Personality-related differences in response to habitat in Mediterranean blue tits

Habitat-specific selection pressures have been widely recognized, but whether selection favours different personality types in different habitats has rarely been evaluated. This study aimed to test whether personality-related differences in annual reproductive success differed between two populations of blue tits (Cyanistes caeruleus) occupying different Mediterranean habitats (oakwood and pinewood). We measured exploration and parental provisioning behaviours and used a path analysis to ask how the interplay between these two behavioural traits affected reproductive success in each of these two habitats. We found that blue tits breeding in the pinewood were slow-exploring compared to blue tits breeding in the oakwood, suggesting the occurrence of personality-related differences in settlement, or behavioural plasticity in response to habitat. Exploration behaviour and feeding rates were positively associated, suggesting that they affect each other or that there is an environmental factor affecting both traits simultaneously. Finally, fast explorers were favoured in the pinewood, while there was no selection acting on exploration behaviour in the oak habitat. These findings emphasize the importance of integrating habitat selection, plasticity and personality in the study of behavioural evolution.