Stone anvil damage by wild bearded capuchins (Sapajus libidinosus) during pounding tool use: a field experiment.
We recorded the damage that wild bearded capuchin monkeys (Sapajus libidinosus) caused to a sandstone anvil during pounding stone tool use, in an experimental setting. The anvil was undamaged when set up at the Fazenda Boa Vista (FBV) field laboratory in Piauí, Brazil, and subsequently the monkeys indirectly created a series of pits and destroyed the anvil surface by cracking palm nuts on it. We measured the size and rate of pit formation, and recorded when adult and immature monkeys removed loose material from the anvil surface. We found that new pits were formed with approximately every 10 nuts cracked, (corresponding to an average of 38 strikes with a stone tool), and that adult males were the primary initiators of new pit positions on the anvil. Whole nuts were preferentially placed within pits for cracking, and partially-broken nuts outside the established pits. Visible anvil damage was rapid, occurring within a day of the anvil's introduction to the field laboratory. Destruction of the anvil through use has continued for three years since the experiment, resulting in both a pitted surface and a surrounding archaeological debris field that replicate features seen at natural FBV anvils.
Research Laboratory for Archaeology and the History of Art, University of Oxford, Oxford, United Kingdom.
Michael
M
Haslam
Institute of Psychology, University of São Paulo, São Paulo, Brazil.
Raphael Moura
RM
Cardoso
Istituto di Scienze e Tecnologie della Cognizione, Consiglio Nazionale delle Ricerche, Roma, Italy.
Elisabetta
E
Visalberghi
Department of Psychology, University of Georgia, Athens, Georgia, United States of America.
Dorothy
D
Fragaszy
D000818:Animals; D002428:Cebus; D053001:Tool Use Behavior