No evidence of adaptive tolerance of parasitism in a cavity-nesting brood parasite host

Acceptance of avian brood parasitism by hosts is one of the most enigmatic aspects of brood parasite-host coevolution. The most common explanation for acceptance of parasitism by hosts of the brown-headed cowbird (Molothrus ater) is evolutionary lag, which suggests that hosts have not had enough time to evolve defenses against parasitism. Alternatively, acceptance may be the optimal strategy when the costs of rejecting parasitism exceed the benefits. The lack of nest site hypothesis applies to secondary cavity-nesting birds that cannot excavate their own nests and predicts that hosts accept parasitism instead of deserting a parasitized nest when there are no vacant nest sites available in which to renest. I tested this hypothesis using the prothonotary warbler (Pronotaria citrea), a commonly parasitized, cavity-nesting cowbird host. I used a paired nest box design and predicted that if hosts accept parasitism because of a lack of alternative nest sites, they should desert parasitized ne..., , , # No evidence of adaptive tolerance of parasitism in a cavity-nesting brood parasite host [https://doi.org/10.5061/dryad.3r2280gr7](https://doi.org/10.5061/dryad.3r2280gr7) Dataset on prothonotary warbler response to cowbird parasitism. ## Description of the data and file structure Dataset includes nest number, year, experiment, number of cowbird eggs laid, and whether nest was deserted.宿主对鸟类巢寄生（avian brood parasitism）的接纳行为，是巢寄生者与宿主的协同演化（brood parasite-host coevolution）研究中最令人费解的核心议题之一。针对褐头牛鹂（Molothrus ater）宿主接纳寄生行为的主流解释为演化滞后假说（evolutionary lag），该假说提出宿主尚未获得足够的演化时间，以进化出对抗巢寄生的防御机制。另一种替代性解释则认为，当拒绝寄生所需付出的代价高于其所能获得的收益时，接纳寄生便是宿主的最优生存策略。巢位匮乏假说（the lack of nest site hypothesis）适用于自身无法自主挖掘巢穴的次级洞巢鸟类（secondary cavity-nesting birds），该假说预测：当没有可用于二次筑巢的空闲巢位时，宿主会选择接纳寄生，而非直接弃置已被寄生的巢穴。本研究以常被牛鹂寄生的洞巢宿主——原镰莺（Pronotaria citrea）为研究对象，对该假说进行了验证。本研究采用配对巢箱实验设计，并提出预测：若宿主因缺乏可选巢位而接纳寄生，那么它们应当弃置被寄生的巢穴……，，，# 洞巢巢寄生宿主中未发现寄生适应性接纳的证据 https://doi.org/10.5061/dryad.3r2280gr7 本数据集记录了原镰莺对牛鹂寄生的响应情况。 ## 数据与文件结构说明 数据集包含巢箱编号、研究年份、实验处理、所产牛鹂卵数量，以及巢穴是否被弃置等核心信息。