Evolutionary and behavioural ecologists have long been interested in factors shaping the variation in mating behaviour observed in nature. Whereas much of the research on this topic has focused on the consequences of mate choice and mate change on annual reproductive success, studies of a potential positive link between mate fidelity and adult demographic rates have been comparatively rare. This is particularly true for long-lived birds with multi-year, socially monogamous pair bonds. We used a 26-year capture-mark-recapture dataset of 3,330 black brent (Branta bernicla nigricans) to test whether breeding with a familiar mate improved future breeding propensity and survival. We predicted that experienced breeders nesting with a new partner would have rates of survival similar to familiar pairs because long-lived species avoid jeopardizing survival since their lifetime fitness is sensitive to this vital rate. In contrast, we expected that any costs of breeding with a new partner would be paid through skipping the subsequent breeding attempt. We found that unfamiliar pairs had lower subsequent breeding propensity than faithful partners. However, contrary to our expectations, individuals breeding with a new mate also suffered reduced survival. These results add to a small number of studies indicating that a positive relationship between mate retention and adult demographic rates may exist in a diverse array of avian species. Given these results, researchers should consider costs of mate change that extend beyond within-season reproductive success to fully understand the potential adaptive basis for perennial social monogamy. We caution that if mate retention enhances survival prospects, improvements in annual reproductive success with pair-bond length could be a secondary factor favoring perennial social monogamy, particularly in species with slower life history strategies. Further, cases where annual reproductive success does not improve with pair-bond duration, yet multi-year pair bonds are common, could be explained by benefits afforded by mate fidelity to adult vital rates.

中文翻译：

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配偶保真度提高长寿鸟类的生存和繁殖倾向

进化和行为生态学家长期以来一直对影响自然界观察到的交配行为变化的因素感兴趣。尽管关于这一主题的大部分研究都集中在配偶选择和配偶变化对年度生殖成功的影响上，但对配偶忠诚度和成人人口统计率之间潜在正相关关系的研究相对较少。对于具有多年社会一夫一妻制配对关系的长寿鸟类而言尤其如此。我们使用了 3,330 只黑布伦特 (Branta bernicla nigricans) 的 26 年捕获-标记-重新捕获数据集来测试与熟悉的配偶繁殖是否会改善未来的繁殖倾向和存活率。我们预测，与新伙伴筑巢的经验丰富的繁殖者的存活率将与熟悉的配对相似，因为长寿物种避免危及生存，因为它们的终生健康对这一重要速率很敏感。相比之下，我们预计与新伙伴育种的任何成本都将通过跳过随后的育种尝试来支付。我们发现不熟悉的配对比忠实的配对具有更低的后续繁殖倾向。然而，与我们的预期相反，与新配偶交配的个体的存活率也降低了。这些结果增加了少数研究表明，配偶保留率和成年人口比率之间可能存在正相关关系，可能存在于多种鸟类物种中。鉴于这些结果，研究人员应该考虑超出季节内繁殖成功范围的配偶更换成本，以充分了解常年社会一夫一妻制的潜在适应性基础。我们警告说，如果保留配偶可以提高生存前景，那么通过配对长度提高年度繁殖成功率可能是有利于长期社会一夫一妻制的次要因素，特别是在生活史策略较慢的物种中。此外，年度繁殖成功率不会随着配对持续时间而提高，但多年配对债券很常见的情况可以解释为配偶对成年生命率的忠诚度提供的好处。配对债券长度的年度繁殖成功率的提高可能是有利于长期社会一夫一妻制的次要因素，特别是在生活史策略较慢的物种中。此外，年度繁殖成功率不会随着配对持续时间而提高，但多年配对债券很常见的情况可以解释为配偶对成年生命率的忠诚度提供的好处。配对债券长度的年度繁殖成功率的提高可能是有利于长期社会一夫一妻制的次要因素，特别是在生活史策略较慢的物种中。此外，年度繁殖成功率不会随着配对持续时间而提高，但多年配对债券很常见的情况可以解释为配偶对成年生命率的忠诚度提供的好处。