Intersexual differences in the exploratory behaviour of blue tits (Cyanistes caeruleus)

Breeding performance and survival are mechanisms through which animal personality affects fitness. Exploration behaviour (EB) is an easily obtainable personality trait that correlates to multiple life-history traits, thus it has been widely used in animal personality studies. Through in situ Novel Environment exploration tests, we assessed the exploration behaviour of blue tits (Cyanistes caeruleus) during two breeding seasons. A principal component analysis revealed two behavioural axes regarding the exploration behaviour: slow-fast and timid-daring. We found that male blue tits are significantly slower explorers than female blue tits, suggesting that evolutionary processes act unequally across sexes in our study area. To investigate these processes, we assessed the relationship between exploration behaviour and two fitness aspects: reproduction and survival. Slower-exploring males bred in nests with significantly shorter incubation periods, and timid males had higher local return ratios. Interactions between male and female EB revealed that disassortative pairs were more successful breeders than assortative ones. Further research should explore potential evolutionary implications of intersexual EB differences.

Automated summary

Breeding performance and survival are influenced by animal personality, specifically exploration behavior. In this study, we examined the exploration behavior of blue tits and found sex differences, with males being slower explorers. Slower-exploring males had shorter incubation periods and timid males had higher local return ratios, suggesting the importance of exploration behavior in reproductive success. Additionally, disassortative pairs had higher breeding success than assortative pairs. Further research is needed to explore the evolutionary implications of intersexual exploration behavior differences.