1. Division of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland;
2. Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna, Vienna, Austria
3. Department of Biology and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
4. Clodomiro Picado Institute, University of Costa Rica, San José, Costa Rica
5. Faculty of Biological Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany