1. Sea Mammal Research Unit, Gatty Marine Laboratory, University of St. Andrews, St. Andrews, Scotland, United Kingdom
2. National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Silver Spring, Maryland, USA
3. Department of Animal Biology and GRUMM, Parc Cientific de Barcelona, University of Barcelona, Barcelona, Spain
4. Chicago Zoological Society, Mote Marine Laboratory, Sarasota, Florida, USA
5. Alterra–Marine and Coastal Zone Research, Den Burg, the Netherlands