The early lives of the islanders: Stable isotope analysis of incremental dentine collagen from the prehispanic period of the Canary Islands

Abstract

Objectives: This study presents isotopic information for incremental dentine collagen and bone bulk collagen from individuals from the Canary Islands (Tenerife and Gran Canaria) to explore dietary differences during childhood life. Materials and Methods: Eight individuals have been studied, which comprises 122 δ15N and δ13C incremental dentine measurements and eight bulk bone collagen analyses. A baseline of potentially consumed food sources has been developed for comparative purposes. A food reconstruction using isotopic transferred signals (FRUITS) model of probable contributions of each food source towards the diet of each individual has been developed. All samples but one belongs to the later period of indigenous occupation of the archipelago. Results: The dentine collagen data are presented in correlated δ13C and δ15N plots per individual, showing the isotopic changes throughout time. δ15N values for each individual tend to be variable whereas δ13C data are generally more stable with a range of +9.1 to +14‰ for δ15N and −17.4 to −20.8‰ for δ13C. Conclusion: The isotopic analysis allows for the reconstruction of eight dietary profiles, which allow us to estimate the different dietary protein sources. The FRUITS model shows different percentages of the primary food sources for each individual. Where both δ13C and δ15N are elevated, this could be indicative of a higher marine contribution to the diet. There appear to be two main dietary profiles identifiable in the dataset and these may be related to changes in status or place of residence. Short-term variations in δ13C and δ15N and opposing co-variance of isotopic values can be indicative of nutritional stress, although metabolic changes during growth are also considered.