Age and environment are important determinants of reproductive parameters in long-lived organisms. These factors may interact to determine breeding responses to environmental change, yet few studies have examined the environmental dependence of aging patterns across the entire life span. We do so, using a 20-yr longitudinal data set of reproductive phenotypes in long-lived female Nazca boobies (Sula granti), a monogamous seabird breeding in the eastern tropical Pacific. Young and old females may suffer from inexperience and senescence, respectively, and/or practice reproductive restraint. Breeding performance (for breeding participation, breeding date, clutch size, egg volume, and offspring production) was expected to be lower in these age classes, particularly under environmental challenge, in comparison with middle-aged breeders. Sea surface temperature anomalies (SSTA) represented interannual variation in the El Niño–Southern Oscillation (ENSO) and were one proxy for environmental quality (a population count of clutch initiations was a second). Although only females lay eggs, both sexes care for eggs and nestlings, and the male partner’s age, alone or in interaction with female age, was evaluated as a predictor of breeding performance. Middle-aged females performed better than young and old birds for all reproductive traits. Pairing with a young male delayed breeding (particularly for old females) and reduced clutch size, and pairing with an old male reduced offspring production. Challenging environments increased age effects on breeding probability and breeding date across young to middle ages and for offspring production across middle to old ages. However, important exceptions to the predicted patterns for clutch size and fledging success across young to middle ages suggested that trade-offs between fitness components may complicate patterns of trait expression across the life span. Relationships between breeding participation, environment, and individual quality and/or experience in young females may also contribute to unexpected patterns for clutch size and fledging success, traits expressed only in breeders. Finally, independent of age, breeding responses of female Nazca boobies to the ENSO did not follow expectations derived from oceanic forcing of primary productivity. During El Niño-like conditions, egg-laying traits (clutch size, breeding date) improved, but offspring production declined, whereas La Niña-like conditions were “poor” environments throughout the breeding cycle.

中文翻译：

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雌性纳斯卡鲣鸟对环境变化的繁殖反应取决于年龄和性状

年龄和环境是长寿生物生殖参数的重要决定因素。这些因素可能相互作用来决定育种对环境变化的反应，但很少有研究检查整个生命周期中衰老模式的环境依赖性。我们这样做，使用了长寿雌性纳斯卡鲣鸟（Sula granti)，一种在热带太平洋东部繁殖的一夫一妻制海鸟。年轻和年老的女性可能分别遭受经验不足和衰老，和/或实行生殖限制。与中年育种者相比，预计这些年龄段的育种性能（育种参与、育种日期、产蛋量、产蛋量和后代产量）较低，尤其是在环境挑战下。海面温度异常 (SSTA) 代表厄尔尼诺 - 南方涛动 (ENSO) 的年际变化，并且是环境质量的一个代表（离合器启动的人口计数为秒）。虽然只有雌性产卵，但雌雄都会照顾卵和雏鸟，雄性伴侣的年龄，单独或与雌​​性年龄相互作用，被评估为繁殖性能的预测指标。中年雌鸟在所有繁殖性状上的表现都优于幼鸟和老鸟。与年轻雄性配对延迟繁殖（尤其是老年雌性）并减少离合器大小，与年长雄性配对减少后代产量。具有挑战性的环境增加了年龄对青年到中年的繁殖概率和繁殖日期以及中年到老年后代生产的影响。然而，对于离合器大小的预测模式和年轻到中年的羽翼未丰的成功的预测模式的重要例外表明，健身成分之间的权衡可能会使整个生命周期的特征表达模式复杂化。年轻雌性的繁殖参与、环境和个体质量和/或经验之间的关系也可能导致意外的离合器大小和羽化成功的模式，性状只在育种者身上表现出来。最后，与年龄无关，雌性纳斯卡鲣鸟对 ENSO 的繁殖反应不符合海洋强迫初级生产力的预期。在类似厄尔尼诺的条件下，产卵性状（离合器大小、繁殖日期）有所改善，但后代产量下降，而类似拉尼娜的条件在整个繁殖周期中都是“恶劣”的环境。