1. CCMAR (Centro de Ciências do Mar), Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
2. Marine Behavioural Ecology Group, Department of Zoology, University of Cambridge, Downing St, Cambridge CB2 3EJ, UK
3. School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK