Non-human primates using stones in nature provide a rare opportunity to compare directly the behaviour of use with the resulting lithic artifacts. Wild Japanese macaques (Macaca fuscata) customarily do "stone handling" (SH = spontaneous, solitary, non-instrumental and seemingly playful manipulation of stones). Ten populations of monkeys show at least 48 behavioral variants, 13 of which entail repeated stone-on-stone or stone-on-substrate contact that is likely to yield recognizable wear patterns. We collected 10 assemblages of stones after seeing them being used, as well as "control" stones from a nearby hillside. In the first experiment, human subjects of varying degrees of knowledge of SH were asked to separate handled versus non-handled stones. Overall they were unable to do so, but the best-informed subjects were more accurate than the totally naïve ones. In the second experiment, another set of totally naïve subjects was tutored on key points derived from the first experiment. They scored significantly higher, showing that monkey artifacts are distinguishable and that discrimination can be easily taught. Nonhuman as well as human primates have lithic technology, which means that they too have an archaeological record. This complicates prehistory, at least in places in Africa where apes and hominins likely co-existed from the late Miocene onwards. Distinguishing between the hominin "pre-Oldowan" and its ape counterpart industries is a challenge only recently recognized in archaeology. Primate archaeologists tackling these issues in extant species have available not only the standard theory and methods of archaeology but also the behaviour of the makers and users of artifacts. But are non-human primate lithics discernable in the absence of their observed use? If so, then (in principle at least) we may infer multiple archaeological records, even if they coincide in space and time. If not, then our predicament may be compounded, not improved, by the advent of primate archaeology. The aim of the study reported here is simple: to see if stones used by monkeys can be detected, when the only evidence available is the stones themselves. © W. S. Maney &amp
Son Ltd 2014.