A critical evaluation of radiocarbon dates and Indigenous settlement patterns on Santa Catalina Island, California

On the California Channel Islands, scholars have suggested that mega droughts and climatic perturbations are causally linked to the emergence of hereditary leadership as groups of people consolidated their communities around the most productive habitats. Santa Catalina Island, one of eight islands in the Channel Islands archipelago, has been excavated for over a century, yet the majority of cultural materials from these expeditions have never been analyzed. Here we report the first comprehensive radiocarbon (C-14) database from Santa Catalina Island, and critically evaluate the dates so that meaningful interpretations of Indigenous history can be formulated. The results span similar to 6000 cal BP years of Island Tongva history and highlight the novel ways that Indigenous communities adapted to persistent droughts. People established more settlements throughout the Late Holocene and appear to have increased the number of habitation sites throughout mega droughts of the Medieval Climatic Anomaly (MCA; 1150-600 cal BP) and subsequent centuries. Our study underscores the tremendous value in utilizing legacy collections as a community-based participatory research method in order to address topics important to Indigenous stakeholders and the public, such as constructing regional chronologies and investigating human adaptation to climatic perturbations in circumscribed island landscapes.