REU: Collaborative Research: Ecology of Migratory Passerine Birds on Breeding and Wintering Areas - Demographic Experimental Studies

这项研究是两种雀形目候鸟在其繁殖地、新罕布夏州中部森林地区和牙买加越冬地点对种群动态和栖息地选择的长期研究的继续和扩展。它结合了实验、观察和人口统计学的方法来检验这些物种的种群在夏季和冬季都是有限的这一假设。在这两个领域将使用三个步骤：(1)测试栖息地选择是否依赖于密度和/或专制(即，年轻的个体或雌性受到社会支配的老年雄性的制约)，这反映在栖息地梯度的分布格局中，并通过直接测试优势行为；(2)测试优势行为对特定年龄和性别的繁殖和/或栖息地生存的影响，以及(3)确定时间和空间上可变的食物供应(特别是繁殖区的落叶毛虫)和捕食者作为观察到的人口模式的可能生态原因的重要性。最后，将评估时变生态条件对这些种群的年龄结构和丰度的相对重要性。由于这些迁徙物种在繁殖区和越冬区的栖息地迅速丧失，自然资源保护者迫切需要这些信息。

This study is a continuation and expansion of long-term studies of population dynamics and habitat selection by two migratory passerine bird species on their breeding grounds, in forested parts of central New Hampshire and on wintering sites in Jamaica. It combines experimental, observational, and demographic approaches to test the hypothesis that populations of these species are limited both in summer and winter. Three steps will be used in both areas: (1) a test whether habitat selection is density dependent and/or despotic (i.e., younger individuals or females are constrained by socially dominant older males), as reflected in distribution patterns along habitat gradients, and by testing for dominance behavior directly; (2) a test for consequences of dominance behavior on age- and sex-specific reproduction and/or survival by habitat, and (3) a determination of the importance of temporally and spatially variable food supplies (especially a defoliating caterpillar in breeding areas) and predators as possible ecological causes of demographic patterns observed. Finally, the relative importance of temporally variable ecological conditions on age-structure and abundances of these populations will be assessed. Such information is urgently needed by conservationists, due to rapid habitat loss for these migratory species on both breeding and wintering areas.