1. Nicholas School of the Environment Duke University PO Box 90328 Durham NC 27708 USA
2. Agence Nationale des Parcs Nationaux Batterie IV Libreville BP 20379 Gabon
3. Institut de Recherche en Ecologie Tropicale Libreville BP 1354 Gabon
4. African Forest Ecology Group School of Natural Sciences University of Stirling Stirling UK