Exploration is dependent on reproductive state, not social state, in a cooperatively breeding bird

Personality is an intriguing phenomenon in populations because it constrains behavioural flexibility. One theory suggests that personality could be generated and maintained if dependent on asset protection. It is predicted that trade–offs with fitness expectations and survival probability encourage consistent behavioural differences among individuals (personality). Although not mutually exclusive, the social niche specialisation hypothesis suggests that a group of individuals that repeatedly interact will develop personality to avoid costly social conflict. The point at which behavioural consistency originates in the social niche hypothesis is still unclear, with predictions for development after a change in social status. In the facultative cooperatively breeding Seychelles warbler (Acrocephalus sechellensis), residing on Cousin Island, breeding vacancies are limited and this forces individuals into different social roles. We used this system to test whether reproductive and social state predicted among–individual differences in exploration. We had two predictions. Firstly, that an individual’s start in life can predict personality, whereby young, and/or dominant individuals with a good start to life (associated with early age reproduction and earlier onset survival senescence) are fast explorers, suggesting reproductive state–dependence. Secondly, that an individual’s social status can predict personality, whereby dominant individuals will be fast explorers suggesting that the behaviour is social state–dependent. Neither of the behaviours were associated with social state and social state did not affect behavioural consistency. However, novel object exploration was associated with a proxy of reproductive state. Our results provide further support for state being a mechanism for generating individual differences in behaviour.