Abstract Parents are expected to reduce offspring investment when confronted with reliable cues of compromised parentage, yet establishing which cues are reliable is an empirical challenge. Presenting a potential cuckolder to a breeding male is often used in experiments as an indirect cue of paternity loss. However, determining the reliability and hence the utility of this cue is an important but often-overlooked research step. Furthermore, cues of compromised parentage are typically manipulated only during the narrow time window(s) when copulations take place, and so we currently have a poor understanding of whether these cues also convey useful information at other critical timepoints in the reproductive cycle, such as during nest site selection. Here, we present a series of field and laboratory studies using a paternal care giving toadfish, the plainfin midshipman fish ( Porichthys notatus ) to address these questions. We tested whether the presence of a potential cuckolder near a potential nesting site reduces the odds that males will choose to nest at that site, or reduces the amount of care they provide for offspring. Overall, we found no clear effect of cuckolder presence on the likelihood that a male would occupy nor abandon a nesting site, nor on the amount of paternal care provided. The presentation of a single sneaker male may have been too weak a signal of cuckoldry to elicit a response from guarder males. Alternatively, a single sneaker male may not represent a severe enough threat to paternity to warrant a response. We highlight the importance of considering the diverse range of natural history and ecological factors that underlie paternity cue utility across different model organisms. Significance statement Breeding decisions, such as which nesting sites to occupy or how much to invest into offspring, may be affected by external cues of parentage loss (e.g. cuckoldry) or risk thereof. Here, we tested whether the presence of a cuckolder male in the breeding environment affects male nest site selection and paternal care. Despite being a commonly used putative indirect cue of sperm competition and paternity loss, we found no clear evidence that the presence of a single sneaker male affected these breeding decisions. Our results underscore the importance of first establishing the utility of various cues, which involves considering the ecological context from which the cues arise, before using them to assess the mechanisms underlying animal decision-making.

中文翻译：

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亲子关系不确定性的间接线索不影响太平洋蟾蜍的筑巢地点选择或父母照顾

摘要 当面临亲子关系受损的可靠线索时，父母应该减少对后代的投资，但确定哪些线索是可靠的是一项经验挑战。在实验中经常将潜在的戴绿帽者呈现给繁殖雄性，作为失去亲子关系的间接线索。然而，确定该线索的可靠性和效用是一个重要但经常被忽视的研究步骤。此外，亲子关系的线索通常仅在交配发生的狭窄时间窗口内被操纵，因此我们目前对这些线索是否也在生殖周期的其他关键时间点传达有用信息知之甚少，例如在巢址选择过程中。在这里，我们展示了一系列使用父系护理给予蟾鱼的实地和实验室研究，平鳍见习官鱼 (Porichthys notatus) 来解决这些问题。我们测试了在潜在筑巢地点附近存在潜在戴绿帽者是否会降低雄性选择在该地点筑巢的几率，或减少它们为后代提供的照顾量。总的来说，我们发现戴绿帽子的存在对雄性占据或放弃筑巢地点的可能性没有明显影响，也没有对提供的父亲照顾的数量产生明显影响。一个单一的运动鞋男性的展示可能太弱了一个戴绿帽子的信号，无法引起守卫男性的反应。或者，单个运动鞋男性可能不会对亲子关系构成严重到足以保证回应的威胁。我们强调考虑各种自然历史和生态因素的重要性，这些因素是不同模式生物的亲子关系线索效用的基础。重要性声明 繁殖决定，例如占据哪些筑巢地点或对后代投资多少，可能会受到亲子关系丧失（例如戴绿帽子）的外部线索或其风险的影响。在这里，我们测试了繁殖环境中是否存在戴绿帽子的雄性会影响雄性巢址选择和父亲的照顾。尽管是精子竞争和亲子关系丧失的常用假定间接线索，但我们没有发现明确的证据表明单个运动鞋男性的存在会影响这些育种决定。我们的结果强调了首先建立各种线索的效用的重要性，