1. Department of Behavioural Neurobiology Max Planck Institute for Ornithology Seewiesen Germany
2. Research Group Animal Communication and Urban Ecology Max Planck Institute for Ornithology Seewiesen Germany
3. Behavioral Ecology and Sociobiology Unit German Primate Center Göttingen Germany
4. Department of Sociobiology/Anthropology University of Göttingen Göttingen Germany