1. University of Alabama at Birmingham, Birmingham, AL 35294–6024, USA.
2. Gombe Stream Research Centre, Kigoma, Tanzania.
3. Howard Hughes Medical Institute, Birmingham, AL 35294–6024, USA.
4. University of Nottingham, Nottingham NG7 2UH, UK.
5. Harvard University, Cambridge, MA 02138, USA.
6. Centre Pasteur du Cameroun, BP 1274 Yaoundé, Cameroun.
7. Yerkes Primate Research Center, Atlanta, GA 30329, USA.
8. Primate Research Centre, Rijswijk ZH 2288 GJ, Netherlands.
9. University of Minnesota, St. Paul, MN 55108, USA.
10. Max-Planck Institute, 04301 Leipzig, Germany.
11. Jane Goodall Institute, Silver Spring, MD 20911, USA.