1. Department for Sociobiology/Anthropology, Institute for Zoology & Anthropology, University of GöttingenBerliner Strasse 28, D-37073 Götingen, Germany
2. Ludwig-Boltzmann-Institute for Urban EthologyAlthanstrasse 14, A-1090 Vienna, Austria
3. Department for Anthropology, University of ViennaAlthanstrasse 14, A-1090 Vienna, Austria
4. Department of Psychology, University of Central LancashirePreston PR1 2HE, UK