1. Ethology Unit, Department of Biology, University of Pisa, Pisa, Italy
2. Faculty of Veterinary Medicine, University of Calgary, Calgary Alberta, Canada
3. UMR CNRS 6249 Chrono-environnement, Université Franche-Comté, Besançon, France
4. Gruppo Ornitologico Maremmano, Studi Naturalistici “A. Ademollo”, c/o Museo di Storia Naturale della Maremma, Grosseto, Italy