Applying dynamics and comparing life tables for Pleistocene Equidae in anthropic (Bau de l'Aubesier, Combe-Grenal) and carnivore (Fouvent) contexts with modern feral horse populations (Akagera, Pryor Mountain)

Abstract

In this study, we propose a method based on life tables currently used in population dynamics and ecology to compare the mortality curves of Equidae from anthropic and carnivore fossil assemblages with those from modern populations. The combined analysis of frequency ( f x ) with various ecological parameters such as mortality rate ( q x ), survival rate ( l x ), fecundity rate ( m x ), and killing factor ( k x ), established for each age class, allows us to characterize the stability of fossil populations. These ecological parameters, developed in demography, correspond to many curves and constitute a complementary approach to interpret the two main mortality models, attritional and catastrophic, often evoked in zooarchaeology. The age structures of fossil horses from the anthropic sites of Bau de l'Aubesier (Vaucluse, France) and Combe-Grenal (Dordogne, France) and the hyena den of Fouvent (Haute-Saône, France) are compared to typical catastrophic modern populations of Equidae from the National Park of Akagera (Rwanda). We also used data collected by the Bureau of Land Management for present day feral horses from Pryor Mountain (Montana, USA) which constitutes a reliable referential of a stable living population. The characterization of age structures in those different contexts is discussed as well as the impact of Neanderthals and hyenas on fossil assemblages.