Horse sense: social status of horses (Equus caballus) affects their likelihood of copying other horses’ behavior
Animals that live in stable social groups need to gather information on their own relative position in the group’s social hierarchy, either by directly threatening or challenging others, or in a less costly manner, by observing interactions among others. Such indirect inference of dominance relationships has previously been reported from primates, rats, and birds and fish. Here, we show that domestic horses, Equus caballus, are similarly capable of social cognition. Taking advantage of a specific “following behavior” that horses show towards humans in a riding arena, we investigated whether bystander horses adjust their response to an experimenter according to the observed interaction and their own dominance relationship with the horse whose reaction to the experimenter they had observed before. Horses copied the following behavior towards an experimenter after watching a dominant horse following, but did not follow after observing a subordinate horse or a horse from another social group doing so. The following behavior which horses show towards an experimenter therefore appears to be affected by the demonstrator’s behavior and social status relative to the observer.
The effects of age, rank and neophobia on social learning in horses
Social learning is said to meet the demands of complex environments in which individuals compete over resources and co-operate to share resources. Horses (Equus caballus) were thought to lack social learning skills because they feed on homogenously distributed resources with few reasons for conflict. However, the horse's social environment is complex, which raises the possibility that its capacity for social transfer of feeding behaviour has been underestimated. We conducted a social learning experiment using 30 socially kept horses of different ages. Five horses, one from each group, were chosen as demonstrators, and the remaining 25 horses were designated observers. Observers from each group were allowed to watch their group demonstrator opening a feeding apparatus. We found that young, low ranking, and more exploratory horses learned by observing older members of their own group, and the older the horse, the more slowly it appeared to learn. Social learning may be an adaptive specialisation to the social environment. Older animals may avoid the potential costs of acquiring complex and potentially disadvantageous feeding behaviours from younger group members. We argue that horses show social learning in the context of their social ecology, and that research procedures must take such contexts into account. Misconceptions about the horse's sociality may have hampered earlier studies.