1. Instituto Superior de Psicologia Aplicada, Unidade de Investigação em Eco-Etologia, Integrative Behavioural Biology Group, Rua Jardim do Tabaco 34, 1149-041 Lisboa, Portugal
2. Institut de Biologie, Université de Neuchâtel, Emile-Argand 11, Case Postale 158, 2009 Neuchâtel, Switzerland
3. Department of Biology and Evolution, University of Ferrara, Via Luigi Borsari 46, 44100 Ferrara, Italy
4. Max-Planck-Institut für Ornithologie, 82319 Seewiesen and 78315 Radolfzell, Germany
5. Champalimaud Neuroscience Programme, Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal