Prey Body Size and Ranking in Zooarchaeology: Theory, Empirical Evidence, and Applications from the Northern Great Basin

The use of body size as an index of prey rank in zooarchaeology has fostered a widely applied approach to understanding variability in foraging efficiency. This approach has, however, been critiqued—most recently by the suggestion that large prey have high probabilities of failed pursuits. Here, we clarify the logic and history of using body size as a measure of prey rank and summarize empirical data on the body size-return rate relationship. With few exceptions, these data document strong positive relationships between prey size and return rate. We then illustrate, with studies from the Great Basin, the utility of body size-based abundance indices (e.g., the Artiodactyl Index) when used as one component of multidimensional analyses of prehistoric diet breadth. We use foraging theory to derive predictions about Holocene variability in diet breadth and test those predictions using the Artiodactyl Index and over a dozen other archaeological indices. The results indicate close fits between the predictions and the data and thus support the use of body size-based abundance indices as measures of foraging efficiency. These conclusions have implications for reconstructions of Holocene trends in large game hunting in western North America and for zooarchaeological applications of foraging theory in general.