Horse Lab

Heterospecific referential communication in horses

A project led by Rachele Malavasi, SEE - School of Ethical Equitation, Moncigoli di Fivizzano, MS ITALY, in cooperation with Ludwig Huber, Messerli Research Institute

 

Several studies provide evidence for the existence of advanced cognitive abilities in horses, such as categoriztion, cross-modal individual recognition, social learning and numerical discrimination. In this project we tested if domestic horses (Equus caballus) act like active informers and are able to recognize recipients as communicative agents. Referential communication occurs when a sender elaborates its gestures to direct the attention of a recipient to its role in pursuit of the desired goal, e.g. by pointing or showing an object, thereby informing the recipient what it wants. If the gesture is successful, the sender and the recipient focus their attention simultaneously on a third entity, the target. Here we investigated the ability of horses to communicate referentially with a human observer about the location of a desired target, a bucket of food out of reach.

Left: The horse is looking back in the direction of the experimenter. Right: Horses use attention-getting behaviours (head nodding, tail swishing, pointing) to catch the attention of the observer.
 

Indeed, we found that the horses tried to influence the behaviour of a human experimenter using their eyes, providing evidence they understand that intentions can be communicated between individuals using gaze. They also activated mechanisms promoting shared attention depending on that individuals attentional state. Actually, they used both indicative (pointing) and nonindicative (nods and shakes) head gestures in the relevant test conditions. Horses also elaborated their communication by switching from a visual to a tactile signal and demonstrated perseverance in their communication. These are the first such findings in an ungulate species.

We therefore suggest adding horses to the species capable of flexible and
intentional use of communicative signals, along with several primate species, dogs, corvids, dolphins and reef fish. It remains an open question whether intentional communication and referential signalling require advanced cognitive processes like perspective taking and strategic thinking. After dogs, horses would be the second domesticated species for which this ability to communicate with humans has been shown. Further research is required to understand whether this ability occurs only in horses living with humans.
Anyhow, these findings provide strong reasons to revise the view of horses as simply good executors and prompt us to enforce proper ethical management of horses in domestic settings.

Publication

Malavasi, R. & Huber, L. (2016). Evidence of heterospecific referential communication from domestic horses (Equus caballus) to humans. Animal Cognition, 1-11. doi:10.1007/s10071-016-0987-0