Przewalski’s horses and domestic horses probably experience the same emotions, but might have developed different priorities and, hence, ways of communicating them. | Photo: iStock

We imagine “cave men” grunting and squealing to communicate—a far cry from our modern languages. So what about “cave horses”? Those plains-roaming ancient equids depicted in cave paintings might have whinnied and nickered differently from our domestic steeds.

While we will probably never know what those prehistoric horses sounded like, we can listen to Przewalski’s horses—long believed to be the last remaining truly wild horses. And that’s exactly what a group of Swiss scientists did in hopes of helping researchers develop noninvasive tools to assess these endangered equids’ emotional state and welfare.

In a recent study, they recorded and analyzed Przewalski’s horse calls to find out how they express emotions. Then, they compared those findings to similar research conducted with domestic horses and found remarkable similarities as well as differences