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.

Chemical analysis of pottery reveals the transition from a maritime to a plant-based economy in pre-colonial coastal Brazil

“…Among the Guarani it was widely used, consumed as a fermented beverage, and likely mixed with other foodstuffs as part of routine culinary practices. This finding is supported by the sparse number of isotopic analyses, so far, conducted on coastal Tupi-Guarani human remains 27 , 62 and zooarchaeological studies 63 , that also show a departure from previous coastal oriented economies and, at least, a broadening of the subsistence base at this juncture.…”

“…phytoliths, starch and pollen) from both the inland 20 – 23 , and the coast 3 , 24 , 25 , an approach not without methodological limitations 26 . Stable isotope analysis of human remains from inland Guarani has highlighted the dietary importance of maize 20 , 27 , 28 but in coastal settings this approach is limited by the near absence of skeletal remains. The few isotope studies of coastal Guarani in Southern Brazil show some 13 C-enrichment in collagen 27 but cannot be securely interpreted as maize consumption, as marine resources would likely produce similar values.…”

Bridging archaeology and marine conservation in the Neotropics

“…From 1200 to 500 years ago, groups who produced ceramic artefacts attributed to the Taquara-Itarare ´cultural tradition also exploited fish as the main source of dietary protein in the southern Atlantic Forest coast [58,59]. Finally, Tupiguarani and Guarani groups who settled in these coastal areas from around 1000 years ago until European contact [60], complemented their plant-based economies with fish from coastal environments [61].…”

Bridging archaeology and marine conservation in the Neotropics

“…From 1200 to 500 years ago, groups who produced ceramic artefacts attributed to the Taquara-Itararé cultural tradition also exploited sh as the main source of dietary protein in the southern Atlantic Forest coast 56,57 . Finally, Tupiguarani and Guarani groups who settled in these coastal areas from around 1000 years ago until European contact 58 complemented their plant-based economies with sh from coastal environments 59,60 .…”