Data from: Experiencing El Niño conditions during early life reduces recruiting probabilities but not adult survival

In wild long-lived animals, analysis of impacts of stressful natal conditions on adult performance has rarely embraced the entire age-span, and the possibility that costs are expressed late in life has seldom been examined. Using 26 years of data from 8,541 fledglings and 1,310 adults of the blue-footed booby (Sula nebouxii), a marine bird that can live up to 23 years, we tested whether experiencing the warm waters and food scarcity associated with El Niño in the natal year reduces recruitment or survival over the adult lifetime. Warm water in the natal year reduced the probability of recruiting; each additional degree (°C) of water temperature meant a reduction of roughly 50% in fledglings’ probability of returning to the natal colony as breeders. Warm water in the current year impacted adult survival, with greater effect at the oldest ages than during early adulthood. However, warm water in the natal year did not affect survival at any age over the adult lifespan. A previous study showed that early recruitment and widely spaced breeding allow boobies that experience warm waters in the natal year to achieve normal fledgling production over the first 10 years; our results now show that this reproductive effort incurs no survival penalty, not even late in life. This pattern is additional evidence of buffering against stressful natal conditions via life-history adjustments.针对野生长寿动物，现有研究极少能覆盖全寿命周期以分析育幼期压力环境对成体表现的影响，且极少有研究探讨生存代价在生命后期显现的可能性。本研究以寿命可达23年的海鸟蓝脚鲣鸟（Sula nebouxii）为研究对象，利用8541只离巢幼鸟与1310只成体的26年监测数据，检验育幼期遭遇与厄尔尼诺（El Niño）相关的暖水环境与食物匮乏状况，是否会降低个体的繁殖补充成功率或成年终生存活率。研究发现，育幼期的暖水环境会降低个体的繁殖补充概率：海水温度每升高1摄氏度，幼鸟日后作为繁殖个体返回原繁殖群的概率便会下降约50%。当年度的暖水环境则会影响成体存活率，且对老龄个体的影响强于成年早期个体。但育幼期遭遇暖水环境，并不会对成体阶段任何年龄段的存活率产生影响。此前有研究表明，育幼期遭遇暖水环境的蓝脚鲣鸟，可以通过提早繁殖与拉长繁殖间隔，在生命最初10年维持正常的幼鸟产出量；本研究结果进一步证实，这类繁殖投入并不会带来生存代价，即便在生命后期亦是如此。该模式为通过生活史策略调整以缓冲育幼期压力环境影响提供了新的实证依据。