Application of morphometric and stable isotope analyses for distinguishing domestic and wild geese

Abstract

Investigating the origins of goose domestication relies on successful identification of this species and, specifically, distinguishing it from its wild, morphologically similar, form. Here we present the first attempt to separate wild and domestic geese recovered from Estonian archaeological assemblages using a combination of morphometrics and stable isotope analysis. To this aim, measurements from 159 archaeological bones were compared with modern specimens. Twenty-five archaeological samples were chosen for stable isotope analysis based on their morphometrics. The results of this paper show that bones identified as "domestic" by their size and shape had significantly higher δ 15 N values compared with those identified as "wild." The higher δ 15 N could be a result of dietary differences, for example, the role of manured crops and/or animal protein in the diets of domestic geese.

Multi-isotopic analysis of zooarchaeological material from Estonia (ca. 200–1800 CE): Variation among food webs and geographical regions

“…Geese comprise a separate group as domestic and wild geese are hard to differentiate based on bone morphometrics alone. While at least some of the geese sampled here were most likely domestic [ 65 ], specifically those with high δ 15 N values indicative of fattening, it is still noteworthy that geese occupy a completely unique niche among other sampled terrestrial fauna. Their low δ 13 C values are indicative of influences from freshwater environments and/or uncultivated landscapes.…”

“…Interestingly, several geese (sampled from a single context) all have very similar δ 34 S values (furthermore, their δ 13 C and δ 15 N values are also very much alike). These particular geese were probably domestic and kept for food since their high δ 15 N values and large bone size were indicative of fattening [ 65 ]. It seems likely that these birds were kept locally and possibly on a controlled diet (i.e.…”

“…Although geese ( Anser sp./ Branta sp.) specimens are listed under ‘wild animals’, it is possible that some of these were likely domestic birds [ 65 ].…”

Zooarchaeological evidence for the exploitation of birds in medieval and early modern Estonia (ca 1200–1800)

“…These are mostly medieval specimens from urban sites in southern (inland) Estonia (Tartu, Viljandi), while early modern samples are from rural Lohkva and the coastal town of Pärnu. Ehrlich et al (2022a) also has information about 23 analysed goose bones (δ 13 C and δ 15 N values), with their respective sulphur isotopic values published in Aguraiuja-Lätti et al (2022). The goose bones are from various contexts across the study area, ranging from the Late Iron Age up until the Early Modern Period.…”

“…While differentiating between wild and domestic geese is problematic and the wide variation in the isotopic values of the sampled geese may represent wild specimens with diverse habitat and feeding preferences, the available evidence (considered together with morphometrics) does suggest that the majority of the geese sampled for stable isotopes were domestic (Ehrlich et al 2022a). This is supported by the fact that most geese also had δ 34 S values similar to the regional terrestrial sulphur isotopic baseline (Aguraiuja-Lätti et al they could have been local in origin (i.e.…”