1. Department of Ecology and Genetics; Evolutionary Biology Centre, Uppsala University; Uppsala Sweden
2. Primatology Department; Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6; Leipzig Germany
3. Dian Fossey Gorilla Fund International, 800 Cherokee Avenue; Atlanta Georgia
4. Institut Congolais pour la Conservation de la Nature, N4; Réserve de Faune à Okapis Democratic Republic of Congo
5. Department of Anthropology; University of California, Davis, One Shields Ave; Davis California