The barn owl as an accumulator of bone remains in central western Argentina: multi-taxa neo-taphonomic approach and implications for Holocene contexts

Barn owls are the most widely distributed group of owls in the world and are among the most common accumulators of small vertebrate remains at archeological and paleontological sites. Despite its importance as a bone remains accumulator and predictor of paleoenvironmental conditions due to its generalist habits, the vertebrate prey of this raptor has been scarcely studied from an ecological community perspective, especially considering the diverse range of prey it captures. Archeological, paleontological, and taphonomic studies typically reveal taxon-specific patterns, focusing primarily on small rodents. In order to overcome this problem, we studied an assemblage of vertebrate bones from barn owl pellets in the central Monte Desert of Argentina. Our analysis included the full range of prey taxa, including rodents, marsupials, birds, and reptiles, addressed from both an ecological and neo-taphonomic perspective. We compare the taxonomic and taphonomic findings with those from regional small vertebrate records obtained from various sampling types over the past 50 years to explore recent environmental changes within the Anthropocene. The assemblage of small vertebrate prey presented here comprises five species of cricetids, one species from the Caviidae family, and at least one ctenomyid rodent species. Additionally, the assemblage includes one species of didelphid marsupial, one reptile species, and at least six passeriform bird species that belong to separate families. The overall taphonomic trends are consistent with the typical barn owl pattern. However, our analysis identified a larger percentage of postcranial elements exhibiting signs of digestion compared to pellet-derived vertebrate bone assemblages previously documented. Furthermore, it is important to note that a significant proportion of avian bone fragments exhibit distinct signs of digestion.