Absence of the pace-of-life syndrome in a territorial passerine, <i>Acrocephalus sechellensis</i>

The pace-of-life syndrome (POLS) hypothesis posits that consistent between-individual variation in behavioural traits (‘animal personalities’) facilitate trade-offs in life history. Individuals who display risk averse behaviours are expected to follow a ‘slow’ pace-of-life, including short lifespan and delayed reproduction, compared to their risk-taking, ‘fast’, counterparts. Despite a breadth of empirical research testing the POLS hypothesis, findings are equivocal. This is likely due to core assumptions of the POLS hypothesis not being met, including clear trade-offs in life history, resource limited conditions, and evidence for a functional role of the behavioural trait being investigated. Here, we use long-term data from a closed island population of individually-marked Seychelles warblers to determine the relationship between repeatable exploration–avoidance personalities and an individual’s age at first breeding, lifespan and lifetime reproductive success, separately in males and females. In this population, there is a clear trade-off in reproduction and survival: individuals with a higher age at first breeding display delayed survival senescence. Further, high intraspecific competition for breeding vacancies, as well as a functional role of exploratory traits in accessing these vacancies, also exist. Using multivariate models, we found no evidence for covariation between exploratory and life history traits in either sex. We thus found no support for the POLS hypothesis, despite accounting for core components that may have masked the prevalence of POLS. Our results demonstrate that whilst particular behavioural traits may play functional roles in certain aspects of life history, they may not necessarily be influential enough to have overarching effects on an individual’s pace-of-life