Stable Isotopes (13C and 15N) of Holocene caviomorph rodents from Northwestern Patagonia: human subsistence and paleoenvironments issues

FERNANDO J. FERNÁNDEZ; ADOLFO GIL; ANDREW UGAN; GUSTAVO NEME

San Rafael

Congreso; 12th Conferencia ICAZ (International Council for Archaeozoology); 2014

Here we present a study of stable isotopes of δ13C and δ15N from bony remains of the caviomorph rodents Dolichotis patagonum,Myocastor coypus, Lagostomus maximus, Lagidium viscacia, Microcavia australis, Galea leucoblephara and Ctenomys sp. The bone samples were recovered from archaeological (N=27) and recent (N=60) contexts of Monte and Patagonian phytogeographic units of Northwestern Patagonia (specifically southern Mendoza and extreme north of Neuquén). The δ15N comparison between archaeological samples of caviomorph rodents and human tissues (N=58), indicates a weak signal of anthropic consumption of these resources. This information confirms previous taphonomic studies performed in the same region. However, the δ13C values point out the potential human consumption of Ctenomys, Lagidium and Dolichotis at Patagonian unit, and Ctenomys, Lagostomus and Galea at Monte unit. Finally, the temporal and spatial variation (evaluated only for Ctenomys), showed changes between diet of Late Holocene and recent times (recent δ13C sample values are more enriched according to prevalence of C4 plants, than archaeological ones), suggesting climatic variations and/or overgrazing effect. The climatic change could have involved the advance of Monte unit into some parts of Patagonian unit, due to several factors such as a decrease of average annual precipitation with a summer pattern, and an increase of the mean annual temperature.