Dolphin 'smiles' may truly be a sign of playfulness

Dolphins seem to make open-mouthed facial expressions most often while they are visible to a playmate, suggesting such displays may be similar to human smiles. While we often perceive these as a smile, there has been little research on facial communication in dolphins. We're finally realising that many species are To find out more, Elisabetta Palagi at the University of Pisa, Italy, and her colleagues analysed the behaviour of 22 captive bottlenose dolphins (Tursiops truncatus) at two wildlife parks: Zoomarine Rome in Italy and Planète Sauvage in Port-Saint-Père, France. In 80 hours of footage, the team observed a total of 1288 open-mouth expressions during social play sessions. More than 90 per cent of these events occurred during play between dolphins, with the rest happening during interactions between the dolphins and people.