DISSERTATION RESEARCH: The Evolution of Hummingbird Coloration and Courtship Displays

动物拥有令人难以置信的多种夸张特征，它们利用这些特征进行交流，动物通常使用多种特征进行交流。这种信号多样性是如何产生的，以及为什么动物使用不止一种特征来交流，这一直是科学家们感兴趣的问题。为了理解多种信号特征的多样性是如何进化的，我们正在研究蜂鸟的彩虹色羽毛和夸张的求爱表现。彩虹色依赖于角度，蜂鸟可以很容易地操纵观察到的颜色，因为它们的行为显示。pi们正在探索彩虹羽毛的表面和内部结构是如何与蜂鸟的求偶表演（穿梭）共同进化的。PIs的工作结合了微观和纳米尺度结构形态学的测量与行为生态学和进化理论，使PIs能够理解蜂鸟从行为到羽毛结构的交流。此外，pi将收集蜂鸟交配和求偶生物学的数据，特别是蜂鸟在求偶时如何利用环境的数据，这可能对未来的保护工作有用。此外，最近对彩虹蝴蝶翅膀鳞片结构的研究有助于开发更高效的太阳能电池板。通过更好地了解生物材料如何定向反射特定波长的光，PIs对蜂鸟羽毛的角度依赖纳米结构的研究可以进一步帮助提高太阳能电池板的效率。动物具有多种多样的观赏特征和展示行为，许多动物具有多种用于交流的观赏特征和展示行为。之前的研究通过研究这些特征与环境的关系来解释这些特征的多样性；然而，这些特征在展示时也可以相互作用，这将进一步塑造它们的进化史。通过对蜜蜂蜂鸟部落中几个物种的比较研究，pi正在测试观赏性状、展示行为和环境之间的相互作用如何影响这些性状的多样性。蜂鸟是这类研究的理想对象，因为它们具有两种明显的视觉特征——彩虹色的羽毛和刻板的求偶表现（穿梭）——而这两种特征在不同物种之间是不同的。彩虹色与角度有关，因此观察到的颜色根据羽毛结构和观察/光照角度而变化。因此，感知到的颜色是行为表现、环境以及彩虹羽毛的微观和纳米结构之间相互作用的结果。pi目前正在研究几种蜂鸟中这些因素之间复杂的相互作用，以了解每种蜂鸟如何产生被接收器感知的特定颜色，以及这种颜色在种间如何变化。pi正在通过评估羽毛的荧光微观和纳米结构的变化如何帮助形成蜜蜂蜂鸟羽毛，展示和环境之间的进化关系来扩展这项工作。这项工作使pi能够研究蜂鸟的交流是如何在多个层面上进化的，从行为到它们装饰品的纳米结构。

Non-technical paragraphAnimals possess an incredible diversity of exaggerated traits that they use for communication, and often animals communicate using multiple traits. How this signal diversity came about and why animals use more than one trait to communicate has long interested scientists. To understand why and how this diversity in multiple signaling traits evolved, we are studying hummingbird iridescent plumage and exaggerated courtship displays. Iridescent coloration is angle-dependent and hummingbirds can easily manipulate the color observed as they behaviorally display. The PIs are exploring how the surface and internal structures of iridescent feathers co-evolved with courtship displays (shuttles) across hummingbird species. The PIs work combines measurements of micro- and nano-scale structural morphology with behavioral ecology and evolutionary theory, allowing the PIs to understand hummingbird communication from the behavior down to feather architecture. Additionally, the PIs will collect data on hummingbird mating and courtship biology, especially in terms of how hummingbirds use their environment while courting, which could prove useful to future conservation efforts. Additionally, recent work on the structure of iridescent butterfly wing scales has helped the development of more efficient solar panels. The PIs work on the angle-dependent nanostructures of hummingbird feathers could further help improve solar panel efficiency through a better understanding of how biological materials directionally reflect specific wavelengths of light.Technical paragraphAnimals exhibit a great diversity of ornamental traits and display behaviors, and many animals possess multiple such traits that they use to communicate. Previous work has explained the diversity in these traits by examining how they evolved in relation to the environment; however these traits can also interact with each other as they are displayed, which will further shape their evolutionary history. The PIs are testing how interactions between ornamental traits, display behaviors, and environment influence the diversity of these traits through a comparative study on several species in the bee hummingbird tribe. Bee hummingbirds are ideal for this type of study because they possess two types of conspicuous visual traits - iridescent plumage coloration and stereotyped courtship displays (shuttles) - that vary across species. Iridescent coloration is angle-dependent, such that the observed color changes depending upon the feather structure and viewing/lighting angles. Thus, perceived coloration is the result of interactions between behavioral displays, the environment, and the micro- and nanostructures of iridescent feathers. The PIs are currently studying the complex interactions between these factors in several hummingbird species to understand how each species produces a specific color that is perceived by a receiver, and how this varies interspecifically. The PIs are expanding this work by evaluating how variation in iridescent micro- and nanostructure of feathers helped shaped the evolutionary relationships between bee hummingbird plumage, display, and environment. This work allows the PIs to study how hummingbird communication evolved at multiple levels, from behaviors to nanostructure of their ornaments.