Life history theory suggests a trade-off between costly activities such as breeding and migration and somatic self-maintenance. However, how the short-term cost of parental effort is expressed in species with a slow pace-of-life is not well understood. Also, investigating carry-over effects of migration is most meaningful when comparing migratory strategies within the same population, but this has rarely been done. We explore this hypothesis in a long-lived, pelagic seabird, the Cory’s Shearwater, Calonectris borealis, where males display partial migration. By manipulating reproductive effort and taking advantage of the natural variation in migratory strategy, we investigate whether early reproductive failure and migratory strategy had implications on the physical condition of males on return to the colony the following year. We experimentally induced breeding failure from mid-incubation, tracked the over-winter movements of these males and of males that invested in parental effort, and assessed innate immunity, stress, and residual body mass the following year. Early breeding failure resulted in earlier return to the colony among all males, associated with greater probability of reproductive success. Residents had a lower tail feather fault bar intensity, an indicator of stress during the non-breeding period, compared to migrants. Reproductive effort and migratory strategy had no impact on physiological condition otherwise. Our results provide evidence that in species with a slow-pace of life, such as the Cory’s Shearwater, somatic maintenance is prioritised, with the costs of reproduction and migration paid in delayed arrival date.

生命史理论建议在繁琐的活动（例如繁殖和迁徙）与躯体自我维持之间进行权衡。然而，人们对于如何在生活节奏缓慢的物种中表达父母付出的短期代价却知之甚少。同样，在比较同一人口中的迁移策略时，调查迁移的遗留效应是最有意义的，但是很少这样做。我们在一个长寿的中上层海鸟，科里氏剪切水，Calonectrisborealis中探索了这一假设，其中男性表现出部分迁移。通过操纵生殖努力并利用迁徙策略的自然变异，我们调查了早期生殖衰竭和迁徙策略是否会影响次年返回殖民地的男性身体状况。我们从孵化中期实验性地诱导了繁殖失败，追踪了这些雄性和投入父母努力的雄性的越冬运动，并在第二年评估了先天免疫力，压力和残余体重。较早的繁殖失败导致所有雄性较早地返回该群体，这与繁殖成功的可能性更大有关。与移民相比，居民的尾羽断筋强度低，这是非繁殖时期的压力指标。生殖力和迁徙策略对生理状况没有影响。我们的结果提供了证据，表明在诸如Cory's Shearwater之类的生活节奏缓慢的物种中，体细胞维持是优先考虑的问题，繁殖和迁移的成本要在延迟到达日期之前支付。