1.Physiological processes, including those that disrupt oxidative balance, have been proposed as key to understanding fundamental life history trade-offs. Yet examination of changes in oxidative balance within wild animals across time, space and major life history challenges remain uncommon. For example, migration presents substantial physiological challenges for individuals, and data on migratory individuals would provide crucial context for exposing the importance of relationships between oxidative balance and fitness outcomes. 2.Here we examined the consistency of commonly used measures of oxidative balance in longitudinally sampled free-living individuals of a long-lived, long-distance migrant, the Brent goose Branta bernicla hrota over periods of months to years. 3.Although inter-individual and temporal variation in measures of oxidative balance were substantial, we found high consistency in measures of lipid peroxidation and circulating non-enzymatic antioxidants in longitudinally sampled individuals. This suggests the potential for the existence of individual oxidative phenotypes. 4.Given intra-individual consistency, we then examined how these physiological measures relate to survival and reproductive success across all sampled individuals. Surprisingly, lower survival was predicted for individuals with lower levels of damage, with no measured physiological metric associated with reproductive success. 5.Our results demonstrate that snapshot measurements of a consistent measure of oxidative balance can inform our understanding of differences in a key demographic trait. However, the positive relationship between oxidative damage and survival emphasises the need to investigate relationships between the oxidative system and fitness outcomes in other species undergoing similar physiologically challenging lifecycles. This would highlight the extent to which variation in such traits and resource allocation trade-offs is a result of adaptation to different life history strategies.

中文翻译：

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氧化平衡的一致测量预测远距离迁徙者的存活而不是繁殖

1.生理过程，包括那些破坏氧化平衡的过程，已被认为是理解基本生命史权衡的关键。然而，跨时间、空间和主要生活史挑战检查野生动物体内氧化平衡的变化仍然不常见。例如，迁徙给个体带来了巨大的生理挑战，而迁徙个体的数据将为揭示氧化平衡与健康结果之间关系的重要性提供关键背景。2. 在这里，我们研究了长期、长途迁徙的布伦特鹅 Branta bernicla hrota 纵向采样的自由生活个体在几个月到几年的时间里，常用的氧化平衡测量的一致性。3. 尽管氧化平衡测量的个体间和时间变化很大，但我们发现纵向采样的个体中脂质过氧化和循环非酶抗氧化剂的测量具有高度一致性。这表明存在个体氧化表型的可能性。4.鉴于个体内部的一致性，我们随后检查了这些生理测量与所有采样个体的生存和繁殖成功之间的关系。令人惊讶的是，对于具有较低损伤水平的个体，预测较低的存活率，没有与繁殖成功相关的生理指标。5.我们的结果表明，对氧化平衡的一致测量的快照测量可以告知我们对关键人口特征差异的理解。然而，氧化损伤与存活之间的正相关关系强调需要研究氧化系统与经历类似生理挑战生命周期的其他物种的健康结果之间的关系。这将突出这些特征和资源分配权衡的变化程度是适应不同生活史策略的结果。