Bioarchaeological observations and dietary practices at Viking Age Havor, Gotland: A reconstruction of diet and life histories

The Havor burial site, located in Hablingbo parish on the island of Gotland, spans from the Pre-Roman Iron Age to the Late Viking Age and is characterized by a heterogeneous burial landscape interpreted as potentially reflecting multiple spatially distinct burial communities. This study investigates whether these proposed burial groups are reflected in dietary practices and life histories. Stable carbon (δ 13 C) and nitrogen (δ 15 N) isotope analysis of bone and dentine collagen was applied to examine diet in relation to burial affiliation, sex, and individual life history. The results indicate diets based predominantly on C 3 terrestrial resources, with variation in the consumption of higher-trophic-level protein. Elevated δ 15 N values among some individuals that are combined with comparatively high δ 13 C values may reflect greater consumption of terrestrial animal protein and/or dairy products, while a contribution from brackish-water fish is also a possibility. All sampled individuals (n = 5) from the western burial group had δ 15 N values above 12‰, whereas the eastern (n = 14) and central (n = 18) groups displayed greater variability in δ 15 N values. Given the small and uneven sample sizes, this pattern should be considered preliminary. While no significant dietary differences between males and females were observed in bone collagen, variation in dentine collagen points to possible sex-related differences in middle and late childhood. Intra-individual isotopic variation further reveals dietary shifts across the life course for several individuals. As the first isotopic study of Havor, these findings provide new insight into the relationship between burial organization and lived experiences, highlighting community-level differences within Viking Age populations.