Dates, Demography, and Disease: Cultural Contacts and Possible Evidence for Old World Epidemics Among the Protohistoric Island Chumash

For the California coast, the Protohistoric period (ca. AD 15421769) was long regarded as a final respite before Mission period colonial expansion devastated traditional California Indian societies. Recent papers have argued that epidemics of Old World diseases may have impacted the Chumash and other California tribes well before the first missions were established, but the evidence for such epidemics has been largely circumstantial. We discuss the encroachment of Old World disease frontiers on Alta California and the extent of Protohistoric contacts between Europeans and southern California’s coastal tribes, then examine archaeological evidence for changes in Island Chumash settlement over the past 2000 years. Analyzing the temporal distribution of 215 14C dates from Island Chumash sites, we found that the number of dated sites occupied in the century following Cabrillo’s AD 1542-43 expedition declines dramatically. If this pattern holds true as more sites are dated, it may provide circumstantial evidence for the Protohistoric transmission of Old World diseases to the Island Chumash.