DISSERTATION RESEARCH: Offspring Recognition and Brood Parasitism in African Finches: Implications for Signal Mimicry and Diversification

非洲雀类的后代识别和幼鸟寄生：信号模仿和多样化的含义大卫·W·温克勒和贾斯汀·G·舒茨父母和后代之间的沟通在鸟类中很普遍。然而，雏鸟在对话中使用的信号在只有两个鸟类家族中进行了极端的阐述，这两个家族是雌雀和幼鸟寄生的Viduid雀。雌鸟的嘴巴图案非常多样；每个物种都有独特的斑点、颜色和舌头上的斑点、颜色和斑纹的组合。Viduid雏鸟与Estrilid寄主雏鸟一起长大，它们的嘴巴印记与它们所利用的寄主物种的嘴印精确匹配。据推测，模仿的发生是因为饲养寄生虫的成本很高，而且因为歧视长得像外国人的年轻人的寄宿父母受到自然选择的青睐。然而，到目前为止，几乎没有证据表明雌虫的筑巢识别，而且只进行了少数野生寄主种群的研究。以前的工作表明，食物的可获得性、宿主的学习和雏鸟的表型可能会影响寄主父母是否识别和拒绝雏鸟。对照的鸟类实验结合野外工作将有助于评估这些变量的相对重要性。已知年龄的寄主和寄生虫的圈养种群已经建立，坦桑尼亚的研究将允许对雏鸟歧视进行测试。在坦桑尼亚，一只袋鼠利用不止一个寄主物种。在整个鸟舍和野外工作中，将记录物种内和物种间雏鸟形态的变化。除了让我们了解后代的识别行为外，这项研究的结果还将深入了解宿主与寄生虫的相互作用以及影响动物信号进化的过程。

Offspring Recognition and Brood Parasitism in African Finches: Implications for Signal Mimicry and DiversificationDavid W. Winkler and Justin G. SchuetzCommunication between parents and offspring is widespread among birds. However, the signals that nestlings employ in this dialogue have undergone extreme elaboration in only two families of birds, the Estrildid finches and the brood parasitic Viduid finches. The mouth patterns of estrildid nestlings are incredibly diverse; each species possesses a unique combination of spots, colors, and markings on its palate and tongue. Viduid nestlings, which are raised alongside estrildid host nestlings, have mouth markings that precisely match those of the host species they exploit. Presumably, mimicry occurs because raising parasites is costly and because host parents that discriminate against foreign-looking young are favored by natural selection. However, to date, there is scanty evidence for nestling recognition in estrildids and only a few studies of wild host populations have been undertaken. Previous work suggests that food availability, host learning, and nestling phenotypes may influence whether host parents recognize and reject nestlings. Controlled aviary experiments in combination with fieldwork will help to assess the relative importance of these variables. Captive populations of known-age hosts and parasites have already been established, and research in Tanzania, where a viduid exploits more than one host species, will allow for tests of nestling discrimination. Throughout aviary and fieldwork, variation in nestling morphologies within and across species will be documented. In addition to informing our understanding of offspring recognition behavior, results from this research will provide insight into host-parasite interactions and the processes that affect the evolution of animal signals.