Abstract: Knowledge about social recognition and memory in animals can help us to determine appropriate management and husbandry techniques. In this study, we used a habituation–discrimination procedure to investigate the ability of horses (Equus caballus) to distinguish between the body odour samples of unfamiliar conspecifics. To pick up body odour, we rubbed material on the coat of horses and presented these unknown body odours to 16 different conspecifics of the same sex and similar age. The test consisted of two successive two-min presentations of a sample from one individual (e.g. individual ‘A’) and a simultaneous presentation of samples from individual ‘A’ and a novel individual (e.g. individual ‘B’) during a final third presentation. The results showed that horses, regardless of sex, decreased the time they spent investigating conspecific body odour across the initial two presentations—demonstrating habituation. In the final presentation, the results demonstrated successful discrimination of the previously experienced odour because horses investigated the novel olfactory sample (‘B’) significantly more than the pre-exposed sample (‘A’). Taken together, these findings suggest, for the first time, that horses are able to discriminate two stimuli derived from body odours of unfamiliar conspecifics over short period of time.

Abstract: Humans, great apes and old world monkeys show selective attention to faces depending on conspecificity, familiarity, and social status supporting the view that primates share similar face processing mechanisms. Although many studies have been done on face scanning strategy in monkeys and humans, the mechanisms influencing viewing preference have received little attention. To determine how face categories influence viewing preference in humans and rhesus macaques (Macaca mulatta), we performed two eye-tracking experiments using a visual preference task whereby pairs of faces from different species were presented simultaneously. The results indicated that viewing time was significantly influenced by the pairing of the face categories. Humans showed a strong bias towards an own-race face in an Asian–Caucasian condition. Rhesus macaques directed more attention towards non-human primate faces when they were paired with human faces, regardless of the species. When rhesus faces were paired with faces from Barbary macaques (Macaca sylvanus) or chimpanzees (Pan troglodytes), the novel species’ faces attracted more attention. These results indicate that monkeys’ viewing preferences, as assessed by a visual preference task, are modulated by several factors, species and dominance being the most influential.

Abstract: Social learning is taxonomically widespread and can provide distinct behavioural advantages, such as in finding food or avoiding predators more efficiently. Although extensively studied in bony fishes, no such empirical evidence exists for cartilaginous fishes. Our aim in this study was to experimentally investigate the social learning capabilities of juvenile lemon sharks, Negaprion brevirostris. We designed a novel food task, where sharks were required to enter a start zone and subsequently make physical contact with a target in order to receive a food reward. Naive sharks were then able to interact with and observe (a) pre-trained sharks, that is, ‘demonstrators’, or (b) sharks with no previous experience, that is, ‘sham demonstrators’. On completion, observer sharks were then isolated and tested individually in a similar task. During the exposure phase observers paired with ‘demonstrator’ sharks performed a greater number of task-related behaviours and made significantly more transitions from the start zone to the target, than observers paired with ‘sham demonstrators’. When tested in isolation, observers previously paired with ‘demonstrator’ sharks completed a greater number of trials and made contact with the target significantly more often than observers previously paired with ‘sham demonstrators’. Such experience also tended to result in faster overall task performance. These results indicate that juvenile lemon sharks, like numerous other animals, are capable of using socially derived information to learn about novel features in their environment. The results likely have important implications for behavioural processes, ecotourism and fisheries.

Abstract: Brain lateralization enables preferential processing of certain stimuli and more effective utilization of these stimuli in either the left or the right cerebral hemisphere. Horses show both motor and sensory lateralization patterns. Our aim was to determine whether a lateralized response could be detected in foals during the naturally side-biased behaviour, suckling. The foals’ preferred suckling side could be the effect of either visual or motor lateralization. In the case of a visual lateralized response, foals are expected to suck more often from the mother’s right side, so potential danger can be detected by the better adapted right hemisphere (i.e. left eye). Motor lateralization can be identified when a foal will suck predominantly from one side, either left or right. We found no population trend in the preferred suckling side, but we detected significant differences amongst individual foals. One-third (35.4 %) of 79 foals showed a strong, either right or left side preference which increased with age. The mothers did not influence the foals’ suckling side preferences either by side-biased rejection or termination of suckling. According to our findings, a general pattern of sucking with the left eye open for better danger detection and recognition is unlikely in foals up to 7 months old. Foals of this age are probably young or fully focused on suckling and rely on their mothers’ vigilance. Individual side preferences amongst foals are suggested to be based on motor lateralization.

Abstract: All current evidence of visual perspective taking in dogs can possibly be explained by dogs reacting to certain stimuli rather than understanding what others see. In the current study, we set up a situation in which contextual information and social cues are in conflict. A human always forbade the dog from taking a piece of food. The part of the room being illuminated was then varied, for example, either the area where the human was seated or the area where the food was located was lit. Results show that dogs steal significantly more food when it is dark compared to when it is light. While stealing forbidden food the dog’s behaviour also depends on the type of illumination in the room. Illumination around the food, but not the human, affected the dogs’ behaviour. This indicates that dogs do not take the sight of the human as a signal to avoid the food. It also cannot be explained by a low-level associative rule of avoiding illuminated food which dogs actually approach faster when they are in private. The current finding therefore raises the possibility that dogs take into account the human’s visual access to the food while making their decision to steal it.