Revisiting hominin scavenging through the lens of optimal foraging theory

Scavenging has been a key topic in human evolution for decades, mainly focused on the 'hunting vs. scavenging' debate and the role of meat in the diet of early hominins. Scavenging is frequently considered a marginal activity by archaeologists; however, recent theoretical developments and experimental observations in the field of carrion ecology suggest that this is a misconception that should be addressed. Here, we analyze hominin scavenging in the framework of optimal foraging theory and compare the assumptions made in archaeology and paleoanthropology based on current ecological knowledge. We discuss the constraints and opportunities for hominins as facultative scavengers across ecological contexts, both in Africa and beyond. Hominins exhibited several anatomical, physical, and behavioral adaptations that enabled them to detect carcasses from a long distance, reach them relatively quickly, confront other scavengers, if necessary, and process the carcass to obtain food. Carrion should be considered a high-quality resource that is ubiquitous and more predictable than previously assumed. Particularly relevant is the abundant carrion from sources other than predation, especially from megaherbivores. Moreover, hominins likely benefited from carrion partitioning strategies and interspecific facilitation-especially with vultures-which have traditionally been overlooked in archaeological and paleoanthropological research. Thus, we propose that carrion was a valuable resource exploited by all hominin species and populations to varying degrees, especially during periods of food shortage in seasonal environments. We conclude that the 'hunting vs scavenging' dichotomy is no longer supported as hominins are omnivorous, exploiting animal food through hunting or scavenging depending on environmental conditions and their technological and cognitive capacities.