1. Juan I. Areta, Laboratorio de Ecología, Comportamiento y Sonidos Naturales (ECOSON), Instituto de Bio y Geociencias del Noroeste Argentino (IBIGEO-CONICET), Salta, Argentina, e-mail: .
2. Matthew R. Halley, Delaware Museum of Nature & Science, Wilmington, DE, USA, e-mail: .
3. Guy M. Kirwan, Bird Group, Natural History Museum, Akeman Street, Tring, Herts. HP23 6AP, UK; Research Associate, Field Museum of Natural History, 1400 South Lakeshore Drive, Chicago, IL 60605, USA; and Setor de Ornitologia, Departamento de Vertebrad
4. Heraldo V. Norambuena, Centro Bahía Lomas, Facultad de Ciencias, Universidad Santo Tomás, Chile; and Red de Observadores de Aves y Vida Silvestre de Chile ROC, Santiago, Chile.
5. Niels K. Krabbe, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark.
6. Vítor Q. Piacentini, Departamento de Biologia e Zoologia & Programa de Pós-graduação em Zoologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Cuiabá, Brazil.