Collaborative Research: A Field-experimental Test for Evolutionary Trait-mediated Indirect Effects in Food Webs

这个项目利用加勒比北方的一组小岛屿作为模型系统，以了解生态、进化和行为因素之间的相互作用如何决定生物群落的主要特征。该项目的中心是一个大规模的实验，其中大型捕食性蜥蜴的存在/不存在在一系列岛屿上是不同的。大型蜥蜴会影响较小的、中等大小的捕食性蜥蜴，这种影响会通过食草昆虫向下传递到植物。顶端捕食者对较低营养级的影响主要是通过对中间捕食者的影响来介导的。这种影响可以由物种密度的变化驱动，但也可以取决于特定的行为和进化特征。这些性状的变化对食物网相互作用的影响将在多代中进行跟踪。预计中间捕食者最初会减少，但随后会恢复，因为它的行为和进化调整增加捕食风险。密度变化的模式加上生境的转变，应该会导致食物网较低层次的重大变化。 一项比较研究平行的实验，以确定产生实验结果的食物网途径。 这项研究将告诉我们关于生态学，行为和进化之间的相互作用在复杂的食物网。这项研究大大促进了本科生在实地和实验室研究的经验，并针对在科学中代表性不足的群体。 该研究还提供研究生培训，并通过流行文章，公开演讲，纪录片和博物馆展览向公众传达研究结果。尽一切努力将这项研究与应用科学联系起来，如改善农业生态系统，处理生物入侵，保护物种和栖息地。

This project utilizes a set of small islands in the northern Caribbean as a model system to understand how interactions between ecological, evolutionary and behavioral factors determine major features of biological communities. The project centers on a large-scale experiment in which presence/absence of large predatory lizards is varied across a series of islands. Large lizards affect smaller, intermediate-size predatory lizards, and the effects cascade down through insect herbivores to the plants. The effects of the top predator on lower trophic levels are mediated largely through effects on the intermediate predator. Such effects can be driven by changes in species densities, but can also depend on specific behavioral and evolutionary traits. The effects of variation in these traits on food-web interactions will be followed over multiple generations. The intermediate predator would be expected to initially decrease but then recover as it behaviorally and evolutionarily adjusts to increased predation risk. The pattern of density change combined with the habitat shift should cause major changes in lower levels of the food web. A comparative study parallels the experiment to determine the food-web pathways generating the experimental results. This study will inform us regarding the interplay between ecology, behavior, and evolution in complex food webs.This study substantially promotes undergraduate research experiences in field and lab studies and targets groups underrepresented in science. The study also provides graduate-student training and communicates findings to the public via popular articles, public presentations, documentary films, and museum exhibits. Every effort is made to relate this research to applied sciences such as improving agroecosystems, dealing with biological invasions, and preserving species and habitats.