Data from: Better the devil you know: common terns stay with a previous partner although pair bond duration does not affect breeding output

In a monogamous species two partners contribute to the breeding process. We study pair formation as well as the effect of pair bond length and age on breeding performance, incorporating individual heterogeneity, based on a high-quality dataset of a long-lived seabird, the common tern (Sterna hirundo). To handle missing information and model the complicated processes driving reproduction, we use a hierarchical Bayesian model of the steps that lead to the number of fledglings, including processes at the individual and the pair level. The results show that the age of both partners is important for reproductive performance, with similar patterns for both sexes and individual heterogeneity in reproductive performance, but pair bond length is not. The terns are more likely to choose a former partner independent of the previous breeding outcome with that partner, which suggests a tendency to retain the partner chosen at the beginning of the breeding career.

在单配制物种中，双方伴侣共同参与繁殖过程。本研究基于一种长寿命海鸟——普通燕鸥（Sterna hirundo）的高质量数据集，纳入个体异质性因素，探究配对形成机制，以及配偶结合时长与年龄对繁殖表现的影响。为处理缺失信息并建模驱动繁殖的复杂过程，我们采用分层贝叶斯模型对影响离巢幼鸟数量的各环节进行建模，涵盖个体层面与配对层面的过程。研究结果显示，双方伴侣的年龄均对繁殖性能具有显著影响，两性呈现相似模式，且繁殖表现存在个体异质性，但配偶结合时长则无此关联。此外，燕鸥更倾向于选择过往伴侣，且该选择与此前和该伴侣的繁殖结果无关，这表明它们倾向于保留繁殖生涯初期选定的伴侣。