Dissertation Research: Dead-Leaf Foraging Specialization by Tropical Forest Birds

论文研究：热带森林鸟类的枯叶觅食专业化

• 批准号: 8800905
• 负责人: James Remsen
• 金额: $ 0.61万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1989-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8800905&HistoricalAwards=false
• 关键词: Dissertation; Research; Dead; Leaf; Foraging

This research will document an extreme foraging specialization that is unique to diverse tropical bird communities, and then test specific hypotheses concerning the maintenance of this specialization. A dozen bird species at each of two Amazonian rainforest sites were found to forage primarily by extracting arthropods from curled dead leaves suspended in the forest understory. Because the dead leaves represent discrete resource patches, this research can quantify leaf availability and use, as well as the abundance of available prey. A preliminary empirical study suggests the following predictions to be tested in a series of outdoor cage experiments on wild-caught birds and arthropods: 1) dead leaf specialists have fixed preferences for dead leaf vs. other substrates, but are flexible with respect to particular types; 2) specialists are more efficient than co-occurring generalists at capturing prey hiding in dead leaves; 3) dead-leaf arthropods have fixed preferences for hiding in these leaves; and 4) these arthropods exhibit stereotyped behavioral responses to bird predation that in turn influence the bird's foraging efficiency. This study differs from most other insectivorous bird studies in two important ways; first, food availability and diets are measured directly rather than inferred from feeding behavior or morphology, and second, the amenability of this resource system to experimental manipulation provides a rare opportunity to evaluate the role of the various processes that may promote specialization.

这项研究将记录不同热带鸟类群落独有的极端觅食专业化，然后测试有关维持这种专业化的具体假设。人们发现，亚马逊雨林的两个地点都有十几种鸟类主要通过从悬浮在森林下层的卷曲枯叶中获取节肢动物来觅食。 由于枯叶代表离散的资源斑块，因此这项研究可以量化叶子的可用性和使用，以及可用猎物的丰富度。 一项初步的实证研究表明，以下预测需要在一系列针对野生捕获的鸟类和节肢动物的户外笼子实验中进行测试：1）死叶专家对死叶与其他基质有固定的偏好，但对于特定类型具有灵活性； 2）在捕捉隐藏在枯叶中的猎物方面，专家比同时出现的通才更有效； 3）死叶节肢动物对隐藏在这些叶子中具有固定的偏好； 4）这些节肢动物对鸟类捕食表现出刻板的行为反应，进而影响鸟类的觅食效率。 这项研究与大多数其他食虫鸟类研究有两个重要的不同之处： 首先，食物供应和饮食是直接测量的，而不是根据摄食行为或形态推断的；其次，该资源系统对实验操作的适应性提供了一个难得的机会来评估可能促进专业化的各种过程的作用。