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

LÓPEZ, JOSÉ MANUEL; NEME, GUSTAVO; ABBONA, CINTHIA; LUNA, MARTÍN; PEREYRA-LOBOS, ROBERTO; GIL, ADOLFO F.

Ushuaia

Taller; IV Taller de Arqueología e isótopos estables en el sur de Sudamérica; 2023

CONICET

Isotopic information of camelids is a useful tool to reconstruct its behavior and ecology, to modelling trophic present and past relationships. Traditional regional archaeological models interpreted late Holocene human settlement patterns strongly influenced by the annual guanacos’ action ranges, the highest ranked prey in the region. We evaluate local isotopic guanaco signals, to connect with the availability of C3-C4 plants; and to explore the isotopic variation of guanaco bone samples in areas of north Mendoza. The isotopic values (δ13Ccol, δ15N) obtained for 24 modern bone samples and 2 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 not show differences statistically significant among them both in C and N. Isotopic values not were influenced by altitude (between 1400 to 4500 masl). We found greater variability in lower altitudes (ca. 1400-2100 m asl) than in higher altitudes (ca. 2200-4500 masl). An interesting result is the high δ15N values in the areas of higher altitudes of the Andean areas sampled. New and reported isotopic data on regional archaeological late Holocene wild camelids are also used here. Archaeological Lama guanicoe bone collagen results a mean of δ13C-18.35‰ ±1.85 and δ15N mean=4.58‰ ±2.08. There are significant differences in 13C and 15N in comparison with modern guanaco bone samples. We observe higher variability in archaeological samples than in modern ones. We compare and explore modern and archaeological Lama sp. bone samples to explore spatial and temporal trends that will allow us to assess human strategies in the past.