1. Vincent Bretagnolle, CEBC-CNRS, UMR 7372, CNRS & La Rochelle Université, Beauvoir sur Niort, 79360, France, e-mail: .
2. Robert L. Flood, FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, Univ. of Cape Town, Rondebosch 7701, South Africa, e-mail: .
3. Sabrina Gaba, INRAE, USC 1339 Agripop, Centre d'Etudes Biologiques de Chizé, 79360 Villiers-en-Bois, France, e-mail: .
4. Hadoram Shirihai, Naturhistorisches Museum der Burgergemeinde Bern, Bernastrasse 15, 3005, Bern, Switzerland, e-mail: