Dissertation Research: Comparing habitat vs. nutrition limits of abundance in an avian herbivore

鸟类繁殖地选择的研究大多集中在不同空间尺度下植物类型和景观结构的粗略特征上。一种更广泛的方法是将可能影响某一特定地点某一特定鸟类的存在和数量的其他因素（例如，食物等资源的丰富程度）纳入其中。然而，很少有可能限制鸟类数量的其他因素的比较。本研究将测试和比较限制濒危沼泽鸟类夏威夷摩尔亨丰度的三个潜在因素：(1)当地栖息地结构和景观特征；(2)食物植物的能量含量和能量丰度；(3)食物植物的营养成分。mororhen丰度将使用一套统计模型进行预测，这些模型将进行比较，以确定最具预测性的丰度关系。限制物种分布和丰度的因素是生态学中的一个核心问题，对大多数物种，包括鸟类，知之甚少。这将是第二个对如此广泛的潜在限制因素进行丰度调查的鸟类。这项研究的结果也将为夏威夷湿地管理者如何更好地管理这种濒危物种提供重要信息。

Most research on bird breeding site selection focuses on coarse characteristics of plant type and landscape structure at a variety of spatial scales. A broader approach would be to incorporate other factors (e.g., abundance of resources such as food) that might influence the presence and abundance of a given bird species at a particular site. However, there have been few comparisons of alternative factors that might limit bird populations. This study will test and compare three potential factors limiting the abundance of the Hawaiian moorhen, an endangered marsh bird: (1) local habitat structure and landscape features, (2) energy content and energy abundance of food plants, (3) and nutrient components of food plants. Moorhen abundance will be predicted using a suite of statistical models that will be compared to determine the most predictive relationships of abundance. Factors limiting the distribution and abundance of species are a central problem in ecology, and are poorly understood for most species, including birds. This will be only the second bird species for which such a wide suite of potentially limiting factors on abundance has been investigated. Results of this research also will provide important information for wetland managers in Hawaii on how to better manage this endangered species.