1. Animal Ecology Research Group Utrecht University Utrecht The Netherlands
2. Centre for Research & Conservation (CRC) Royal Zoological Society of Antwerp (RZSA) Antwerp Belgium
3. Association de la Protection de Grands Singes (APGS) Yaoundé Cameroon
4. Department of Forestry Dschang University Dschang Cameroon
5. Ethology Research Biomedical Primate Research Centre Rijswijk The Netherlands
6. Terrestrial Ecology Unit Ghent University Ghent Belgium