Exploring Seasonal Aspects of Past Herding Systems Using Bayesian Modeling of Animal δ13C and δ18O Enamel Isotopic Profiles

Summary

This is an abstract from the "Novel Statistical Techniques in Archaeology II (QUANTARCH II)" session, at the 84th annual meeting of the Society for American Archaeology.

Intra-tooth samples of enamel δ18O and δ13C isotopic values produce isotopic profiles that reflect seasonal fluctuations in temperature, precipitation, and dietary composition. Archaeologists have interpreted trends found in animal isotopic profiles to estimate birth seasonality and to elucidate past management strategies (e.g., seasonal foddering) and variability in these aspects of herding systems across communities and over time. These research aims rely on comparisons of isotopic profiles. To help standardize such comparisons across teeth, Balasse and colleagues (2012) developed parametric summaries of isotopic profiles. These summaries typically work best with an intensive intra-tooth sampling strategy, however, preservation and budgetary constraints preclude this approach in all situations. This poster explains how to estimate isotopic profiles precisely using Bayesian statistics. Fitting a seasonal regression model to isotopic profiles of enamel δ18O and δ13C values in sheep and cattle teeth, researchers can produce parameter estimates and uncertainty statements surrounding isotopic profiles for teeth sampled as few as 5-6 times. This method may greatly expand the sample of specimens an archaeologist can use to explore seasonal differences in herds’ diets and birth patterns as well as the strength of seasonality in the past. Model outputs also provide a straightforward way to evaluate hypotheses probabilistically.

This Resource is Part of the Following Collections

• Novel Statistical Techniques in Archaeology II (QUANTARCH II)   •
• Society for American Archaeology 84th Annual Meeting, Albuquerque, NM (2019)

Keywords

Record Identifiers

Abstract Id(s): 24645