Stable isotopes (δ13Ccol, δ15N) of guanacos (Lama guanicoe) from northwestern Mendoza (Argentina): connecting modern and archaeological samples to understand past human ecology

JOSÉ MANUEL LÓPEZ; GUSTAVO NEME; CINTHIA ABBONA; MARTÍN LUNA; ROBERTO PEREYRA LOBOS; ADOLFO GIL

Ushuaia

Taller; IV TALLER DE ARQUEOLOGÍA E ISÓTOPOS ESTABLES EN EL SUR DE SUDAMÉRICA; 2023

CADIC

Isotopic information of camelids is a useful tool to reconstruct its behavior and ecology, tomodelling trophic present and past relationships. Traditional regional archaeological modelsinterpreted late Holocene human settlement patterns strongly influenced by the annualguanacos’ action ranges, the highest ranked prey in the region. We evaluate local isotopicguanaco signals to connect with the availability of C3-C4 plants and to explore the isotopicvariation of guanaco bone samples in areas of north Mendoza. The isotopic values (δ13Ccol,δ15N) obtained for 24 modern bone samples and two from archaeological sites are reported.The stable isotopes values obtained for modern Lama guanicoe report to δ13C a median = -21.21 ‰ ± 1.09 and δ15N median =3.84‰ ±0.73. Modern samples by sampling localities notshow differences statistically significant among them both in C and N. Isotopic values notwere influenced by altitude (between 1400 to 4500 masl). We found greater variability inlower altitudes (ca. 1400-2100 m asl) than in higher altitudes (ca. 2200-4500 masl). Aninteresting result is the high δ15N values in the areas of higher altitudes of the Andean areassampled. New and reported isotopic data on regional archaeological late Holocene wildcamelids are also used here. Archaeological Lama guanicoe bone collagen results a mean ofδ13C = -18.35 ± 1.85 ‰ and δ15N mean = 4.58 ± 2.08 ‰. There are significant differences in13C and 15N in comparison with modern guanaco bone samples. We observe higher variabilityin archaeological samples than in modern ones. We compare and explore modern andarchaeological Lama sp. bone samples to explore spatial and temporal trends that will allowus to assess human strategies in the past.