1. Projet Grands Singes (PGS), Cameroon Centre for Research and Conservation (CRC) Royal Zoological Society of Antwerp (RZSA) Antwerpen Belgium
2. Terrestrial Ecology Unit (TEREC) Department of Biology Ghent University (UGent) Ghent Belgium
3. Department of Forestry Faculty of Agronomy and Agricultural Sciences (FASA) University of Dschang Dschang Cameroon