DISSERTATION RESEARCH: Sources of Selection on a Complex Signal in Sparrows

动物使用信号来识别自己物种的潜在配偶，并评估潜在配偶的质量。 因此，个体选择配偶的过程可能在物种形成中发挥作用。 鸟鸣是研究动物信号（包括人类语音）的产生、感知、发展和功能的重要模型系统。 这项研究的目的是确定鸟鸣的产生、感知和功能如何影响鸟鸣随着时间的推移而变化的方式。 一个有趣的变化模式，颤音部分的歌曲在30年的时间内，最近在五个不同的种群的白冠麻雀（Zonotrichia leucophrys）。 这种模式表明，颤音可能会改变，由于女性的选择或通过相关的变化与形态或栖息地结构的选择。 拟议中的研究使用实验和观察来测试女性的选择，形态变化和栖息地的变化在解释颤音进化模式的相对重要性。 这项研究是第一个评估在一个单一的物种是否这些多种力量的影响，随着时间的推移，歌曲的变化和选择和限制之间的潜在平衡，在多个人口的歌曲。 该项目的智力价值是增加对动物信号如何以及为什么随着时间的推移而变化的理解，并更普遍地增加对推动物种形成过程的科学理解。更广泛的影响：该项目将支持培训一名女研究生，并增加她实现作为科学界女性的职业目标的机会。 该项目的初步工作已经为几名理科女大学生的研究教育做出了额外贡献，其中包括来自代表性不足群体的女大学生。 该项目还将支持杜克大学和雷耶斯角鸟类观测站（PRBO）之间的合作。 这项合作的一部分将包括关于白冠麻雀繁殖栖息地和歌曲行为的长期趋势的知识交流，这可以在了解影响鸣禽种群生存能力的因素方面发挥宝贵的作用，从而有助于未来的保护。 最后，该项目的工作将导致长期保存和提供一套重要的现场录音的白冠麻雀种群超过30年的时间，目前存档在加州科学院。

Animals use signals to identify potential mates of their own species, and also to assess the quality of potential mates. Thus, the processes by which individuals choose mates may play a role in speciation. Bird song is an important model system for studying the production, perception, development, and function of animal signals, including human speech. The proposed research aims to identify how the production, perception and function of bird song influence the way bird song changes over time. An interesting pattern of change in the trilled portion of songs over a 30-year period was demonstrated recently in five different populations of white-crowned sparrows (Zonotrichia leucophrys). This pattern suggests that trills may be changing due to selection by female choice or through correlated change with morphology or with habitat structure. The proposed research uses experiments and observations to test the relative importance of female choice, morphological change, and habitat change in explaining patterns of trill evolution. This study is the first to assess in a single species whether these multiple forces influence changes in song over time and the potential balance between selection and constraints on song in multiple populations. The intellectual merit of this project is to increase understanding of how and why animal signals change over time and more generally to increase scientific understanding of processes driving speciation.Broader impacts: This project will support the training of one female graduate student and increase her chances of achieving her professional goals as a woman in science. Preliminary work on this project has already additionally contributed to the research education of several undergraduate women in science, including those from under represented groups. This project also will support collaboration between Duke University and the Point Reyes Bird Observatory (PRBO). Part of this collaboration will include an exchange of knowledge on long-term trends in white-crowned sparrow breeding habitat and song behavior, which can play a valuable role in understanding the factors that affect the viability of songbird populations and thus contribute to their conservation in the future. Finally, work on this project will lead to long-term preservation and availability of an important set of field audio recordings of white-crowned sparrow populations over a 30-year period and currently archived at the California Academy of Science.