Sex differences in the drivers of reproductive skew in a cooperative breeder
Sex differences in the drivers of reproductive skew in a cooperative breeder
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DOI：
10.1111/mec.14587
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发表时间：
2018-05-01
影响因子：
4.9
通讯作者：
Ridley, Amanda R.
中科院分区：
文献类型：
--
作者：
Nelson-Flower, Martha J.;Flower, Tom P.;Ridley, Amanda R.
许多合作繁殖社会的特点是高生殖偏斜，例如一些社会主导的个体繁殖，而社会从属的个体提供帮助。避免近亲繁殖是许多高偏斜社会中生殖偏斜的一个来源，但很少有实证研究研究探讨了与避免近亲繁殖一起运作的偏斜来源，或将个体生殖尝试（生殖竞争）与个体生殖成功进行比较。在这里，我们使用长期的遗传和观察数据，以研究影响生殖偏斜的高偏斜合作繁殖南方画眉（Turdoides双色）的因素。当下属可以繁殖时，偏斜仍然很高，这表明除了避免近亲繁殖外，还有其他因素驱动偏斜。下属女性更有可能竞争繁殖时，年龄较大或当生态限制扩散高，但沉重的下属女性更有可能成功繁殖。下属男性更有可能竞争时，他们是老年人，在高生态限制，或当他们与占主导地位的男性，但只有存在组内无关的下属女性预测下属男性繁殖成功。生殖偏斜不是由生殖努力驱动的，而是由内在的身体限制和性内冲突（对于女性）或女性配偶选择，男性配偶保护和潜在的生殖限制（对于男性）等力量驱动的。生态条件或外部选择影响生殖冲突的发生，支持最近的合成偏态模型的预测。避免近亲繁殖以及获得生殖的竞争可能会在动物社会中产生高偏斜，并且不同的过程可能会在同一物种中维持雄性与雌性的生殖偏斜。
Many cooperatively breeding societies are characterized by high reproductive skew, such that some socially dominant individuals breed, while socially subordinate individuals provide help. Inbreeding avoidance serves as a source of reproductive skew in many high-skew societies, but few empirical studies have examined sources of skew operating alongside inbreeding avoidance or compared individual attempts to reproduce (reproductive competition) with individual reproductive success. Here, we use long-term genetic and observational data to examine factors affecting reproductive skew in the high-skew cooperatively breeding southern pied babbler (Turdoides bicolor). When subordinates can breed, skew remains high, suggesting factors additional to inbreeding avoidance drive skew. Subordinate females are more likely to compete to breed when older or when ecological constraints on dispersal are high, but heavy subordinate females are more likely to successfully breed. Subordinate males are more likely to compete when they are older, during high ecological constraints, or when they are related to the dominant male, but only the presence of within-group unrelated subordinate females predicts subordinate male breeding success. Reproductive skew is not driven by reproductive effort, but by forces such as intrinsic physical limitations and intrasexual conflict (for females) or female mate choice, male mate-guarding and potentially reproductive restraint (for males). Ecological conditions or outside options affect the occurrence of reproductive conflict, supporting predictions of recent synthetic skew models. Inbreeding avoidance together with competition for access to reproduction may generate high skew in animal societies, and disparate processes may be operating to maintain male vs. female reproductive skew in the same species.