1. Department of Biology, University of Konstanz, Konstanz, Germany
2. Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany
3. Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
4. Department of Veterinary Sciences, AG Immunology, LMU Munich, Planegg, Germany
5. Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden