Data from: High fidelity: extra-pair fertilisations in eight Charadrius plover species are not associated with parental relatedness or social mating system

Extra-pair paternity is a common reproductive strategy in many bird species. However, it remains unclear why extra-pair paternity occurs and why it varies among species and populations. Plovers (Charadrius spp.) exhibit considerable variation in reproductive behaviour and ecology, making them excellent models to investigate the evolution of social and genetic mating systems. We investigated inter- and intra-specific patterns of extra-pair parentage and evaluated three major hypotheses explaining extra-pair paternity using a comparative approach based on the microsatellite genotypes of 2,049 individuals from 510 plover families sampled from twelve populations that constituted eight species. Extra-pair paternity rates were very low (0 to 4.1% of chicks per population). No evidence was found in support of the sexual conflict or genetic compatibility hypotheses, and there was no seasonal pattern of extra-pair paternity (EPP). The low prevalence of EPP is consistent with a number of alternative hypotheses, including the parental investment hypothesis, which suggests that high contribution to care by males restricts female plovers from engaging in extra-pair copulations. Further studies are needed to critically test the importance of this hypothesis to plover mate choice.

婚外父权（Extra-pair paternity）是众多鸟类物种中常见的繁殖策略。然而，学界至今仍未明确婚外父权现象的成因，以及其在不同物种和种群间存在差异的原因。鸻属（Charadrius）鸟类在繁殖行为与生态特征上表现出显著变异，是探究社会与遗传交配系统演化的理想模型类群。本研究分析了婚外父权的种间与种内分布模式，并基于覆盖8个物种、12个种群的510个鸻类家系的2049个个体的微卫星基因型数据，采用比较研究法对解释婚外父权现象的三大核心假说进行了检验。各种群的婚外父权率极低，雏鸟占比仅为0至4.1%。未发现支持性冲突（sexual conflict）假说与遗传相容性（genetic compatibility）假说的证据，且婚外父权（EPP）未呈现季节性规律。婚外父权的低发生率与多项替代假说相符，其中亲代投入（parental investment）假说提出，雄性对育雏的高投入会限制雌性鸻类开展婚外交配行为。未来仍需开展进一步研究，以严谨检验该假说在鸻类配偶选择中的重要性。