1. Behavioural and Physiological Ecology; Groningen Institute for Evolutionary Life Sciences; University of Groningen; Groningen The Netherlands
2. Behavioural Biology; Groningen Institute for Evolutionary Life Sciences; University of Groningen; Groningen The Netherlands
3. Terrestrial Ecology Unit; Department Biology; Ghent University; Ghent Belgium
4. Department of Animal Behaviour; Bielefeld University; Bielefeld Germany