DISSERTATION RESEARCH: An Experimental Test of Generalist Foraging Behavior as a Community Stabilization Mechanism

由于许多原因，物种可能会变得稀有或常见。科学家们越来越感兴趣的是，一个物种丰度的这种变化如何影响其他物种，特别是那些以稀有物种为食的物种。一些科学家认为，一个物种的稀缺性导致依赖该物种的其他物种的稀缺性，有可能导致大量局部灭绝--甚至可能导致整个生态系统的崩溃。其他科学家则不同意这种说法。他们认为，如果第一个物种可能与第二个物种竞争，一个物种的减少可以使其他物种受益，从而导致一个稳定的生态系统，在这个生态系统中，相对于那些减少的物种，增加的物种数量总体上是平衡的。预测动植物对环境变化的脆弱性的关键是找出这些相反的观点中哪一种最有可能。这样的理解将有助于管理者、政策制定者和科学家制定支持地球生物多样性的战略。这个项目的目标是测试沿海生态系统如何对干扰做出反应，特别是顶级捕食者是否能够适应猎物数量的变化。这项研究使用了俄勒冈州海岸的一只捕食性幼虫来研究多面手捕食者的不同可能的觅食策略如何影响岩石潮间带群落的稳定性。研究人员将使用在实验室中对不同猎物训练的海螺来复制不同的野外觅食方法(例如，恒定的猎物偏好和适应性觅食)。这些海螺将在野外暴露在两种自然的脉冲补充扰动中。研究人员将利用扰动后物种密度的变化来确定群落的弹性和抵抗力。这将使研究人员能够检查多面手在促进社区稳定方面所起的作用，以及哪些形式的多面手觅食最有可能稳定社区。这项研究将支持研究生和本科生的培训，并将通过为科学中心开发一个展览来提供推广机会，该展览将解释食物网的概念，以及食物网如何影响科学中心参观者的日常生活。

Species can become rare or common for many reasons. Scientists are increasingly interested in how such changes in the abundance of one species can impact other species, particularly those that eat species that become rare. Some scientists think that the rareness of one species leads to the rareness of other species that rely on this species, potentially causing a lot of local extinctions -- perhaps even the collapse of an entire ecosystem. Other scientists disagree. They think that declines in one species can benefit other species if the first species might compete with the second, leading to a stable ecosystem in which there is an overall balance in the number of species that are increasing relative to those that are decreasing. Key to predicting the vulnerability of plants and animals to changes in their environment is figuring out which of these opposing views is most likely. Such understanding will help managers, policy makers and scientists develop strategies to support the diversity of life on earth. The goal of this project is to test how a coastal ecosystem responds to disturbances and, in particular, whether a top predator can adjust to changes in the abundance in its prey.This research uses a predatory whelk on the Oregon coast to examine how different possible foraging strategies of generalist predators influence the stability of rocky intertidal communities. The researchers will use whelks trained on different prey in the laboratory to replicate different methods of generalist foraging in the field (e.g., constant prey preferences and adaptive foraging). The whelks will be exposed to two natural pulse recruitment perturbations in the field. Researchers will use the changes in species densities following the perturbations to determine the resilience and resistance of the communities. This will allow the researchers to examine the role that generalists play in promoting community stability and what forms of generalist foraging are the most likely to stabilize communities. This study will support the training of a graduate and undergraduate students and will provide opportunities for outreach through the development of an exhibit for a science center that explains the concept of food webs and how food webs influence the everyday lives of visitors to the science center.