Collaborative Research: Ecology of Migratory Passerine Birds in Breeding and Wintering Areas: Demographic and Experimental Studies

这项研究的目的是确定哪些因素限制了 或控制在北方繁殖的候鸟数量 温带森林和新热带地区的冬天。 的根本问题 关注这些因素是否在夏季更重要 在温带纬度的繁殖区，在新热带冬季 四季，或两季。 通过人口统计和 实验研究，假设将被测试，以确定（1）如果 限制发生在夏季和冬季，（2）如果栖息地 占有是由社会支配（专制）或其他因素决定的。 抢先行为，（3）如果个体之间的适应性不同， 栖息地，也就是专制栖息地的人口后果 选择;（4）哪些生态变量影响生境质量 也就是健身 重点将放在差异适应性上 在夏季和冬季的栖息地之间，包括第二次生长 森林、农田和其他人类改造的栖息地。 结果将促进我们对人口的了解 这些候鸟物种的动态和社区关系， 以及影响其种群丰度的因素。 等 信息还将有助于发展健全的 有效的保护政策。

The objectives of this research are to determine what factors limit or regulate populations of migratory birds that breed in the north temperate forests and winter in the Neotropics. The basic question concerns whether these factors operate more importantly in summer breeding areas at temperate latitudes, in neotropical winter quarters, or during both seasons. Through demographic and experimental studies, hypothesis will be tested to determine (1) if limitations occur in both summer and winter, (2) if habitat occupancy is determined by social dominance (despotism) or other preemptive behavior, (3) if individuals vary in fitness among habitats, that is, the demographic consequences of despotic habitat selection, and (4) what ecological variable affect habitat quality and therefore fitness. Emphasis will be on differential fitness among habitats in both summer and winter, including second-growth forests, agricultural lands, and other human-modified habitats. The results will advance our understanding of the population dynamics and community relations of these migrant bird species, as well as the factors affecting their population abundances. Such information also will contribute to the development of sound and effective conservation policies.