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

鸟类繁殖地选择的研究主要集中在不同空间尺度上的植物类型和景观结构的粗略特征上。一个更广泛的办法是纳入可能影响某一特定地点某一特定鸟类的存在和丰富程度的其他因素(例如，食物等资源的丰富程度)。然而，很少有人对可能限制鸟类数量的替代因素进行比较。这项研究将测试和比较三个限制夏威夷沼泽鸟类丰度的潜在因素：(1)当地栖息地结构和景观特征，(2)食用植物的能量含量和能量丰度，(3)食用植物的营养成分。沼泽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中心问题，对包括鸟类在内的大多数物种都知之甚少。这将只是第二种鸟类被调查了如此广泛的一系列潜在限制因素的丰度。这项研究的结果也将为夏威夷的湿地管理者提供重要信息，帮助他们更好地管理这种濒危物种。

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.