First Advisor

Luis A. Ruedas

Date of Publication


Document Type


Degree Name

Master of Science (M.S.) in Biology




American pika -- Pacific Northwest -- Geographical distribution, American pika -- Pacific Northwest -- Phylogeny



Physical Description

1 online resource (61 p.)


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).


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