| Summary: | Social interactions influence how individuals handle environmental challenges. Jackdaws (Corvus monedula) are gregarious corvids that vary in how they respond to environmental challenges, but the reason for this variation is not understood. In other avian species, individual variation relates to social network structure, dominance hierarchies, and pairbonding. Jackdaw group structure is hierarchical, containing both long-term and transient relationships, and fitness is linked to social interactions. Group dynamics are therefore expected to play a role in individual variation in response to environmental challenges. I studied two groups of captive jackdaws from fledging until their second breeding season. I quantified the* ontogeny of social network structure, dominance relations, and active affiliative relationships. I found evidence that individuals maintain affiliative relationships outside of the pairbond. I assessed individual variation in a naturally occurring challenge, parasites, through the presence of faecal parasite eggs and oocysts over eight months. More aggressive, dominant individuals had higher parasite burdens, suggesting that dominance is a social stressor in the species. I further assessed how individuals responded to the challenge of novel resources. I firstly measured wariness of novelty, neophobia, in a group setting by presenting novel objects alongside food. Dominant birds were less neophobic than lower ranking group members. I then examined neophobia, exploration, and problem solving by presenting a novel foraging apparatus. Dominant birds were less neophobic and more exploratory. More central group members were less neophobic and habituated faster to the apparatus, perhaps due to increased access to social information. In this thesis, I show that social interactions are related to health in jackdaws. I also show that individuals vary by network position in how they take advantage of changes in their environment. My thesis shows that understanding group structure is crucial for understanding both variation in behaviour and the fitness implications of such variation.
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