Human and dog Bayesian dietary mixing models using bone collagen stable isotope ratios from ancestral Iroquoian sites in southern Ontario

Abstract

Under the archaeological canine surrogacy approach (CSA) it is assumed that because dogs were reliant on humans for food, they had similar diets to the people with whom they lived. As a result, the stable isotope ratios of their tissues (bone collagen and apatite, tooth enamel and dentine collagen) will be close to those of the humans with whom they cohabited. Therefore, in the absence of human tissue, dog tissue isotopes can be used to help reconstruct past human diets. Here δ13C and δ15N ratios on previously published dog and human bone collagen from fourteenth-seventeenth century AD ancestral Iroquoian village archaeological sites and ossuaries in southern Ontario are used with MixSIAR, a Bayesian dietary mixing model, to determine if the dog stable isotope ratios are good proxies for human isotope ratios in dietary modeling for this context. The modeling results indicate that human dietary protein came primarily from maize and high trophic level fish and dogs from maize, terrestrial animals, low trophic level fish, and human feces. While isotopes from dog tissues can be used as general analogs for human tissue isotopes under CSA, greater insights into dog diets can be achieved with Bayesian dietary mixing models.

"Until death do us part". A multidisciplinary study on human- Animal co- burials from the Late Iron Age necropolis of Seminario Vescovile in Verona (Northern Italy, 3rd-1st c. BCE)

“…One possibility is therefore that the outlier position of US 2757 for nitrogen may actually be related to a brief deviation in the diet of this animal before death rather than to a continued, differential access to food sources. Another factor worth considering is caecotrophy (feces consumption), a typical habit in dogs [ 146 , 147 ] which has been previously signaled as a possible influence on the isotopic ratios observed for this taxon [ 148 ]. Differences between fecal and dietary isotopic ratios have been indeed confirmed experimentally by a study [ 149 ] carried out on fecal samples from 14 human subjects fed controlled diets.…”

Patagonian partnerships: the extinct Dusicyon avus and its interaction with prehistoric human communities

“…Beyond human's best friend, societies have equally maintained diverse relationships with wild canid species sharing their environment [25][26][27][28][29]. Additionally, ancient dogs' remains have also been extensively studied because of their potential as proxies for human palaeodiet [30][31][32][33][34][35].…”

Dogs in Lithuania from the 12th to 18th C AD: Diet and Health According to Stable Isotope, Zooarchaeological, and Historical Data

“…The relatively high δ 15 N values of the urban canines from Vilnius and Kaunas were likely not due to higher meat or fish consumption, but rather to the high proportion of feces and animal waste (i.e., bones) of city dwellers comprising their diet, as well as chronic starvation. Presumably, a high number of the urban canines were stray dogs, suffering from food shortages, and feeding on feces and bones [12,74]. Thus, their nitrogen stable isotope values would have been higher than those of elite dogs, who were fed on plant-based foods like porridge or game animals.…”

“…Estimating fecal consumption is challenging, as fecal stable isotope values depend on a variety of factors, such as human diet (vegetarian, fish or meat based), exposure time in the open environment, etc. [12,48,49,74]. As there are no stable isotope studies of medieval and early modern coastal populations in Lithuania, the fecal values of Vilnius urban populations were included in the modelling of the Klaip ėda/Memelburg dog intakes.…”

“…Thus, some researchers have suggested that the canine diet may also reflect human nutrition [8,9]. However, such analogies are not fully supported by other studies [10][11][12][13].…”