Extrapair copulations in western bluebirds (Sialia mexicana):: female receptivity favors older males
Extrapair copulations in western bluebirds (Sialia mexicana):: female receptivity favors older males
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DOI：
10.1007/s002650100381
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发表时间：
2001-10-01
影响因子：
2.3
通讯作者：
Dickinson, JL
中科院分区：
文献类型：
--
作者：
Dickinson, JL
对外亲子关系一直是许多社会一夫一妻制鸟类研究的焦点，但对外雄性-雌性相互作用的动力学研究相对较少。在西部蓝知更鸟（Sialia mexicana），一个物种，20% extrapair的父亲，两到四个观察员监测extrapair交配（EPCs）发生在女性的家乡领土，而她的社会伴侣被拘留在一个笼子里附近的巢。拘留的频率和可见性的EPCs的提高，所以我们可以得分的女性接受可识别的extrapair男性没有干扰的男性间的侵略。大多数入侵的extrapair男性是邻居的繁殖者访问自己的配偶的生育期以外。被拘留的男性的当地男性亲属试图与非乱伦的EPC，但邻近的儿子并没有试图与他们的母亲交配，在某些情况下，赶走了入侵者。女性接受性不受是否被拘留的配偶是视觉上存在或隐藏在布后面，并没有增加的持久性或相对大小的extrapair男性。女性的接受性增加的年龄差异之间的extrapair男性和女性的社会伴侣，表明女性更喜欢年长的男性作为extrapair的合作伙伴。这项研究表明，成本的阻力是相对不重要的，在确定女性在西部蓝知更鸟的容受性，但确定优先容受性，以老年男性之间的结果和内部的冲突超过父权的一个潜在因素。
Extrapair paternity has been the focus of numerous studies of socially monogamous birds, but the dynamics of extrapair male-female interactions have been explored in relatively few. In western bluebirds (Sialia mexicana), a species with 20% extrapair paternity, two to four observers monitored extrapair copulations (EPCs) occurring on the female's home territory while her social mate was detained in a cage near the nest. Detention elevated the frequency and visibility of EPCs, so we could score receptivity of females to identifiable extrapair males without the interference of intermale aggression. Most intruding extrapair males were neighboring breeders visiting outside their own mate's fertile period. Local male relatives of the detained male attempted nonincestuous EPCs, but neighboring sons did not attempt to copulate with their mothers and, in some cases, chased away intruders. Female receptivity was not influenced by whether the detained mate was visually present or hidden behind cloth and did not increase with the persistence or relative size of the extrapair male. Female receptivity increased with the age difference between the extrapair male and the female's social mate, suggesting that females prefer older males as extrapair partners. This study suggests that costs of resistance are relatively unimportant in determining female receptivity in western bluebirds, but identifies preferential receptivity to older males as a potential factor in the outcome of inter- and intrasexual conflict over paternity.