Adaptive explanations for the evolution of extra‐pair paternity (EPP) suggest that females seek extra‐pair copulations with high quality males. Still, the link between ornamentation, individual quality, and paternity remains unclear. Moreover, honest signaling is essential when explaining EPP because it is needed for sexual selection to occur; yet, it is understudied in multiple ornaments. Because blue tits (Cyanistes caeruleus) show variable color expression in several plumage patches, we tested: (i) over two seasons, whether males in better condition, more ornamented and less infected by blood parasites gain EPP and have higher reproductive success, and (ii) over three seasons, whether mating patterns affect color change. Males with more saturated yellow feathers, brighter tails, and in better condition had higher reproductive success in one of the seasons. Contrary to expectation, in another season, males that gained EPP were parasitized by blood parasites, suggesting increased vector exposure during extra‐pair copulations. Our results for two seasons show that males siring more extra‐pair young were older and grew brighter cheek or tail feathers for the following season. Despite the increased mating costs, in socially monogamous avian systems, high quality males incur in EPP without compromising traits that may be under sexual selection.

中文翻译：

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蓝山雀中的个体品质和额外配对：性感男性承担成本

对额外配对亲子关系（EPP）进化的适应性解释表明，女性寻求与高质量男性的额外配对交配。尽管如此，装饰、个人品质和亲子关系之间的联系仍不清楚。此外，在解释 EPP 时，诚实的信号是必不可少的，因为它是发生性选择所必需的；然而，它在多种装饰品中都没有得到充分研究。因为蓝山雀（Cyanistes caeruleus）在几个羽毛斑块中表现出不同的颜色表达，我们测试了：（i）在两个季节中，状态更好、装饰更多、被血液寄生虫感染更少的雄性是否获得 EPP 并具有更高的繁殖成功率，以及（ ii) 超过三个季节，交配模式是否影响颜色变化。雄性的黄色羽毛更饱和，尾巴更亮，并且在更好的条件下在其中一个季节具有更高的繁殖成功率。与预期相反，在另一个季节，获得 EPP 的雄性被血液寄生虫寄生，这表明在额外的交配期间载体暴露增加。我们两个季节的结果表明，在接下来的季节里，生育更多一对幼崽的雄性年龄更大，脸颊或尾羽长得更亮。尽管交配成本增加，但在社会一夫一妻制的鸟类系统中，高质量的雄性会产生 EPP，而不会影响可能处于性选择下的特征。我们两个季节的结果表明，在接下来的季节里，生育更多一对幼崽的雄性年龄更大，脸颊或尾羽变得更亮。尽管交配成本增加，但在社会一夫一妻制的鸟类系统中，高质量的雄性会产生 EPP，而不会影响可能处于性选择下的特征。我们两个季节的结果表明，在接下来的季节里，生育更多一对幼崽的雄性年龄更大，脸颊或尾羽长得更亮。尽管交配成本增加，但在社会一夫一妻制的鸟类系统中，高质量的雄性会产生 EPP，而不会影响可能处于性选择下的特征。