1. Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
2. ARC Centre of Excellence in Plant Energy Biology, MCS Building M310, The University of Western Australia 6009, Crawley, Australia
3. Centre for Evolutionary Biology, School of Animal Biology (MO92), The University of Western Australia 6009, Crawley, Australia
4. Behavioural and Evolutionary Ecology, Université Libre de Bruxelles, Avenue F. D. Roosevelt 50, 1050 Brussels, Belgium