Sexual dimorphism among Mesoamerican turkeys: A key for understanding past husbandry Aurélie Manin a,b, ⁎, Raphaël Cornette c , Christine Lefèvre a a Archéozoologie, archéobotanique: sociétés, pratiques et environnement (UMR 7209), Sorbonne Universités, Muséum national d'Histoire naturelle, CNRS, CP 55, 55, rue Buffon, 75005 Paris, France b Centre d'Etudes Mexicaines et Centraméricaines (CEMCA), UMIFRE 16, CNRS, Sierra Leona 330, Delegación Miguel Hidalgo, México 11000 D.F., Mexico c Institut de systématique, évolution, biodiversité (UMR 7205), Sorbonne Universités, Muséum national d'Histoire naturelle, CNRS, 45, rue Buffon, 75005 Paris, France abstract article info Article history: Received 26 August 2015 Received in revised form 20 March 2016 Accepted 28 May 2016 Available online xxxx Few animals have been domesticated in Mesoamerica and the organization of husbandry practices in this part of the world remains little known. The turkey (Meleagris gallopavo), one of these few animals, shows an evident sexual dimorphism that allows for the analysis of past demographic structure from the study of archaeological bone remains. Here we document sexual dimorphism in turkey populations from the Classic to the Post classic (200–1521 CE) in northern Mesoamerica. We present a morphometric approach based on both size and shape that allows the distinction of two groups in the archaeological populations, corresponding to males and females. Group delimitation with no prior knowledge of their number and parameters is conducted with Gaussian mix- ture analyses. The accuracy of the method was first evaluated using bibliographic data from the Southwestern USA and then applied on 120 Mesoamerican bone remains of unknown sex coming from five archaeological sites. We point out an imbalanced sex-ratio in Mesoamerican turkey flocks that account for more females than males. We also show that there were no significant size variations between the different sites tested in this study even if they are situated in both lowlands and highlands. © 2016 Elsevier Ltd. All rights reserved. Keywords: Gaussian mixtures Log size index Log shape ratio Meleagris gallopavo Morphometrics Zooarchaeology 1. Introduction Turkey (Meleagris gallopavo) was one of the few domesticated ani- mals in Mesoamerica at the time of the European contact. The details re- ported by Sahagun in his description of the bird, the existence of multiple Nahuatl terms to depict the different body parts, and the ex- pressions related to turkeys in common language (Dibble and Anderson, 1975) all show its importance in Aztecs daily life, as do more sporadic mentions of other 17th century authors (see review in Latsanopoulos, 2011). However, few studies have been conducted on the conditions of its domestication and on husbandry practices. According to Schorger (1966), the extent of the natural distribution of the wild turkey coincides with the northern part of Mesoamerica (Fig. 1). The earliest evidence of its management is the discovery of six bones of wild turkey outside of its natural range, in the Pre-classic deposits (cal 327 BCE–54 CE) of El Mirador, northern Guatemala (Thornton et al., 2012) enabling archaeologists to consider turkey as a domesticate in pre-Hispanic southern Mesoamerica. Nonetheless, in central Mexico, because the wild turkey is present in the natural environment and, so far, no clear morphological traits have been found to successfully distin- guish domestic and wild forms, we suggest in this paper to consider husbandry practices as distinct from the domestication concept. Indeed, as introduced by Jarman et al. (1976), the term of animal husbandry is not necessarily restricted to domestic animals but deals with the behav- ioral aspects of the relationships between man and animals, without re- quiring any selective breeding, whether intentional or not. If we can establish the population structure of an archaeological sample, in particular sex-ratio, we then gain specific information on human strategies regarding animal selection. This topic has been widely used to characterize wild mammals hunting strategies (e.g. Fernández and Monchot, 2007; Jones, 2006; Monchot, 1999; Weinstock, 2000), the first steps of mammal domestication (e.g. Helmer et al., 2005; Vigne et al., 2012; Zeder, 2001) and economic systems of mammal hus- bandry (cf. the model proposed by Payne, 1973). Fewer studies dealing with birds have been conducted towards this purpose. Bird sex-ratios seem highly dependent upon the species con- sidered and its natural behavior. For example, as they are polygamous birds, domestic fowls can be raised with a ratio of one male for five fe- males in a mixed “meat and eggs” economy, while monogamous geese would need a balanced sex ratio to reproduce (Albarella, 1997; Serjeantson, 2002). Turkeys show a clear sexual dimorphism enabling an analysis of sex-ratio from archaeological bone sample. It has been Journal of Archaeological Science: Reports xxx (2016) xxx–xxx ⁎ Corresponding author at: UMR 7209 Archéozoologie, archéobotanique: sociétés, pratiques et environnement, CP 55, 55, rue Buffon, 75005 Paris, France. E-mail address: amanin@mnhn.fr (A. Manin). JASREP-00503; No of Pages 8 http://dx.doi.org/10.1016/j.jasrep.2016.05.066 2352-409X/© 2016 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Journal of Archaeological Science: Reports journal homepage: www.elsevier.com/locate/jasrep Please cite this article as: Manin, A., et al., Sexual dimorphism among Mesoamerican turkeys: A key for understanding past husbandry, Journal of Archaeological Science: Reports (2016), http://dx.doi.org/10.1016/j.jasrep.2016.05.066