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

Bruce Lyon(Pi)和Daizaburo Shizuka Proposal#：IOS-0808579适应的认知限制：雏鸟识别为宿主防御同种幼体寄生虫当父母能够区分自己的后代时，通常优先照顾自己的后代。一些鸟类，通常被称为孵化寄生虫，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，这种生殖寄生的受害者为什么要照顾其他个体甚至其他物种的后代，特别是在后代与自己的后代截然不同的情况下。考虑到幼虫的宿主通常已经进化出识别和拒绝看起来很像它们自己的幼虫卵的能力，这种识别失败尤其令人惊讶。在这项研究中，Shizuka和Lyon开发了一个理论模型，以说明学习识别后代的一般过程中的限制因素如何解释为什么一些物种接受幼虫寄生后代，而另一些物种不接受。然后，这项研究的实验部分将讨论该模型是否适用于水鸟--美洲黄姑鱼(Fulica Americana)。雌性雄鸟在彼此的巢中产卵，其中许多寄生卵与寄主的卵一起孵化。初步数据表明，一些父母识别寄生的雏鸟，并将它们与自己的幼鸟区别对待。这些实验将决定(A)COOTS是否能够识别和区分寄主和外国雏鸟，(B)什么类型的学习机制被用来发展识别，以及(C)雏鸡发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，这项研究将有助于更好地理解生物用来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，研究结果将被纳入针对当地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.