1. Center for Conservation Biology; Department of Biology; Stanford University; Stanford; CA; 94305; USA
2. Department of Environmental Science, Policy, and Management; University of California; Berkeley; CA; 94720; USA
3. Unión de Ornitólogos de Costa Rica; Apartado 182-4200; Naranjo de Alajuela; Costa Rica
4. National Center for Ecological Analysis and Synthesis; University of California; Santa Barbara; CA; 93101; USA