Abstract

Of the approximately 716 bird species that breed in North America, 386 (54%) are considered Nearctic–Neotropical migrants by the U.S. Fish and Wildlife Service. In the past 50 yr, scores of these migratory species, including some once considered common, have declined dramatically. Nearctic–Neotropical migrants normally spend 6–8 months in tropical habitats, making the identification, availability, and management of Neotropical habitats critical issues for their conservation. Yet, for most species, complete and nuanced information about their use of tropical habitats and the relative effects of breeding vs. wintering conditions on survival, productivity, and population trends is not available, though many studies point to Neotropical overwintering habitats as being a strong driver of population change. Particularly important for long-distance Nearctic–Neotropical migrants is an understanding of how “carry-over effects” arise and influence population trends when conditions on wintering grounds and tropical stopover areas affect subsequent reproductive performance on breeding grounds. For example, why some species show strong carry-over effects from tropical habitats while others do not is not fully understood. In recent years, many studies have offered insights into these issues by taking advantage of new scientific methods and technological innovations. In this review, we explore threats facing North American breeding birds that migrate to the Neotropics, summarize knowledge of habitat selection and use on the wintering grounds, describe how conditions at one point in the annual cycle may manifest in subsequent seasons or life history stages, and discuss conservation concerns such as climate change and the potential for phenological mismatch.

中文翻译：

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非繁殖地近北向热带候鸟的栖息地生态

摘要

在北美繁殖的约716种鸟类中，有386种（54％）被美国鱼类和野生动物服务局视为近北向新移民。在过去的50年中，这些迁徙物种的数量急剧下降，其中包括曾经被视为常见的一些物种。南北向—新移民通常在热带栖息地中度过6到8个月，这使新热带栖息地的识别，可用性和管理成为其保护的关键问题。但是，对于大多数物种，尚无法获得有关其使用热带栖息地以及繁殖与越冬条件对生存，生产力和种群趋势的相对影响的完整而细致的信息，尽管许多研究指出，新热带越冬栖息地是一个强有力的选择。人口变化的驱动力。对于长距离近北向新移民而言，特别重要的是要了解越冬地和热带中转区的状况影响繁殖地随后的繁殖表现时，“残留效应”如何产生并影响种群趋势。例如，为什么某些物种显示出来自热带栖息地的强烈残留效应，而另一些却没有完全理解。近年来，许多研究通过利用新的科学方法和技术创新提供了对这些问题的见解。在这篇评论中，我们探讨了迁移到新热带地区的北美种禽面临的威胁，总结了越冬地栖息地选择和使用的知识，描述了在随后的季节或生活史阶段，一年周期中某一点的状况可能如何表现，