Portland State University. Department of Biology
Luis A. Ruedas
Date of Award
Master of Science (M.S.) in Biology
1 online resource (61 p.)
American pika -- Pacific Northwest -- Geographical distribution, American pika -- Pacific Northwest -- Phylogeny
The American pika (Ochotona princeps) finds moderately warm temperatures (>25°C) lethally stressful, and at the end of the last Ice Age 10,000 years ago was forced to disperse to cooler, "sky island" mountaintops where they are almost exclusively found today. Thirty six subspecies are recognized, all established using morphological characters, and it is uncertain whether these subspecies' designations are corroborated by genetic analyses. This study elucidates three hypotheses regarding populations in Oregon and southern Washington: 1) O. p. fumosa constitutes a subspecies distinct form O. p. brunnescens, 2) the Columbia River constitutes a barrier to gene flow giving rise to two subspecies rather than the single subspecies O. p. brunnescens, and 3) populations in eastern Oregon ( O. p. jewetti and O. p. taylori) are genetically distinct from populations in the Cascade Range ( 0. p. brunnescens and O. p. fumosa).
Batten, George Washington III, "Biogeography of the American Pika (Ochotona princeps) in Oregon and Southern Washington : illuminating genetic relationships among disjunct populations" (2010). Dissertations and Theses. Paper 3553.