Experimentally Derived Extraction Rates for Marrow: Implications for Body Part Exploitation Strategies of Plio-Pleistocene Hominid Scavengers

Abstract

Through systematic butchering experiments the processing costs (in time) for limb bone marrow, head and foot contents are quantified for four different medium-sized (40–250kg) East African taxa. These data are used to determine the caloric return rates from processing skeletal elements of animals in different stages of fat depletion. Analysis of these data have three important results. First, for some taxa the feet and head are more efficiently processed than certain limb bones. Second, the exploitation of malnourished carcasses may not be reflected by the selective processing of the bones with marrow that retain fat. Finally, processing costs vary as a function of carcass size and are higher than previous estimates. Skeletal part representation of medium and larger- sized taxa from FLKZinjanthropusare reanalysed in light of these data. Results of this analysis challenge previous characterizations of early hominids as efficient and selective scavengers with access to high quality animal carcasses. These results have implications for the risk factors and predictability of scavenging opportunities encountered by early hominids.