Seasonal fluctuations in diet and death during the late horizon: a stable isotopic analysis of hair and nail from the central coast of Peru

The goal of the isotopic analysis of hair and nail from Puruchuco-Huaquerones is to reconstruct short term paleodiet using the stable isotopes of carbon and nitrogen in one centimetre increments of hair and two discrete points (distal and proximal) on the nail. This sampling method allows for the reconstruction of diet on a monthly basis (hair) and also diet at two periods (nail): four months and two weeks antemortem. The analysis of these two tissues demonstrates that diet varied from month to month and that food was not stored in any significant quantity. The patterning of the isotope data appears to be closely tied to the agricultural cycle, although a vertical economy cannot be rejected as an alternative explanation. Isotope data for both short (e.g., hair and nail) and long term diet (e.g., bone) are similar; this is interpreted as evidence for the continuity of the settlement in this area. There are no significant differences in the season of death between males or females or between the winter and summer months. The slightly higher mortality rate in the summer may be due to crop failure and subsequent food shortages.