Individual Breastfeeding and Weaning Histories in Iron Age South Italy using Stable Isotope Analysis of Incremental Dentine Sections and Bone Collagen

Abstract

This thesis investigates breastfeeding and weaning patterns in an Iron Age (7th – 4th century BCE) sample of subadults (n=12) and adults (n=9) buried at the sites of Botromagno, Parco San Stefano and Padreterno in southern Italy. Stable isotope analysis of both human tooth dentine and bone collagen for each subadult, and tooth dentine for adults, was undertaken to create early-life feeding histories. The dentine serial sections were used to determine the onset and completion of weaning for each individual, as well as distinguish general trends in early feeding practices at these Iron Age sites. Results indicate that the average onset of weaning in subadults occurred at 8 ± 3.4 months and weaning was completed by 4 years of age at the latest for all individuals; however, the patterns of breastfeeding and weaning were variable in this sample. This study also explores variation in early childhood diet between survivors and non-survivors (i.e., < 4 years of age). Non-survivors were weaned more rapidly than survivors – possibly contributing to their earlier death – and some non-survivors demonstrated elevated δ15N values that may have been a result of physiological stress. It is, however, difficult to distinguish signals of breastfeeding versus stress in young children who were still likely consuming breast milk. Finally, differences in isotope data between dentine serial sampling and bulk-bone sampling of rib and femoral collagen from the same individuals were investigated. The results show that the combined use of dentine and bone data contribute to more nuanced interpretations of weaning. Further, rib samples represent diet closer to the time of death than femoral samples, as faster bone turnover rate in ribs allow for the incorporation of more recent dietary changes.