Intrasite Spatial Analysis of Bone: Subtracting the Effect of Secondary Carnivore Consumers

Animal bones discarded by people are commonly subject to disturbance by carnivores. These carnivores are present throughout the world and include wolves, coyotes, hyenas, and many others. This disturbance not only modifies and destroys bone, but also moves many of the bone fragments away from their original position of discard. Intrasite spatial analyses of bone that seek patterns meaningful to human behavior thus need to subtract the effect of carnivore disturbance. Experimental studies with spotted hyenas show that the position of a bone fragment on a limb bone, combined with bone surface modification, can be used to identify a class of bone fragments that are minimally affected by carnivores and are thus the best indicators of spatial patterning resulting from human behavior. Limb-bone ends are moved significant distances, as are shaft fragments as a general class. However, middle-shaft portions of limb bones that preserve percussion marks from hammerstone breakage retain nearly the precise spatial position as originally discarded by hominids. Thus, any spatial analysis of bone, when carnivores are implicated as contributors or consumers at an archaeological site, should focus on middle-shaft portions of limb bones with percussion marks.