1. Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Bücklestraße 5a, Konstanz, 78467, Germany
2. Animal Behaviour and Cognition, Department of Biology, Utrecht University, Padualaan 8, Utrecht, CA 3584, The Netherlands
3. Department of Biology, University of Konstanz, Universitätsstraße 10, Konstanz 78464, Germany
4. Behavioral Ecology and Ecophysiology Group, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
5. Centre for Research and Conservation, Royal Zoological Society of Antwerp, K. Astridplein 26, B 2018 Antwerp, Belgium