1. National Center for Ecological Analysis and Synthesis, 735 State Street, Suite 300, Santa Barbara, CA 93101, USA.
2. Department of Ecology, Evolution, and Behavior, University of Minnesota, Saint Paul, MN 55108, USA.
3. Smithsonian Tropical Research Institute, Post Office Box 0843-03092, Balboa Ancón, Republic of Panamá.
4. Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90024, USA.