Age specific reproduction in female pied flycatcher: evidence for asynchronous aging

Age-related variation in demographic performance is central for the understanding of population dynamics and evolutionary processes. Our understanding of age-trajectories in vital rates has long been limited by the lack of distinction between patterns occurring at the population and the individual levels, and by the lack of comparative studies of age trajectories among traits. Thus, we poorly know how sets of demographic traits change within individuals according to the age. Based on a 40 years monitoring, we investigated age-related variation in five reproductive traits in females pied flycatcher. We disentangled within from between individual processes and assessed the relative contribution of within-individual age-related changes and selective appearance and disappearance. Finally, we compared the aging pattern among these five reproductive traits. We found strong evidence for age-specific performance including both early-life improvement and late-life decline in four of the five rep...