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

该项目利用加勒比海北部的一组小岛作为模型系统，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。该项目以大规模实验为中心，在一系列岛屿上，大型掠食性蜥蜴的存在/缺失是不同的。大型蜥蜴会影响较小的中型掠食性蜥蜴，并通过昆虫食草动物向下影响植物。上层捕食者对下层营养水平的影响主要通过对中间捕食者的影响来调节。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。这些性状的变异对食物网相互作用的影响将被跟踪数代。中间捕食者最初会减少，但随后会随着行为和进化的调整而恢复，以适应增加的捕食风险。密度变化的模式与栖息地的转移相结合，应该会导致食物网较低层次的重大变化。一项比较研究与实验平行，以确定产生实验结果的食物网途径。这项研究将告诉我们在复杂的食物网中生态、行为和进化之间的相互作用。这项研究极大地促进了本科生在实地和实验室研究方面的研究经验，并针对科学领域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播研究结果。我们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、应对生物入侵、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.