Patterns of habitat use by breeding birds were studied in cottonwood riparian forests along 100 km of the South Fork of the Snake River in southeastern Idaho, United States, from 1991 to 1994. A hierarchical approach was used to examine habitat use at three spatial scales: microhabitat (local vegetation characteristics), macrohabitat (cottonwood forest patch characteristics), and landscape (composition and patterning of surrounding [matrix] vegetation types and land uses). This paper addresses a series of predictions about species’ distributions that incorporate the different spatial scales. Bird distribution and abundance and vegetation data were collected on 57 cottonwood forest patches ranging in size from 0.40 ha to 205 ha. The surrounding landscape changed from a valley surrounded by mountains, on the upstream end of the study area, to a narrow canyon adjacent to natural upland vegetation in the middle section, and to a wide, open floodplain dominated by agriculture on the downstream end. The best predictors of high species richness (r2 = 0.71) were natural and heterogeneous landscapes, large cottonwood patches, close proximity to other cottonwood patches, and microhabitats with relatively open canopies. Distribution and frequency of occurrence were evaluated for 32 species of small land birds. The most frequent significant predictor of species occurrence was the landscape component: increases in upland natural vegetation with decreases in agriculture. Both interior and edge specialists were found in arid land, cottonwood riparian forests that are linear in nature, with large amounts of edge. Nest predators, brood parasites, and exotic species responded positively to human‐altered landscapes. Landscape patterns were the primary influence on distribution and occurrence of most bird species, whereas macrohabitat and microhabitat were of secondary importance. Thus, surrounding landscape (matrix) features should be a primary consideration for selecting riparian reserve areas.

long-term studies on how cavity-nesting birds respond to different fire conditions in ponderosa pine1Douglas-fir forests of western Idaho. The work was started in response to the high-intensity wildfires of 1992 and 1994 on the Boise National Forest. This publication provides information to managers and biologists on the effects of stand-replacement wildfire (a no-action alternative to the Forest Health Initiative [USDA 1994a1) and salvage logging on cavity-nesting birds.Cavity-nesting birds were selected for these studies because many are (1) dependent on fire processes and patterns over large landscapes for their dispersal and movements, (2) designated as sensitive species by Federal or State agencies, and(3) responsive to fire and timber management activities. We know little about the implications of fire suppression, stand-replacement wildfire, or prescribed fire with timber management for sensitive bird species. Thus, we need to gather information on the "forest health" action and no-action alternatives to understand the trade-offs associated with future decisions in green areas for sensitive cavity-nesting birds, and to identify possible conflicts for sensitive species management.The first phase of the project was to evaluate effects of high-intensity, standreplacement wildfire on cavity-nesting birds and their associated habitats. This paper summarized results from 1994 to 1996 and was first distributed as a progresslinterim report in 1997 (Study No. 4202-1-7-7, Progress Report 94-96, April 1997). We encourage managers and biologists to provide comments on this ongoing project.

We defined habitat requirements (source habitats) and assessed trends in these habitats for 91 species of terrestrial vertebrates on 58 million ha (145 million acres) of public and private lands within the interior Columbia basin (hereafter referred to as the basin). We also summarized knowledge about species-road relations for each species and mapped source habitats in relation to road densities for four species of terrestrial carnivores. Our assessment was conducted as part of the Interior Columbia Basin Ecosystem Management Project (ICBEMP), a multiresource, multidisciplinary effort by the USDA Forest Service (FS) and the USDI Bureau of Land Management (BLM) to develop an ecosystem-based strategy for managing FS and BLM lands within the basin. Our assessment was designed to provide technical support for the ICBEMP and was done in five steps. First, we identified species of terrestrial vertebrates for which there was ongoing concern about population or habitat status (species of focus), and for which habitats could be estimated reliably by using a large mapping unit (pixel size) of 100 ha (247 acres) and broad-scale methods of spatial analysis. Second, we evaluated change in source habitats from early European settlement (historical, circa 1850 to 1890) to current (circa 1985 to 1995) conditions for each species and for hierarchically nested groups of species and families of groups at the spatial scales of the watershed (5th hydrologic unit code [HUC]), subbasin (4th HUC), ecological reporting unit, and basin. Third, we summarized the effects of roads and road-associated factors on populations and habitats for each of the 91 species and described the results in relation to broad-scale patterns of road density. Fourth, we mapped classes of the current abundance of source habitats for four species of terrestrial carnivores in relation to classes of road density across the 164 subbasins and used the maps to identify areas having high potential to support persistent populations. And fifth, we used our results, along with results from other studies, to describe broad-scale implications for managing habitats deemed to have undergone long-term decline and for managing species negatively affected by roads or road-associated factors.Our results indicated that habitats for species, groups, and families associated with old-forest structural stages, with native grasslands, or with native shrublands have undergone strong, widespread decline. Implications of these results for managing old-forest structural stages include consideration of (1) conservation of habitats in subbasins and watersheds where decline in old forests has been strongest; (2) silvicultural manipulations of mid-seral forests to accelerate development of late-seral stages; and (3) long-term silvicultural manipulations and long-term accommodation of fire and other disturbance regimes in all forested structural stages to hasten development and improvement in the amount, quality, and distribution of old-forest stages. Implications of our results for managing ...

Prescribed fire is a management tool used to reduce fuel loads on public lands in forested areas in the western United States. Identifying the impacts of prescribed fire on bird communities in ponderosa pine (Pinus ponderosa) forests is necessary for providing land management agencies with information regarding the effects of fuel reduction on sensitive, threatened, and migratory bird species. Recent developments in occupancy modeling have established a framework for quantifying the impacts of management practices on wildlife community dynamics. We describe a Bayesian hierarchical model of multi-species occupancy accounting for detection probability, and we demonstrate the model's usefulness for identifying effects of habitat disturbances on wildlife communities. Advantages to using the model include the ability to estimate the effects of environmental impacts on rare or elusive species, the intuitive nature of the modeling, the incorporation of detection probability, the estimation of parameter uncertainty, the flexibility of the model to suit a variety of experimental designs, and the composite estimate of the response that applies to the collection of observed species as opposed to merely a small subset of common species. Our modeling of the impacts of prescribed fire on avian communities in a ponderosa pine forest in Washington indicate that prescribed fire treatments result in increased occupancy rates for several bark-insectivore, cavity-nesting species including a management species of interest, Black-backed Woodpeckers (Picoides arcticus). Three aerial insectivore species, and the ground insectivore, American Robin (Turdus migratorius), also responded positively to prescribed fire, whereas three foliage insectivores and two seed specialists, Clark's Nutcracker (Nucifraga columbiana) and the Pine Siskin (Carduelis pinus), declined following treatments. Land management agencies interested in determining the effects of habitat manipulations on wildlife communities can use these methods to provide guidance for future management activities.