In a parasite species, the dispersal of individuals should be dependent on the host species to which they are specialized; thus, any sexual/individual difference in host specificity may influence their dispersal patterns and, hence, population genetic structures. However, such predictions remain poorly verified in generalist avian brood parasites that are composed of multiple lineages of host-specific races. Here, we show the dispersal consequences inferred from spatial genetic structures and their association with host specificity in brood parasitic common cuckoos Cuculus canorus in which female-specific host race formation has been widely accepted. Genetic sampling from adult cuckoos confirmed restricted dispersal in both sexes and resultant genetic structures between populations where different host species breed allopatrically, whereas it was not the case between distant areas inhabited by the same host species. Contrary to the female host race hypothesis, our results demonstrate that male cuckoos may also have host specificity and disperse accordingly, conclusively allowing us to hypothesize the formation of a host race including both sexes.

中文翻译：

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依赖宿主的扩散显示杜鹃的双性宿主特异性

在寄生虫物种中，个体的扩散应取决于他们专门针对的宿主物种。因此，宿主特异性的任何性别/个体差异都可能影响它们的传播方式，从而影响种群的遗传结构。但是，这种预言在由宿主特定种族的多个谱系组成的多面手禽育种寄生虫中仍未得到很好的验证。在这里，我们显示了从空间遗传结构推断出的扩散结果及其与寄主寄生杜鹃Cuculus canorus寄主特异性的关联其中特定于女性的宿主种族的形成已被广泛接受。来自成年杜鹃的基因采样证实了在两性中的散布受到限制，以及由此产生的遗传结构在不同寄主物种异位繁殖的种群之间的局限性，而在同一寄主物种所居住的遥远地区之间的情况并非如此。与女性寄主种族假说相反，我们的研究结果表明，杜鹃雄性也可能具有寄主特异性并因此而分散，最终使我们能够假设包括性别在内的寄主种族的形成。