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Highlights • We examined equine social learning in a detour task with the group leader as the demonstrator. • We refined previous studies by using non observer and social facilitation controls. • Our results show a significant role of social facilitation unrelated to learning. • We found no evidence for higher level learning processes. • Simple mechanisms could account for much complex social behaviour in horses. Abstract Learning through the observation of others allows the transfer of information without the costs incurred during individual trial and error learning. Horses (Equus caballus) are a highly social species, which might be expected to be capable of learning from others, but experimental findings are inconsistent, and potentially confounded by social facilitation effects not related directly to the learning of the task. We refined the methods used in previous equine social learning studies, to examine and distinguish specific social influences on learning of a task: we used predefined group leaders rather than agonistically dominant individuals to demonstrate a detour task to familiar conspecific observers; in addition we had two control groups: a non-observer (true control) and a group with the demonstrator simply present at the goal (social facilitation control). 44 socially kept horses were allocated to one of the three test conditions and took part in five trials each. Success rate, latency and detour direction were recorded. There was no significant difference between the three groups in the likelihood of them succeeding in the task nor latency to succeed; however there was a significant difference in the route chosen by the groups, with the true control choosing the side with the entrance gate significantly more than either the observer group or social facilitation group. Both of the latter two groups chose to go in the same direction relative to themselves, regardless of which side the gate was. Seven out of nine horses in the observer group chose the same direction as their demonstrator every time. Our results show a significant role of social facilitation on detour behaviour and highlight the importance of including adequate controls for simpler cognitive influences on behaviour before claims can be made about the specific learning of motor actions or goal directed behaviour. Social cues may be important to horses if the task is sufficiently challenging and motivationally important, so future work should consider more demanding, but ecologically relevant situations, in order to maximise the potential revelation of social learning effects which do not depend on simple local or stimulus enhancement effects. [ABSTRACT FROM AUTHOR]

Hens in a group usually synchronize dustbathing, such that when one hen starts to dustbathe she will often be joined by others. The sight of another hen dustbathing could thus possibly act as a stimulus increasing motivation for dustbathing, with important implications for hens in furnished cages, where the size of the dustbath normally allows only one hen to dustbathe at a time. If a hen is more motivated to dustbathe when she can see another hen dustbathing but she cannot get access to the litter since the dustbath is occupied, frustration may arise. The aim of this study was to investigate the effect of social stimuli on dustbathing motivation. Pairs of hens were exposed to one of three stimuli while being thwarted of dustbathing and they were thereafter given access to dustbathing material. The stimuli were (1) the sight of other hens dustbathing (DB-HEN), (2) the sight of a dustbath with other hens not dustbathing (NODB-HEN) and (3) the sight of a dustbath only (NO-HEN). Twelve pairs of hens were tested both deprived and non-deprived of litter in a balanced within-subject design. Irrespective of deprivation state, hens walked more and spent more time facing the stimulus in DB-HEN than in NO-HEN, and when they were not deprived they also walked more in DB-HEN than in NODB-HEN. Subsequent dustbathing behaviour when hens were given access to litter after the stimulus exposure was unaffected by the type of stimuli. We suggested that subtle effects of social stimuli on dustbathing motivation may have been masked by the effect of long litter deprivation and that it may be important for the birds to be able to join the stimulus birds to dustbathe together. For these reasons we repeated the experiment with individual hens and with a shorter litter deprivation time and a shorter stimulus exposure, after which the test hen was allowed to join the stimulus hen. Furthermore, in this second experiment hens were tested only in DB-HEN and NODB-HEN treatments. We found more displacement preening and less time facing the stimulus in DB-HEN than in NODB-HEN, but dustbathing behaviour was still unaffected by previous social stimuli. In summary, dustbathing behaviour of the test hens was not affected by seeing other hens dustbathing, but increased walking and displacement preening indicated a possible change in the motivation of test hens observing other dustbathing hens. [Copyright &y& Elsevier]