1. Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
2. Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria
3. Behavioural Ecology Research Group, University of Leipzig, 04103 Leipzig, Germany
4. Department of Primatology, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
5. Arctic Centre, University of Groningen, 9718 CW Groningen, The Netherlands
6. Department of Toxicology, Wageningen University, 6700 EA Wageningen, The Netherlands