Archaeological excavation of wild macaque stone tools.

More than 3 million years of excavated archaeological evidence underlies most major insights into the evolution of human behaviour. However, we have seen almost no use of archaeological excavation to similarly broaden our understanding of behaviour in other animal lineages. The few published examples include recovery of a late Holocene assemblage of stones from the Ivory Coast, attributed to the agency of both humans (Homo sapiens) and chimpanzees (Pan troglodytes verus), and exploration of the occupation sites of nontool-using species such as penguins and other birds. The development of viable methods for identifying and interpreting past non-human tool use landscapes is essential if we are to gain a better understanding of technological evolution within other animals, including our close relatives, the primates. Recently, the growth of primate archaeology has built on the close phylogenetic relationship between humans and other primates to begin filling in this lacuna. Here, we present thefirst report on an archaeologically excavated Old World monkey tool use site, which was created by wild Burmese long-tailed macaques (Macaca fascicularis aurea) during shellfish-processing activities in coastal Thailand. These macaques use stone and shell pounding tools to access a wide variety of coastal and inter-tidal resources, including shellfish, crabs and nuts, and previous work has demonstrated that use-wear on the stone tools permits reconstruction of past macaque activities (Haslam et al., 2013). Uncovering the history of this foraging behaviour opens up opportunities to study its evolution within the macaque lineage and, more broadly, to retrieve comparative data for researchers studying human and primate coastal exploitation.