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Invasion and expansion of non-native and native plants have altered vegetation structure in many terrestrial ecosystems. Small mammals influence multiple ecosystem processes through their roles as ecosystem engineers, predators, and prey, and changes to vegetation structure can affect habitat use, community composition, and predator-prey interactions for this assemblage of wildlife. In the sagebrush (Artemisia spp.) shrublands of the western United States, invasion by nonnative grasses and expansion of native conifer trees beyond their historical range has altered vegetation structure. These changes may potentially affect distributions and interactions of deer mice (Peromyscus maniculatus), which are generalist omnivores, and Columbia Plateau pocket mice (Perognathus parvus), more specialized granivores. To assess the extent to which altered habitat affects small-mammal density, survival, and home-range size, we examined these aspects of smallmammal ecology along a gradient of cheatgrass (Bromus tectorum) invasion and western juniper (Juniperus occidentalis) establishment in sagebrush shrublands in southwestern Idaho, USA. From 2017-2019, we used a spatially explicit markrecapture design to examine attributes of small-mammal ecology along an invasion gradient. We did not find support for an effect of cheatgrass cover on density or survival of either species. Home-range size of deer mice was 2.3 times smaller in heavier cheatgrass cover (60%) compared to areas with little or no cheatgrass cover. Density of deer mice was highest (5 individuals/ha) in areas with 10% juniper cover and decreased with increasing juniper cover, whereas density of pocket mice was positively influenced by shrub cover. Survival of deer mice declined as juniper stem density increased. Conversely, survival of pocket mice increased with increasing juniper stem density. We found evidence for interspecific interactions between these 2 species, in the form of a densitydependent effect of deer mice on pocket mouse home-range size. Home-range size for pocket mice was 2 times smaller in areas with the highest estimated density of deer mice compared to areas with low densities of deer mice. Our data provides unique information about how small mammals in the sagebrush steppe are affected by expanding and invasive plant species and potential ways that habitat restoration efforts, in the form of conifer removal, may influence small mammals. Understanding the response of small mammals to conifer expansion or removal may shed light on the demographic and numerical responses of other wildlife associated with the sagebrush biome, including predators. [ABSTRACT FROM AUTHOR]

We examined age-related reproductive success and the short-term consequences of dispersal by known-aged Cliff Swallows (Petrochelidon pyrrhonota) breeding in Texas from 1975-86. Clutch size increased with age in females, and males and females [greater than or equal to]2 yrs old fledged more young than yearlings. Sixteen percent (76/463) of birds dispersed between breeding seasons and we observed female-biased dispersal. Birds that dispersed to a different colony at age 2 produced 0.91 fewer fledglings post-dispersal compared to the previous year. and birds that dispersed at age 3 produced 0.34 more fledglings post-dispersal compared to the previous year; females experienced greater benefits than males when they dispersed at age 3 yrs. Younger dispersers incur short-term costs which might have important consequences for lifetime reproductive success for a short-lived passerine. However, potential population-level consequences from dispersal costs is likely minimal given the low rate of dispersal we observed. Keywords: age-dependent. Cliff Swallow, colonial, dispersal, Petrochelidon pyrrhonala. reproductive success, Dispersal is widely acknowledged as an important aspect of avian life history due to its effects on population dynamics, gene flow, and the distribution of species (Johnson & Gaines 1990). [...]

The article presents a study examining mesic meadow response to varying levels of grazing utilization in south central Idaho. Topics discussed include the prevalent issue of livestock grazing in riparian and mesic meadow habitats in rangeland management; ways in which livestock grazing is associated with plant phenology and nutrient levels in mesic meadows; and ways in which livestock grazing utilization influences vegetative biomass and nutrient values in mesic meadow pastures.

Given the uncertain population status of low-density, widely-occurring raptors, monitoring changes in abundance and distribution is critical to conserving populations. Nest-based monitoring is a common, useful approach, but the difficulty and expense of monitoring raptor nests and importance of reliable trend data to conservation requires that limited resources are allocated efficiently. Power analyses offer a helpful tool to ensure that monitoring programs have the ability to detect trends and to optimize financial resources devoted to monitoring. We evaluated alternative monitoring designs for raptors to identify appropriate survey effort to detect population trends. We used data collected from a territory-occupancy study of ferruginous hawks throughout Wyoming to guide simulations and evaluate the ability to detect trends in occupancy rates. Results suggest that greater gains in precision of trend estimation may be achieved through the addition of more sites and not more visits; statistical power was ≥80% when monitoring lasted 20 years and population declines were 20%; and probability of detection affected statistical power less than rates of population decline. Monitoring at least 150 sites for 20 years would provide reasonable estimates of trend in occupancy given certain rates of detection and occupancy, but only for population declines of 20%. Removal sampling did not result in substantial changes of any metrics used to evaluate simulations, providing little justification for employing the standard design if territory occupancy is the variable of interest. Initial rates of territory occupancy may be biased high, a problem inherent to many studies that monitor territory occupancy. We explored the effects of lower rates of initial occupancy on the ability to detect trends. Although we present data from a study of ferruginous hawks, our simulations can be applied to other raptor species with similar life history and population dynamics to provide guidance for future trend estimation of territory occupancy. [ABSTRACT FROM AUTHOR]

Although novel ecosystems are increasing globally, their utility for biodiversity conservation is poorly understood. Native fauna are predicted to use novel ecosystems when those ecosystems provide structure and resources similar to the native habitat. We modified existing terminology on wildlife functional groups to develop a conceptual model that illustrates fundamental differences in how native wildlife respond to novel ecosystems: novel ecosystem avoiders, novel ecosystem utilizers, and novel ecosystem flourishers. We postulate that species membership in these functional groups is related to the relative importance habitat physiognomy and floristics play in habitat selection cues. An excellent opportunity to test this conceptual model exists with birds in historic and novel ecosystems. A long-standing, equivocal literature investigating relative contribution of physiognomy vs. floristics to avian abundance and community diversity in native ecosystems exists. Using data from grassland and woodland biomes in western North America (Oregon, USA) and Western Australia, respectively, we evaluated use of habitats by indigenous bird species in relation to physiognomy and floristics. Our two case studies represent two extremes on the novelty spectrum: (1) urban gardens in the metropolitan region of Perth, Western Australia, which are designed ecosystems that vary in the percentage of native plantings; and (2) the Zumwalt Prairie in northeastern Oregon where native grassland plants still dominate the ecosystem but non-native plants are present and available for use as breeding sites. Using an information-theoretic perspective, we asked whether habitat use based on occurrence (Perth gardens) or breeding success (Oregon grassland) was best explained by physiognomy, floristics, or both. Using these two case studies, our evidence shows that species or guilds within a community will not respond equally to novelty as predicted. We found strong evidence for only one taxon showing sensitivity to floristics and two to physiognomy. All taxa considered were either grouped as novel ecosystem avoiders or utilizers; no flourishers were identified. These results suggest novel ecosystems providing appropriate physiognomy can provision suitable habitat for some taxa. [ABSTRACT FROM AUTHOR]

Mountain pine beetle (Dendroctonus ponderosae) (MPB) outbreaks are increasingly prevalent in western North America, causing considerable ecological change in pine (Pinus spp.) forests with important implications for wildlife. We reviewed studies examining wildlife responses to MPB outbreaks and post outbreak salvage logging to inform forest management and guide future research. Our review included 16 studies describing MPB outbreak relationships with 89 bird species and 6 studies describing relationships with 11 mammalian species, but no studies of reptiles or amphibians. We included studies that compared wildlife response metrics temporally (before versus after the outbreak) and spatially (across sites that varied in severity of outbreak) in relation to beetle outbreaks. Outbreaks ranged in size from 20,600 to ⩾ 107 ha and studies occurred 1-30 years after the peak MPB outbreak, but most studies were conducted over the short-term (i.e., ⩽ 6 years after the peak of MPB-induced tree mortality). Birds were the only taxa studied frequently; however, high variability existed among those studies to allow many inferences, although some patterns were evident. Avian studies concluded that cavity-nesting species responded more favorably to beetle-killed forests than species with open-cup nests, and species nesting in the shrub layer favored outbreak forests compared with ground and open-cup canopy nesters that generally showed mixed relationships. Bark-drilling species as a group clearly demonstrated a positive short-term association with MPB epidemics compared with that of other foraging assemblages. Cavity-nesting birds that do not consume bark beetles (i.e., secondary cavity-nesting species and nonbark-drilling woodpeckers) also exhibited some positive responses to MPB outbreaks, although not as pronounced or consistent as those of bark-drilling woodpeckers. Mammalian responses to MPB outbreaks were mixed. Studies consistently reported negative effects of MPB outbreaks on red squirrels (Tamiasciurus hudsonicus). However, there is evidence that red squirrels can persist after an outbreak under some conditions, e.g., when non host tree species are present. For small mammal species associated with forest understories, responses may be most pronounced during the postepidemic period ( > 6 years after the peak of beetle-induced tree mortality) when snags fall to produce coarse woody debris. Post outbreak salvage logging studies (n = 6) reported results that lacked consensus. Post outbreak salvage logging may have an impact on fewer wildlife species than postfire salvage logging, probably because only host-specific tree species are removed after beetle outbreaks. [ABSTRACT FROM AUTHOR]

Highlights: [•] Conifer mortality generally increased with bole diameter. [•] Patterns of mortality were influenced by management history. [•] Large diameter conifers near patch cuts escaped attack by bark beetles. [•] Mortality of smaller lodgepole pine was higher >15m from patch cuts. [Copyright &y& Elsevier]

The quantity and nutritional quality of forage are key drivers for ungulate populations, including mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus nelsoni), in the western U.S., but current vegetation maps are too coarse spatially and temporally to effectively characterize fine-scale habitat. To address some of these gaps, we tested a novel approach using existing vegetation surveys, maps, and remotely sensed data to develop fine-scale forage species distribution models (SDMs) across Idaho, USA. We modelled 20 forage species that are suitable for mule deer and Rocky Mountain elk. Climatic, topographic, soil, vegetation, and disturbance variables were attributed to approximately 44.3 million habitat patches generated using multi-scale object-oriented image analysis. Lasso logistic regression was implemented to produce predictive SDMs. We evaluated if the inclusion of distal environmental variables (i.e., indirect effects) improved model performance beyond the inclusion of proximal variables (i.e., direct physiological effect) only. Our results showed that all models provided higher predictive accuracy than chance, with an average AUC across the 20 forage species of 0.84 for distal and proximal variables and 0.81 for proximal variables only. This indicated that the addition of distal variables improved model performance. We validated the models using two independent datasets from two regions of Idaho. We found that predicted forage species occurrence was on average within 10% of observed occurrence at both sites. However, predicted occurrences had much less variability between habitat patches than the validation data, implying that the models did not fully capture fine-scale heterogeneity. We suggest that future efforts will benefit from additional fine resolution (i.e., less than 30 m) environmental predictor variables and greater accounting of environmental disturbances (i.e., wildfire, grazing) in the training data. Our approach was novel both in methodology and spatial scale (i.e., resolution and extent). Our models can inform ungulate nutrition by predicting the occurrence of forage species and aide habitat management strategies to improve nutritional quality. • Forage species occurrence was predicted at a fine-scale across Idaho, USA • Lasso logistic regression provided high predictive accuracy • Indirect model predictors improved performance beyond direct ones • Wildlife managers can use models to inform ungulate nutritional ecology • Future direction for modelling and validation is outlined [ABSTRACT FROM AUTHOR]

This article focuses on Kansas Army Ammunition Plant (KSAAP) in southeast Kansas. It was historically dominated by native bluestem grasses and deciduous forest, but now consists of agricultural crops and pastures planted with tall fescue (Lolium arundinaceum), an exotic cool season grass. The fescue-dominated pastures, which are maintained by annual fertilization, provide poor habitat for wildlife compared to native tallgrass prairie. Cattle preferentially choose the tender, actively growing fescue shoots for grazing, which should decrease tall fescue biomass over time through repeated defoliation and removal of reproductive structures.