Mobility, competition, and Plio-Pleistocene hominid foraging groups

Evidence for carcass access times and levels of early hominid mobility is synthesized using studies of carnivore ethology and theories of interspecific competition to arrive at tentative conclusions about the organization of Plio-Pleistocene hominid foraging groups. The model presented suggests that group foraging tactics, in combination with high mobility, are central to successful confrontational scavenging (interference competition), whereas individual foraging tactics and high mobility are central to successful nonconfrontational scavenging (exploitative competition). In contrast, group or individual foraging tactics and low mobility characterize the acquisition of fresh carcasses in low-competition contexts. Individual foraging tactics and low mobility are employed in response to extreme competition over marginal resources. Preliminary tests with data from Bed I Olduvai Gorge and Koobi Fora suggest that Plio-Pleistocene hominids, like other large-bodied predators, employed flexible foraging tactics involving changes in group size and levels of mobility to gain access to carcasses in both low-and high-competition contexts.