Robin E. Russell

Nest densities of cavity-nesting birds in relation to postfire salvage logging and time since wildfire

Abstract ABSTRACT We monitored the nest densities and nest survival of seven cavity-nesting bird species, including four open-space foragers (American Kestrel [Falco sparverius], Lewiss Woodpecker [Melanerpes lewis], Western Bluebird [Sialia mexicana], and Mountain Bluebird [S. currucoides]) and three wood-foragers (Hairy Woodpecker [Picoides villosus], Black-backed Woodpecker [P. arcticus], and Northern Flicker [Colaptes auratus]), after two wildfires (one partially salvage-logged and one unlogged) in western Idaho from 1994–2004. We estimated the relationship between nest density and time since fire, tested for statistical differences in nest densities and nest survival in the partially salvage-logged vs. unlogged wildfires, and tested for differences in nest survival between early (1–4 years after fire) and late (5–12 years after fire) postfire periods. Nest densities of open-space foragers and Northern Flickers generally increased with time since fire, whereas nest densities of Black-backed and Hairy Woodpeckers peaked 4–5 years postfire. Nest densities of wood-foraging species and Mountain Bluebirds were significantly higher in the unlogged burn, whereas Lewiss Woodpeckers had significantly higher nest densities in the partially logged burn. Kestrels tended to favor the partially logged burn, while Western Bluebird nest densities were nearly equal in both burned areas. For most species, postfire period and treatment (partially logged vs. unlogged) had little influence on nest survival. However, Hairy Woodpecker nest survival was significantly lower in the partially logged burn versus the unlogged wildfire in the early postfire period, and Lewiss Woodpecker nest survival was significantly reduced in the later postfire period versus the early postfire period in the partially logged burn. Importantly, the salvage logging was designed to retain more than half of the snags over 23 cm in diameter, which provided suitable nesting habitat for open-space foragers during the decade following fire.

Modeling the effects of environmental disturbance on wildlife communities: avian responses to prescribed fire

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 models 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, Clarks 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.

Habitat‐Suitability Models for Cavity‐Nesting Birds in a Postfire Landscape

Abstract Models of habitat suitability in postfire landscapes are needed by land managers to make timely decisions regarding postfire timber harvest and other management activities. Many species of cavity-nesting birds are dependent on postfire landscapes for breeding and other aspects of their life history and are responsive to postfire management activities (e.g., timber harvest). In addition, several cavity nesters are designated as species at risk. We compare the ability of 2 types of models to distinguish between nest and non-nest locations of 6 cavity-nesting bird species (Lewiss woodpecker [Melanerpes lewis], black-backed woodpecker [Picoides arcticus], hairy woodpecker [P. villosus], northern flicker [Colaptes auratus], western bluebird [Sialia mexicana], and mountain bluebird [S. currucoides]) in the early postfire years for a ponderosa pine (Pinus ponderosa) forest in Idaho, USA. The 2 model sets consisted of 1) models based on readily available remotely sensed data and 2) models containing field-collected data in addition to remotely sensed data (combination models). We evaluated models of nesting habitat by quantifying the models ability to correctly identify nest and non-nest locations and by determining the percentage of correctly identified nest locations. Additionally, we developed relative habitat-suitability maps for nesting habitat of black-backed and Lewiss woodpeckers from the best models. For all species except Lewiss woodpeckers, model performance improved with the addition of field-collected data. Models containing remotely sensed data adequately distinguished between nest and non-nest locations for black-backed woodpecker and Lewiss woodpecker only, whereas models containing both field-collected and remotely sensed data were adequate for all 6 species. Improvements in the availability of more accurate remote sensing technology would likely lead to improvements in the ability of the models to predict nesting locations. External validation with data from other wildfires is necessary to confirm the general applicability of our habitat-suitability models to other forests. Land managers responsible for maintaining habitat for cavity-nesting birds in postfire landscapes can use these models to identify potential nesting areas for these species and select areas in burned forests where postfire salvage logging is most likely to have minimal impacts on cavity-nesting bird habitats.

Modeling nest survival of cavity-nesting birds in relation to postfire salvage logging

ABSTRACT Salvage logging practices in recently burned forests often have direct effects on species associated with dead trees, particularly cavity-nesting birds. As such, evaluation of postfire management practices on nest survival rates of cavity nesters is necessary for determining conservation strategies. We monitored 1,797 nests of 6 cavity-nesting bird species: Lewiss woodpecker (Melanerpes lewis), hairy woodpecker (Picoides villosus), black-backed woodpecker (P. arcticus), northern flicker (Colaptes auratus), western bluebird (Sialia mexicana), and mountain bluebird (S. currucoides) from 1994 to 2004 in ponderosa pine (Pinus ponderosa), mixed-severity burned forests (partially logged and unlogged) of Idaho, USA. Based on a priori hypotheses, we modeled daily survival rate (DSR) of nests as a function of abiotic (temperature, precipitation), temporal (time since fire, calendar year) and biotic factors (distance to unburned forest, nest height, and tree harvest [partial-salvage logging vs. unlogged]). Multiple abiotic and biotic factors, other than direct effects of salvage logging, affected daily survival rates of breeding cavity-nesting birds. Hairy woodpecker was the only species in which partial-salvage logging had a measurable, negative impact on DSR. Managers implementing carefully planned salvage logging prescriptions that include both unlogged reserves and partially logged areas can expect to maintain habitat for successfully breeding cavity-nesting birds of the interior northwestern United States. Our results also suggest that nest survival for some species of cavitynesting birds could be improved if unlogged reserves are located centrally in postfire forests, distant from unburned habitats that potentially serve as sources of nest predators.

Short-Term Responses of Red Squirrels to Prescribed Burning in the Interior Pacific Northwest, USA

Abstract We quantified changes in density of red squirrels (Tamiasciurus hudsonicus) in response to prescribed fire in mixed coniferous forests of Idaho and Washington, USA, using a Before-After-Control-Impact design. We found no evidence that low-severity prescribed fires affected density of red squirrels; we estimated the change in red squirrel densities due to prescribed fire as −0.15 squirrels/ha (95% CI  =  −0.405–0.105). Squirrel density did, however, increase with increasing live tree density, shrub cover, and density of large downed logs, and varied across years and states. These results indicate that land managers implementing prescribed fire treatments to reduce fuel loads on public lands can reduce the impacts of fire on squirrel populations by formulating prescriptions to retain large live trees and large downed logs.

Birds and burns of the interior West: descriptions, habitats, and management in western forests.

This publication provides information about prescribed fire effects on habitats and populations of birds of the interior West and a synthesis of existing information on bird responses to fire across North America. Our literature synthesis indicated that aerial, ground, and bark insectivores favored recently burned habitats, whereas foliage gleaners preferred unburned habitats.

Detection probabilities of Woodpecker nests in mixed conifer forests in Oregon.

Abstract Accurate estimates of Black-backed (Picoides arcticus) and Hairy Woodpecker (P. villosus) nests and nest survival rates in post-fire landscapes provide land managers with information on the relative importance of burned forests to nesting woodpeckers. We conducted multiple-observer surveys in burned and unburned mixed coniferous forests in Oregon to identify important factors influencing detection rates of woodpecker nests. We found 21 Black-backed Woodpecker nests and 38 Hairy Woodpecker nests in burned forest, and three Hairy Woodpecker nests in unburned forest. Competing models of detection probability in Program MARK indicated that nest-detection probability differed by nest stage. We found no evidence to indicate that detection rates of nests were associated with survey timing during the nesting season. Raw nest counts in burned coniferous forests may underestimate nest numbers, especially for nests in early stages of development. Black-backed Woodpecker nests were slightly more detectable than those of Hairy Woodpeckers in burned forests, and observers may differ in their abilities to detect nests.

Occupancy and Habitat Associations of Four Species of Sciurids in Ponderosa Pine-Gambel Oak (Pinus ponderosa-Quercus gambelii) Forests in Northern Arizona

Abstract In ponderosa pine-Gambel oak (Pinus ponderosa-Quercus gambelii) forests of north-central Arizona, we examined occupancy and habitats of four species of sciurids (rock squirrel Spermophilus variegatus, golden-mantled ground squirrel S. lateralis, gray-collared chipmunk Tamias cinereicollis, cliff chipmunk T. dorsalis). Numbers of captures were highly variable, suggesting a patchy distribution of species. All four species co-occurred on only one of the study sites. Gray-collared chipmunks and golden-mantled ground squirrels were relatively common on one site only. Golden-mantled ground squirrels were associated with mature forests with high canopy cover and low basal area, whereas gray-collared chipmunks were in locations with large numbers of logs and shallow litter. The two species of chipmunks appeared to be separated in space; gray-collared chipmunks were more common where cliff chipmunks were least common. Rock squirrels were relatively ubiquitous. There was evidence for an association of rock squirrels with increasing rocky cover and decreasing canopy cover, whereas cliff chipmunks occupied rocky areas with high canopy cover and numerous shrubs.