Livestock grazing is the most common land-use practice in aridland ecosystems of the American West. Widespread and long-term declines of greater sage-grouse (Centrocercus urophasianus), an umbrella species for other sagebrush-associated vertebrates, has challenged land managers to find solutions to help bolster populations. Human infrastructure among western rangelands (e.g. fences) are one potential negative factor on sage-grouse populations, as nest survival – a key demographic vital rate for sage-grouse ­– can be 4x higher when placed >100 m away from the nearest fence. We implemented the first-ever, large-scale (>70 km), controlled experiment designed to evaluate changes in nest survival related to fence modifications in southwest Montana, USA. Fence modification included perch deterrents placed atop fence posts, and raised bottom fence wires (> 45 cm from the ground) intended to reduce the search efficiency of avian and ground-dwelling nest predators. We found that fence modifications increased 28-day nest survival within 100 m of mitigated fences by an average of 11.4% (90% CRI: 3.2%, 20.0%) using a Bayesian framework. The difference in survival between fence types was greater for modified fences in both low elevations and in areas with higher moisture potential. Our findings suggest that modifying fences designed to reduce the search efficiency of avian and ground-dwelling predators will likely benefit nest survival in sage-grouse across the sagebrush biome. This fence modification technique offers practitioners a tool to advance grazing practices, while reducing conflict between human infrastructure and wildlife conservation.

Animal species often have diverse requirements at different life history stages. Individuals may best meet these requirements by occupying areas with diverse heterogenous resources. Human activities such as agriculture may affect available habitat and heterogenous resources, but current understanding of possible effects is incomplete. We investigated habitat use and survival of an avian habitat specialist species with broods, the greater sage-grouse, in a landscape with different ecological types of sagebrush communities and livestock grazing. We used data from radio-collared females with broods to evaluate: 1) whether and when broods use heterogeneous resources across different sagebrush types; 2) effects of this heterogeneity on offspring fitness; and 3) management implications of our findings. Using a regression-based framework, we found that 26 of 99 broods capitalized on available heterogeneity by moving among ecologically distinct sagebrush types. The probability of switching was positively related to shrub cover and negatively related to forb cover, and distance to the nearest water tank and mesic area. Broods that switched had greater movement rates which resulted in narrower foraging niche at higher trophic levels. For broods that did not switch, survival was negatively related to Lepidoptera biomass and positively related to slope position, distance to mesic area, and accumulated grass cover. For broods that used heterogenous resources across different sagebrush types, survival remained constant across the range of observed conditions. Our findings provide rare evidence that use of heterogeneous resources can mitigate variation in change related to the environment and livestock grazing on components of offspring fitness.

Abstract The army cutworm, Euxoa auxiliaris (Grote), is a migratory noctuid that is both an agricultural pest and an important late-season food source for grizzly bears, Ursus arctos horribilis (Linnaeus, Carnivora: Ursidae), within the Greater Yellowstone Ecosystem. Beyond the confirmation of the moths' seasonal, elevational migration in the mid-1900s, little else has been documented about their migratory patterns. To address this missing ecological component, we examined (1) migratory routes during their spring and fall migratory periods throughout their natal range, the Great Plains, and (2) natal origin at two of their summering ranges using stable hydrogen (δ2H) analyses of wings from samples collected within the areas of interest. Stable carbon (δ13C) and stable nitrogen (δ15N) analyses of wings were used to evaluate larval feeding habits of the migrants and agricultural intensity of natal origin sites, respectively. Results suggest that, rather than migrating exclusively east to west, army cutworm moths are also migrating north to south during their spring migration. Moths did not exhibit natal origin site fidelity when returning to the Great Plains. Migrants collected from the Absaroka Range had the highest probability of natal origin in Alberta, British Columbia, Saskatchewan, the most southern region of the Northwest Territories, and second highest probability of origin in Montana, Wyoming, and Idaho. Migrants collected in the Lewis Range had the highest probability of origin in the same provinces of Canada. Results suggest that migrants of the Absaroka Range fed exclusively on C3 plants as larvae and rarely fed in heavily fertilized agroecosystems.

Stable isotope techniques can be used to assess nutrient acquisition and allocation strategies used to produce offspring. Before stable isotope techniques can be employed, researchers need reliable isotope discrimination values. In this context, isotope discrimination compares the difference in the isotope ratio between the maternal-offspring tissue that occurs during nutrient transfer prior to egg laying. Currently, isotope discrimination values are unknown between the maternal blood constituents - that reflect different temporal scales of integration - and downy feathers of their offspring. In this study, we experimentally derive isotope discrimination relationships between maternal diet-blood constituents for egg laying, and between maternal blood constituents-down feathers of offspring in an experiment with 3 types of domesticated gallinaceous birds raised on known diets. Our experiment is the first to report isotope discrimination values for maternal blood constituents-down of offspring in avian taxa and provides a new sampling technique that is less invasive than previously available as collecting down does not require sampling viable eggs or individuals. Future researchers can use these results to assist in identifying nutrient sources used by adult birds to produce young.

Variation in nutrient allocation can influence the timing of breeding and ultimately reproductive output. Time and space constraints might exist, however, if fewer food resources are available to meet the costs of reproduction early during the reproductive season. Here, for the first time, we test whether nutrient-allocation strategies for reproduction in a shrub-dependent avian species differ with timing of breeding in different ecoregions: a high-elevation landscape, containing spatially complex vegetation (Rocky Mountains) vs. a low-elevation, more homogenous landscape (Great Plains). We analyzed data collected from radio-telemetry and stable isotopes to assess the degree to which endogenous (body) reserves are used for reproduction and whether variation in allocation strategies was associated with time of year, ecoregion, habitat quality (including sagebrush type and plant greenness), or maternal characteristics. Using a Bayesian statistical framework, we found that females relied on a similar amount of endogenous reserves for reproduction in first nesting and renesting attempts. Additionally, endogenous contributions declined more rapidly throughout the nesting season in the Rocky Mountains than in the Great Plains. Individuals in high- and intermediate-elevation sagebrush types in the Rocky Mountains used similar amounts of endogenous reserves, whereas females nesting in low-elevation sagebrush used less. Females nesting at intermediate elevations, which experience the greatest flush of new green vegetation during the nesting season, switched their reliance from endogenous-to-exogenous sources for reproduction as green vegetation became available during spring. Our study highlights adaptations of a nutrient-allocation strategy across areas with varying levels of resources in time and space in a habitat specialist bird. Nutrient allocation by individuals residing in high-elevation areas favors a strategy that mainly uses nutrients gained from wintering habitats, whereas individuals residing in low-elevation areas mainly use exogenous sources for reproduction.

Dormant season livestock grazing reduces reliance on harvested feeds, but typically requires protein supplementation to maintain animal performance. Individual variation in supplement intake can impact animal performance; however, it is unknown if this variation leads to individual or herd-level effects on grazing behavior, resource utilization, and grazing impacts to native rangelands. To examine effects of protein supplementation on dormant season cattle resource use and, subsequently, post-grazing habitat conditions, we examined cattle grazing behavior, resource utilization and biomass removal of vegetation on a native rangeland in Montana. A commercial herd of 272 (yr 1) and 302 (yr 2) cows grazed a 329-ha rangeland pasture from November to January. Intake of a 30% crude protein supplement was measured for each individual. Five individuals within each of six age groups were equipped with GPS collars. Time spent grazing declined with supplement intake ([Formula: see text] = -0.05 ± 0.02; P < 0.01). Distance traveled per day had a positive asymptotic association with supplement intake ([Formula: see text] = 0.35 ± 0.09; P < 0.01). On average, resource utilization by cattle grazing dormant season forage decreased with terrain ruggedness ([Formula: see text] = -0.09 ± 0.03), but was unrelated to aspect, temperature and wind speed. Notably, we observed high individual variability in resource utilization for elevation, distance from supplement and water. A post-hoc analysis suggested that individual attributes (age, body weight, supplement intake) influenced cattle resource use. At moderate stocking rates, dormant season livestock grazing did not affect residual vegetation conditions (P values > 0.22). However, residual cover of forbs and litter increased with relative grazing intensity ([Formula: see text] = 1.04 ± 0.41; [Formula: see text] = 3.06 ± 0.89; P ≤ 0.05). In summary, high individual variability in grazing resource utilization of cattle suggests individual-level factors could be the dominant drivers in grazing behavior and landscape use.

Grazing dormant forage under low-input heifer development strategies typically exposes cattle to low-quality forage. Protein supplementation while grazing dormant range can enhance heifer growth and reproductive performance. We examined resource utilization of heifers and the effects of dormant season grazing on residual vegetation characteristics under two supplementation management strategies. Approximately 100 weaned composite heifer calves were randomly selected and placed into one of two supplementation treatments in each of 2 yr, one receiving a free access 62% crude protein self-fed concentrate and the other receiving a daily hand-fed 20% crude protein cake. Grazing occurred from December (2015 and 2016) through March (2016 and 2017). Thirty transects were randomly located within each pasture for measuring vegetation quality and structure before and after grazing. Daily space use and behavior was evaluated for 21 individuals within each treatment using global positioning system (GPS) collars and resource utilization functions. Heifers supplemented with concentrated protein spent more time grazing per day than heifers supplemented with cake (6.92 +/- 0.18, 6.24 +/- 0.17 h). Relative use by heifers in the cake treatment was negatively related to horizontal distance from the supplement delivery site early to midwinter ((beta) over bar = -0.41 +/- 0.16, -0.53 +/- 0.17). Both treatments selected grazing locations relative to standing biomass of perennial grasses ((beta) over bar = 0.0005 +/- 0.00004) and crude protein ((beta) over bar = 0.12 +/- 0.007). However, resource selection was highly variable among individuals for both supplementation treatments. We found no treatment effects on pre-post grazing differences in residual cover of litter, grass, forbs and shrubs (P > 0.24). However, the time period when grazing occurred had an effect on residual vegetation conditions (P < 0.01). Our results indicate high levels of variability in grazing site selection by heifers, suggesting future research should incorporate individual animal measurements in an attempt to account for individual animal variability. (C) 2019 The Society for Range Management. Published by Elsevier Inc. All rights reserved.

Animals are expected to select habitats that maximize their fitness over evolutionary time scales. Yet in human-modified landscapes, habitat selection might not always lead to increased fitness because animals undervalue high-quality resources that appear less attractive than those of lower quality. In the American West, agriculture has modified landscapes, yet little is known about whether agricultural changes alter the reliability of the cues animals use to identify habitat quality; ultimately forming maladaptive breeding strategies where behavioral cues are mismatched with survival outcomes. Using the greater sage-grouse, a species highly dependent upon sagebrush landscapes, we (1) evaluated how females select nesting habitats based on sagebrush type, along with livestock grazing related linear and point features, and other biotic, abiotic characteristics, given hypothesized influences on hiding cover, microclimate and predator travel routes and perches, (2) compared habitat selection information with results for nest survival estimates to evaluate if selection appears to be adaptive or not, and (3) used our results to evaluate the most appropriate strategies for this species in a grazing-modified landscape. Nest-site selection for sagebrush type appears to be maladaptive: in the most-preferred sagebrush type, nest survival rate was one-fourth the rate realized by females nesting in the sagebrush type avoided. Nest survival was four times higher for nests placed away from (>100 m), rather than next to (1 m), the nearest fence, and survival was lower within sites with higher cow pie density (a proxy for previous grazing intensity). Live and dead grasses influenced selection and survival in opposing ways such that dead grass was selected for but resulted in reduced survival while live grass was avoided but resulted in increased survival. Results collectively provide the first empirical evidence that a specific type of sagebrush acts as an ecological trap while another sagebrush type is undervalued. These results also suggest that adding more fences to control livestock grazing systems will likely reduce sage-grouse nest survival.

Reductions in whitebark pine (Pinus albicaulis) due to blister rust (Cronartium ribicola) and mountain pine beetle (Dendroctonus ponderosae) have prompted some forest managers to consider selective thinning and prescribed fire to reduce competition of whitebark pine with other conifer species. Whitebark pine is an important food source for grizzly bears (Ursus arctos horribilis) in the Greater Yellowstone Ecosystem, but most of the seeds are obtained by raiding red squirrel (Tamiasciurus hudsonicus) middens. Therefore, it is important to understand which attributes maximize red squirrel midden site selection. The objectives of this study were to estimate active midden site selection criteria and quantify the ideal conifer composition associated with red squirrel middens in the Cooke City Basin, MT. Active midden counts were collected in 810, 30-meter diameter circular plots, equally spaced along 27 transect lines in the basin. We used generalized linear mixed models to assess variables associated with middens. Midden occurrence probability was positively associated in a curvilinear relationship with conifer canopy cover and the amount of topographic shading. Midden occurrence increased as the percent of whitebark pine increased up to 44 percent. A conifer composition of 44 percent whitebark and 56 percent mixture of subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmannii) was ideal for midden sites. Whitebark pine treatments to reduce fir and spruce competition should acknowledge the tradeoff to foraging grizzly bears.

Beavers (Castor canadensis) disappeared from drainages north of Yellowstone National Park in the mid-1900s because of trapping, a potential tularemia outbreak, and willow (Salix spp.) stand degradation by ungulates. Beavers were reintroduced in 1986 after a 40–yr absence with inventories of active-beaver structures completed each fall after reintroduction for 24 consecutive yr. We used this inventory to evaluate the expansion of beaver populations in a riparian environment recovering from past overuse by ungulates. Specifically, we investigated the density of active-beaver colonies and dams, the change in willow cover, and habitats associated with beaver expansion since reintroduction. Successful establishment and expansion of beavers indicate that sufficient resources were available to the population despite the suboptimal condition of riparian vegetation. Carrying capacity on third-order streams was reached approximately 14 yr after reintroduction (2000) with an average annual density of 1.33 (95th percentile = 1.23−1.44 active colonies/stream km) between 2000 and 2010. The average annual density of beaver dams during this time was 2.37 (2.04−2.71 active dams/stream km). Despite the beaver population being at carrying capacity in meadows since 2000, willow cover increased by 16% between 1981 and 2011. We speculate that beaver activities, together with reduced ungulate browsing from predation and habitat loss, combined to increase willow cover. Willow cover and height were positively associated with colony longevity, but numerous other influencing variables included secondary channels, sinuosity, stream depth, and sandbar width. Our results provide evidence that beaver reintroduction can be successful in riparian areas where willow stand condition is less than optimal and that beavers might ultimately improve willow condition. We suggest that reducing ungulate use of overgrazed riparian environments will facilitate the reestablishment of beaver populations. We also provide managers with habitats that should be identified in an environment targeted for reintroduction.

Selection of nest sites directly influences reproductive success for Greater Sage-Grouse (Centrocercus urophasianus); thus, regional evaluation of how this species selects nest sites is necessary for effective habitat management. We evaluated fine-scale nest site selection of Greater Sage-Grouse in the Centennial Valley of southwest Montana. We conducted vegetation surveys at nest sites (n=90) of radio-tagged Greater Sage-Grouse and paired random locations across 2 breeding seasons (2014-2015). The majority of nests were located under mountain big sagebrush (Artemisia tridentata ssp. vaseyana), three-tip sagebrush (A. tripartita), and basin big sagebrush (A. tridentata ssp. tridentata) shrubs. We used generalized linear models and information theory to evaluate competing hypotheses about nest site selection. Our top model indicated that nest site selection was primarily associated with nest shrub morphological characteristics and cover provided by the nest shrub. Mountain big sagebrush and three-tip sagebrush provided twice the amount of lateral cover that basin big sagebrush shrubs provided. Our results suggest that herbaceous cover was unimportant at fine scale nest site selection of Greater Sage-Grouse in our study area. Managers should focus on conserving large intact stands of mountain big sagebrush and three-tip sagebrush habitats because they provided the most lateral cover and supported the majority of nest sites.

In the greater Yellowstone ecosystem (GYE), alpine aggregations of army cutworm moths (Euxoa auxiliaris) are an important food source for grizzly bears (Ursus arctos horribilis). The number of grizzly bears utilizing this food source has increased since initial documentation in 1986 in the Shoshone National Forest, Wyoming. Dozens of bears congregate and feed on moths offering a unique viewing opportunity for bear-enthusiasts, professional media, and hikers. Currently, there is a limited understanding of how bears use these areas and no information on human use. The proximity of grizzly bears and humans poses a management concern for grizzly bears and human safety. Our objectives are to quantify grizzly bear and human use patterns and to identify areas of bear-human interactions. Our methods include occupancy and written surveys, GPS tracking unit deployment, and GIS analysis. Preliminary results from our first year of bear observations (n=220) showed 48% of bears foraging on moths, 20% foraging on vegetation, and 23% travelling. We recorded 5 groups and 26 groups of human use at two locations. We documented 18 bearhuman interactions, all on high-use travel routes common to bears and humans. Despite low human use all interactions between bears and humans resulted in bear avoidance of humans. At present, bear-human interactions appear to be very low but if human use increases, interactions will increase due to lack of alternate travel routes.

Vegetative characteristics of 146 greater sage-grouse (Centrocercus urophasianus) nest sites and 48 brood rearing sites were compared with paired random sites to determine if hens were selecting sites with certain vegetative attributes at three study areas in central Montana in 2003 and 2004. Ninety-seven percent of all nest locations and 92% of all brood rearing locations were in Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young) plants. Therefore, only attributes of Wyoming big sagebrush plants were analyzed. Shrub characteristics such as percent cover, density (shrubs/m2), average shrub height (cm), nest shrub height (cm) and nest shrub production (g/shrub) were recorded. Herbaceous measurements such as forb cover (%), grass cover (%), total cover (%) and grass height (cm) were recorded. Sage-grouse hen nest sites had greater (P ≤ 0.05) average shrub height (36 vs 31 cm) and more (P ≤ 0.05) nest shrub production (55 vs 48 g/shrub) than random sites. There were no differences in sagebrush cover density or nest shrub height or any herbaceous characteristics between nest and random sites. Fifty percent of all nests were successful. Successful nest sites were not different from unsuccessful nest sites in any shrub or herbaceous component. There were no differences in shrub or herbaceous measurements between yearling and adult nest sites. Shrub and herbaceous characteristics of brood sites did not differ from random sites. Average shrub height was greater (P ≤ 0.05) for adult brood rearing sites compared to yearling sites (35 vs 31 cm). Brood site shrub cover was less (P < 0.05) than nest shrub cover (14 vs 21%). Our results suggest that even though nesting sage-grouse hens selected for taller and more productive Wyoming big sagebrush plants, these attributes did not improve nesting success. Grazing guidelines suggested to increase herbaceous vegetation may not improve nesting or brood rearing success. Although brood rearing vegetative characteristics were lower (P £ 0.05) in sagebrush cover and production than nesting sites, managers should not reduce Wyoming big sagebrush cover or production to emphasize one stage of sage-grouse production since this plant is vital for all life phases.

One hundred-one crossbred beef heifers (average weight 256.1 kg) were used to evaluate the effects of diet during an 84-day period, on growth and reproductive performance. The four treatments were: 1) grass hay; 2) grass hay + 0.9 kg/day barley; 3) grass hay + 1.8 kg/day barley; and 4) alfalfa hay. Heifers were assigned randomly to 12 pens by weight (three pens/treatment). Prior to feeding, barley was cracked through a roller-mill. Heifers consuming alfalfa hay or grass hay + 1.8 kg barley gained 39% faster (0.68 and 0.74 kg/day, respectively; P = 0.01) than heifers consuming grass hay alone (0.51 kg/day). Heifers consuming grass hay + 0.9 kg barley were intermediate in average daily gain (ADG; 0.63 kg/day). Hay intake was 16% greater (P < 0.10) by heifers consuming alfalfa hay, grass hay, and grass hay + 0.9 kg barley compared with those consuming grass hay + 1.8 kg barley (average 8.1 vs 7.0 kg/day). Using costs (USD) of $0.066/kg, $0.099/kg, and $0.0935/kg for grass hay, alfalfa hay, and barley, respectively, feed cost/day was greatest (P < 0.01) for alfalfa hay ($0.81/day), intermediate for the grass hay + barley diets (average $0.63/day), and lowest for grass hay ($0.53/day). Cost/kg gain was less (P < 0.10) for grass hay + 1.8 kg barley compared with alfalfa hay. No diet differences (P > 0.70) were found in reproductive performance of the heifers. Feeding replacement heifers alfalfa hay resulted in performance equivalent to feeding grass hay + 1.8 kg barley, but the alfalfa hay diet had a higher cost.

The objectives of this study were to evaluate the effects of spring application of glyphosate (1.1 kg/ha) on 1) crested wheatgrass (Agropyron cristatum (L.) Gaertn) phytomass, 2) seedling establishment of native grasses and forbs using no-till reseeding and 3) non-target plant species responses. Field trials were conducted at five sites in central and eastern Montana in 2002 and 2003. Each site contained sixteen 36x36 m plots to test four treatments. The treatments included control, glyphosate only, glyphosate plus cool season plants no-till seeded in the fall, and glyphosate plus spring no-till seeding of cool season plants in 2002. In 2003, one half of the plots were sprayed a second time with glyphosate to control crested wheatgrass growth. Five 0.25 m2 quadrats per plot sampled in August were used to estimate crested wheatgrass, seeding and non-target phytomass. Split plot error was the testing term for glyphosate treatment differences, and the whole plot error was the testing term for planting treatments. Data that was not normally distributed was rank-transformed. Data was analyzed by site due to site by treatment interactions. Application of glyphosate for two consecutive years reduced crested wheatgrass phytomass 91% compared to controls. Application for one year reduced phytomass 56% across all sites but two sites showed no reduction in phytomass one year after application. No-till seeding failed on four of five sites due to lack of adequate moisture and did not influence seedling phytomass a year after planting. Non-target plant species biomass was increased by glyphosate application on four of five sites. Application of glyphosate did not increase seedling establishment planted under low moisture conditions, but it increased biomass of non-seeded plants.

Redistribution of wildlife resulting from human alteration of environments is of growing management concern in North America.  Habituation, which can coincide with redistribution, seems to be particularity prevalent in national park systems because millions of visitors interact with wildlife. For example, Glacier National Park in northwestern Montana, USA, receives approximately 2.2 million visitors over the months of June, July, and August each year—with the majority of their activity concentrated along the Going-to-Sun Road. The Going-to-Sun Road corridor is well-known for its habituated mountain goats (Oreamnos americanus).  Habituation, however, was identified as a priority management concern in Glacier National Park.  Successful management actions require a clear understanding of the causes and consequences of complex ecological issues such as habituation. Through experimental and observation effort this project has identified human-created predation refugia, or human shields, where mountain goats are escaping predation through interaction with people.  Reductions in predation risk have resulted in mountain goat redistribution and changes in behavior.  We found mountain goats using sites with human shields were less vigilant and were found in smaller groups.  Furthermore, goats in areas with human-mediated predation refuge had reduced use cliff security terrain. Additionally, mountain goats that exploited people as shields from predators showed a weakened response to an experimentally presented predator model. Reductions in predator risk appear to be the primary driver of mountain goat redistribution and the use of humans as buffers from predation has led to close contact between people and wildlife, resulting in compromised safety and altered ecological interactions.

We measured 328 sites in northern, central, and southern Montana and northern Wyoming during 2003 to test the competitive relationship of herbaceous cover in the interspaces to Wyoming big sagebrush (Artemisia tridentata wyomingensis) cover. Long term annual precipitation at all sites was approximately 31 cm. Sagebrush and total herbaceous cover varied from 5 to 45 percent and 3.5 to 55 percent, respectively. Simple linear regression was the best fit model for predicting herbaceous cover from sagebrush cover using the highest Ra2 values as the model selection criteria. In northern Montana, herbaceous vegetation was predicted by sagebrush cover with the following model: Y = 37.4 – 0.61X (Ra2 = 0.16, P < 0.001, n = 87). In central Montana, the model was Y = 14.0 – 0.00X (Ra2 = 0.00, P = 1.0, n = 155). In southern Montana, the model was Y = 35.9 – 0.39X (Ra2 = 0.14, P < 0.001, n = 86). When all sites were combined, the best fit model was Y = 23.7 – 0.15X (Ra2 = 0.01, P < 0.061, n = 328). This analysis determined that only 1 percent of the variation in herbaceous vegetation cover was associated with Wyoming big sagebrush cover. Management suggestions to reduce Wyoming big sagebrush in order to increase long-term herbaceous production for greater sage-grouse (Centrocercus urophasianus) would not be recommended.

Greater sage-grouse ( Centrocercus urophasianus) is a high priority species for federal and state land management agencies in the Western United States. Sage-grouse are sagebrush ( Artemisia spp .) obligates requiring sagebrush for their survival throughout the year. Sagebrush has been removed and replaced with crested wheatgrass ( Agropyron cristatum & A. desertorum ) throughout the West. The objectives of this paper were to review the literature (100 papers), as well as consult experts, to determine which methods are most likely to eliminate crested wheatgrass and establish sagebrush. No technique eliminates crested wheatgrass in a single application but research suggests it should not comprise more than 14% cover for successful reseeding of other species. Grazing and fire have no long-term impacts on crested wheatgrass. Mechanical treatments, such as plowing, disking, and cultivating reduce and eradicate crested wheatgrass, but a flush of invasive annual grasses following mechanical disturbance can make establishment of seeded species difficult. If invasive plant establishment is a problem with mechanical treatments, crested wheatgrass stands should be treated with glyphosate in early spring for two consecutive years at a rate of 1.1 kg/ha of active ingredient. Then, sagebrush should be seeded in the late fall using a compact row seeder or Brillion cultipacker at a rate of 0.22 kg/ha pure live seed.

The Northern Yellowstone Winter Range (NYWR) in northwestern Wyoming and southwestern Montana is an important winter migratory destination for ungulates. The NYWR is within the Greater Yellowstone Ecosystem (GYE), a landscape characterized by a complex ecological system of predators, scavengers, and ungulates. Grizzly bears (Ursus arctos) are dominant members of the scavenging community throughout the spring. However, little is known about factors associated with grizzly bear use of carcasses. Of particular interest to managers is how habitat and anthropogenic factors are associated with carcass use. Such information, for example, may be useful to manage spring recreation in important bear foraging areas to reduce conflict and support conservation efforts. We used logistic regression to analyze spring survey data from 23 transects located in Yellowstone National Park and the Gallatin National Forest during 1997–2012, to identify factors associated with grizzly bear scavenging of winter- or predator-killed ungulates. Multi-model inference was used to evaluate relative support for a set of a priori candidate models containing environmental and temporal correlates. Our preliminary findings showed support for models with distance to forest edge, road density, and elevation. Results indicated negative relationships between these factors and probability of carcass use. Our results suggest that spatial heterogeneity in landscape-level habitat characteristics and human activity affect grizzly bear use of a valuable spring food source.

Greater sage-grouse (Centrocercus urophasianus) habitat characteristics were studied in central Montana primarily on Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young) dominated rangeland. The primary objective was to compare shrub and herbaceous parameters within (use, random or non-use) and between seasonal habitats (nest, brood, winter). Two study sites (Musselshell and Golden Valley counties), and 2 years (2004 and 2005) were compared. Nest, brood, and random sites were compared for herbaceous cover, and grass height (n = 648). Nest, brood, random, winter use and winter non-use sites were evaluated for shrub cover, density, and height. All differences were considered significant at P ≤ 0.05. Sage-grouse nested in areas with greater total shrub cover and height, and taller live and residual grass than was randomly available. No differences were found between brood and paired random sites for any of the herbaceous or shrub parameters measured. Shrub cover and density were greater at winter use sites than non-use sites. Winter use sites had less shrub cover than nest sites. The nest and brood habitat had similar shrub cover, density, and height on the study area. Sage-grouse habitats should be managed to include sagebrush, forbs, and grass. Herbaceous vegetation was more important during nesting and brood rearing than during the winter. Therefore, some portions of sage-grouse habitat may benefit from management for greater herbaceous cover, but not at the expense of removing sagebrush. Sagebrush cover from 10 to 15 percent was the most consistent component of sage-grouse habitat.