A method for constructing demographic profiles of Capra aegagrus/C. hircus using logarithm size index scaling

Abstract

Sex-specific demographic profiles of archaeological animal bone assemblages are key to being able to reconstruct the varied strategies used by ancient hunters and herders to harvest animals from both wild and managed herds. Nearly 25 years ago Zeder developed a method for constructing these profiles based on the study of a large collection of modern wild and domestic caprines that combined metric data and a refined system for determining age of death of archaeological caprine bones (Zeder, 2001, 2006a, 2008; Zeder and Hesse, 2000). The utility of this method was limited, however, by its reliance on individual dimensions from single elements, subjecting the method to sample size limitations. This paper presents a new method for constructing demographic profiles for assemblages of goat remains from archaeological sites drawing on a method developed by Zeder and Lemoine for Sus scrofa (Zeder and Lemoine, 2020a). The method uses normalized metric data following the Logarithm Size Index (LSI) scaling technique designed to address sample size issues. LSI values of post-crania metric data are shown to reflect the strong sexual dimorphism in body size in modern wild goats which is evident in the post-crania of animals over one year of age. Once adjusted for regional body size differences, as well as differences in the scaling of different post-cranial elements, the mid-point of the range of LSI values is shown to be a reliable and highly accurate way of distinguishing between the elements of females and males and for constructing sex-specific age profiles based on these identifications. This method is applied to metric data of goat assemblages from four archaeological sites in the Zagros — two representing hunted animals (Yafteh Cave and Asiab) and two representing early managed herds (Ganj Dareh and Ali Kosh). The paper concludes by offering recommendations, and caveats, for the use of this method in building sex-specific demographic profiles of ancient goat assemblages.