Recent research indicates that the relationship between humans and extinct megafauna in South America may be more complex than previously thought. The study led by Prates and his team suggests that humans coexisted with these large animals for less than 3,000 years, over 10,000 years ago. This brief overlap significantly lowers the chances of preserving archaeological evidence from that time period. Many excavation sites reveal a mix of Pleistocene and Holocene layers, which could distort findings by showing a preference for smaller prey that survived the Ice Age.
The researchers concentrated on 20 specific sites where timelines were clearer, allowing them to better assess human activities prior to 11,600 years ago, when megafauna were still potentially part of the human diet. While some studies have sought to absolve humans of significant blame for the extinction of these large animals, Prates and his colleagues’ findings provide a contrasting perspective.
“Our results,” the researchers assert, “put human foragers again at the heart of the debate.”
Pleistocene hunters and their dietary strategies
The “prey choice model” serves as a framework for understanding how hunter-gatherers determined their hunting targets. It posits that megafauna are ideal prey due to the high caloric return relative to the effort involved in hunting them. Animals such as giant sloths, giant armadillos, and extinct American horses consistently rank high in this model.
Pleistocene hunters demonstrated intelligence comparable to modern humans and possessed a deep understanding of their environments, likely employing their own versions of the prey choice model. This leads to the hypothesis that they may have favored bulk hunting of larger game.
Interestingly, today’s megafauna like guanaco, taruca, and vicuña score lower on the prey-choice scale when compared with their extinct counterparts. Although hunting a taruca could sustain a group of hunter-gatherers, it is far less efficient than pursuing giant sloths. This shift in hunting choices likely occurred as the more desirable prey became scarce. The current conservation efforts might also elucidate why these remaining species are still extant today.
Science Advances, 2025. DOI: 10.1126/sciadv.adx2615 10.1126/sciadv.adx2615; (About DOIs).
