Dataset for: "Beyond mood: maternal aggression in canaries is unrelated to affective state as measured by a judgement bias test"

This dataset contains behavioural data collected from a cognitive judgement bias test (JBT) conducted with breeding female Fife Fancy canaries (Serinus canaria) at the University of Antwerp. The study investigated whether individual variation in affective state, inferred from responses to an ambiguous stimulus, predicts the probability of maternal aggression (MA) .
We tested this hypothesis in breeding female canaries (Serinus canaria) using a cognitive judgement bias test (JBT), in which latency to approach an ambiguous stimulus served as a proxy for affective valence. First, females reliably discriminated between rewarded and unrewarded stimuli. Responses to the ambiguous stimulus were more similar to the rewarded condition, indicating a population-level optimistic bias and confirming successful validation of the JBT. However, contrary to our prediction, MA and non-aggressive females did not differ significantly in their approach latency to the ambiguous stimulus, providing no evidence that MA is associated with a more pessimistic affective disposition. Our results suggest that MA in canaries is not a straightforward outcome of a pessimistic affective state and highlight the importance of distinguishing between the stable affective dispositions captured by a single JBT session and the transient emotional fluctuations that could, though not necessarily, trigger offspring-directed aggression in studies of parental behaviour.