Previous work based on molecular evidence has shown that most socially monogamous birds follow a genetic polyandrous mating system. However, our knowledge about avian mating systems is heavily biased toward the north temperate zone, with data on tropical birds remaining relatively scarce. This uneven distribution of both phylogenetic and spatial sampling has hampered our understanding and interpretation of results. In this study, we investigated the frequency of extra-pair paternity (EPP) in a tropical population of yellow-bellied prinias ( Prinia flaviventris) in Guangxi, southern China. A total of 129 individuals belonging to 24 nests were sampled, among which 12 out of 83 chicks (14.46%) in seven nests were found to be EPP offspring. In nests in which all nestlings were sampled, only five out of 56 chicks were EPP offspring, accounting for an unbiased EPP rate of 8.93%. This rate is below the average rate of EPP in the family Sylviidae. The possible causes of EPP in prinias and the occurrence of EPP in birds with high resource investment and intensive parental care are discussed. This study highlights the value of genome-wide markers in determining relatedness in a wild bird species without a reference genome.
先前基于分子生物学证据的研究表明，大多数社会性单配制的鸟类在遗传上呈现出一妻多夫的婚配制度。然而，我们对鸟类婚配制度的了解很大程度上来自于北半球的研究案例，而有关热带鸟类的研究资料则相对匮乏。这种在系统发育和空间采样上的不均匀性妨碍了我们对鸟类婚配制度的理解和解释。该研究探讨了华南地区黄腹山鹪莺（ Prinia flaviventris）的广西热带种群的婚外父权的比率。对24巢129个个体（83只雏鸟和46只亲鸟）进行取样，83只雏鸟中有12只为婚外子代（占比14.46%），隶属于7巢。对雏鸟数据完整的13巢进行分析发现，56只雏鸟中仅5只为婚外子代（占比8.93%）。黄腹山鹪莺的婚外父权比率低于莺科其它种类的平均比率，其较低的婚外父权比率可能与亲鸟在繁殖期较高的资源投入和较强的亲代抚育有关。我们的研究强调了全基因组标记在推断无参考基因组的野生鸟类物种亲缘关系时的价值。.
Keywords: Energy constraint; Extra-pair paternity; Mating system; Yellow-bellied prinia.