1. Centre de recherche de la Tour du Valat; Le Sambuc 13200 Arles France
2. Department of Ecology, Environment and Plant Sciences; Stockholm University; Lilla Frescati SE-10691 Stockholm Sweden
3. Centre d'Ecologie Fonctionnelle et Evolutive, CEFE-CNRS UMR 5175; 1919 roue de Mende 34293 Montpellier Cedex 5 France
4. Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, Department of Biological Sciences, University of Cape Town; Rondebosch 7701 South Africa
5. Departement Chrono-Environnement; UMR UFC/CNRS 6249 USC INRA, Université de Franche-Comté; Besançon France