Dissertation Research: Significance of Inter-Specific Variation in Plumage Patterns of Birds

[3311004]谢弗：对物种颜色模式差异的解释通常涉及感知系统的变化，例如女性的偏好。因为颜色的显著性取决于环境，所以环境的特性也会影响颜色模式的演变。通过观察和实验研究，Karen Marchetti女士已经表明，可以从影响信号传输的环境和行为特征来预测毛状黄莺属物种之间颜色模式的差异。她在繁殖季节在一个地方进行了研究，重点研究了性选择机制（雌性选择和雄性竞争）。现在，她将把研究范围扩大到非繁殖季节和地理变化。首先，她将通过实验操纵一种鸟类的羽毛模式，以检验潜在的选择性力量（如捕食），这种力量可以在繁殖季节平衡已确定的选择性力量。其次，她将在繁殖季节研究一个新的地方，测量（物种内）颜色的地理变化与栖息地地理变化的关系程度。第三，她将研究其他鸟类群体的栖息地联系和展示运动，以确定影响Phylloscopus颜色进化的因素可以推广到何种程度。这篇博士论文的研究将对进化和行为生物学的许多重要领域做出贡献。它将揭示导致雄性和雌性外表相同或不同的条件，性选择的机制，以及非繁殖季节对影响外观和羽毛图案进化的重要性。

9311004 Shaffer Explanations for species differences in color patterns have usually invoked variation in perceptual systems, such as female preferences. Because conspicuousness of color depends upon context, properties of the environment should also affect the evolution of color patterns. Through observational and experimental studies, Ms. Karen Marchetti has shown that differences in color patterns among warbler species of the genus Phylloscopus can be predicted from environmental and behavioral features that affect signal transmission. Her studies were conducted at one locality in the breeding season, and concentrated on mechanisms of sexual selection (female choice and male-male competition). Now she will extend the study to encompass the non-breeding season and geographical variation. First, she will experimentally manipulate plumage patterns of one species, which maintains individual territories through the winter, in order to examine potential selective forces (such as predation) that could balance identified selective forces in the breeding season. Second, she will study a new locality in the breeding season, measuring the extent to which geographical variation in coloration (within species) is associated with geographic variation in habitat. Third, she will examine habitat associations and display movements in other groups of birds to determine the extent to which factors influencing the evolution of coloration in Phylloscopus can be generalized. This doctoral-dissertation research will contribute to a number of important areas in evolutionary and behavioral biology. It will shed light on the conditions that lead to sameness or difference in appearance between males and females, on the mechanisms of sexual selection, and on the importance of the non-breeding season in affecting the evolution of displays and plumage patterns.