A team of scientists from the University of Sussex (United Kingdom) states that horses show some facial expressions similar to humans and also those of chimpanzees, including gestures with the nose, lips or eyes to alter their gestures in different social situations. The study has been published in the journal PloS One .
“ Horses are predominantly visual animals , their vision is better than that of domestic cats and dogs, yet their use of facial expressions has been largely overlooked. We were surprised by the rich repertoire of complex facial movements that they have and that many of them are similar to humans, ”says Jennifer Wathan, co-author of the study.
The experts devised a target coding system dubbed Equine Facial Action Coding (EquiFACS) that identifies different individual facial expressions based on muscle movement. Thus, they have identified up to 17 facial movements by analyzing video images of a wide range of natural horse behaviors as well as an anatomical examination of the facial muscles that support each of these movements.
These identified facial movements were compared with 27 movements in humans, 13 in chimpanzees, and 16 in dogs. The results suggest an evolutionary parallel in different animal species regarding how the face is used for communication. “What we are going to study now is how these expressions are linked to emotional states,” concludes Wathan.
“In addition to improving our understanding of social cognition and comparative psychology, ultimately, the findings should provide important information for veterinary and animal welfare clinics, ” the authors say.
