Degree Name

MS (Master of Science)



Date of Award


Committee Chair or Co-Chairs

Chris Widga

Committee Members

T. Andrew Joyner, Joshua X. Samuels, Blaine W. Schubert


The national mammal of the United States, the American Bison (Bison bison) was once nearly extinct. Populations have recovered to the degree that thousands roam the Great Plains today. Due to their large numbers and body size, this species has an oversized impact on the ecological communities where it lives and is considered a keystone herbivore in modern North American grasslands. This study explores the detailed, seasonally resolved, paleoecology of seven bison from the Greater Yellowstone Ecosystem during the Late Holocene through stable isotope analyses and species niche modeling. Isotopic analyses of δ13C, δ15N, and δ18O reveal that bison within high elevations regularly foraged on C3 vegetation while traveling among the valleys and ridges of ecoregions similar to those of modern-day. Species distribution models provide a bimodal niche, with best-suited temperatures of 4-8°C and 16-26°C, and topographic ranges of 250-800m and 2,000-4000m.

Document Type

Thesis - unrestricted


Copyright by the authors.