Data from: The adaptive significance of provisioning and foraging coordination between breeding partners

Sexual conflict over parental care relies on the fundamental assumption that parents do not share the cost of their partner’s effort on future reproduction. However, this is unlikely to be true whenever partners breed together more than once. In that case, individuals should try to optimize the cost and benefits for the pair, rather than only for themselves. Here we seek to establish whether the synchronization of parents’ provisioning visits to the nest could fulfill this function. We conducted a brood-size manipulation experiment on wild zebra finches to test whether nest visit synchrony was flexible and beneficial for nestlings’ growth, while controlling for the confounding effects of pair “quality” and synchrony away from the nest during foraging. Using a network of readers to track parents at nests and feeding stations, we found that nest visit synchrony responded directly to the brood manipulation and increased with brood size. Synchrony at the nest and while foraging were correlated, but the latter better predicted nestling mass, possibly because it was associated with more regular provisioning patterns. Our findings suggest that parental coordination could indeed play an important role in partners’ investment decisions, underpinning the evolution of the most prominent mating system in birds.育幼行为（parental care）相关的性冲突（sexual conflict），其成立的核心前提为：双亲不会分担伴侣为未来繁殖所付出的代价。然而，当伴侣双方多次共同繁殖时，这一前提大概率不成立。在此情境下，个体应致力于优化配对整体的成本与收益，而非仅考量自身得失。本研究旨在探讨：双亲往返巢区的投喂同步性是否可承担这一优化功能。我们对野生斑胸草雀（zebra finches）开展了窝雏数操控实验（brood-size manipulation experiment），以检验巢区投喂同步性是否具备可塑性，并能否助力雏鸟生长；实验同时控制了配对"质量"以及觅食阶段非巢区同步性带来的混淆效应（confounding effects）。我们借助阅读器网络（reader network）追踪巢区与投喂站的亲鸟活动，结果发现：巢区投喂同步性会直接响应窝雏数操控，并随窝雏数增加而提升。巢区投喂同步性与觅食阶段的同步性存在相关性，但后者更能预测雏鸟体重（nestling mass），这可能是因为觅食同步性与更规律的投喂模式存在关联。本研究结果表明：亲鸟间的协调行为确实可对伴侣双方的繁殖投入决策产生重要影响，进而支撑了鸟类最主流婚配制度（mating system）的演化。