REU: Causes of Selective Predation and Costs of Predator- Avoidance by Stream Insects

本研究旨在探讨河栖石蝇选择性捕食的机制和进化原因，并测量蜉蝣干扰的致死和亚致死代价、取食率、生长率和繁殖力。录像行为观察和捕食试验将测试频率依赖的猎物选择，诱导喂养偏好，捕食者和猎物对流体动力学线索的反应，以及“威胁敏感性假说”，该假说认为捕食者回避行为与被捕食的风险有关。重复的环形河道实验将测试捕食者和猎物的微栖息地重叠，使石蝇的生长速度和繁殖力得以比较。选择室实验将测试捕食者对浮游植物资源斑块的影响。功能反应和底栖生物数据将用于确定石蝇捕食对猎物种群动态的致死和亚致死效应的潜在影响。这项研究的主要贡献将是测试关于选择性捕食和捕食者躲避模式的行为机制的新假设，以及为什么自然选择可能偏爱某些捕食者和猎物行为的第一个已知的实验研究。

The objectives of this research are to resolve the mechanistic and evolutionary causation of selective predation by stream dwelling stoneflies and measure the lethal and sublethal costs of disturbance by mayflies, feeding rates, growth rates and fecundity. Videotaped behavioral observations, and predation trials will test for frequency-dependent prey selection, induction of feeding preference, responses of predators and prey to hydrodynamic clues, and the "threat sensitivity hypothesis", which states that predator-avoidance behavior esculates with risk of predation. Replicated circular stream channel experiments will test for microhabitat overlap of predators and prey, enable comparison of growth rates and fecundities of stoneflies. Choice chamber experiments will test effects of predators on mayfly use of periphyton resource patches. Functional response and benthic data will be used to determine the potential impact of lethal and sublethal effects of stonefly predation on prey population dynamics. The key contributions of the research will be tests of new hypotheses on behavioral mechanisms underlying patterns of selective predation and predator-avoidance and the first known experimental study of why natural selection might have favored certain predator and prey behaviors.