![\"\"](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/10\/02114211\/SEI_224020234.jpg\")
<\/div>Bottlenose dolphins make an open-mouthed expression that resembles a smile<\/p>\n
ZOOMARINE, ITALY<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
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.<\/p>\n
While we often perceive these as a smile, there has been little research on facial communication in dolphins.<\/p>\n
To find out more, Elisabetta Palagi<\/a> at the University of Pisa, Italy, and her colleagues analysed the behaviour of 22 captive bottlenose dolphins (Tursiops truncatus<\/em>) at two wildlife parks: Zoomarine Rome in Italy and Plan\u00e8te Sauvage in Port-Saint-P\u00e8re, France.<\/p>\n 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.<\/p>\n The animals were more likely to assume the open-mouth expression when their face was within the playmate\u2019s field of view \u2014 89 per cent were displayed in this context. When the playmate saw the \u201csmile\u201d, they appeared to smile back 33 per cent of the time.<\/p>\n <\/p>\n \u201cSome might argue that dolphins mimic others\u2019 open-mouth expressions by pure chance, given that they are often engaged in the same activity or context,\u201d says Palagi. \u201cBut this doesn\u2019t explain why the probability of imitating another dolphin\u2019s open-mouth expression within 1 second is 13 times higher when the receiver actually sees the original expression.\u201d<\/p>\n Some other animals, including monkeys, wolves and meerkats, make a \u201cplay face\u201d with a relaxed open mouth, but there is debate about whether this is driven by emotions or a way to communicate intention.<\/p>\n \u201cIt is not easy to say if an open-mouth expression in dolphins conveys an emotional mood or is used to simply communicate to others, \u2018Hey, don\u2019t be scared, I am just playing!\u2019, or both,\u201d says Palagi.<\/p>\n She says the study can\u2019t say conclusively whether it is comparable with smiling in humans. \u201cWe do not claim to clarify dolphin communication strategies during play with a single piece of research. However, we hope to open a new line of research in which the visual component is also taken into consideration.\u201d<\/p>\n