Dynamics of Polynesian Subsistence: Insights from Archaeofauna and Stable Isotope Studies, Aitutaki, Southern Cook Islands

Human colonists of Remote Oceania readily took advantage of the naive virgin fauna encountered on previously uninhabited islands, a bounty that was quickly depleted. Subsequent developments in Polynesian subsistence economies were more subtle, varied, and complex. These features are illustrated in a comparison of two quite different subsistence archives from the postcolonization period: archaeofaunal assemblages and stable isotope (δ13C and δ15N) records of humans, pigs, and dogs from the same archaeological contexts. The samples come from four stratified sites, with a total of 22 distinct occupational strata that represent a 600-year period on the small (18.4 km2) almost-atoll of Aitutaki in the southern Cook Islands. Benefits and challenges of integrating these quite different records are considered in the context of specific findings, with implications for subsistence studies elsewhere. In particular, differences in formation processes, taxonomic resolution, and contrasting spatial and temporal scales represented by each record are highlighted. A complex, multiscalar picture of subsistence change emerges, showing variability within and across the three species and the two subsistence archives. Findings support prior interpretations that established (not colonial) settlements are represented by the currently known Aitutaki archaeological record. Within the relatively stable and largely anthropogenic food web, humans occupy a central position throughout the sequence. Through time, a reduction in fishing and decreased consumption of marine carnivores is indicated; these changes are likely to be an outcome of both repeated storm events and considerable shoreline disruption in the fourteenth century A.D., and cultural decisions about the relative costs and benefits of various fishing activities vis-à-vis other subsistence needs. An apparent reduction in variability of pig diets in late prehistory could reflect interspecific competition between pigs and their human managers, although small sample sizes constrain interpretations. Overall, use of two quite different subsistence archives provides a more robust, but also more complex, view of subsistence change across individuals and communities on Aitutaki.