Thule dog diets in the Hudson Bay reflect human dietary variability: Implications for palaeodietary studies and past human–dog relationships in the Canadian Arctic

• Stable isotope ratios of canids from the Silumiut site in NW Hudson Bay were analyzed. • Dogs and humans show dietary similarities, but dogs ate more terrestrial resources. • Juvenile dog's isotopic composition suggests seasonal dietary shift. • Economic, cultural, and environmental factors influenced dog provisioning. The stable isotopic compositions of domestic dogs have frequently been used to investigate questions related to ancient human subsistence, leading to the development of analogical frameworks such as the Canine Surrogacy Approach (CSA). In this paper, we compared the stable carbon and nitrogen isotope ratios from canid (dogs and wolves) bone and dentine collagen with previously published human and dog stable isotope ratios at the Silumiut site (KkJg-1; northwestern Hudson Bay, Canada). We found a clear dietary relationship between humans and dogs at Silumiut, suggesting that dogs were heavily influenced by human provisioning. Despite their isotopic similarities, mixing models (MixSIAR) estimated that the dogs consumed a greater proportion of terrestrial resources than humans, particularly a juvenile dog at the site, which we interpreted as reflecting a seasonal dietary signal. The isotopic variability observed among the adult dogs reflected that of humans, despite the much smaller number of dogs. This may reflect small-scale differences in the care and provisioning of dogs at this site. Based on these results, we suggest that dogs are best served as a source of indirect information about human subsistence and human–dog relationships, rather than as direct dietary proxies for humans in palaeodietary studies in this region.