Isotopic Evidence for Middle Horizon to 16th Century Camelid Herding in the Osmore Valley, Peru

Archaeological and zooarchaeological data indicate that camelid pastoralism was a subsistence and economic mainstay of Middle Horizon and more recent cultures in the Osmore region of southern Peru. However, it is not known whether camelids were primarily herded in highland puna pastures or near lower elevation sites in the middle valley or along the coast. This research examines the elevation of archaeological camelid herding in the Osmore Valley using stable isotope analysis. Stable carbon (delta C-13) and nitrogen (delta N-15) isotope ratios were measured on 28 archaeological camelid bone samples from the Middle Horizon sites of Cerro Baul and Cerro Mejia, the Late Intermediate site of Yaral and the late pre-Hispanic to Colonial period site of Torata Alta. Twenty-three archaeological camelids have delta C-13 and delta N-15 values similar to five modern camelids maintained in highland puna pastures. In contrast, three camelids from the high status Wari site of Cerro Baul, and two from Yaral have unexpectedly high delta C-13 and/or delta N-15 values outside the expected range for camelids pastured in highland puna habitats. The results may be explained by differences in foddering practices, altitudinal herding range or climatic conditions. Strontium isotope ratios (Sr-87/Sr-86) were also assessed to infer pasture elevation using the camelid remains from Cerro Baul (n = 11). One individual in this sub-sample exhibits a non-local Sr-87/Sr-86 value indicative of an origin in the highland puna region east or south of Lake Titicaca. It was not possible to further distinguish between camelids herded in lower to middle elevation habitats outside the Lake Titicaca basin using Sr-87/Sr-86 values. This study suggests that multiple isotope proxies may be used to identify animals primarily pastured in lowland coastal versus highland puna (> 4000 masl (meters above sea level)) habitats, but are less useful at distinguishing between animals pastured in lower to middle elevation settings. Copyright (C) 2010 John Wiley & Sons, Ltd.