Effects of recent burning on breeding bird community structures in aspen forests.

Authors(s): J. S. Dieni and S. H. Anderson

Publication: J Field Ornithol

Publisher:

Publication Date: 0000-00-00

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Abstract: Fire is an important disturbance that stimulates aspen regeneration and expansion in the western United States. We investigated the impacts of burning aspen-dominated habitats on landbird community structure in the western foothills of the Wind River Range, Wyoming. Habitat structure, breeding bird species composition, richness, and relative abundance were compared in 1994 and 1995 between six independent pairs of sites, each pair consisting of a recently burned aspen site and a control site. Burned sites typically had lower canopy cover and depth, greater snag densities and aspen regeneration, and less shrub growth. We observed 45 diurnal woodland bird species overall. Western Wood-Pewees (Contopus sordidulus) and Warbling Vireos (Vireo gilvus) were detected significantly less often in the burned sites, while Mountain Bluebirds (Sialia currucoides) and Pine Siskins (Carduelis pinus) were detected significantly more often in the burned sites. Orange-crowned Warblers (Vermivora celata), Red-naped Sapsuckers (Sphyrapicus nuchalis), and chickadees (Poecile spp.) were significantly less abundant in the burned aspen when burn size or year was factored into the analysis. For many other commonly detected species, we had relatively low power to detect meaningful differences in abundance between recently burned and unburned aspen stands. Bird species richness was similar between treatments. Bird species composition differed consistently among burned-control pairs, but our data suggested that inter-site variability in species composition in aspen is the norm in the absence of burning.

Keywords: Rocky Mountain, breeding, fire, animal, bird, Aves, ornithology, Wind River Range, population, habitat, warbling vireo, Vireo gilvus, western wood pewee, Contopus sordidulusi, pine siskin, Carduelis pinus, Mountain Bluebird, Sialia currucoides, Orange-crowned Warbler, Vermivora celata, Red-naped Sapsucker, Sphyrapicus nuchalis, chickadee , Poecile spp.