Abstract: Early developmental environment can have profound effects on individual physiology, behaviour, and learning. In birds and mammals, social isolation during development is known to negatively affect learning ability; yet in other taxa, like reptiles, the effect of social isolation during development on learning ability is unknown. We investigated how social environment affects learning ability in the family-living tree skink (Egernia striolata). We hypothesized that early social environment shapes cognitive development in skinks and predicted that skinks raised in social isolation would have reduced learning ability compared to skinks raised socially. Offspring were separated at birth into two rearing treatments: (1) raised alone or (2) in a pair. After 1 year, we quantified spatial learning ability of skinks in these rearing treatments (N = 14 solitary, 14 social). We found no effect of rearing treatment on learning ability. The number of skinks to successfully learn the task, the number of trials taken to learn the task, the latency to perform the task, and the number of errors in each trial did not differ between isolated and socially reared skinks. Our results were unexpected, yet the facultative nature of this species' social system may result in a reduced effect of social isolation on behaviour when compared to species with obligate sociality. Overall, our findings do not provide evidence that social environment affects development of spatial learning ability in this family-living lizard.

Abstract: Previous empirical work on animal social learning has found that many species lack the ability to learn entire action sequences solely through reliance on social information. Conversely, acquiring action sequences through asocial learning can be difficult due to the large number of potential sequences arising from even a small number of base actions. In spite of this, several studies report that some primates use action sequences in the wild. We investigate how social information can be integrated with asocial learning to facilitate the learning of action sequences. We formalize this problem by examining how learners using temporal difference learning, a widely applicable model of reinforcement learning, can combine social cues with their own experiences to acquire action sequences. The learning problem is modeled as a Markov decision process. The learning of nettle processing by mountain gorillas serves as a focal example. Through simulations, we find that the social facilitation of component actions can combine with individual learning to facilitate the acquisition of action sequences. Our analysis illustrates that how even simple forms of social learning, combined with asocial learning, generate substantially faster learning of action sequences compared to asocial processes alone, and that the benefits of social information increase with the length of the action sequence and the number of base actions.

Abstract: The domestication process leads to a change in behavioural traits, usually towards individuals that are less attentive to changes in their environment and less aggressive. Empirical evidence for a difference in cognitive performance, however, is scarce. Recently, a functional linkage between an individual's behaviour and cognitive performance has been proposed in the framework of animal personalities via a shared risk-reward trade-off. Following this assumption, bolder and more aggressive animals (usually the wild form) should learn faster. Differences in behaviour may arise during ontogeny due to individual experiences or represent adaptations that occurred over the course of evolution. Both might singly or taken together account for differences in cognitive performance between wild and domestic lineages. To test for such possible linkages, we compared wild cavies and domestic guinea pigs, both kept in a university stock for more than 30 years under highly comparable conditions. Animals were tested in three behavioural tests as well as for initial and reversal learning performance. Guinea pigs were less bold and aggressive than their wild congeners, but learnt an association faster. Additionally, the personality structure was altered during the domestication process. The most likely explanation for these findings is that a shift in behavioural traits and their connectivity led to an altered cognitive performance. A functional linkage between behavioural and cognitive traits seems to exist in the proposed way only under natural selection, but not in animals that have been selected artificially over centuries.

Abstract: Keas, a species of parrots from New Zealand, are an interesting species for comparative studies of problem solving and cognition because they are known not only for efficient capacities for object manipulation but also for explorative and playful behaviors. To what extent are they efficient or explorative, and what cognitive abilities do they use? We examined how keas would solve several versions of artificial-fruit box problems having multiple locks. After training keas to remove a metal rod from over a Plexiglas lid that had to be opened, we exposed the birds to a variety of tasks having two or more locks. We also introduced a preview phase during which the keas had extended opportunity to look at the tasks before the experimenter allowed the birds to solve them, to examine whether the preview phase would facilitate the birds' performance on the tasks. In a large number of tests, the keas showed a strong trend to solve the tasks with no positive effect of previewing the tasks. When the tasks became complex, however, the keas corrected inappropriate responses more quickly when they had had chance to preview the problems than when they had not. The results suggest that the keas primarily used explorative strategies in solving the lock problems but might have obtained some information about the tasks before starting to solve them. This may reflect a good compromise of keas' trial-and-error tendency and their good cognitive ability that result from a selection pressure they have faced in their natural habitat.

Abstract: This field study tested the hypothesis that domestic horses living under putatively challenging-to-welfare conditions (for example involving social, spatial, feeding constraints) would present signs of poor welfare and co-occurring pessimistic judgement biases. Our subjects were 34 horses who had been housed for over 3 years in either restricted riding school situations (e.g. kept in single boxes, with limited roughage, ridden by inexperienced riders; N = 25) or under more naturalistic conditions (e.g. access to free-range, kept in stable social groups, leisure riding; N = 9). The horses' welfare was assessed by recording health-related, behavioural and postural indicators. Additionally, after learning a location task to discriminate a bucket containing either edible food ('positive' location) or unpalatable food ('negative' location), the horses were presented with a bucket located near the positive position, near the negative position and halfway between the positive and negative positions to assess their judgement biases. The riding school horses displayed the highest levels of behavioural and health-related problems and a pessimistic judgment bias, whereas the horses living under more naturalistic conditions displayed indications of good welfare and an optimistic bias. Moreover, pessimistic bias data strongly correlated with poor welfare data. This suggests that a lowered mood impacts a non-human species' perception of its environment and highlights cognitive biases as an appropriate tool to assess the impact of chronic living conditions on horse welfare.