Dissertation Research: The Role of Habitat Selection Behavior in Mediating Trophic Interactions

了解消费者如何选择栖息地对于预测群落对捕食者和资源操纵的反应至关重要。目前的模型预测的是不同栖息地之间的死亡风险和摄食率不同时的个体栖息地选择，但没有考虑动态资源。本研究将扩展这些模型以包括资源动态，显示消费者在生境之间的分布如何取决于死亡率风险和资源生产率。具体来说，消费者和资源对捕食者和养分操纵的反应将在简单的两个栖息地实验系统中进行测试。在这些系统中，小蓝鳃鱼（Lepomis macrochirus）可以在成对的实验池之间自由移动，但它们的捕食者大口黑鲈（Micropterus salmoides）被限制在特定的池中。这些水池也包含了自给自足的浮游动物种群（蓝鳃鱼的资源）。该研究将解决以下具体问题：1)在消费者可以选择具有不同死亡风险和自我更新资源的生境的情况下，消费者是否最优地利用生境？ 2)不同生境中消费者人口的比例如何随资源生产率的变化而变化？ 3)消费者生境选择对生境内资源动态的影响是什么？这些研究首次提供了将栖息地选择行为与其对群落动态的影响联系起来的理论的实证检验。

An understanding of how consumers choose among habitats is essential to predicting community level responses to predator and resource manipulations. Current models predict individual habitat choice when mortality risk and feeding rates vary among habitats, but do not incorporate dynamic resources. This study will extend these models to include resource dynamics, showing how the distribution of consumers among habitats is dependent on mortality risk and resource productivity. Specifically, the response of consumers and resources to predator and nutrient manipulations in simple, two habitat, experimental systems will be tested. In these systems, small bluegills (Lepomis macrochirus) are free to move between paired experimental pools, but their predators, largemouth bass (Micropterus salmoides) are confined to specific pools. These pools also contain self-supporting populations of zooplankton (the bluegill's resource). The research will address the following specific questions: 1) Under the situation where consumers can choose among habitats with differing mortality risks and self-renewing resources, do consumers use habitats optimally, 2) How does the portion of the consumer population in each habitat vary with varying resource productivity, and 3) What are the consequences of consumer habitat choice to resource dynamics within habitats? These studies provide the first empirical test of theory linking the behavior of habitat selection to its consequences for community dynamics.