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.对于野生长寿动物而言，鲜有研究覆盖完整的年龄跨度，分析育幼期压力环境对成体生存表现的影响，且极少有研究探讨生存成本在生命晚期显现的可能性。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26年间采集的8541只出飞幼鸟与1310只成体的观测数据，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，是否会降低其成体期的种群招募率或终身存活率。研究发现，育幼期的暖水环境会降低个体的招募概率：海水温度每升高1℃，出飞幼鸟后续作为繁殖个体返回出生地繁殖种群的概率便会下降约50%。成体当年遭遇的暖水环境会影响其存活率，且在最年长的个体中，这种影响相较于成年早期更为显著。但育幼期的暖水环境，并未对成体期任何年龄段的存活率产生影响。此前一项研究表明，育幼期遭遇暖水环境的蓝脚鲣鸟，可通过提早招募个体与拉大繁殖间隔，在生命前10年维持正常的雏鸟产出量；本研究结果进一步显示，这种繁殖投入并不会带来生存代价，即便在生命晚期亦是如此。该模式为通过生活史策略调整以缓冲育幼期逆境影响，提供了又一实证依据。