We estimated model parameters of competing hypotheses of annual maxima of bison migrating beyond the northern and western boundaries of Yellowstone National Park during 1990–2009.

Point estimates represent medians and ranges are 95% credible intervals of posterior distributions. Abbreviations for models of north migration are intercept (β0), central herd size (β1), northern herd size (β2), accumulated SWE (β3), aboveground dried biomass (β4), interaction between the sum of herd sizes and accumulated SWE (β5), saturation (a), and count detection (d). Abbreviations for models of west migration are intercept (β0), central herd size (β1), accumulated SWE (β2), aboveground dried biomass (β3), interaction between the central herd size and accumulated SWE (β4), saturation (a), and count detection (d). The negative exponential and modified negative exponential models violated convergence criteria and results are not reported.