Sex differences, social context and personality in zebra finches, Taeniopygia guttata

Despite burgeoning interest in consistent individual differences in behaviour (animal ‘personality’), the influence of social interactions on the performance of different behavioural types is poorly understood. Similarly, the ecological and evolutionary consequences of personality differences in social contexts remain unexplored. Moreover, the possibility that the sexes differ in the degree to which they exhibit personality in both social and nonsocial contexts has not yet received serious attention, despite the sexes usually being subject to differing selection pressures. Using a highly gregarious species, the zebra finch, we tested for consistent behavioural differences (in exploration) between individuals of both sexes in both nonsocial and social contexts, the latter considering the behavioural influence of opposite-sex companions. We then investigated how exploratory tendencies relate to behaviour in a potentially risky foraging context in mixed-sex dyads of individuals with differing personalities. Males were not more exploratory on average but were more consistent in their exploratory tendencies than females. Additionally, males behaved more consistently across the social and asocial contexts than females, even though individuals of both sexes similarly influenced each other's exploratory behaviour within the social context: the more exploratory the companion, the more exploratory the focal individual (relative to its level of exploration in the asocial context). An individual's exploration also affected its performance in the social foraging context. Our results stress the importance of looking for sex differences in personality and of considering the influence of social context in animal personality studies. We discuss our findings and their implications in the light of the biology of the species and set them in a broader ecological and evolutionary context.