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BIRD COMMUNITIES IN MIXED CONIFER FORESTS OF THE INTERIOR NORTHWEST

H. Reed Sanderson Range Scientist Pacific Northwest Forest and Range Experiment Station, USDA Forest Service, La Grande, Oregon Evelyn L. Bull Wildlife Biologist Pacific Northwest Forest and Range Experiment Station, USDA Forest Service, La Grande, Oregon Paul J. Edgerton Wildlife Biologist Pacific Northwest Forest and Range Experiment Station, USDA Forest Service, La Grande, Oregon

ABSTRACT

Forest management practices adjust the direction and pace of succession. The species composition and st~ucture are altered, and, in turn, the avian species. Forest management must include wildlife as an integral part of the management decision. A wildlife biologist must provide sound biological alternatives for the land manager's consideration. We present a discussion of ecological concepts that ~ildlife biologists can use to predict the response of bird alterations in the interior Northwest mixed conifer forest type.

KEYWORDS: mixed conifer forest, silviculture, birds, nongame habitat.

Society's demand for products is the primary driving force for the management of our natural resources. Whatever that management is, it also affects wildlife populations whenever habitat is altered. As the human population increases in number and affluence, the demand for products will also increase (Maser 1979). Although timber harvest, livestock grazing, and wildlife harvest provide products, they also " ••• stir man's economic interest and, in the longer term, protective interest" (Maser and Thomas 1978:2). Economic demands must now be balanced by ecological consequences because of such laws as the Environmental

224 Policy Act, Federal Land Policy and Management Act, and the Forest Policy Act. Specifically, a land manager is to be held responsible for the consequences of his decisions and their resulting impact on the resource, land, and environment. A wildlife biologist's role is to provide a land manager with a set of management alternatives and their respective consequences to habitats and attendant wildlife species. The responsibility of wildlife biologists is to provide biologically sound data. We can no longer shirk our responsibility with the too often heard wildlife biologists' rationalization that, "We do not have enough information."

Our objective is to provide wildlife biologists with some ecological concepts to assist in predicting the generalized responses of both plant communities and birds to habitat alterations in the interior Northwest mixed conifer forests.

VEGETATION

The interior Northwest is characterized by a wide range of physical features that create a variety of habitats for different kinds of biotic communities. Diversity in these communities results not only from physiography, soils, and climate, but also from fire, insects, disease, and management activities such as timber harvesting and livestock grazing.

Foresters and ecologists have studied the vegetation of the mixed conifer forests that occupy about 10.5 million hectares of the interior Northwest. Kuchler (1964) broadly mapped this area as Douglas-fir (Pseudotsuga menziesii)­11 in the northern Rocky Mountains and Washington, cedar-hemlock-pine (Thuja-Tsuga­ Pinus) forests in the northern Rocky Mountains, and grand fir () - Douglas-fir forests in central Idaho, eastern Oregon, and southeastern Washington. Regional ecologists have refined these forest descripti_ons to provide an ecologically based system of land stratification for use by local resource planners and land managers. They include Franklin and Dyrness (1973), Oregon and Washington; Hall (1973), the Blue Mountains of eastern Oregon and southeastern Washingon; Daubenmire and Daubenmire (1968), northern Idaho and adjacent Washington; Steele et al. (Being prepared), central Idaho; and Pfister et al. (1977) for Montana.

Interior Northwest coniferous forests occur along a predictable environmental gradient. Climax Douglas-fir associations are usually found at mid-elevations where they intergrade with the upper limits of more xeric ponderosa pine () forests. In some areas, such as north-central Washington and the east slopes of the northern Rocky Mountains, however, climax ponderosa pine may be absent and Douglas-fir forests may border grasslands or -steppe vegetation. In Idaho and the Blue Mountains of Oregon and Washington, climax Douglas-fir forest is less common. Instead, it is an important component of mixed conifer communities transitional from ponderosa pine to grand fir. Douglas-fir and grand fir generally dominate climax stands, but Engelmann spruce () may be locally abundant on moist sites, and subalpine fir () becomes an important component at higher elevations.

Fire has played a major role in determining the composition and stucture of mixed conifer forests. Ponderosa pine, lodgepole pine (Pinus contorta), western white pine (Pinus monticola), or western larch (Larix occidentalis) dominate seral stands because they are better adapted to severe disturbance, especially fire, than are the climax species. Ponderosa pine or lodgepole pine

1/ Nomenclature follows that of Garrison et al. (1976).

225 may persist on harsher sites as a fire climax. On the other hand, grand fir and Douglas~fir regenerate abundantly in either mature, undisturbed stands, or seral stands. In the latter situation, they gradually assume dominance as the stand develops.

Composition and structure of the associated understory vegetation is diverse and depends on interactions of site, plant community, fire, and forest management activities. On drier sites dominated by Douglas-fir or mixed Douglas-fir and ponderosa pine, grasses mixed with scattered low and forbs characterize the understory. Dense, multilayered understories of grasses, sedges, forbs, and tall shrubs occur on moist sites where Douglas-fir dominates the overstory. Some characteristic species are pinegrass (), elk sedge (Carex geyeri), arnica (Arnica spp.), ninebark ( malvaceus), and snowberry (). The understory of mature or old-growth mixed conifer forest dominated by grand fir is often characterized by low growing such as American twinflower (Linnaea borealis), queencup beadlily (Clintonia uniflora), and princespine (Chimaphila spp.). Wild rose (Rosa spp.), huckleberries (Vaccinium spp.), yew (Taxus sp.), and other shrubs are abundant in some communities.

Fire can be an important influence in understory development. Intense heat generated by either wildfire or prescribed burns can destroy understory vegetation and favor the germination and establishment of seral shrubs. Dense fields of shrubs, such as snowbrush ceanothus (Ceanothus velutinus) and ninebark may dominate disturbed Douglas-fir sites for 25 years or longer while the seral forest develops. On the other hand, periodic, light underburning once maintained open stands of Douglas-fir mixed with ponderosa pine (Hall 1977).

BIRDS OF THE _MIXED CONIFER FOREST

More than 90 species of birds use the mixed conifer forests in the interior Northwest (Thomas 1979, Sundstrom 1978). None of these birds, however, restrict their feeding and reproductive activities to a single forest type or to a particular tree species. Because interior Northwest forests tend to be a mosaic of forest types instead of large continuous blocks, management objectives generally are not restricted to a particular forest type. Also, birds apparently respond more to vegetative structure than they do to plant species composition per se (Verner 1975). Consequently, management of bird communities should not be considered by forest type, but rather by the overall impact of management on forest structure.

Vegetative structure can be broadly equated to forest succession. As succession progresses, plant species diversity and biomass increase; vegetative structure becomes more complex, which in turn, creates more available niches that result in increased bird species diversity (Meslow 1978) (Fig. 1). We have characterized the mixed conifer forest type with six successional stages, and have listed the birds that feed or reproduce in each successional stage (Appendix 1).

Although we may not have all the specific information about habitat requirements for all birds, we can fairly well predict the impact of various management schemes on vegetative structure and plant succession and, consequently, on bird species. Forest managers may wish to maintain as many naturally occurring habitats as possible so future generations can have the same management options we have today (Balda 1976). "Wildlife Habitats in Managed Forests"

226 (Thomas 1979) and "A Holistic Approach to Wildlife and Fish Habitat Management" (Sundstrom 1978) are two publications that can be used to predict impacts of forest management decisions on birds.

80

(/} w u- /"""" ,...... ,..... w / £L (/} 60 / Feeding 0 0::: / £1) Reproduction LL 40 0 0::: w co 2 :::> 20 z

Grass- Shrub- Pole­ Young Mature Old Forb Seed I i ng Sapling Growth

FOREST SUCCESSIONAL STAGES

Figure 1.--Enumeration of bird species orientation to forest successional stages in the mixed conifer forest type of the interior Northwest.

FOREST MANAGEMENT

Forest management is the dominant land management activity in the interior Northwest forests. Forest management is bird habitat management and can achieve habitat management goals with attentive planning and execution (Thomas 1979).

A forest manager is limited in the selection of silvicultural options because of stand conditions due to past logging practices, insect and disease problems, control of fire, and so on. Therefore the selection of a silvicultural system

227 must be made on a stand by stand basis. Generally healthy, mixed-aged stands are suitable for uneven-aged management, but care must be taken to prevent a shift in species composition, especially in the mixed conifer forests of eastern Oregon and Washington. But, an even-age management system is usually recommended to control dwarf mistletoe (Arceuthobium spp.) and western spruce budworm (Choristoneura occidentalis Freeman), that are prevalent throughout the area (Seidel 1973, Wellner and Ryker 1973). Open stands favor larch and pine, and closed stands favor the shade tolerant firs. Douglas-fir is a shade requiring species in the interior Northwest, and seedling establishment is best in partial shade, but growth is best in full sunlight (Seidel 1973). Because each silvicultural system has a specific impact on habitats, wildlife biologists must have a basic understanding of these systems to predict the consequences of their application.

There are four generalized forest management systems that adjust the direction and pace of plant succession and, in turn, determine the avian species associated with the various successsional stages.

1. Even-aged management produces a monoculture of trees approximately the same size and height. A stand has an identified establishment period, and the entire stand is generally removed at maturity (Franklin and DeBell 1973, USDA Forest Service 1973). Even-aged management reduces vertical vegetative complexity and results in a decrease in bird species diversity (MacArthur and MacArthur 1961). Horizontal vegetative complexity (spacing) is increased by creating different successional stages between the various stands or cutting units. Edges are also created where different successional stages meet, thereby enhancing bird species richness (Thomas et al. 1978).

All guilds (a group of species that use the habitat in a similar way; Root 1967) could be represented through several even-aged stands, but this depends on the successional stages present within a particular time.

2. In contrast, uneven-aged management develops vertical vegetative complexity, but eliminates horizontal complexity by harvesting only mature trees, by not cutting the entire stand, and by maintaining trees in a variety of size classes (Franklin 1977, Hann and Bare 1979). Edges and early successional stages are minimized, as well as, the characteristics of old-growth stands. Bird species characteristic of the related plant communities would also be reduced. For example, aerial-searchers and ground-brush foragers would decrease, while bark and foliage gleaners and drillers would increase. 3. Intensive forest management shortens early successional stages and eliminates the final stages by emphasizing stand regeneration, growth, and harvest (Edgerton and Thomas 1978). Silviculture practices may include brush control, tree planting, fertilization, and thinning--all of which tend to accelerate tree establishment and growth and reduce plant species diversity and structural complexity.

228 Intensive forest management potentially decreases bird species diversity. Succession is accelerated; maturity is brief.

Harvest of climax old-growth stands eliminates the associated specialized bird species, such as the brown creeper (Certhia familiaris), pileated woodpecker (Dryocopus pileatus), and great gray owl (Strix nebulosa).

4. Salvage and sanitation logging and debris disposal activities remove snag recruits and snags and reduce the amount of dead and downed woody material that provides feeding and nesting sites for drilling and bark­ gleaning guilds (Maser et al. 1979, Thomas et al. 1979). Snags also are needed for nest sites for a wide variety of birds. In addition, snags and broken-topped trees are needed for nesting and perching sites for such large birds as eagles (Aquila and Haliaeetus spp.) and osprey (Pandion haliaetus).

The main management tool available to a wildlife biologist is to direct the size, shape, location, and timing of silviculture practices.

Size of a treatment area has a direct relationship to the number of species present (Galli et al. 1976). Thomas et al. (1978) estimated that bird species richness is optimized at about 34 ha in the Blue Mountains. Such area figures must be applied with caution, however, because they tend to become policy. Verner (1975) suggested that a better approach would be to use the territory size of large raptors, such as hawks and owls, because they could also serve as indicators of the bird population vitality.

The shape of an area is related to the amount of edge produced--the more irregular the shape, the greater the edge. Irregular shapes are also more pleasing to a viewer and provide a more natural condition.

Location of a treatment area refers to its relationship to other forest communities. Edges differ in their degree of contrast. For example, a sapling stage against pole stage has a low degree of contrast, whereas a grass stage against a mature forest stage has a high degree of contrast. Considering six generalized successional stages, there is a possible combination of 15 edges, all with a varying degree of contrast (Thomas et al. 1978). The juxtaposition of various treatments can be used to achieve habitat diversity.

The final variable is time--time in relation to season of the year, and time in relation to rotation age or number of years from tree establishment to cutting. For example, timing of a prescribed burn may be critical to ground and shrub nesting birds if it is done in the spring of the year, but the distribution of silvicultural practices over years and ages of a stand affects both the pace and direction of succession.

In summary, we paraphrase a portion of The Wildlife Society's position statement on "Wildlife Needs in Forest Management" as adopted on March 24, 1979:

Forest management practices alter species composition and structure of plant communities and thereby affect attendant wildlife. Wildlife species may increase, or decline, or be unaffected. Species with a narrow range of tolerance for habitat change may require special consideration.

229 Forest and wildlife management objectives can be coordinated by maintaining diversity of plant species, age classes, and stand densities; by retaining snags and dead and down woody materials; and by varying the size, shape, age, and juxtaposition of stands. Management plans must be flexible but also must be specific enough to meet local conditions. Management practices must be prescribed according to site conditions, plant and animal species involved, successional relationships, and such local factors that ensure a diversity of wildlife species.

Wildlife should be an intentional product of forest management. It is a wildlife biologist's responsibility to provide a manager with a set of alternatives. It is a land manager's responsibility to review the consequences of these alternatives and the trade-offs on wildlife and their habitats (The Wildlife Society 1979). We submit that this is our professional charge.

LITERATURE CITED

American Ornithologists' Union. 1957. Check-list of North American birds. 5th ed. 691 p. Port City Press, Inc., Baltimore, MD.

American Ornithologists' Union. 1973a. Thirty-second supplement to the American Ornithologists' Union check-list of North American birds. Auk 90(2):411-419.

American Ornithologists' Union. 1973b. Corrections and additions to the "Thirty-second supplement to the American Ornithologists' Union check-list of North American birds." Auk 90(4):887.

American Ornithologists' Union. 1976. Thirty-third supplement to the American Ornithologists' Union check-list of North American birds. Auk 90(4):875-879.

Balda, Russell P. 1976. Vegetation structure and breeding bird diversity. In Symposium on management of forest and range habitats for nongame birdS: Dixie R. Smith, Tech. Coord. p. 59-80. USDA For. Serv. Gen. Tech. Rep. W0-1. U.S. Gov. Print. Off., Wash., D.C.

Daubenmire, R., and Jean B. Daubenmire. 1968. Forest vegetation of eastern Washington and northern Idaho. Wash. Agric. Exp. Stn. Tech. Bull. 60. 104 p.

Edgerton, Paul J., and Jack Ward Thomas. 1978. Silviculture options and habitat values in coniferous forests. In Proceedings of Workshop on nongame bird habitat management in the coniferous forests of the western United States. Richard M. DeGraaf, Tech. Coord. p. 56-65. USDA For. Serv. Gen. Tech. Rep. PNW-64. Pac. Northwest For. and Range Exp. Stn., Portland, Oreg.

230 Franklin, Jerry F. 1977. Effects of uneven-aged management on species composition. In Uneven-aged silviculture and management in the western United States. Proc. In-Service Workshop, Oct. 19-21, 1976. Redding, Calif. Franklin, Jerry F., and DeanS. DeBell. 1973. Effects of various harvesting on forest regeneration. In Even-aged management. Richard K. Hermann and Denis P. Lavender, Compilers and Editors. Pap. 848, p. 29-57. Sch. For., Oreg. State Univ., Corvallis.

Franklin, Jerry F., and C. T. Dyrness. 1973. Natural vegetation of Oregon and Washington. USDA For. Serv. Gen. Tech. Rep. PNW-8. 417 p. Pac. Northwest For. and Range Exp. Stn., Portland, .Oreg.

Galli, Anne E., Charles F. Leek, and RichardT. T. Forman. 1976. Avian distribution patterns in forest islands of different sizes in central New Jersey. Auk 93(2):356-364. Garrison, G. A., J. M. Skovlin, C. E. Poulton, and A. H. Winward. 1976. Northwest plant names and symbols for ecosystem inventory and analysis. 4th ed. USDA For. Serv. Gen. Tech. Rep. PNW-46. 263 p. Pac. Northwest For. and Range Exp. Stn., Portland, Oreg.

Hall, Frederick C. 1973. Plant communities of the Blue Mountains in eastern Oregon and Washington. USDA For. Serv., Reg. 6 Area Guide 3-1. 62 p. Portland, Oreg.

Hall, Frederick C. 1977. Ecology of natural underburning in the Blue Mountains of Oregon. USDA For. Serv. Reg. 6, R6-ECOL-79-001. 11 p. Portland, Oreg. Hann, David W., and B. Bruce Bare. 1979. Uneven-aged forest management: state of the art (or science?). USDA For. Serv. Gen. Tech. Rep. INT-58. 18 p. Intermt. For. and Range Exp. Stn., Ogden, Utah.

Kuchler, A. W. 1964. Potential natural vegetation of the conterminous United States. Am. Geogr. Soc. Spec. Pub!. 36. 116 p. New York.

MacArthur, Robert H., and John W. MacArthur. 1961. On bird species diversity. Ecology 45(3):594-598.

Maser, Chris. 1979. Holistic management--can we achieve it? 30th Conf. Wild!. Soc., Portland, Oreg. (abstract)

Maser, Chris, Ralph G. Anderson, Kermit Cromack, Jr., Jerry T. Williams, and Robert E. Martin. 1979. Dead and down woody material. In Wildlife habitats in managed forests-­ the Blue Mountains of Oregon and Washington. Jack Ward Thomas, Tech. Ed. p. 78-95. USDA For. Serv. Agric. Handb. 553. U.S. Gov. Print. Off., Wash., D.C.

231 Maser, Chris, and Jack Ward Thomas. 1978. Ecosystems, habitats, wildlife, and management. In Proceedings of Workshop on nongame bird habitat management in the coniferous forests of the western United States. Richard M. DeGraaf, Tech. Coord. p. 1-4. USDA For. Serv. Gen. Tech. Rep. PNW-64. Pac. Northwest For. and Range Exp. Stn., Portland, Oreg.

Meslow, E. Charles. 1978. The relationship of birds to habitat, plant communities, and successional stages. In Proceedings of Workshop on nongame bird habitat management in the coniferous forests of the western United States. Richard M. DeGraaf, Tech. Coord. p. 12-18. USDA For. Serv. Gen. Tech. Rep. PNW-64. Pac. Northwest For. and Range Exp. Stn., Portland, Oreg.

Pfister, Robert D., Bernard L. Kovalchik, Stephen F. Arno, and Richard C. Presby. 1977. Forest habitat types of Montana. USDA For. Serv. Gen. Tech. Rep. INT-34. 174 p. Intermt. For. and Range Exp. Stn., Ogden, Utah.

Root, Richard B. 1967. The niche exploitation pattern of the blue-gray gnatcatcher. Ecol. Monogr. 37(4):317-350.

Seidel, K. W. 1973. Mixed pine-fir of eastern Oregon and Washington. In Silvicultural systems for major forest types of the United States. p-.-15-17. USDA For. Serv. Agric. Handb. 445. U.S. Gov. Print. Off., Wash., D.C.

Steele, Robert, Robert D. Pfister, Russell A. Ryker, and Jay A. Kitams. Being prepared. Forest habitat types of central Idaho. U.S. Dep. Agric. For. Serv. Intermt. For. and Range Exp. Stn., Odgen, Utah.

Sundstrom, Charles. 1978. A holistic approach to wildlife and fish habitat management. 135 ?· Beaverhead National Forest, Dillon, Mont.

The Wildlife Society. 1979. Position statement of The Wildlife Society on recognition of wildlife needs in forest management. Oreg. Chap. Newsletter, Nov. 1979. 8 p.

Thomas, Jack Ward. (Tech. Ed.). 1979. Wildlife habitats in managed forests--the Blue Mountains of Oregon and Washington. USDA For. Serv. Agric. Handb. 553. 512 p. U.S. Gov. Print. Off., Wash., D.C.

Thomas, Jack Ward, Ralph G. Anderson, Chris Maser, and Evelyn Bull. 1979. Snags. In Wildlife habitats in managed forests--the Blue Mountains of Oregon and Washington. Jack Ward Thomas, Tech. Ed. p. 60-77. USDA ~or. Serv. Agric. Handb. 553. U.S. Gov. Print. Off., Wash., D.C.

Thomas, Jack Ward, Chris Maser, and Jon E. Rodiek. 1978. Edges--their interspersion, resulting diversity, and its measurement. In Proceedings of Workshop on nongame bird habitat management in the coniferous forests of the western United States. Richard M. DeGraaf, Tech. Coord. p. 91-100. USDA For. Serv. Gen. Tech. Rep. PNW-64. Pac. Northwest For. and Range Exp. Stn., Portland, Oreg.

232 United States Department of Agriculture, Forest Service. 1973. Silvicultural systems for major forest types of the United States. U.S. Dep. Agric. Handb. 445. 114 p. U.S. Gov. Print. Off., Wash., D.C.

Verner, Jared. 1975. Avian behavior and habitat management. In Symposium on management of forest and range habitats for nongame birds. Dixie R. Smith, Tech. Coord. p. 39-58. USDA For. Serv. Gen. Tech. Rep. W0-1. U.S. Gov. Print. Off., Wash., D.C.

Wellner, Charles A., and Russell A. Ryker. 1973. Ponderosa pine and Rocky Mountain Douglas-fir. In Silvicultural systems for major forest types of the United States. p. 35-37: USDA For. Serv. Agric. Handb. 445. U.S. Gov. Print. Off., Wash., D.C.

Appendix 1.--Bird species feeding (F) or reproducing (R) in the mixed conifer forest successional stages of the interior Northwest

Forest Successional Stage

Grass- Shrub- Pole- Old- Species forb seeding sapling Young Mature growth

1/ Wood duck- F F F F R F R F Aix sponsa Barrow's goldeneye F F F F R F R F Bucephala islandica Bufflehead F F F F R F R F Bucephala albeola Harlequin duck F F F R F R F R F Histrionicus histrionicus Hooded merganser F F F F R F R F Lophodytes cucullatus Turkey vulture R F R F R F Cathartes aura Goshawk F F R F R F Accipiter gentilis Sharp-shinned hawk F R F R F R F F Accipiter striatus Cooper's hawk F F F R F R F F Accipiter cooperii Red-tailed hawk F F F R F R F R F Buteo jamaicensis ·. Golden eagle F F F F R F R F Aquila chrysaetos Bald eagle F F R F R F Haliaeetus leucocephalus Osprey F F F F R F R F ~: ~ . Pandion haliaetus

1/ Nomenclature follows that of American Ornithologists' Union (1957, 1973a, 1973b, 1976).

233 Appendix 1.--Continued.

Forest Successional Stage

Grass- Shrub- Pole- Old- Species forb seeding sapling Young Mature growth

Peregrine falcon R F R F R F R F R F R F Falco peregrinus Merlin F F F F R F R F Falco columbarius American kestrel F F R R R F Falco sparverius Blue grouse F R F R F F F F Dendragapus obscurus Franklin's grouse F R F R F R F F Canachites canadensis Ruffed grouse R F R F R F R F Bonasa umbellus Turkey F R F R R F F Meleagris gallopavo Barn owl F F R F R F ~ alba Flammulated owl F F R R F R F Otus flammeolus Great horned owl F F F R F R F R F Bubo virginianus Pygmy owl F F F R F R F R F Glaucidium gnoma Barred owl F F R F R F Strix varia Great gray owl F R F F F Strix nebulosa Long-eared owl F F F R F R F R F Asio otus Saw-whet owl R R F R F Aegolius acadicus Vaux's swift R F R F Chaetura vauxi Black-chinned hummingbird F R F R F F F F Archilochus alexandri Rufous hummingbird F R F R R R F R Selasphorus rufus Calliope hummingbird F R F R F F F F Stellula calliope Belted kingfisher R F F F F F F Megaceryle alcyon Common flicker F F F R F R F R F Colaptes auratus Pileated woodpecker R F R F Dryocopus pileatus Lewis' woodpecker R R R F R F R F Melanerpes lewis

234 Appendix 1.--Continued.

Forest Successional Stage

Grass- Shrub- Pole- Old- Species forb seeding sapling Young Mature growth

Williamson's sapsucker R F R F Sphyrapicus thyroideus Hairy woodpecker R F R F R F Picoides villosus White-headed woodpecker R F R F Picoides albolarvatus Black-backed three-toed woodpecker R F R F R F Picoides arcticus Alder flycatcher F R F R F Empidonax alnorum Willow flycatcher F R F R F Empidonax traillii Hammond's flycatcher F F F R F R F Empidonax hammondii Dusky flycatcher F R F R F R F R F R F Empidonax oberholseri Western flycatcher F F R F R F R F Empidonax difficilis Western wood pewee F F R F R F R F Contopus sordidulus Olive-sided flycatcher F F R F R F R F R F Nuttalornis borealis Tree swallow F F R R R F Iridoprocne bicolor Gray jay F R F R F R F F Perisoreus canadensis Steller's jay F F R F R F R F R F Cyanocitta stelleri Black-billed magpie F R F R F R F {i F R F Pica pica Common raven R F R F R F Corvus corax Common crow F F F R F R F R F Corvus brachirhinchos Clark's nutcracker F R F R F Nucifraga columbiana Mountain chickadee R F R F R F R F Parus gambeli Chestnut-backed chickadee R F R F R F R F Parus rufescens White-breasted nuthatch R F R F Sitta carolinensis Red-breasted nuthatch R F R F R F Sitta canadensis

235 Appendix 1.--Continued.

Forest Successional Stage

Grass- Shrub- Pole- Old- Species forb seeding sapling Young Mature growth

Pygmy nuthatch R F R F Sitta pygmaea Brown creeper F R F R F Certhia familiaris Dipper R F R F R F R F R F R F Cinclus mexicanus House wren F F R F R R R Troglodytes aedon Winter wren R F R F F R F R F Troglodytes troglodytes Rock wren R F R F Salpincles obsoletus American robin F R F R F R F R F R F Turdus migratorius Varied thrush F R F R F R F R F Ixoreus naevius Hermit thrush F F R F R F Catharus guttatus Swainson's thrush R F R F R F R F R F Catharus ustulatus Western bluebird F F R R R Sialia mexicana Mountain bluebird F F R R R Sialia currucoides Golden-crowned kinglet F F R F R F R F Regulus satrapa Ruby-crowned kinglet F F R F R F Regulus calendula Solitary vireo R F R F R F R F Vireo solitarius Nashville warbler R F F F Vermivora ruficapilla Yellow-rumped warbler F R F R F R F Dendroica coronata Black-throated gray warbler R F R F R F R F R F Dendroica ni~rescens Townsend's warbler F R F R F Dendroica townsendi MacGillivray's warbler R F R F R F R F Oporornis tolmiei Wilson's warbler R F R F R F R F Wilsonia pusilla Northern waterthrush R F R F Seiurus noveboracensis Yellow-breasted chat R F R F R F R F F Icteria virens

236 Appendix 1.--Continued.

Forest Successional Stage

Grass- Shrub- Pole- Old- Species forb seeding sapling Young Mature growth

Northern oriole R F R F R F R F Icterus galbula Brewer's blackbird F R F R F R F R F· R F Euphagus cyanocephalus Brown-headed cowbird R F R F R F R F R F F Molothrlls ater Western tanager F F R F R F R F Piranga ludoviciana Black-headed grosbeak F F R F R F R F Pheucticus melanocephalus Evening grosbeak F F F R F R F Hesperiphona vespertina Purple finch F F R F R F R F R F Carpodacus purpureus Cassin's finch F F F R F R F R F Carpodacus cassinii House finch F R F R F R F R F F Carpodacus mexicanus Pine grosbeak F F R F R F Pinicola enucleator Pine siskin F F R F R F R F R F Carduelis pinus Red crossbill F R F R F Loxia curvirostra Dark-eyed junco R F R F R F R F R F R F Junco hyemalis Chipping sparrow F R F R F R F R F R F Spizella passerina Song sparrow R J.t· R F R F R F Melospiza melodia

237