Yawning is contagious for animals as well as humans, but researchers can’t quite figure out why. Now, new research on lions suggests a potential function for the contagious yawn for at least one creature. The study, published last month in the journal Animal Behaviour, finds that after a yawn sweeps through a group of lions, the animals tend to coordinate their subsequent movements, reports Mary Bates for National Geographic.
For New Scientist, Christa Leste-Lasserre reports the results are the first to show that communal yawning can orchestrate synchronized behavior in animals.
“Lions share a lot of things, like highly organized hunts and caring for [cubs],” Elisabetta Palagi, an ethologist at the University of Pisa in Italy, tells New Scientist. “So obviously they need to synchronize movement, and they need to communicate and anticipate the actions of their companions.”
The study came about after Palagi saw videos recorded by her master’s students in South Africa. Time and time again, after a yawn ricocheted through a group of lions, she observed the animals standing up and moving in near unison just a few moments later, according to New Scientist.
Inspired to look into the phenomenon formally, Palagi directed her team to spend five months filming 19 lions from two prides living in the Makalali Game Reserve in northeastern South Africa.
After analyzing the results, the team found lions that had just seen another pride member yawn were 139 times more likely to yawn themselves within three minutes compared to lions that hadn’t seen the behavior. The big cats were also 11 times more likely to mirror the movements of the lion that initiated the bout of contagious yawning, which the researchers call the “trigger,” according to New Scientist.
“After they yawned together, if the trigger stood up, then within seconds the second lion did the same,” Palagi tells New Scientist.
Palagi tells National Geographic that the findings show a clear correlation between contagious yawning and coordinated action, which suggests the behavior may be important for lions and other highly social species that rely on each other to find food and defend the group from danger.
Andrew Gallup, a biopsychologist at the State University of New York Polytechnic Institute who was not involved in the research, tells National Geographic that the study’s findings support the notion that the synchrony that follows contagious yawning may give animals that live in groups “advantages for collective awareness and threat detection.”