Semester

Fall

Date of Graduation

2005

Document Type

Dissertation

Degree Type

PhD

College

Davis College of Agriculture, Natural Resources and Design

Department

Wildlife and Fisheries Resources

Committee Chair

Petra Bohall Wood.

Abstract

Four thrush species breed sympatrically in the Allegheny Mountain region of West Virginia, U.S.A.: American Robin (Turdus migratorius), Hermit Thrush (Catharus guttatus), Veery (Catharus fuscescens), and Wood Thrush (Hylocichla mustelina). How nesting habitat is partitioned among the species is unclear, as is the effect of logging activities on the guild. My objectives were to identify nesting habitat characteristics that are partitioned among the species and to determine their effects on nest survival.;I conducted point count surveys and monitored nests of four thrush species on a managed forest. I measured habitat variables at three scales: (1) nest substrate, (2) nest site, and (3) territory. I also measured nest site variables at paired, random plots. Using GIS software, I then digitized land cover into five forest land covers based on harvesting practices.;Habitat partitioning among the four thrush species occurred at all three scales sampled, and the most important partitioning variables included nest height, distance to edge, sapling density, and elevation. Wood Thrushes occurred more often than would be expected in deciduous partial harvests, increased in occurrence as the percent of partial harvests increased on the landscape, and had higher nest survival in partially harvested stands than they did in mature forest. In contrast, the other three species selected against deciduous partial harvests and had lower nest survival within them than they did in mature forest. Hermit Thrushes selected for mature mixed forest and selected against mature deciduous forest, even-aged harvests, and harvested edges. American Robins, Veeries and Wood Thrushes did not avoid the edges of even-aged harvests, and nested within harvested stands beginning at four years post-harvest.;For the American Robin, Veery, and Wood Thrush, nest survival was highest in even-aged harvests; and for all but the Wood Thrush, it was lowest in partial harvests and intermediate in mature forest. Most of the variables I measured were unrelated to survival; thus, the guild appears to be partitioning the available habitat successfully and to be tolerant of forest disturbance at its current intensity.

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