Interactions between migratory shorebirds and soft-sediment intertidal systems in Atlantic Canada

北美许多种类的滨鸟正在经历种群数量的下降。长距离迁徙的滨鸟在整个活动范围内都容易受到栖息地退化的影响，包括在迁徙中途停留的地点。因此，维护中途停留地点的完整性是一项重要的保护目标，而对所涉生态系统的结构和功能的清楚了解有助于适当的栖息地管理。大西洋加拿大的沿海地区为大量滨鸟提供了中途停留的地点，这些滨鸟在夏末和秋季从北极迁徙到南部越冬地。芬迪湾是半足琵鹭的重要中途停留地。对这些鸟类对海湾的利用以及与该地区泥滩相关的生态群落进行了大量的研究。然而，其他沿海地区，如新不伦瑞克东部和新斯科舍省南部，对多种物种也很重要，但受到的关注要少得多。我建议研究滨鸟是如何与这些地点互动和使用这些地点的。具体地说，我将使用无线电跟踪技术来研究半肢解的琵鹭和半肢解的犁鸟的活动、栖息地利用和停留时间。我还将研究鸟类在现场的行为，并将其与栖息地特征和猎物的可用性联系起来。我将进行一项大范围的抽样研究，以评估整个研究区的场地特征，并将这些特征与大量滨鸟联系起来。在确定重要地点后，我将进行操纵性实验，以评估构成这些地点社区的生态相互作用。我还将调查不同栖息地的使用如何影响琵琶的饮食和育肥率。为了做到这一点，我将收集芬迪湾和其他沿海地区鸟类的血液样本，并分析血浆甘油三酯水平(肥胖率的指标)和稳定同位素水平(估计饮食的一种方法)。然后，我将对这两个地区的鸟类进行无线电跟踪，以确定它们在该地区停留的时间。最后，在这一领域以往工作的基础上，我将在潮间带泥滩上进行操控实验，以帮助我们了解殖民顺序对泥滩群落发展的影响，以及由此产生的滨鸟的猎物可获得性。这里提出的工作将加深我们对滨鸟在该地区迁徙中途停留地点的利用的了解。这将使我们能够测试关于活动和停留时间相对于饮食和肥胖率的假设，并将有助于建立识别关键滨鸟栖息地的预测模型。在我打算研究的这两种滨鸟物种中，加拿大占据了很大比例。因此，我们对保护它们负有重大责任。我的工作将有助于这一努力，为做出明智的保护决策提供一些必要的信息。

Many species of North American shorebirds are experiencing population declines. Shorebirds that migrate long distances are vulnerable to habitat degradation throughout their range, including on migratory stopover sites. Preserving integrity of stopover sites is thus an important conservation objective, and appropriate habitat management is facilitated by a clear understanding of the structure and function of the ecosystems involved. Coastal areas of Atlantic Canada provide stopover sites for large populations of shorebirds migrating from the Arctic to southern wintering grounds in late summer and fall. The Bay of Fundy is a critical stopover area for Semipalmated Sandpipers. Considerable research has been done on use of the Bay by these birds, and on the ecological community associated with mudflats in the region. However, other coastal sites, such as in eastern New Brunswick and southern Nova Scotia, are also important to multiple species but have received much less attention. I propose to examine how shorebirds interact with and use these sites. Specifically, I will use radio-tracking technology to examine movements, habitat use and duration of stay of Semipalmated Sandpipers and Semipalmated Plovers. I will also examine behaviour of birds at sites and link that to habitat characteristics and availability of prey. I will conduct a broad-scale sampling study to assess site characteristics across the study area, and link those with abundance of shorebirds. Following identification of important sites, I will conduct manipulative experiments to assess the ecological interactions that structure communities at these sites. I will also investigate how use of different habitats affects sandpiper diets and fattening rates. To achieve this, I will collect blood samples from birds in the Bay of Fundy and at other coastal sites, and analyze plasma triglyceride levels (an indication of fattening rates) and stable isotope levels (a way to estimate diet). I will then radio-track birds in both areas to determine how long they remain in the region. Finally, following up on previous work in this area, I will conduct manipulative experiments on intertidal mudflats to help us to understand the effects of order of colonization on development of the mudflat community, and resulting prey availability for shorebirds. The work proposed here will enhance our understanding of shorebird use of migratory stopover sites in this region. It will allow us to test hypotheses about movement and duration of stay relative to diet and fattening rate, and will contribute to predictive models identifying key shorebird habitat. Canada hosts a large proportion of the population of both shorebird species I propose to study. As such, we have a significant responsibility their conservation. My work will contribute to this effort, providing some of the information necessary to make informed conservation decisions.