1

SNPLMA RESEARCH PROPOSAL ROUND 10

I. Title Page

Project title: Ecological succession in the Angora fire: Forest management effects on woodpeckers as keystone species

Primary Science Theme # 1: Forest Health Subtheme 1a: Understanding long term ecological effects of forest management Secondary Science Theme# 2: Watershed, Water Quality, and Habitat Restoration Subtheme 2b: Special status species and communities and priority invasive species Team members: Gina Tarbill (Sacramento State University), Dr. Patricia Manley (USFS Pacific Southwest Research Station) Gina Tarbill Graduate Student Sacramento State University 1860 Point View Dr. Placerville, CA 95667 Phone: (925) 408-3684 Email: gtarbill@gmail.com Dr. Patricia Manley

US Forest Service Pacific Southwest Research Station Sierra Nevada Research Center 1731 Research Park Dr. Davis, CA 95618 Phone: (530) 759-1719 Fax: (530) 747-0241 Email: pmanley@fs.fed.us Grants contact: Bernadette Jaquint bjaquint@fs.fed.us ph: (510) 559-6309 fax: (510) 559-6440 Total funding requested: $64,000 In-kind contributions: $29,700

2

II. Project Description a. Abstract

Woodpeckers are considered keystone species, due in part to their important role as cavity excavators. Woodpeckers may have especially strong effects on ecosystem processes after fires, when cavity excavation, drilling, and bark peeling provide cover and foraging areas for other species. These activities may be limited or enhanced by fire severity and restoration treatments, with cascading impacts to secondary cavity users. We will investigate the role of primary cavity excavators in the facilitation of colonization of secondary cavity users. Nest webs illustrate the interrelationships between species that exhibit sequential use of substrates for nesting, resting, or roosting. Nest webs will be created to investigate how secondary cavity users utilize woodpecker cavities in burned and areas under various restoration treatments. These nest webs illustrate where interrelationships between and among species are strongest, and it will allow predictions on both direct and indirect effects of fire severity and post-fire restoration practices on woodpeckers and secondary cavity users. These predictions can guide future management decisions in terms of how best to enhance habitat conditions to promote the restablishment of bird and small mammal communities in burned areas, and enhance conservation strategies of species of special concern in the Lake Tahoe Basin.

b. Justification Statement

Cavity nesting communities are often used as indicators for forest health, largely due to their reliance

on snags and decaying trees (Power, et. al., 1996; Hutto, 2006). Snags are important to all taxa: two thirds of all wildlife species rely on snags at some point in their life cycle (Brown, 2002). Woodpeckers, as primary cavities excavators, may mediate snag use by secondary cavity users, species dependent on cavities that are unable to excavate them (Aitken and Martin, 2007). The most abundant primary cavity excavators in the Lake Tahoe Basin are Hairy (Picoides villosus), Black-backed (P. arcticus), and White-headed woodpeckers (P. albolarvtus) (Table 1). These species are recognized by the US Forest Service and other agencies as unique indicator species or species of concern. Hairy and Black-backed woodpeckers are considered indicator species for snag habitat in green and burned forests, respectively (USFS, 2008). The White-headed woodpecker, relatively common in the Basin, is listed as a species of concern in Idaho, Oregon, and the U.S. Forest Service in the intermountain and northern regions of the west. It is proposed for listing in Washington and is nationally listed as endangered in British Columbia (Garrett, et. al., 1996). Secondary cavity users of the Tahoe Basin include several sensitive species: American martens (Martes americana), Northern flying squirrels (Glaucomys sabrinanus), and California spotted owls (Strix occidentalis) (Table 2) (USDA, 2007).

This study will provide crucial data on interdependencies in these communities and resource use by individual special status members. Creating nest webs for cavity-using communities in the Lake Tahoe Basin will determine the relative importance of different primary cavity users species to the recovery of bird and small mammal communities in burned forests, and the recovery of special status species in post burn, salvage logged or unlogged habitats. Understanding interactions and dependencies among cavity users will identify the most important habitat and community factors to maintain or increase the abundance of individual species and recover the diversity of bird and small mammal communities in burned forests. This study may also provide opportunistic information on the use of cavities by carnivores of special interest and concern, including American marten, California spotted owl, and an invasive species, the barred owl (Strix varia). Understanding how burn severity and restoration treatments affect habitat for species of interest can influence management strategy, aid in conservation, and potentially track the invasion of a nonnative species.

3

c. Background and problem statement

Keystone species are organisms that exert a disproportional effect on the structure or function of their community by virtue of life history traits or interactions with other species (Paine, 1969). Keystone species may affect ecosystems by influencing productivity, nutrient cycling, species richness, or the abundance of one or more dominant species or functional groups of species (Power et al. 1996). Keystone species are particularly important in terms of conservation and management because the loss of these species from a community can have catastrophic effects on those organisms that rely upon them to drive ecosystem processes (Estes and Palmisano, 1974). Focusing conservation efforts on keystone species preserves their large influence on ecosystem function and may also have direct and indirect benefits at the community level (Simberloff, 1998; Power et al. 1996).

Keystone species may impact the community by modifying ecosystem structure (Mills et. al., 1993). Lawton and Jones (1995) identified these species as keystones that modify, maintain, and/or create habitat, directly or indirectly, by modulating resource availability to other species through physical changes in biotic or abiotic materials. Interestingly, some keystone species have also been shown to influence ecological succession (Andersen and MacMahon, 1985; Dangerfield et al., 1998; Rossell et al., 2005). Ecological succession is defined as the change in community composition over time. Secondary succession describes the compositional change of a community after a disturbance such as fire, flood, logging, or overgrazing (Connell and Slatyer, 1977). The outcome of succession is affected by both the severity of disturbance and the ability of colonizers to disperse and establish. The path of ecological succession is unpredictable, and depends on both abiotic factors, such as moisture and light availability, and biotic factors, including the facilitative and inhibitory effects of animals. Facilitative activities of animals include seed dispersal, soil aeration through burrowing, and cavity creation in snags. These activities may accelerate the rate of secondary succession by increasing recruitment or creating habitat in previous unsuitable areas for other organisms (Kelm, et al. 2008; Andersen and MacMahon, 1985; Dangerfield et al., 1998; Rossell et al., 2005). Keystone species that create habitat and colonize disturbed areas may accelerate succession for other organisms relying on their facilitative effects.

Woodpeckers have recently been identified as keystone species in forest habitats, largely due to habitat modification and creation with their unique foraging and nesting activities (Lawton and Jones 1995; Simberloff 1998; Martin and Eadie, 1999; Bonar, 2000; reviewed in Aubrey and Raley, 2002; Martin et al 2004; Bednarz et al., 2004), and may act as facilitators of succession. By scaling bark and pecking and drilling into dead and decaying trees, woodpeckers create foraging areas for other species (Bull et al., 1986; Conner, 1981), accelerate decomposition and nutrient cycling (Farris et al., 2002 and 2004), and mediate insect populations (Otvos, 1970 and 1979). Additionally, as primary cavity excavators, woodpeckers create cavities for nesting and roosting. These cavities are later used by secondary cavity users, species dependent on cavities but unable to excavate them. Cavities in snags and live trees provide nesting, roosting, denning, and resting sites for secondary cavity users (Bull et al., 1997). Natural (non-excavated) cavities are limited in most habitats and secondary cavity users are dependent on primary cavity excavators for cavity creation (Aitken and Martin, 2007). Competition for cavities has been shown to limit population growth of secondary cavity users (Holt and Martin, 1997). This creates a guild structure in the community with strong secondary cavity user dependence on primary cavity excavators (Martin and Eadie, 1999). In terms of secondary succession, this indicates that secondary cavity users may be reliant on primary cavity excavators to re-colonize and modify disturbed habitat to facilitate occupation by secondary cavity users.

These interactions and dependence may be best-investigated using nest webs. Nest webs have been used to study direct and indirect effects of woodpeckers on secondary cavity users and the community at large (Martin and Eadie, 1999; Aitken et al., 2002; Martin et al., 2004; Blanc and Walters, 2007; Gentry and Vierling, 2008). Nest webs are analogous to food webs, with trees/snags as the fundamental “producers”, primary cavity excavators (PCEs) as the “manufacturers”, and secondary cavity users (SCUs) as the “consumers” of cavities (Fig. 1; Martin and Eadie, 1999). Nest webs can also be created at the species level to determine the relative ecological importance of specific excavators on the

4

community (Fig. 2). Nest webs can be used to identify which tree species, decay class or DBH category is selected by the most cavity users, which PCEs create the most cavities, and which SCUs then utilize these cavities. This allows identification of potential keystone species and habitat generalists and specialists, and the relationships between them. Predictions may be made on community responses to changes in the system, such as increases in the number of snags, decreases in snags with large DBH, or decreases in a particular PCE population.

Although woodpecker nest-site selection and nest re-use has been well-studied (Martin and Eadie, 1999; Aitken et al., 2002; Martin et al., 2004; Blanc and Walters, 2007 and 2008; Gentry and Vierling, 2008), there is a lack of knowledge on the impact of fire to these systems (but see Gentry and Vierling, 2008). Fire is a natural and regular disturbance in mixed conifer forest and may create snags, alter arthropod communities, and change forest structure (Kotliar, 2002). Woodpeckers are generally early colonizers of burned areas, likely due to abundance of food (arthropods) and nest (snag) resources (Hutto, 1995). Their unique foraging and nesting strategy may allow them to utilize and exploit resources unavailable to other organisms, while facilitating the recolonization and occupation of other species by creating suitable habitat. Woodpeckers have been shown to select nest sites based on habitat features, including burn severity and presence of bark beetles, and tree features including height, diameter at breast height (DBH), decay class, and species (Saab et. al, 2004). Cavity use by SCUs is also driven by both habitat conditions, including burn severity, and cavity characteristics including height, DBH, decay class, species, cavity height, diameter, and orientation (Aitken et al., 2002; Saab et al. 2004; Gentry and Vierling, 2008; Czeszczewik, et al., 2008). SCUs may prefer cavities excavated by a particular PCE due to similar preferences in habitat or cavity characteristics and therefore presence may be positively correlated between these species. This suggests that different species of woodpeckers may facilitate the recolonization and occupation of different SCUs in areas of different burn severity. The Angora Fire of Lake Tahoe provides an ideal system for investigating the facilitative effects woodpeckers may have on ecological succession through the colonization of disturbed areas by secondary cavity users.

The Angora Fire burned approximately 1,255 hectares in South Lake Tahoe, California in June and July 2007 (Fig. 1). The California Tahoe Conservancy (CTC) owns 229 urban parcels (42 ha) within the fire perimeter, and 177 of them were affected by the fire (~36 ha). The fire occurred in an area with a high level of private and public land intermixed and adjacent to large expanses of undeveloped public land. The severity of the burns varied within the area, resulting in a mosaic of post-fire conditions. The primary post-fire treatments have been to minimize erosion through a variety of measures including mulching, and removing dead and dying trees to reduce risk they pose to human life and property. There are many PCEs and SCUS in the Tahoe Basin, creating the ideal system for investigating the facilitative effects of woodpeckers on colonization by SCUs and the response of this community to restoration efforts.

Table 1. Primary cavity excavators.

Common Name Code Scientific Name

Black-backed Woodpecker BBWO Picoides arcticus

Downy Woodpecker DOWO Picoides pubescens

Hairy Woodpecker HAWO Picoides villosus

Northern Flicker NOFL Colaptes auratus

White-headed Woodpecker WHWO Picoides albolarvatus

Pileated Woodpecker PIWO Dryocopus pileatus

Williamson's Sapsucker WISA Sphyrapicus thyroideus

Red-breasted Sapsucker RBSA Sphyrapicus ruber

5

Table 2. Secondary cavity users.

d. Goals and objectives

The goal of this study is to understand the how primary cavity nesters drive ecological succession following a wildfire and how restoration activities affect the recovery of bird and small mammal communities as a function of its effects on ecological succession. Understanding how primary cavity excavators (PCE) and secondary cavity users (SCU) respond to disturbance is crucial because they drive ecosystem processes and recovery. Disturbances that have positive effects on cavity excavators, such as forest fires that create nesting and foraging habitat for woodpeckers may also benefit species that depend on cavity excavators. Because keystone species, by definition, have great impacts on other identifying these keystone species and understanding their response to disturbance will allow predictions on the community as a whole. These predictions can guide future research, influence management decisions, and enhance conservation practices.

Objectives

1) Understand how woodpecker colonization and modification of burned forest contributes to SCU occupation

2) Determine if management activities affect PCE and/or SCU in a manner that changes the pace or character of ecological succession and recovery of bird and small mammal communities after fire

Hypotheses

1) Secondary cavity use by species is correlated with particular excavator due to similarities in nest site selection i) Secondary cavity use is determined by habitat characteristics that correlate with a PCE

ii) Secondary cavity use is determined by cavity characteristics that correlate with a PCE

2) Keystone species in this system will create cavities used by greatest diversity of SCUs

Birds Mammals

Common Name Scientific Name Common Name Scientific Name

Brown Creeper Certhia americana Douglas squirrel Tamiasciurus

douglasii

European Starling Sturnus vulgaris Flying squirrel Glaucomys

sabrinus

House Wren Troglodytes aedon Western gray squirrel Sciurus griseus

Mountain Chickadee Poecile gambeli Yellow-pine chipmunk Tamias amoenus

Mountain Bluebird Sialia currucoides Least chipmunk Tamias minimus

Pygmy Nuthatch Sitta pygmaea Long-eared chipmunk Tamias

quadrimaculatus

Red-breasted Nuthatch Sitta canadensis Shadow chipmunk Tamias senex

White-breasted Nuthatch Sitta carolinensis Lodgepole chipmunk Tamias speciosus

Tree Swallow Tachycineta bicolor Bushy-tailed woodrat Neotoma cinerea

Western Bluebird Sialia mexicana Porcupine Erethizon dorsatum

American Kestrel Falco sparverius Pine marten Martes americana

Flammulated Owl Otus flammeolus Short-tailed weasel Mustela erminea

Barred Owl Strix varia Long-tailed weasel Mustela frenata

Northern Pygmy Owl Glaucidium gnoma

Northern Saw-whet Owl Aegolius acadicus

6

3) Keystone species in this system will have cavities occupied the greatest proportion of the time 4) Habitat specialist will utilize cavities of few species of PCE 5) Habitat generalist will utilize cavities of many species of PCE

e. Approach, methodology, and location

Study Area

The study will take place in and around the Angora Fire (2007) in South Lake Tahoe, California (Fig. 1). As a mixed conifer forest, pre-fire dominant tree species included Pinus jeffreyii, P. contorta, P. lambertiana, Abies concolor, A. magnifica, Populus tremuloides, and Calecedrus decurrens and dominant shrub species included Artemesia spp, Artostaphylos spp., and Ceanothus spp.

Site selection

Sites were selected that represented a range of burn intensity and post-fire treatment, with emphasis on land with a combination of treatments. The burn intensity grid map created for multi-agency use was utilized to assign sites to different burn intensities. Salvage logging treatment was designated using maps created by the United States Forest Service (USFS). Burn severity and salvage logging was also evaluated on the ground at potential sites to ensure proper designation. The USFS established a systematic grid of points spaced 400-m apart across the fire area to monitor post-fire vegetation response. This grid was used to systematically select sample points to reflect different treatment types and sites were centered around these points. The relatively small size of the burned area and the heterogeneity of burn severity, salvage logging, and habitat conditions precluded a randomized approach. Differing treatments were clustered whenever possible to minimize non-treatment effects. We attempted to obtain an unbiased sample of sites that represented all combinations of burn intensity (no burn, <50% mortality, >50% mortality) and post-fire treatment (none, thin, salvage). Many of the unburned and unlogged sampling points were outside the fire perimeter and systematically selected from CTC monitoring points. A total of 72 sample points were selected for nest searching efforts.

Primary cavity nests – Existing data

Nests were located as part of the SNPLMA funded research project “Biodiversity response to burn intensity and post-fire restoration” (Manley et al. Round 9). Nest searching methodology largely followed protocol described in Martin and Geupel (1993). Birds were observed and followed from a distance to avoid altering their behavior and nests were found during construction, egg laying, incubation, or nestling stages. Observers attempted to find nests of all primary excavators in the study area (Table 1).

Once an active nest was confirmed, the bird species, location of the nest and stage of nest development were recorded, along with the UTM coordinates of the nest site. Nest habitat protocols largely follow the BBIRD protocol (Martin et al. 1997). Habitat data was collected to analyze nest site selection of secondary cavity users. The following characteristics were recorded for each nest at the time of discovery: nest height; nest orientation; substrate species, height, diameter at breast height, decadence, vigor (live or dead), decay, and percent scorch (blackened); distance from and direction to roads, trails, and development within 30 meters; canopy cover at the nest; and percent slope. Additionally, relative cavity size was estimated by standing ten meters from cavity tree and “covering” the cavity with different sized cardboard cut outs held at arm’s length. Distance to roads, trails, and development will be merged into a single averaged value. Decay class will be analyzed as a ranked ordinal variable. These variables will be utilized to determine nest site selection of primary cavity excavators and subsequent secondary cavity users using cavity and tree characteristics.

Forest structure was described in the vicinity of the cavity tree within an 11.3-meter radius circle (adaptation of Martin et al. 1997). The plot boundaries were delineated using four line transects laid out in each cardinal direction, delineating one quarter of the circular plot. Within each quarter plot, the following data was collected: tree (>12.5-cm dbh) species, dbh, vigor, decadence, percent scorch, decay

7

class (if snag) and height (if snag); absolute percent cover of shrubs, forbs, grasses and grass-like plants, litter, bare ground, and trees. For downed wood, the first 0.3 m of each transect at the center of the plot was not sampled. Along the remaining 11 m, data on logs (>10-cm diameter at small end) that intersect the transect line was recorded: small-end diameter, large-end diameter, length, decay class, and species (if possible). If the same log intersects two or more transects, it was only be recorded once. Finally, a 20-factor prism was used to tally trees and snags; the species, DBH, vigor, decadence, decay (snags only), and height (snags only) was recorded for all trees tallied. All quarter plot data will be averaged to determine structure in total area.

Secondary cavity use data collection

All nest cavities located in 2009 and 2010 with positively identified excavators will be monitored to determine occupancy by secondary cavity users (Table 2). Remote-triggered digital cameras will monitor cavities for four-day sessions. The use of cameras allows for detection of elusive, diurnal, and nocturnal organisms. Cameras will be set on a tree facing the cavity at the appropriate height and angle to maximize detections. If no tree is available, a post will be set. Cameras will be tested to ensure functionality and loaded with fresh batteries and empty camera cards. After four days of monitoring, cameras will be collected and photos from cards will be downloaded. All photos will be analyzed, and if detections are observed, photos will be labeled and detections will be recorded in a database. All organisms will be identified to species whenever possible. Additionally, on days when cameras are pulled, contents of cavities will be viewed using a Treetop Peeper (Sandpiper Technologies Manteca, CA). Cavity size will also be re-estimated to determine if cavity enlargement has occurred. If enlargement has occurred, observers will make an effort to determine the species (or appropriate taxon) that enlarged the cavity and this data will be included in nest webs. Cameras will be set several times per year to determine use during breeding (April-July) and nonbreeding seasons (October-November, January-February).

Each cavity will be considered an independent data point, although some may be the result of re-nesting efforts of pairs. Any known re-nesting attempts will be removed from the study. Data will be used to create nest webs for each woodpecker species following Martin and Eadie (1999). Correlations between species of primary excavators and secondary cavity users will be analyzed at both the guild and species level using simple and partial correlation analyses. Relative contributions of cavity substrate (tree species, decay class, and DBH) and cavity excavators will be obtained by determining the proportions of trees/cavities used by primary cavity excavators and secondary cavity users. Relationships will be summarized and any keystone species, habitat generalists, and habitat specialists will be identified (Figure 1 and 2).

Secondary cavity use will also be analyzed by habitat and cavity characteristics, and primary excavator using multiple logistic regression to develop the best model describing nest selection for each species. Variables will be tested for covariance using Spearman rank correlations. A global model utilizing all variables, and reduced models with different combinations of variables will be analyzed. Additionally, to minimize effects of covariance, Akaike’s Information Criterion (AIC) will be calculated for all models. Models with lowest AIC value are most parsimonious. Akaike weights will be calculated to determine the model with greatest support relative to other models.

f. Relationship of the research to previous and current relevant research, monitoring, and

management There are several wildlife studies in the Angora Fire area that will be complemented by this

research. The Angora Wildlife Monitoring Project (AWMP) was a 2-year multi-species investigation of the effects of fire and post-fire management practices on birds and small mammals. The SNPLMA funded project, “Biodiversity response to burn intensity and post-fire restoration” expanded this effort to include a larger number of sites (from 42 to 72), invertebrates, and nest-site selection by woodpeckers.

8

The data obtained in this study will complement and enhance the existing study by investigating the process by which cavity excavators facilitate the recovery of bird and small mammal communities in burned areas, and in what ways management activities help or hinder the restoration process. Agency monitoring efforts include a focus on special status species: willow flycatchers, Northern goshawks, and California spotted owls. This study has the potential to also complement these monitoring efforts because we may locate roost sites in the burned area (Bond et. al., 2009).

Many nest re-use studies have been conducted in the other regions, but few have investigated interactions and dependence of secondary cavity users in the Sierra Nevada (Martin et. al, 2004; Blanc and Walters, 2008) Additionally, the effects of fire and salvage logging on nesting woodpeckers has largely focused on the Rocky Mountains, with little attention to woodpeckers in the Sierra Nevada (Saab and Dudley, 1998; Saab et. al., 2007 and 2009). Understanding how cavity communities are structured in the Lake Tahoe Basin is needed to improve management of snag habitats and conservation of cavity-dependent species.

g. Strategy for engaging with managers and obtaining permits

Because this project is linked with an already established post-fire monitoring project by the US Forest Service, appropriate permits have been obtained and managers have been contacted for permission. Presentations to staff and leadership at the primary agencies involved in forest management (e.g., NDSL Nevada Tahoe Resource Team, US Forest Service LTBMU, California Tahoe Conservancy, California State Parks) will be conducted to disseminate results and engage managers in discussion of importance of cavity communities and effects of fire and post-fire management of these communities

h. Description of deliverables and products

Deliverables will be in the form of a draft report, a final report, a minimum of one peer-reviewed publication, and multiple presentations at local and regional agency, public, and scientific forums, including at least one national scientific meeting. In addition, we will develop a web page that describes the project and its progress. Symposia, conference, workshop presentations:

Lake Tahoe Science Symposium The Wildlife Society National Conference Local and regional forest management and fire conferences

Progress and completion reports and presentations: Draft report and Final Report Presentations to staff and leadership at the primary agencies involved in forest management (e.g., NDSL Nevada Tahoe Resource Team, US Forest Service LTBMU, California Tahoe Conservancy, California State Parks)

Website: Information on the study background, objectives, study area, methods, results, conclusions, and photos will be available on PSW-supported public web site for the project.

9

III. Schedule of major milestones/deliverables Milestone/Deliverables Start Date End Date Description

Spring/summer cavity monitoring

May 1, 2010

July 31, 2010

Monitor cavities

Data entry and analysis August 1, 2010

September 30 1, 2010

Submit year-end interim report

Fall/winter cavity monitoring and data entry

October 1, 2010

March 30, 2011

Monitor cavities

Data analysis and reporting

April 1, 2011

June 30, 2011

Analyze data, produce final report, submit manuscripts for publication

IV. Literature cited

Aitken, K.E.H and Martin, K. (2007) The importance of excavators in hole-nesting communities: availability and use of natural tree holes in old mixed forests of western Canada. Journal of Ornithology 148: S425-S434.

Aitken, K.E.H., Wiebe, K.L., and Martin, K. (2002) Nest-site reuse patterns for a cavity-nesting bird community in interior British Columbia. The Auk 119: 391-402.

Andersen, D.C. and J.A. MacMahon (1985) Plant Succession Following the Mount St. Helens Volcanic Eruption: Facilitation by a Burrowing Rodent, Thomomys talpoides. The American Midland Naturalist. 114: 62-69.

Aubrey, K.B. and Raley, C.M. (2002) The pileated woodpecker as a keystone habitat modifer in the Pacific Northwest. General Technical Report. PSW-GTR-181. Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture.

Bednarz, J.C., Ripper, D., and Radley, P.M. (2004) Emerging concepts and research directions in the study of cavity-nesting birds: keystone ecological processes. The Condor 106:1-4.

Blanc, L.A. and Walters, J.R. (2007) Cavity-nesting community webs as predictive tools: where do we go from here? Journal of Ornithology 148: S417-423.

Blanc, L.A. and Walters, J.R. (2008) Cavity-nest webs in a longleaf pine ecosystem. The Condor 110: 80-92.

Bonar, R.L. (2000) Availability of pileated woodpecker cavities and use by other species. Journal of Wildlife Management 64:52-59.

Bond, M.L., Lee, D.E., Siegel, R.E., and Ward, J.P. (2009) Habitat Use and Selection by California Spotted Owls in a Postfire Landscape. Journal of Wildlife Management 73: 1116-1124.

Brown, T.K. (2002) Creating and maintaining wildlife, insect, and fish habitat structures in dead wood. General technical report PSW-GTR-181:883-892. US Department of Agriculture Forest Service, Albany, CA.

Bull, E.L., Parks, C.G., Torgersen (1997) Trees and logs important to wildlife in the interior Columbia River Basin. USDA Forest Service General Technical Report PNW-GTR-391.

Bull, E.L., Peterson, S.R., Thomas, J.W. (1986) Resource partitioning among woodpeckers in northeastern Oregon. USDA Forest Service Research Note PNW-RN-474.

Connell, J.H. and R.O. Slatyer (1977) Mechanisms of Succession in Natural Communities and Their Role in Community Stability and Organization. American Naturalist 111: 1119-1144.

Conner, R.N. (1981) Seasonal changes in woodpecker foraging patterns. The Auk 98: 562-570.

10

Czeszczewik, D., Walankiewicz, W., and Stanska, M. (2008) Small mammals in nests of cavity-nesting birds: why should ornithologists study rodents? Canadian Journal of Zoology 86: 286-293.

Dangerfield, J.M., McCarthy, T.S. & Ellery, W.N. (1998). The mound-building termite Macrotermes michaelseni as an ecosystem engineer. Journal of Tropical Ecology 14: 507-520.

Estes, J.A. and Palmisano, J.F. (1974) Sea otters: Their role in structuring near shore communities Macrotermes michaelseni as an ecosystem engineer. Journal of Tropical Ecology. Science 185:1058-60.

Farris, K.L., Garton, E.O., Heglund, P.J., Zack, S., and Shea, P.J. (2002) Woodpecker foraging and the successional decay of ponderosa pine. USDA Forest Service General Technical Report. PSW-GTR-181.

Farris, K.L., Huss, M.J., and Zack, S. (2004) The role of foraging woodpeckers on the decomposition of Ponderosa pine snags. The Condor 106:50-59.

Garrett, K. L., M. G. Raphael, and R. D. Dixon. 1996. White-headed Woodpecker (Picoides albolarvatus). In The Birds of North America, No. 252 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornthologists' Union, Washington, D.C.

Gentry, D.J. and Vierling, K.T. (2008) Reuse of woodpecker cavities in the breeding and non-breeding seasons in old burn habitats in the Black Hills, South Dakota. American Midland Naturalist 160: 413-429.

Hanson, C.T. and North, M.P. (2008) Postfire woodpecker foraging in salvage logged and unlogged forests of the Sierra Nevada. The Condor 110: 777-782

Holt, R. and Martin, K. (1997) Landscape modification and patch selection: the demography of two secondary cavity nesters. The Auk 114:443-456.

Hutto, R.L. (1995) Composition of bird communities following stand replacement fires in northern Rocky Mountain (USA) conifer forests. Conservation Biology 9:1041–1058.

Hutto, R. L. (2006) Towards meaningful management guidelines for postfire salvage logging in North American conifer forests. Conservation Biology 20:984-993.

Kelm, D.H., K.R Wiesner, and O. von Helversen (2008) Effects of Artificial Roosts for Frugivorous Bats on Seed Dispersal in a Neotropical Forest Pasture Mosiac. Conservation Biology. 22: 733-741.

Kotliar, N.B., Hejl, S.J., Hutto, R.L., Saab, V.A., Melcher, C.P., and McFadzen, M.E. (2002) Effects of

fire and post-fire salvage logging on avian communities in conifer dominated forests of the western United States. Studies in Avian Biology 25:49-64.

Lawton, JH and Jones, CG. (1995) Linking species and ecosystems: organisms as ecosystem engineers. Pages 141-150 in Jones CG, Lawton JH, eds. Linking species and ecosystems. New York: Chapman and Hall

Lindenmayer, D.B. and Noss, R.E. (2006) Salvage logging, ecosystem processes, and biodiversity conservation. Conservation Biology 20:949-958.

Martin, K. and Eadie, J.M. (1999) Nest webs: A community-wide approach to the management and conservation of cavity-nesting forest birds. Forest Ecology and Management 115: 243-257.

Martin, K., Aitken, K.E.H., and Wiebe, K.L. (2004) Nest sites and nest webs for cavity-nesting communities in interior British Columbia, Canada: nest characteristics and niche partitioning. The Condor 106: 5-19.

Martin, T.E. and Geupel, G.R. (1993) Nest-Monitoring Plots: Methods for Locating Nests and Monitoring Success. Journal of Field Ornithology 64:507-519

Martin, T.E., C. Paine, C. J. Conway, W. M. Hochachka, P. Allen, and W. Jenkins. (1997) BBURD field protocol. Biological Resources Division, Montana Cooperative Research Unit, Missoula, MT.

Mills, L.S., Soul, M.E., and Doak D.F. (1993) The keystone- species concept in ecology and conservation. Bioscience 43: 219-224.

Otvos, I. S. 1979. The effects of insectivorous bird activities in forest ecosystems: an evaluation. Pages 341-374 in J. G. Dickson, E. N. Conner, R. R. Fleet, J. C. Kroll, and J. A. Jackson, eds. The role

11

of insectivorous birds in forest escosystems. Academic Press, New York. 381pp. Otvos, I.S., 1970. Avian predation of the western pine beetle. In:Stark, R., Dahlsten, D. (Eds.), Studies of

the Population Dynamics of the Western Pine Beetle, Dendroctonus brevicomis Leconte (Coleoptera: Scolytidae). University California Press, Berkeley, California, pp. 119–127.

Paine, R.T. (1969) A Note on Trophic Complexity and Community Stability. The American Naturalist 103: 91-93.

Power, M., Tilman, D., Estes, J.A., Menge, B.A., Bond, W.J., Mills, L.S., Daily, G., Castilla, J.C., Lubchenko, J., and Paine, R.T. (1996) Challenges in the quest for keystones. Bioscience 46: 609-620.

Rossell, F., Bozser, O. Collen, P., and Parker, H. (2005) Ecological impact of beavers Castor fiber and Castor Canadensis and their ability to modify ecosystems. Mammal Review 35:248-276.

Saab, V. A. and Dudley, J. (1998) Responses of cavity-nesting birds in stand-replacement fire and salvage logging in ponderosa pine/Douglas-fir forests of Southwestern Idaho. General Technical Report. RMRS-RP-11. Rocky Mountain Research Station, Forest Service, U.S. Department of Agriculture.

Saab, V. A., Russell, R.E., and Dudley, J.G. (2007). Nest densities of cavity-nesting birds in relation to postfire salvage logging and time since wildfire. The Condor 109: 97-108.

Saab, V.A., Dudley. J,, and Thompson, W.L. (2004) Factors influencing occupancy of nest cavities in recently burned forests. The Condor 106:20-36.

Saab, V.A., Russell, R.E., Dudley, J.G. (2009) Nest-site selection by cavity-nesting birds in relation to postfire salvage logging. Forest Ecology and Management 257: 151-159.

Simberloff, D. (1998) Flagships, umbrellas, and keystones: is single species management passé in the landscape era. Biological Conservation 83: 247–257.

United States Department of Agriculture (2007). Region 5 Sensitive Species List (October 15, 2007 Revision). US Forest Service, Region 5, San Francisco, CA.

United States Forest Service. (2008) Sierra Nevada Forests Bioregional Management Indicator Species (MIS) Report: Life history and analysis of Management Indicator Species of the 10 Sierra Nevada National Forests: Eldorado, Inyo, Lassen, Modoc, Plumas, Sequoia, Sierra, Stanislaus, and Tahoe National Forests and the Lake Tahoe Basin Management Unit. Pacific Southwest Region, Vallejo, CA. January 2008.

12

V. Figures

Figure 1. Angora Fire Area

13

Figure 2. Nest Web Structure

modified from Martin and Eadie (1999)Solid lines represent nest cycling or flow; dotted lines represent non-nest interactions

Weak cavity excavator Non-cavity user

Primary cavity excavator

Cavity substrate

Secondary cavity user

Figure 3. Nest Web by Speciesmodified from Martin and Eadie (1999)

PCE 1 PCE 2 PCE 3 PCE 4

SCU1 SCU2 SCU3 SCU4 SCU5 SCU6

<0.100.10-0.490.50-1.0

Nest Use (proportion)Tree 1 Tree 2 Tree 3