PRF/J: The Consequences of Extra-pair Fertilization for Males and Females of the Western Bluebird (Sialia mexicana)

近年来，遗传证据显示，在明显一夫一妻制的鸟类物种中，额外配对的交配比之前认为的更普遍。由于缺乏数据，而且直到最近，现有的基因技术还不足以在自然种群中确定父子关系，因此对于雄性和雌性来说，额外配对交配的成本和好处知之甚少。在这项研究中，将确定在加利福尼亚州中部沿海的西部蓝鸟(Sialia Miciana)巢穴中的幼鸟的亲子关系，并将使用行为、人口统计学和遗传数据来解决额外配对交配的功能后果。在一个以上的雄性照顾幼崽的巢中，幼崽的父母身份将被确定，以及额外的雄性是否是非繁育的帮手，或者实际上是它们在觅食的巢中的后代的父亲。这项研究将阐明西方蓝鲸的交配系统，并将有助于阐明额外配对交配作为严格一夫一妻制的生殖替代方案的程度和成功程度。

In recent years, genetic evidence has revealed that extra- pair mating is more widespread in apparently monogamous bird species than previously thought. The costs and benefits of extra-pair mating are poorly understood for males and females because of a paucity of data and because, until recently, the genetic techniques available were inadequate for determining paternity in natural populations. In this study, parentage of young in nests of western bluebird (Sialia mexicana) pairs in central coastal California will be determined, and behavioral, demographic and genetic data will be used to address the functional consequences of extra-pair mating. Parentage of young in nests where more than one male cares for young will be determined, as well as whether supernumerary males are nonbreeding helpers or actually father offspring in the nests at which they feed. This study will clarify the mating system of the western bluebired and will help to shed light on the extent and success of extra-pair mating as a reproductive alternative to strict monogamy.