DISSERTATION RESEARCH: Cognitive constraints on adaptation: Chick recognition as host defense against conspecific brood parasitism

Bruce Lyon （PI）和Daizaburo shizuka研究报告：适应的认知约束：小鸡识别作为宿主防御同卵寄主寄生虫父母通常在区分自己的后代时优先照顾自己的后代而不是其他后代。有些鸟类，通常被称为寄主，通过在其他鸟类的巢中产卵来利用父母的照顾。一个悬而未决的问题是，为什么这种生殖寄生的受害者会照顾其他个体甚至其他物种的后代，特别是当这些后代与自己的后代差别很大的时候。考虑到寄主通常已经进化出识别和拒绝看起来很像自己的寄主卵的能力，这种识别失败尤其令人惊讶。在这项研究中，Shizuka和Lyon建立了一个理论模型，展示了学习识别后代的一般过程中的约束如何解释为什么某些物种接受寄生后代，而其他物种则不接受寄生后代。然后，研究的实验部分将解决该模型是否适用于美洲白骨顶（Fulica americana），一种水鸟。雌白骨顶在彼此的巢中产卵，许多寄生蛋和寄主的蛋一起孵化。初步数据表明，一些亲本白骨顶能识别寄生雏鸟，并将它们与自己的雏鸟区别对待。实验将确定(a)白骨顶是否能够识别和区分宿主和外来雏鸟，(b)用于发展识别的一般学习机制是什么，以及(c)雏鸟的叫声是否是识别中使用的线索。通过将理论模型与认知的实验操作相结合，本研究将有助于更好地理解生物体用于解决生态问题的机制如何限制适应性进化。该项目将对本科生进行实地研究和分子方法方面的培训，研究结果将被纳入当地K-12学生的生态学讲座项目。

Bruce Lyon (PI) and Daizaburo ShizukaProposal #:IOS-0808579Cognitive constraints on adaptation: chick recognition as host defense against conspecific brood parasitesParents typically preferentially care for their own offspring over the offspring of others when they can tell them apart. Some birds, that are commonly called brood parasites, exploit parental care by laying their eggs in the nests of others. An outstanding question is why victims of this type of reproductive parasitism provide care for the offspring of other individuals or even of other species, particularly when the offspring vary dramatically from their own. This recognition failure is especially surprising considering that hosts of brood parasites have often evolved the ability to recognize and reject brood parasite eggs that look much like their own. In this study, Shizuka and Lyon develop a theoretical model to show how a constraint in the general process of learning to recognize offspring may explain why brood parasitic offspring are accepted in some species, but not others. The experimental portion of the study will then address whether this model can apply to American coots (Fulica americana), a waterbird. Female coots lay eggs in each other's nests, and many of these parasitic eggs hatch along with the host's eggs. Preliminary data suggests that some parent coots recognize parasitic chicks and treat them differently from their own. The experiments will determine (a) whether coots can recognize and discriminate between host and foreign chicks, (b) what general type of learning mechanism is used to develop recognition, and (c) whether chick vocalizations are the cues used in recognition. By integrating a theoretical model with experimental manipulations of cognition, this study will contribute to a greater understanding of how the mechanisms organisms use to solve ecological problems can constrain adaptive evolution. The project will train undergraduate students in field research and molecular methods, and the findings will be incorporated into an Ecology Talk program for local K-12 students.