Learning from eavesdropping on human-human encounters changes feeding location choice in horses (Equus Caballus)

When animals observe human signals, they may learn from them. Such learning from humans has been reported for intentional communication between humans with animals, but animals might also learn socially by observing unintentional information transfer when eavesdropping on humans-human encounters. In this study, 12 of 17 horses significantly changed their preference for a feeding location after observing approval in a human-human interaction there, and horses kept in social housing adapted in a higher percentage of trials to human-human demonstrations than those in individual housing. This indicates, for the first time, that some animals change their feeding strategies after eavesdropping on human-human demonstrations and that this adaptation may be dependent on social experience. As horses maintained the observed preference for a feeding location when the demonstrators were absent, we suggest that they learned by applying individual and social learning mechanisms. The horses social rank, age and sex did not affect their learning performance. However, particular demonstrators tended to have a stronger impact on the horses' performance. Future research should further investigate the durability of this preference change in the absence of repeated demonstrations, and establish whether long-term social learning sets in. This would have important implications for unintentional long-term impacts of human interactions on interspecies communication.