Data from: Sex-specific pathways of parental age effects on offspring lifetime reproductive success in a long-lived seabird

The conditions under which individuals are reared vary and sensitivity of offspring to such variation is often sex-dependent. Parental age is one important natal condition with consequences for aspects of offspring fitness, but reports are mostly limited to short-term fitness consequences and do not take into account offspring sex. Here we used individual-based data from a large colony of a long-lived seabird, the common tern Sterna hirundo, to investigate longitudinal long-term fitness consequences of parental age in relation to both offspring and parental sex. We found that recruited daughters from older mothers suffered from reduced annual reproductive success. Recruited sons from older fathers were found to suffer from reduced lifespan. Both effects translated to reductions in offspring lifetime reproductive success. Besides revealing novel sex-specific pathways of trans-generational parental age effects on offspring fitness, which inspire studies of potential underlying mechanisms, our analyses show that reproductive senescence is only observed in the common tern when including trans-generational age effects. In general, our study shows that estimates of selective pressures underlying the evolution of senescence, as well as processes such as age-dependent mate choice and sex allocation, will depend on whether causal trans-generational effects exist and are taken into account.

个体抚育环境存在异质性，而后代对这类环境差异的敏感性通常呈现性别依赖性。亲本年龄是影响子代适合度多个维度的重要出生相关条件之一，但现有研究大多仅关注短期适合度效应，且未考虑子代性别因素。本研究基于一个大型长寿海鸟种群——普通燕鸥（Sterna hirundo）的个体级监测数据，探究了亲本年龄分别结合子代与亲本自身性别时，对子代适合度产生的长期纵向效应。结果发现，由高龄母亲所产的成功招募子代雌鸟，其年度繁殖成功率显著降低；而由高龄父亲所产的成功招募子代雄鸟，其寿命显著缩短。上述两种效应均会导致子代终生繁殖成功率下降。本研究不仅揭示了亲本年龄通过性别特异性通路对子代适合度产生跨代影响的全新路径，为后续探究其潜在机制指明了方向，同时分析表明，仅当纳入跨代年龄效应时，才能在普通燕鸥中观测到繁殖衰老现象。总体而言，本研究表明，针对衰老演化背后的选择压力，以及年龄依赖性配偶选择、性别分配等过程的评估，将取决于是否存在因果性跨代效应，以及是否将此类效应纳入考量。