1. Department of Primatology, Max Planck Institute for Evolutionary AnthropologyDeutscher Platz 6, 04103 Leipzig, Germany
2. Department of Integrative Biology, University of CaliforniaBerkeley, CA 94720- 3840, USA
3. Department of Anthropology, Harvard UniversityPeabody Museum 11 Divinity Avenue, Cambridge, MA 02138, USA