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

由于许多原因，物种会变得稀有或常见。科学家们越来越感兴趣的是，一个物种的丰度变化如何影响其他物种，尤其是那些以稀有物种为食的物种。一些科学家认为，一种物种的稀缺会导致依赖该物种的其他物种的稀缺，从而可能导致大量的局部灭绝——甚至可能导致整个生态系统的崩溃。其他科学家不同意这种说法。他们认为，如果一个物种的减少可能会与另一个物种竞争，那么其他物种就会受益，从而形成一个稳定的生态系统，在这个生态系统中，物种数量的增加相对于物种数量的减少会达到总体平衡。预测动植物对环境变化的脆弱性的关键是弄清楚这些对立观点中哪一个最有可能。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上生命多样性的策略。该项目的目的是测试沿海生态系统对干扰的反应，特别是顶级捕食者是否能够适应猎物丰度的变化。这项研究使用俄勒冈海岸的捕食性海螺来研究多面手捕食者的不同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进行训练的海螺，在野外复制不同的综合觅食方法（例如，恒定的猎物偏好和适应性觅食）。海螺将在野外暴露于两种自然脉冲招募扰动中。研究人员将利用扰动后物种密度的变化来确定群落的恢复力和抵抗力。这将使研究人员能够研究多面手在促进社区稳定方面所起的作用，以及什么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游客的日常生活。

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.