Reproductive roles in the cooperatively breeding acorn woodpecker: Incest avoidance versus reproductive competition
Reproductive roles in the cooperatively breeding acorn woodpecker: Incest avoidance versus reproductive competition
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DOI：
10.1086/286115
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发表时间：
1998-03-01
影响因子：
2.9
通讯作者：
Stanback, MT
中科院分区：
文献类型：
--
作者：
Koenig, WD;Haydock, J;Stanback, MT
乱伦是罕见的合作繁殖橡子啄木鸟（Melanerpes formicivorus），尽管一夫多妻制的交配系统中，几乎所有的群体成员都是近亲。在这里，我们测试的相对重要性，避免近亲交配（避免乱伦）和繁殖机会（生殖竞争）在确定橡子啄木鸟的交配系统，通过研究生殖角色如何改变后的繁殖空缺。在83%的情况下，其中有同性的帮手在组中，生殖空缺得到解决时，新的无关移民填补了空缺，以排除居民同性帮手，谁一般移民或不繁殖，而他们仍然在组中。异性助手，特别是男性，更有可能留在他们的纳塔尔组，在大约一半的情况下，继承和繁殖后的生殖空缺。这一结果无法用生殖竞争来解释，因为移民的数量往往少于或等于群体中同性助手的数量。明显的乱伦导致了5%的病例。对于有同性别帮手的群体，解决生育空缺所需的时间要长得多。这些结果证实，避免乱伦和生殖竞争是决定这一高度社会化的物种群体内的生殖作用的重要因素。
Incest is rare in the cooperatively breeding acorn woodpecker (Melanerpes formicivorus) despite a polygynandrous mating system in which nearly all group members are close relatives. Here we test the relative importance of avoiding matings between close relatives (incest avoidance) and within-sex competition for breeding opportunities (reproductive competition) in determining the mating system of acorn woodpeckers by examining how reproductive roles change following breeding vacancies. In 83% of cases in which helpers of the same sex were present in the group, reproductive vacancies were resolved when new unrelated immigrants filled the vacancy to the exclusion of resident same-sex helpers, who generally emigrated or did not breed while they remained in the group. Helpers of the opposite sex, especially when male, were significantly more likely to remain in their natal group and in about half the cases inherited and bred following reproductive vacancies. This result was not explainable by reproductive competition, since the number of immigrants was often less than or equal to the number of same-sex helpers in the group. Apparent incest resulted in 5% of cases. The time required to resolve reproductive vacancies was significantly longer for groups with helpers of the same sex as the vacancy. These results confirm that both incest avoidance and reproductive competition are important factors determining reproductive roles within groups of this highly social species.