RUI: Experimental and Landscape Analyses of the Decline of a Neotropical Migrant

本研究将分析景观因素和干扰竞争对新热带迁徙的金翅莺(Vermivora Chrysoptera)数量的影响。这一物种已经衰落，甚至从其活动范围的很大一部分中消失了。这种下降归因于繁殖栖息地的丧失，或与入侵同类的行为相互作用，或冬季栖息地的丧失。野外研究将确定金翅林莺单独使用的筑巢栖息地的植被特征，以及与蓝翅莺(V.Pinus)共生的栖息地的植被特征。景观分析，利用当前和历史的航空照片，将评估区域筑巢栖息地可用性的变化，并将与金翅莺丰度的变化相关联。栖息地是否与邻近的蓝翅莺一起使用，以及在试验性地移除蓝翅莺后使用的变化将被确定。筑巢成功与否将与蓝翅莺的接近程度和筑巢环境的营养特性有关。这些研究将有助于确定这两个同系物的共存是否更多地受到对特定栖息地的专门适应或它们的行为相互作用的限制。这些对繁殖季节的分析可能会让我们洞察冬季栖息地丧失的相对重要性。鉴于全球气候和土地利用模式的快速变化，这一结果也可能具有更普遍的意义。

This research will analyze the effect of landscape factors and interference competition on the abundance of a neotropical migrant, the Golden-winged Warbler (Vermivora chrysoptera). This species has declined and even disappeared from a large portion of its range. This decline has been attributed to a loss of breeding habitat, or to behavioral interactions with an invading congener, or to a loss of winter habitat. Field studies will determine the vegetative characteristics of the nesting habitat used by the Golden-winged Warbler alone and in sympatry with the Blue-winged Warbler (V. pinus). Landscape analyses, utilizing current and historical aerial photographs, will assess changes in the regional availability of nesting habitat, and will be correlated with changes in Golden-winged Warbler abundance. Habitat use with and without neighboring Blue-winged Warblers, and changes in use following experimental removal of Blue-winged Warblers will be determined. Nesting success will be related to Blue-winged Warbler proximity and to vegetative characteristics of nesting habitat. These studies will help determine if coexistence of these two congeners is limited more by specialized adaptations to a particular habitat or by their behavioral interactions. These analyses of the breeding season may provide insight about the relative significance of winter habitat loss. The results may also be of more general significance in light of rapid changes in global Climate and land use patterns.