The cognitive capacity hypothesis was not supported as no correlation was found between song complexity and task performance, suggesting that cognitive abilities and song performance in these birds might not be related.

Unlike controlled lab environments, testing in the wild presents unique challenges and reflects natural conditions more accurately. This study highlights the importance of problem-solving and inhibitory control in natural settings and contributes to the ongoing debate about the relationship between cognition and song complexity in songbirds.

Overall, these findings contribute to a better understanding of the ecology and behavior of pied flycatchers in the wild. They highlight the complex interplay between environmental factors, body condition, song complexity, and mate choice. This study underscores the importance of considering multiple traits and environmental influences when evaluating the honesty of sexual signals in birds.

Future research should continue to investigate cognitive tasks in wild settings, incorporate multiple trials, and use varied measures of song complexity to deepen our understanding of avian cognition and behaviour.