The well-behaved killer: Late Pleistocene humans in Eurasia were significantly associated with living megafauna only

The end of the Pleistocene was characterized by an intense, highly selective extinction event, affecting large bodied terrestrial mammals worldwide. This period coincides with two major events, the last glacial period, and the dispersal of technologically advanced Homo sapiens outside the Old World. Upper Paleolithic hunters were armed with advanced, projectile weapons, and were able to dispatch prey as large as mammoths. As human population size was rapidly expanding, and hence means meat consumption rate was also growing, Paleolithic hunters are often held responsible for the extinction of mammalian megafauna. Yet, whether human focused on megafauna as prey, and drove them to extinction, remains uncertain. Here we model spatial and temporal patterns in habitat suitability for 24 megafauna species and Homo sapiens in Eurasia. We find that within land patches most suitable for humans, the identity of the most abundant herbivorous mammals switched from warm adapted species (such as the wild boar) to cold adapted species (reindeer) as climate switched from mild to cold conditions. Importantly, extinct herbivorous megafauna species were consistently rare within habitat patches optimal for humans. This suggests that humans may have settled under relatively constant climatic conditions, and possibly behaved as efficient predators, exploiting their prey in a cost-effective manner. These results are in accordance with evidence coming from the archaeological record, where medium sized living herbivore species are overrepresented in comparison of their natural abundance. For Late Pleistocene megafauna in Eurasia, human hunting may have been just an additional, non-decisive extinction factor.