The characterization of bearded vulture (Gypaetus barbatus) coprolites in the archaeological record

Abstract

The archaeological record of the Lagar Velho rock shelter (Lapedo Valley, Leiria, Portugal) bears testimony to several significant Upper Palaeolithic occupations, most notably the Lapedo Child burial (LV1) dating from the Gravettian. Excavations undertaken at the site since 2018 have seen the recovery of a large quantity of coprolites, above all in layer 143 (c. 29 ka cal BP). The study of these fossilized remains points to the bearded vulture (Gypaetus barbatus) as the main coprogenic agent and provides the first descriptions of these avian coprolites in archaeological assemblages. The analyses reported involved the comparison of the coprogenic samples with modern bearded vulture scats. A new morphotype is proposed for discriminating the faeces of this avian scavenger based on (1) macroscopic analyses, (2) morphometric comparisons with other fossil and modern scats and (3) their mineralogical and elemental composition. Among the criteria proposed here to identify the coprolites of the bearded vulture are their cylindrical shape, diameter, pointed extremities and homogeneous porous texture, as well as their massive internal texture, hard consistency and total absence of bone inclusions (attributable in all likelihood to a high digastric juice acidity capable of dissolving bones). Our results indicate that, as well as being used by humans for short-term stays, the Lagar Velho rock shelter was used by the bearded vulture as a nesting site. We provide new evidence from Iberia of the activity of this avian scavenger as a bone accumulator in archaeological sites.