1 Kumamoto Sanctuary, Wildlife Research Center, Kyoto University, Kumamoto, Japan. Electronic address: [email protected].
2 School of Psychology and Neuroscience, University of St Andrews, St Andrews, KY16 9JP, UK.
3 School of Psychology and Neuroscience, University of St Andrews, St Andrews, KY16 9JP, UK; Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA. Electronic address: [email protected].