Relatedness, polyandry and extra-group paternity in the cooperatively-breeding white-browed scrubwren (Sericornis frontalis )
Relatedness, polyandry and extra-group paternity in the cooperatively-breeding white-browed scrubwren (Sericornis frontalis )
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合作繁殖的白眉鹩莺 (Sericornis frontalis) 的亲缘关系、一妻多夫制和族外父子关系
DOI：
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发表时间：
1997
影响因子：
2.3
通讯作者：
R. Magrath
中科院分区：
文献类型：
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作者：
L. A. Whittingham;Peter O. Dunn;R. Magrath
摘要利用DNA指纹技术研究了澳大利亚堪培拉合作繁殖的白眉画眉Sericornis frontalis的遗传亲缘关系和交配系统。我们的分析揭示了交配策略和社会组织的显著变化。灌木鹪鹩是成对繁殖的，或者是由一只雌性和两只或更多雄性组成的多雄性群体。女性总是无关的对男性或阿尔法（占主导地位的）男性。在多雄性群体中，我们发现了三种不同的交配策略。首先，当阿尔法和贝塔（下属）男性无关，他们通常分享亲子关系的育雏。这导致两个雄性直接获得生殖利益。第二，当β雄性与雌性没有亲缘关系，但与α雄性有亲缘关系时，β雄性在某些窝中会产生后代。在这种情况下，贝塔男性获得了直接和潜在的间接生殖利益（通过相关的阿尔法男性）。第三，当β雄性与雌性或雌性和α雄性都有关系时，他们留在自己的纳塔尔地，不生任何后代。因此，β雄性只获得间接的生殖益处。总体而言，当组成员关系密切，占主导地位的男性垄断生殖成功，而当成员关系不密切的两个男性平等地分享父权。生殖偏斜模型预测了生殖垄断和亲缘关系之间的正相关，但以前没有在一个单一的鸟类种群中报道过。其他与近亲和不近亲的帮手合作繁殖的鸟类可能会表现出类似的交配策略。最后，我们发现，组外亲子关系是更常见的对（24%的年轻人）比多男性群体（6%），我们讨论了这种差异的三个可能的原因。
Abstract We used DNA fingerprinting to examine the genetic parentage and mating system of the cooperatively breeding white-browed scrubwren, Sericornis frontalis, in Canberra, Australia. Our analyses revealed a remarkable variety of mating tactics and social organization. Scrubwrens bred in pairs or multi-male groups that consisted of a female and two or more males. Females were always unrelated to the pair male or alpha (dominant) male. Among multi-male groups we found three different mating tactics. Firstly, when alpha and beta (subordinate) males were unrelated, they usually shared paternity in the brood. This resulted in both males gaining reproductive benefits directly. Secondly, when beta males were not related to the female but were related to the alpha males, beta males sired offspring in some broods. In this situation, beta males gained reproductive benefits both directly and potentially indirectly (through the related alpha male). Thirdly, when beta males were related to the female or both the female and alpha male, they remained on their natal territory and did not sire any offspring. Thus beta males gained only indirect reproductive benefits. Overall, when group members were related closely, the dominant male monopolized reproductive success, whereas when the members were not related closely the two males shared paternity equally. This positive association between monopolization of reproduction and relatedness is predicted by models of reproductive skew, but has not been reported previously within a single population of birds. Other cooperatively breeding birds with both closely related and unrelated helpers may show a similar variety of mating tactics. Finally, we found that extra-group paternity was more common in pairs (24% of young) than in multi-male groups (6%), and we discuss three possible reasons for this difference.