Opportunistic versus target mode: Prey choice changes in central-western Korean prehistory

Human decision-making processes are usually hierarchical in that higher-level decisions impose constraints on lower-level decisions. As a result, prey choices during individual foraging trips are governed to a large degree by higher-level decisions regarding how to supply resources to satisfy demands, with higher-level decisions typically made prior to foraging trips. Resource selectivity and search bias sometimes take place in this context. By dividing resource procurement modes into opportunistic and target, I discuss how choice of mode on the basis of an overall economic plan affects prey choice during foraging trips and faunal assemblage composition resulting from those trips. An analysis of taxonomic diversity in shellmidden assemblages from the central-western Korean Late Chulmun Period (3500–1300 BC) and Middle and Late Mumun Period (700–100 BC) shows that Late Chulmun people adopted a target mode, while Middle/Late Mumun people adopted an opportunistic mode in their exploitation of marine resources. A decrease in the importance of marine resource in Middle/Late Mumun produced a change in taxonomic diversity by increasing the opportunistic cost of marine resource exploitation.