Slagsvold T
Department of Biology, University of Oslo
Anim Behav. 1997 Dec;54(6):1357-68. doi: 10.1006/anbe.1997.0530.
In some altricial birds with biparental care, it is the female, and in others the male, that provides more food to the smallest offspring within the brood. Many hypotheses have been proposed to account for such puzzling patterns of parental care. A parsimonious explanation is that no difference exists between the parents in priority of care but that differences arise simply from sibling rivalry, with dominant chicks trying to position themselves closest to the parent that provides most care (the sibling rivalry hypothesis). A refinement of the idea is that parents use the way they approach the chicks to counter selfish offspring and in this way control allocation of care (the parental approaching hypothesis). A comparison across species suggested that female care of the smallest chick within a brood is the ancestral and most common pattern. However, strong variation exists within single populations. In one species, the American robin, Turdus migratorius the sibling rivalry hypothesis and the parental approaching hypothesis were both supported because in broods where males provided more care than females, the largest chick was predominantly fed by the male whereas the smallest chick was predominantly fed by the female. When the male provided less care than the female, an opposite result was found. The same patterns of allocation of care also seemed to exist when chicks were quite immobile just after having left the nest and when their positions were experimentally controlled, suggesting parental control.Copyright 1997 The Association for the Study of Animal BehaviourCopyright 1997The Association for the Study of Animal Behaviour.
在一些由双亲共同照料幼雏的晚成鸟中，有的是雌鸟，而在另一些鸟中则是雄鸟，会给一窝幼雏中最小的雏鸟提供更多食物。人们提出了许多假说，试图解释这种令人困惑的亲代抚育模式。一种简洁的解释是，双亲在抚育优先级上并无差异，只是同胞竞争导致了差异，占优势的雏鸟会尽量让自己靠近提供最多照料的亲鸟（同胞竞争假说）。对这一观点的进一步细化是，亲鸟利用接近雏鸟的方式来应对自私的后代，从而控制抚育资源的分配（亲鸟接近假说）。一项跨物种比较表明，雌鸟照料一窝雏鸟中最小的雏鸟是祖传的且最为常见的模式。然而，在单一鸟群中也存在很大差异。在一种名为美洲知更鸟（旅鸫）的物种中，同胞竞争假说和亲鸟接近假说都得到了支持，因为在雄鸟比雌鸟提供更多照料的一窝雏鸟中，最大的雏鸟主要由雄鸟喂食，而最小的雏鸟主要由雌鸟喂食。当雄鸟提供的照料比雌鸟少时，结果则相反。当雏鸟刚离巢后还不太会动，以及它们的位置受到实验控制时，似乎也存在同样的抚育资源分配模式，这表明是亲鸟在控制。版权所有1997动物行为研究协会版权所有1997动物行为研究协会。
