Consequences of Adaptive Individual Behavior, Higher Order Interactions, and Food Web Structure in a Larval Anuran Community

食物网结构调节动物种群大小的方式目前正受到许多理论和经验的关注。这一建议试图从机械上理解由鱼类、无脊椎动物捕食者和两只无尾两栖动物幼虫组成的食物网中相互作用的强度。通过这个食物网传递的间接影响是两种无尾两栖动物在从永久池塘到临时池塘的环境梯度上相对成功的变化的核心。从个体行为到大规模的食物网操作，从机制到对群落现象的理解，食物网的相互作用在几个层面上都得到了研究。该提案的一个重点是对猎物对捕食者存在的行为反应所产生的更高阶相互作用的重要性进行实验评估。在捕食者对猎物没有任何直接死亡影响的情况下，这些更高层次的相互作用改变了猎物之间竞争相互作用的性质。由于猎物对捕食者的行为反应普遍存在，这种高阶相互作用在许多生态系统中可能是重要的。无尾两栖动物的行为反应依次通过生长(竞争能力)-风险权衡来调节，一个通过活动水平，另一个通过栖息地选择。个人行为层面的理论将被开发、测试和使用，以提供理解适应性个人行为的社区后果的理论基础。这两种权衡都与许多分类群中的相互作用有关。最后，由于行为反应通常是个体大小的函数，这项工作将探索个体发育对行为表达的限制以及对物种相互作用的影响。

The manner in which food web structure regulates the size of animal populations is currently receiving much theoretical and empirical attention.. This proposal seeks to develop a mechanistic understanding of the strength of interactions in a food web consisting of fish, invertebrate predators, and two anuran larvae. Indirect effects mediated through this food web are central to changes in relative success of the two anurans along the environmental gradient from permanent to temporary ponds. The food web interactions are approached at several levels ranging from individual behavior to large scale food web manipulations to build from mechanisms to an understanding of community phenomena. A focus of the proposal is an experimental evaluation of the importance of higher order interactions generated by behavioral responses of prey to the presence of their predators. These higher order interactions alter the nature of competitive interactions among prey in the absence of any direct mortality effects of predators on prey. Because of the widespread occurrence of behavioral responses of prey to predators, such higher order interactions are likely important in many ecological systems. The behavioral responses of the anurans in turn are mediated by growth (competitive ability)-risk tradeoffs, one through activity levels and the other through habitat choice. Theory at the individual behavioral level will be developed, tested and used to provide a theoretical basis for understanding the community consequences of adaptive individual behavior. Both of these tradeoffs are relevant to interactions in many taxa. Finally, because behavioral responses are often functions of individual size, the work will explore ontogenetic constraints on behavioral expression and the consequences to species interactions.