Resources at multiple trophic levels mediate foraging by omnivores

我的研究重点是不同生态系统中昆虫之间的相互作用和营养水平之间的相互作用。我的长期目标是了解当食物网的组成部分发生变化时，这些食物网相互作用的异同。我特别感兴趣的是，根据定义，杂食性动物在食物网中的多个层次上觅食，当被提供不同类型的资源时，它们如何改变它们的摄食决定，以及杂食性动物的摄食决定如何影响食物网的其他成员。杂食动物必须在以下两种情况下做出决定：一是以容易获得但质量较低的基本资源为食，二是寻找可能稀缺但质量较高的猎物资源。因此，杂食动物面临着在资源质量、类型和丰度不同的情况下做出觅食决定。我的中心假设是，杂食性动物将以其他有益昆虫(高质量、高风险的猎物)为食，这取决于其他食物来源的类型和质量。我将使用两种不同的杂食动物来验证这一假设，它们在两个不同的食物网中觅食，一个以植物为基础，另一个以死动物为基础。这两个食物网的不同之处在于，对于以植物为食的昆虫杂食性动物来说，植物资源是无限的，而对于以死动物为食的昆虫杂食性动物来说，动物资源随着时间的推移而枯竭。这使得当基础资源和猎物资源在类型、质量和丰度上不同时，可以对杂食性动物进行比较。这也使我能够实现我的短期目标，即评估植物性杂食动物在多大程度上提供了对更广泛范围内杂食性动物机制的洞察。我的研究承诺将对我们理解多种营养水平的资源在调节杂食性动物方面的作用做出重大贡献。通过研究不同生态系统中的昆虫食物网，我探索了生活在非常不同环境中的动物的行为生态学，从而对群落结构和食物网动态有了更广泛的理解。

My research focuses on interactions between insects within and between trophic levels in different ecosystems. My long term goal is to understand the similarities and differences of these food web interactions when the components of the food web changes. In particular, I am interested in how omnivores, which by definition feed at multiple levels within food webs, change their feeding decisions when presented with different types of resources and how the feeding decisions by omnivores impact other members of the food web. Omnivores must make decisions between feeding on basal resources that may be readily available, but of low quality, with searching for prey resources, which may be scarce, but of high quality. Thus, omnivores are faced with making foraging decisions where resources vary in quality, type and abundance. My central hypothesis is that omnivores will feed on other beneficial insects (high quality, high risk prey) depending on the type and quality of other food sources. I will test this hypothesis using two different omnivores that feed within two different food webs, one based on plants and one based on dead animals. These two food webs differ in that for insect omnivores that live on plants, plant resources are unlimited, whereas, for insect omnivores that live on dead animals, the animal resource is depleted over time. This allows comparisons of omnivory when both basal and prey resources vary in type, quality and abundance. It also allows me to achieve my short term goal of evaluating to what degree plant-based omnivores provide insight to mechanisms of omnivory on a broader scope. My research promises to make a strong contribution to our understanding of the role of resources at multiple trophic levels mediating omnivory. By studying insect food webs in different ecosystems, I explore the behavioural ecology of animals living in very different environments and thereby develop a broader understanding of community structure and food web dynamics.