The mountain caracara (Phalcoboenus megalopterus) as an accumulator of faunal remains: neotaphonomic insights for the assessment of Andean zooarchaeological records

Abstract

Archaeological research in the Andes has traditionally focused on stratified sites, while the role of natural agents in the formation of faunal assemblages remains underexplored. This study presents a neotaphonomic analysis of prey remains accumulated by the mountain caracara (Phalcoboenus megalopterus), a facultative scavenger widely distributed across highland Andean environments. Fieldwork was conducted in the southern Puna of central western Argentina, where pellets and non-ingested materials were collected from a caracara nest and roost located near guanaco (Lama guanicoe) kill sites attributed to puma (Puma concolor) predation. Laboratory analyses included taxonomic identification and taphonomic assessment, focusing on skeletal element representation, breakage patterns, chemical digestion, and mechanical modifications. The assemblage is dominated by large-sized mammals, particularly guanaco, alongside smaller proportions of southern mountain viscachas (Lagidium viscacia), rodents, leporids, small birds, and reptiles. Guanaco remains were primarily represented by cervical vertebrae and basipodial elements, with cranial bones notably absent. Ingested specimens exhibited heavy to extreme digestion, while non-ingested remains showed tooth marks, crenulated edges, and helical fractures indicative of both carnivore predation and avian scavenging. The high frequency of juvenile guanaco individuals, the selective representation of skeletal elements, and the combination of mechanical and chemical modifications produced by P. megalopterus constitute a distinctive taphonomic signature. These findings demonstrate that mountain caracaras can significantly contribute to the formation and alteration of bone assemblages in Andean environments. By highlighting the interplay between carnivore hunting and raptor scavenging, this study provides a comparative framework for distinguishing natural from cultural formation processes in zooarchaeological contexts, thereby refining interpretations of human–faunal interactions in highland South America.