1. Department of Behavioral Ecology, Georg-August-Universität Göttingen, Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, Kellnerweg 6, D-37077 Göttingen, Germany
2. Research Group Primate Social Evolution, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
3. Leibniz ScienceCampus Primate Cognition, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
4. Center for Evolution and Medicine, Arizona State University, Tempe, AZ 85281, USA
5. Cognitive Ethology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
6. Department for Primate Cognition, Georg-August-Universität Göttingen, Kellnerweg 4, 37077 Göttingen, Germany