Vertebrate remains preyed upon by the Chaco eagle (Buteogallus coronatus): neo-taphonomic implications for the interpretation of faunal records in open-air contexts from central western Argentina

GUARDIA NICOLÁS; MIGNINO JULIAN; A ZARCO; HORACIO CHIAVAZZA; CAMILA MACCIO; MANUEL LÓPEZ

JOURNAL OF ARCHAEOLOGICAL SCIENCE

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2024

0305-4403

Aeolian sandy formations characterize the eastern plains of the Monte Desert in Central Western Argentina (CWA). This area, which presents shallow and non-stratified contexts of low integrity and temporal resolution, has been overlooked by regional archaeological research, which has focused its work on stratified contexts in the Andean Cordillera sector to the west, mainly on rock shelter sites. In the surface sites of the east, the horizontal distribution of archaeological materials is as important as the vertical distribution observed in stratified sites. By incorporating fieldwork and analyzing archaeological records from largely forgotten sectors of the eastern plains, the importance of these shallow sites for interpreting human adaptations from a regional perspective was demonstrated. These open-air archaeological sites present at surface or shallow levels contain both isolated material and palimpsests. The Chaco eagle (Buteogallus coronatus, Aves: Accipitriformes) is a large, endangered, and little-known bird of prey distributed throughout southern South America. This bird of prey accumulates large amounts of prey remains around its nests in open landscapes. We conducted a neo-taphonomic study in a natural reserve of the eastern plains of the CWA, analyzing ingested and non-ingested remains associated with a modern nest of the Chaco eagle. The prey remains were accumulated between 2018 and 2022. Our taxonomic analysis allowed us to identify the presence of different taxa belonging to two classes, mammals and reptiles. Most of the specimens identified were non-ingested remains. The armadillo Zaedyus pichiy was the most conspicuous prey species, represented by osteoderms and skulls. Armadillos were widely hunted by past regional human populations. We registered several remains of the Chaco tortoise (Chelonoidis chilensis), including endoskeletal remains and osteoderms, as well as bone and tooth remains of two little known and reported species in the study area: the red tegu (Salvator rufescens) and the Patagonian weasel (Lyncodon patagonicus). In addition, we found mandible remains corresponding to two species of small-sized rodents. We also discovered 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 proportions of breakage, on the other hand, were low. We aim to present a reliable neo-taphonomic pattern to distinguish the action of the Chaco Eagle as a potential and important accumulator of faunal remains in open-air archaeological contexts from southern South America.