Award Date

Spring 2010

Degree Type

Dissertation

Degree Name

Doctor of Philosophy in Biological Sciences

Department

Life Sciences

First Committee Member

Brett R. Riddle, Chair

Second Committee Member

John Klicka, Co-chair

Third Committee Member

Dan B. Thompson

Fourth Committee Member

Marcos Pérez-Losada

Graduate Faculty Representative

Stephen M. Rowland

Number of Pages

115

Abstract

Taxa occur across ever changing landscapes on different spatial and temporal scales. Choosing the appropriate scale for collecting data and drawing inferences is critical for understanding the history of a species and its populations. Here, I describe research in which I investigated phylogenetic patterns and population genetics for Flammulated Owls (Otus flammeolus) representing 14 localities from throughout the species' distribution, and compared regional landscape features with the distribution of genetic diversity. This small, insectivorous owl migratory (Family Strigidae) breeds in western conifer and deciduous dry forests of the mountains from southern Mexico to British Columbia. Sedentary populations are found in the southern Sierras of Mexico within the Transvolcanic Belt whereas all other populations are presumed to be migratory. Among all sampled localities, one population from northeastern Mexico showed genetic differentiation and reduced gene flow from all others. High levels of gene flow among all other populations confirm anecdotal evidence of significant natal dispersal. The only sedentary population (southwestern Mexico) did not exhibit separation from populations in Canada and the United States. Low genetic variation in that locality is likely due to a recent expansion from the north or a prolonged genetic bottleneck. Several localities throughout the distribution showed high levels of genetic diversity, frequently combined with large proportions of private haplotypes, indicating long-term population stability. Previously uncovered palaeoecological evidence of flora associated with Flammulated Owl habitat in the southern and northern Rocky Mountains is consistent with the high levels of genetic diversity recovered for owls in this region. On a landscape genetic level, current measures of population sizes, territory density estimates obtained in the field, and habitat suitability averages calculated from ecological niche modeling were good predictors of nucleotide diversity. A patch proximity metric showed a very strong positive relationship with current population sizes in the absence of genetic variables. The results indicated that metapopulation dynamics among habitat patches of various sizes, habitat quality, and population densities are important in shaping genetic diversity and distributions in this species.

Keywords

Flammulated Owls; Genetic diversity; Landscape genetics; Metapopulation dynamics; Otus flammeolus; Phylogeography; Population density; Population genetics; Population history; Western United States

Disciplines

Population Biology | Zoology

Language

English


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