1. Department of Environmental Sciences, Policy and Management, 137 Mulford Hall, University of California, Berkeley, CA 94720-3114, USA.
2. Réseau de la Biodiversité de Madagascar, Wildlife Conservation Society, Villa Ifanomezantsoa, Soavimbahoaka, Boîte Postale 8500, Antananarivo 101, Madagascar.
3. Metapopulation Research Group, Department of Biological and Environmental Sciences, Post Office Box 65, Viikinkaari 1, FI-00014, University of Helsinki, Finland.
4. AT&T Labs-Research, 180 Park Avenue, Florham Park, NJ07932, USA.
5. Department of Biology (Area 18), University of York, Post Office Box 373, York YO10 5YW, UK.