From the Atlantic coast to the lowland forests: stable isotope analysis of the diet of forager‐horticulturists in southern Brazil

Abstract

In this study, we analyze the diet of forager–horticulturalist societies of southeast South America through different isotopic markers (δ13Ccollagen, δ13Capatite, and δ15N). The economy of these populations was based on hunting, fishing, gathering, and, to a greater or lesser extent, horticulture, showing a different emphasis on each one of these options. The samples analyzed here were recovered from different environments, including the Atlantic coast, the highlands of the Brazilian plateau, and the lowland forests of the upper valleys of the Uruguay and Paraná rivers, within a general east–west sampling transect. Most of the samples correspond to individuals recovered from the Guarani and Itararé-Taquara archeological units. We have also included a smaller sample of foragers clustered in the so-called Vieira Tradition, perhaps with some food production, and two individuals buried in shell mounds (“sambaquis”) of the south Brazilian Atlantic coast (“Coastal Tradition”), whose economy was strongly based on marine resources and wild plants. The results indicate that, regardless of the archeological unit in question, the individuals recovered from the seashore settlements show a diet based mostly on marine protein, with a minor contribution of other resources, except in a Guarani sample, where a significant intake of maize is observed. The individuals recovered in the highlands of the Brazilian plateau (“Itararé-Taquara”) present the highest incidence of plant consumption of the entire sample analyzed, within a C3 monoisotopic pattern, probably strongly influenced by the consumption of the araucaria pine nut, and no isotopic signals related to maize intake. Guarani samples recovered from sites located in tropical forests in the interior of the continent show an unquestionable and systematic impact of maize on the diet, in addition to an important consumption of C3 animal proteins. The individuals assigned to the so-called Vieira Tradition show a diet based on C3 protein and both C3 and C4 lipids and carbohydrates. The latter could be related to a small consumption of maize. These results demonstrate the multidirectionality of subsistence strategies in southeastern South America during the late Holocene.