Semester

Fall

Date of Graduation

2003

Document Type

Dissertation

Degree Type

PhD

College

Davis College of Agriculture, Natural Resources and Design

Department

Wood Science and Technology

Committee Chair

Petra Bohall Wood.

Abstract

During 2001 and 2002, I surveyed three mountaintop mining/valley fill (MTMVF) complexes in southern West Virginia to determine vegetation characteristics important to nest site selection and to estimate nest success for Grasshopper Sparrow populations inhabiting these complexes. I also performed genetic analyses to assess overall population structure, mating system, parentage, kinship, and gender of individuals comprising these populations. A total of 415 grasshopper sparrows were captured and systematic searches of study plots produced 75 active nests. Nest survival for 2001--2002 breeding season (33%) is comparable to survival rates previously reported in the literature. Nest survival rates decreased with increased reclamation age suggesting that vegetation changes and the reduction of bare ground on available grasslands may negatively impact reproductive success. Habitat variables measured at nests and at fixed habitat plots suggest differences in several of the ground cover estimates. Percent green and grass height at 1 m were significantly lower at the nest plots while percent bare ground, percent litter at 1 and 5 m from the nest, grass height at 3 m, shrub stem density, and Robel pole indices at the nest were significantly higher at nest plots. Large reclaimed grassland habitats available on the MTMVF complexes appear sufficient to support breeding populations of grasshopper sparrows; however, habitat will become unsuitable as succession occurs. Genetic analyses suggest low but significant differentiation among mine complexes while the genetic structure of breeding assemblages within mine complexes appears to be homogeneous. The five microsatellite loci screened in this study are robust and appear to be effective in allocating parentage when neither parent is known. Using maximum likelihood methods, I was successful at assigning at least one parent to 80% of the offspring surveyed. The lack of extra-pair paternity within the grasshopper sparrow broods implies a socially and genetically monogamous mating system in this species. Gender assignment data obtained for adult Grasshopper Sparrows by application of the 2550F/2718R primers was in 100% agreement with morphological data collected in the field.

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