserve Program and mine reclamation

During 1999 and 2000 we trapped and radio-marked 156 Columbian Sharp-tailed Grouse ( Tympanuchus phasianellus columbianus ) on leks in Conservation Reserve Program (CRP, n = 73) and mine reclamation (MR, n = 83) lands in northwestern Colorado. Median spring--fall home range sizes using the 95% fixed kernal and minimum convex polygon estimators for 54 grouse were 86 ha and 61 ha, respectively. Median fixed kernal home range size did not differ between males (79 ha) and females (87 ha). Home ranges of grouse associated with CRP (112 ha) were larger than those of grouse in MR (75 ha). Directional orientation of movements from leks of capture to wintering areas was nonrandom, and there was a positive elevation gain (median = 102 m) associated with these movements. Movements did not differ between grouse captured in CRP and MR for any season but did differ between genders for the spring--fall period. Males exhibited stronger fidelity and less variation in their movements than females; 96% of males compared with only 77% of females remained within 2.0 km of their lek of capture from spring through fall. Ninety percent of females nested within 2.5 km of their lek of capture. During winter all grouse were found farther (median = 21.5 km) from lek sites than in any other season. Males remained on the breeding range longer in the fall and returned earlier in the spring than females even though they wintered similar distances away (median males = 21.5 km, median females = 21.4 km). Our findings support the 2.0-km radius used in the Habitat Suitability Index model for Columbian Sharptailed Grouse to assess nest and brood-rearing cover around leks, but not the 6.5-km radius used to evaluate winter cover.     

Seasonal microhabitat relationships of blue grouse in southeastern Idaho

Microhabitat characteristics of blue grouse ( Dendragapus obscurus ) were analyzed in breeding and wintering habitats in southeastern Idaho. Breeding habitats typically were open sagebrush ( Artemisia spp.), mixed shrub, mountain mahogany ( Cercocarpus ledifolius ) , and maple ( Acer grandidentatum ) stands on east to south facing aspects of slopes below 2100 m elevation. Breeding blue grouse selected areas with approximately a 50:50 or greater open to cover ratio. Blue grouse selected areas with higher tree coverage than available on average within the mixed shrub vegetation type. Hens with broods preferred sites with relatively tall (>50 cm) herbaceous vegetation. During autumn and winter, blue grouse preferred high elevation (>2285 m) stands of open (50% tree cover) conifer. Douglas-fir ( Pseudotsuga menziesii ) were preferred as winter roost trees. Sites selected in winter had significantly more Douglas-fir than those selected in autumn.&nbsp;     

Predation of artificial Sage Grouse nests in treated and untreated sagebrush

We measured predation on 120 artificial Sage Grouse ( Centrarcus urophasianus ) nests in montane sagebrush grassland in northern Utah. We examined nests in areas that had been chained and seeded 25 years previously (treated areas) and in areas that were untreated. Predation rates of artificial nests were higher in areas of untreated sagebrush, even though these areas had greater sagebrush cover, taller shrubs, and greater horizontal plant cover. These results differ from those previously hypothesized for treated sagebrush habitat and may reflect a greater abundance of other potential prey species, especially lagomorphs, in untreated areas that attracted greater densities of predators. In addition, over 80% of nests were depredated by mammals, which hunt using olfaction and are less likely than avian predators to be affected by nest cover. We conclude that, after treated sagebrush has recovered to some degree, predation rates of Sage Grouse nests may be lower in treated sagebrush. Consequently, factors other than nest predation (e.g., winter food, thermal cover, insects, perennial forb abundance) may be more important reasons for preserving mature sagebrush stands for Sage Grouse.     

Suitability of shrub establishment on Wyoming mined lands reclaimed for wildlife habitat

Restoring coal mined land to pre-mining shrub cover, density, height, community composition, and diversity to renew wildlife habitat quality is a priority for reclamation specialists. Long-term shrub reestablishment success on reclaimed mined land in Wyoming and suitability of these lands for wildlife habitat are unknown. Fourteen reclaimed study sites, 10 yr old or older, were selected on 8 mines in Wyoming to evaluate shrub reestablishment and wildlife habitat value for antelope ( Antilocapra americana ) and sage grouse ( Centrocercus urophasianus ). Five sites were categorized as fourwing saltbush ( Atriplex canescens ) sites and 9 as fourwing saltbush/big sagebrush ( A. canescens/Artemisia tridentata spp. wyomingensis ) sites. Published data describing antelope and sage grouse-preferred habitat requirements in sagebrush-grassland steppe ecosystems were used to evaluate shrub community value of sampled sites for wildlife habitat. Mean shrub canopy cover, density, and height for fourwing saltbush sites were 5.8%, 0.23 m -2 , and 41.6 cm, respectively, compared to 5.6%, 0.61 m -2 , and 31.1 cm for fourwing saltbush/big sagebrush sites. Two fourwing saltbush and 4 fourwing saltbush/big sagebrush sites provided sufficient cover for antelope, while 2 fourwing saltbush and 4 fourwing saltbush/big sagebrush sites were adequate for sage grouse. Only 1 fourwing saltbush/big sagebrush site provided high enough shrub densities for sage grouse. One fourwing saltbush and 7 fourwing saltbush/big sagebrush sites provided ample shrub heights for antelope, while 1 fourwing saltbush and 8 fourwing saltbush/big sagebrush sites were sufficient for sage grouse. One fourwing saltbush and 1 fourwing saltbush/big sagebrush site provided enough grass, forb, and shrub composition for antelope, while no site in either reclamation type was satisfactory for sage grouse. Shrub diversity was 3 times higher for fourwing saltbush/big sagebrush sites (0.984) than for fourwing saltbush sites (0.328). Individually, sites seeded with multiple shrub species had higher canopy cover, density, and diversity compared with single-species shrub seedings. Achieving premining shrub cover, density, height, community composition, and diversity within existing bond-release time frames is unrealistic, considering that some native shrublands require 30-60 yr to reach maturity.     

Ruffed Grouse ( Bonasa umbellus ) drumming log and habitat use in Grand Teton National Park, Wyoming

We described 15 Ruffed Grouse ( Bonasa umbellus ) drumming logs and adjacent habitat within Grand Teton National Park, Wyoming. Drumming logs and adjacent habitat differed from 30 random non-drumming sites. Drumming logs had fewer limbs (8; P = 0.003) and a smaller percentage of bark remaining (12%; P = 0.0001). These logs were in advanced stages of decay but were still firm to the touch. Additionally, drumming logs were found close to clearings but in areas with increased amounts of undergrowth and mature trees. Adjacent habitat analysis (0.04-ha circular plot centered on logs) indicated drumming locations had significantly greater average canopy height, more vegetative cover consisting of conifer and total canopy cover, and more vertical foliage between 0.3 m and 3.0 m in height. Adjacent habitat was in advanced stages of maturity as indicated by significant numbers of both large-diameter logs and largediameter lodgepole pine ( Pinus contorta ) and quaking aspen ( Populus tremuloides ) snags. Tree species dominating the canopy and subcanopy were large-diameter Engelmann spruce ( Picea engelmannii ), lodgepole pine, and quaking aspen. Subalpine fir ( Abies lasiocarpa ) and quaking aspen saplings were more numerous at used sites. Ruffed Grouse drummed in coniferous areas within close proximity of quaking aspen.     

Effects of grazing exclusions on rangeland vegetation and soils, east central Idaho

Nineteen exclosures on sagebrush steppe and shadscale rangelands, varying in age from 18 to 38 years, were sampled for plant species richness, plant composition, indicators of soil erosion, ground cover, vegetative cover, and herb-low shrub layer screening cover. Features within the exclosures were compared with adjacent sites of the same size that were open to grazing by livestock and wildlife. Species richness typically was slightly greater inside exclosures than in adjacent grazed sites (median = 2 more species inside exclosures), but the difference was not significant ( P = 0.16). Similarity of plant community composition between exclosures and adjacent grazed sites ranged from 45% to 82%. Evidences of soil movement, soil pedestals, and soil flow patterns were all more pronounced outside exclosures than inside ( P ≤ 0.02), even though many sites were on flat to mild slopes (median slope = 12%). Meta-analysis of the 19 exclosure sites indicated that grazing exclusion resulted in less bare ground cover compared with adjacent grazed sites ( P ≤ 0.05). The effect of grazing exclusion on visible soil surface cryptogams was significant ( P ≤ 0.05), with generally greater cover inside exclosures. Cryptogam cover differences between grazed sites and exclosures tended to increase with the number of years of grazing exclusion ( r = 0.64, P = 0.046). Pseudoroegneria spicata , a principal livestock forage, averaged greater basal cover inside exclosures than outside on 4 of 10 sites where it occurred, although no exclosure sites had greater P. spicata cover on grazed sites. Meta-analysis of the 10 sites indicated that grazing exclusion resulted in greater P. spicata cover compared with adjacent grazed areas ( P ≤ 0.05). Poa secunda , a short-growing grass that initiates growth early in the spring and is not important livestock forage, averaged greater basal cover outside exclosures on 5 of 15 sites where it occurred. Meta-analysis of the 15 sites indicated a significant treatment effect ( P ≤ 0.05), with greater Poa secunda basal cover outside exclosures. Grazing exclusion resulted in greater screening cover in the herb-low shrub layer (0-0.5 m height; P ≤ 0.05). These results indicate that despite improved livestock grazing management over the past half century, livestock grazing still can limit the potential of native plant communities in sagebrush steppe ecosystems, and that the health of semiarid ecosystems can improve with livestock exclusion in the absence of other disturbances. A few exclosure sites were similar for the measured parameters, suggesting that these sites were ecologically stable and that exclusion of livestock grazing was not sufficient to move succession toward more pristine conditions, at least within the time periods studied. Managed disturbance such as fire or mechanical brush treatments may be necessary to restore herb productivity on these ecologically stable sites.     

Short-term effects of a prescribed burn on songbirds and vegetation in mountain big sagebrush

I measured songbird abundance and vegetation cover in and around a 420-ha prescribed burn in a mountain big sagebrush community located at 2133 m elevation. Data were collected during the 3rd growing season after the fire. Brewer's Sparrow and Sage Thrasher occurred in lower abundance on sites that were largely or completely burned relative to sites that were outside the fire perimeter or within unburned islands of shrubs. The number of Brewer's Sparrow detections was linearly related to remaining sagebrush cover. In contrast, Horned Lark occurred at higher abundances on sites where shrub cover had been removed in the prescribed burn. Cover of perennial grasses and cover of 4 of the 5 most common forbs was greater on burned sites than on unburned sites.     

Nest-site selection by Sage Thrashers in southeastern Idaho

Nest sites selected by Sage Thrashers ( Oreoscoptes montanus ) in southeastern Idaho were characterized and compared with available habitat. Microhabitats within 5 m of nests had taller and more aggregated shrubs and less bare ground than the study area in general. Big sagebrush ( Artemisia tridentata wyomingensis ) plants used for nesting were taller than average ,available shrubs, had greater foliage density, were more often living, and more frequently had branches and foliage within 30 cm of the ground. Nest placement was specific with respect to relative nest height and distance from the top and perimeter of the support shrub. Sage Thrashers disproportionately used easterly exposures and underused westerly exposures for their nests.     

Mule deer and pronghorn use of wastewater ponds in a cold desert

Pronghorn ( Antilocapra americana ) and mule deer ( Odocoileus hemionus ) were counted at wastewater ponds at the Idaho National Engineering and Environmental Laboratory (INEEL) in southeastern Idaho 4 to 8 times per month from August 1989 through July 1991. Mule deer used wastewater ponds ( n = 15) from June through December and were most commonly observed August through November. Pronghorn frequented wastewater ponds from May through November and were most common from July through September, the driest and warmest months; ponds were also used heavily in November 1990. Diel activity was studied from July through October. Mule deer use of ponds varied in relation to 8 diel time periods in August ( P = 0.02) and September ( P = 0.01) while pronghorn use varied by time period ( P P P < 0.01) August through October. Mule deer and pronghorn use of ponds was not related to distance from site facilities (groups of buildings used for research and other purposes). Pronghorn made greater use of individual ponds lacking additional nearby watering sites, and both pronghorn and mule deer were attracted to ponds with grass/forb and shrub cover around the upland periphery.     

Long-term effects of tebuthiuron on Bromus tectorum

Use of herbicides to thin dense stands of Artemisia spp. (sagebrush) can free up resources for herbaceous plants and increase forage production, but may also facilitate weed invasion. We revisited a sagebrush thinning experiment in a north central Wyoming big sagebrush–grassland 11 years after application of tebuthiuron (N-[5-(1,1- dimethylethyl)-1,3,4-thiadiazol-2-yl]-N-N′-dimethylurea) to determine the long-term responses of shrubs, available soil resources, perennial grasses, and Bromus tectorum L. (downy brome). Tebuthiuron reduced shrub cover by more than half, from 31% in untreated plots to 15% in treated plots ( P = 0.002), and increased downy brome cover approximately 4-fold, from 0.9% in untreated plots to 3.5% in treated plots ( P = 0.02). Treatment with tebuthiuron also resulted in marginally significant increases in cover of perennial grasses (from 9% to 12.3%; P = 0.07) and bare ground (from 39.1% to 43.9%; P = 0.08). In comparisons of resource availability among microsites, available NO 3 was higher under dead sagebrush than under live sagebrush ( P = 0.03). No significant differences in soil water content were detected. The relatively recent expansion of downy brome populations at this site and the high NO 3 –N levels observed under dead sagebrush suggest that conditions facilitating downy brome invasion may persist for many years following sagebrush thinning. We demonstrate that sagebrush thinning can cause increases in downy brome populations years after initial treatment and suggest that managers should use caution when considering thinning sagebrush if downy brome is present, even if initial populations are small.     

Salvage logging and replanting reduce understory cover and richness compared to unsalvaged unplanted sites at Mount St. Helens, Washington

The 1980 eruption of Mount St. Helens killed trees in a broad 600-km2 swath north of the crater. Over most of the blast zone, dead trees were salvage logged and Abies procera was planted, except in areas within the Mount St. Helens National Volcanic Monument. We compared salvage-replanted sites and unsalvaged sites in 1 area of the blast zone where the sites were adjacent by using twenty-five 200-m 2 plots for each treatment. Salvaged-replanted plots had significantly lower herb and shrub cover, richness, diversity, litter depth, downed woody debris, nitrate, and phosphate. Salvaged-replanted sites also had significantly more stumps, bare area, and moss cover than unsalvaged plots. Soil organic matter and nonnative species cover did not differ. Nonnative species were not important components of any plots. Nitrate, total nitrogen, organic matter, and litter were correlated with the major patterns of species distribution in a canonical correspondence analysis of the salvaged-replanted plots. In the unsalvaged plots, slope, downed woody debris, and elevation were correlated with the major patterns of species distribution.     

Dam-site selection by beavers in an eastern Oregon basin

We compared physical and vegetative habitat characteristics at 14 dam sites occupied by beaver ( Castor Canadensis ) with those at 41 random unoccupied reaches to identify features important to dam-site selection in the Long Creek basin, Grant County, Oregon. Stream reaches with dams were shallower and had a lower gradient than unoccupied reaches. Beaver did not build dams at sites with a rock substrate. Bank slopes at occupied reaches were not as steep as those at unoccupied reaches; and occupied stream reaches had greater tree canopy cover, especially of thinleaf alder ( Alnus tenuifolia ), than did unused reaches. A discriminant model using transformations of bank slope, stream gradient, and hardwood cover classified all beaver dam sites correctly and 35 of 41 random sites as unoccupied sites. The 6 misclassified sites had rock substrates. We also tested four habitat suitability models for beaver in this basin. Three models produced significantly different ( P < .05) scores between occupied and random unoccupied reaches, suggesting that they might have some utility for this region.     

Ruffed grouse ( Bonasa umbellus ) foraging in aspen stands during winter in northern Utah

Ruffed Grouse ( Bonasa umbellus ) population densities are lower in the Intermountain West than elsewhere in the species' range. Throughout much of its range, the Ruffed Grouse is closely associated with quaking aspen ( Populus tremuloides ), in part because aspen buds are an important winter food. Because population fluctuations of Ruffed Grouse have been associated with changes in aspen abundance or chemical composition, we studied winter foraging of the species in the Intermountain West where it has received little attention. Aspen buds were the most prominent forage in the bird's diet, although in contrast to other Ruffed Grouse food habits studies, reproductive buds were not eaten more than vegetative buds, and buds of other deciduous plants were also important (>20% of the diet). Excretion of high concentrations of ammonium nitrogen suggests that grouse in northern Utah are ingesting higher levels of secondary plant compounds than reported elsewhere. Our results show aspen is important in the winter ecology of Ruffed Grouse in northern Utah and suggest that continued loss of aspen may impact grouse populations.     

Effects of browsing by native ungulates on the shrubs in big sagebrush communities in Yellowstone National Park

The effects of elk ( Cervus elaphus ), pronghorn ( Antilocapra americana ), and mule deer ( Odocoileus hemionus ) browsing on shrubs in big sagebrush ( Artemisia tridentata ) communities were monitored over a 31-year period in Yellowstone National Park. Ungulates were restricting Wyoming big sagebrush (spp. wyomingensis ) heights, size, and recruitment on the lower-elevation stratum only, while no such suppression was observed on the high-elevation stratum. Parallel increases in mountain big sagebrush (spp. vaseyana ) densities and cover occurred over the study period on both browsed and unbrowsed sites at the higher-elevation stratum, although big sagebrush, green rabbitbrush ( Chrysothamnus viscidiflorus ), and horsebrush ( Tetradymia canescens ) were slightly taller and crown sizes were slightly larger on unbrowsed than browsed sites. Wyoming big sagebrush utilization (percent leader use) was eight times higher (￣ x = 87 ± 7.2% by pronghorns, mule deer, and elk) on the low-elevation winter ranges stratum (the Boundary Line Area [BLA] portion of the winter range), while mostly mountain big sagebrush with leader use averaged only 11 ± 4.1% (nearly all by elk) on the high-elevation range stratum. In addition, annual aboveground biomass production of big sagebrush did not differ between browsed and unbrowsed study sites on the high-elevation stratum of the winter range. Population turnover was higher on browsed plots versus unbrowsed plots. No difference was observed in percent dieback of big sagebrush adult plants between browsed and unbrowsed plots at the higher stratum. Browsing did not influence the number of leaves or seedstalks per plant ( P > .05), but leaves averaged 45% longer and seedstalks 42% longer on browsed big sagebrush. Ungulate browsing, however, apparently suppressed production, germination, and survival of Wyoming big sagebrush on the low-elevation stratum. Numbers of Wyoming big sagebrush declined 43% and cover declined 29%, 1957-1990, on browsed sites on the BLA. Annual biomass production on browsed sites at the low-elevation stratum was only 6-35% that of unbrowsed sites, and big sagebrush recruitment was less on browsed sites. Percent leader use of big sagebrush did not differ between the period of ungulate reductions, 1962-1969, and the 1980s on the lower stratum (￣ x = 87% leader use), but utilization was less on higher portions of the winter range during the period of elk reductions (￣ x = 2%) than during the 1980s following cessation of elk controls (￣ x = 11%).     

Nesting and brood-rearing characteristics of Chukars in west central Idaho

We analyzed attributes from 23 nests (10 renests) and 46 brood locations of radio-marked Chukars ( Alectoris chukar ) in the lower Salmon River canyon of west central Idaho in 1995 and 1996. Nesting effort was 100%, apparent nest success was 45%, and estimated time from destruction or abandonment of a nest to initiation of laying a subsequent nest averaged 13 ± 5 days s x . Average clutch size for 1st nests (14.5 ± 1.0) was greater ( P = 0.017) than renests (10.4 ± 1.1). Cover types used by nesting Chukars included grass/forb (48% of nests), rock (43%), and shrub (9%), whereas the most common structure used for nests was rock outcrop (57%). Chukars did not use yellow starthistle ( Centaurea solstitialis ) habitats differently from what was expected ( P = 0.08) for nesting, but birds with broods selected areas with less starthistle ( P < 0.001). Chukar broods, which averaged 12.0 ± 1.1 chicks, used shrub and grass/forb cover types approximately equally (43% and 47% of locations, respectively) but rock habitats infrequently (11%).