The sex of animal remains from paleozoological contexts can offer information of prehistoric faunal exploitation and spatiotemporal changes in body size. Traditional approaches to sex determination use multiple univariate statistical analysis of bone measurements to distinguish males, females, and subadult individuals. Multivariate statistical analyses offer an alternative, quantitative method to capture the same information that is not dependent on relatively subjective analysts’ assessments. A large sample of bison data published by (M. E. Hill, Jr., et al. 2008) illustrate the potential of this method for future research.

The proximate cause of reduction in the overall size of late Quaternary bison is the focus of continued debate. Some researchers contend that size reduction did not occur despite well documented changes in climate and vegetation, while others link directional change in body size to changes in forage quality and availability or human predation. Historically, assessments of bison size have used standard measurements, ratio diagrams, univariate and bivariate plots, and summary statistics 1) to distinguish males and females; and 2) to generate mean body size data. Application of various multivariate methods to 1,600+ calcanea from 40+ localities is used to eliminate the subjectivity of sex determination and, in turn, supply a refined understanding of spatio-temporal patterns in bison body size. Results confirm that late Pleistocene animals were substantially larger than their late Holocene counterparts.