Data from: Maternal age at birth shapes offspring life-history trajectory across generations in long-lived Asian elephants

1. Advanced maternal age at birth can have pronounced consequences for offspring health, survival and reproduction. If carried over to the next generation, such fitness effects could have important implications for population dynamics and the evolution of ageing, but these remain poorly understood. While many laboratory studies have investigated maternal age effects, relatively few studies have been conducted in natural populations, and they usually only present a "snapshot" of an offspring's lifetime. 2. In the present study, we focus on how maternal age influences offspring life-history trajectories and performance in a long-lived mammal. 3. We use a multigenerational demographic dataset of semi-captive Asian elephants to investigate maternal age effects on several offspring life-history traits: condition, reproductive success, and overall survival. 4. We show that offspring born to older mothers display reduced overall survival but higher reproductive success, and reduced survival of their own progeny. Our results show evidence of a persistent effect of maternal age on fitness across generations in a long-lived mammal. 5. By highlighting transgenerational effects on the fitness of the next generation associated with maternal age, the present study helps increase our understanding of factors contributing to individual variation in ageing rates and fitness.

1. 分娩时的母方高龄会对子代的健康、存活与繁殖产生显著影响。若这种适合度（fitness）效应传递至下一代，可能对种群动态及衰老演化具有重要意义，但目前相关机制仍未得到充分阐释。尽管已有诸多实验室研究探讨了母龄效应，但针对自然种群的相关研究相对匮乏，且现有研究大多仅能呈现子代一生的"快照式"结果。2. 本研究聚焦于母龄如何影响一种长寿哺乳动物的子代生活史轨迹与表现。3. 我们利用半圈养亚洲象的多代种群统计数据集，探究母龄对子代多项生活史性状的影响，包括身体状况、繁殖成功率及整体存活情况。4. 研究结果显示，高龄母象所产子代的整体存活率更低，但自身繁殖成功率更高，且其自身后代的存活率亦有所降低。本研究结果证实，在长寿哺乳动物中，母龄对适合度的跨代效应具有持续性。5. 本研究通过揭示母龄相关的跨代效应对下一代适合度的影响，有助于我们进一步理解导致个体衰老速率与适合度存在差异的各类因素。