Non-ingested vertebrate prey remains accumulated by the Chaco eagle (Buteogallus coronatus): neo-taphonomy to evaluate open-air faunal records in central western Argentina

Abstract

The Chaco eagle (Buteogallus coronatus) is a large, endangered, and little-known bird of prey distributedthroughout southern South America. This bird of prey accumulates large amounts of prey remains around itsnests in open landscapes. To present a reliable pattern to distinguish the action of the Chaco Eagle as a potentialaccumulator of faunal remains in open-air archaeological contexts, we conducted a neo-taphonomic study in anarea of the eastern plains of the CWA, analyzing modern remains accumulated around a nest of the Chaco eagle.Our taxonomic analysis allowed us to identify the presence of different taxa belonging to two classes: mammalsand reptiles. Most of the specimens identified were non-ingested remains. The armadillo Zaedyus pichiy was themost conspicuous prey species, represented by osteoderms and skulls. We registered several endoskeletal remainsand osteoderms of the Chaco tortoise (Chelonoidis chilensis), as well as bone and tooth remains of two little-knownand reported species in the study area: the red tegu (Salvator rufescens) and the Patagonian weasel (Lyncodonpatagonicus). In addition, we found remains corresponding to two species of small-sized rodents. We alsodiscovered strongly digested vertebrae of an indeterminate small Ophidia preserved in the only recovered pellet.The proportion of weathering was high, with stages 1 and 2 identified as the most dominant degrees. Notably,specimens with two stages of weathering were detected based on the side grounded to the floor. The proportionsof breakage, on the other hand, were low. We hope this work contributes to the distinction of accumulatingagents in the region’s archaeological sites, especially considering the high importance that armadillos have hadfor the past human populations of the area.