1. Department of Migration, Max Planck Institute of Animal Behavior, 78315 Radolfzell, Germany
2. Department of Biology, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany
3. Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, UK
4. Centre for the Advanced Study of Collective Behaviour, University of Konstanz, 78457 Konstanz, Germany
5. Extreme Environments Research Group, University of Portsmouth, Spinnaker Building, Cambridge Road, Portsmouth PO1 2EF, UK
6. Hatherly Laboratories, University of Exeter, College of Life and Environmental Sciences, Exeter EX4 4PS, UK