1 Kumamoto Sanctuary, Wildlife Research Center, Kyoto University, Kumamoto, Japan; Primate Research Institute, Kyoto University, Inuyama, Japan. Electronic address: [email protected].
2 Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany. Electronic address: [email protected].
3 Kumamoto Sanctuary, Wildlife Research Center, Kyoto University, Kumamoto, Japan.
4 Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; School of Psychology and Neuroscience, University of St. Andrews, St. Andrews, UK.
5 Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Department of Psychology and Neuroscience, Duke University, Durham, NC, USA.