Mechanics and Evolution of Tonal Sounds Produced by Feathers

鸟类被广泛认为是高度发声的，几十年来，研究人员一直在探索鸟类发声器官--鸣管的力学和生理学。 然而，鸟类也产生各种各样的非声乐交流声音。 例子包括鹬用尾羽发出的“扬场”声，或鸭子和鸽子在飞行时用翅膀发出的“哨声”。 这个研究项目将探讨一些羽毛在飞行过程中如何摆动产生响亮的音调声音的物理机制，以及羽毛产生的声音如何以及为什么一再导致鸟类非声乐声学通信的进化。 首先，将调查产生这些声音的20多个鸟类家族的自然历史收藏品（博物馆皮肤和录音），以确定这些声音的羽毛形态和多样性。 第二，将在孤立的羽毛上进行风洞测试，以测试羽毛如何摆动以产生声音的生物力学。 第三，以一系列蜂鸟为实验对象，进行野外实验，探索蜂鸟的行为表现与发出的声音之间的关系，以及这些信号的演变。通过研究，揭示羽毛发出音调声音的物理机制，以及不同大小和形状的羽毛如何发出不同的声音。 这些声音通常是在精心制作的求偶表演中产生的，了解羽毛如何产生音调声音的机制将有助于了解信号的演变。 更广泛地说，这项研究将通过与拉丁美洲科学家的合作促进国外的科学发展。 这项研究的结果将通过同行评审的科学出版物传播，并通过面向中学生理科学生的教育模块等方式向更广泛的公众受众传播。 最终，这项研究可能会有技术应用，例如新型的发声设备。

Birds are widely appreciated as being highly vocal, and for decades researchers have explored the mechanics and physiology of birds' vocal apparatus, the syrinx. However, birds also produce a wide variety of non-vocal communication sounds. Examples include the 'winnowing' sound snipe make with their tail-feathers, or the 'whistling' sounds ducks and doves make with their wings during flight. This research project will examine the physical mechanics of how some feathers flutter to produce loud tonal sounds during flight, and how and why sounds produced by feathers has repeatedly resulted in the evolution of non-vocal acoustic communication in birds.Three complementary approaches will be used. First, natural history collections (museum skins and sound recordings) of over 20 families of birds that produce these sounds will be surveyed to establish the feather morphologies and diversity of these sounds. Second, wind tunnel tests will be conducted on isolated feathers to test the biomechanics of how feathers flutter to produce sound. Third, field experiments will be conducted on a range of hummingbird species as a benchmark for the laboratory experiments, to explore the relationship between behavioral displays and sounds that are produced, and to examine the evolution of these signals.This research will uncover the physical mechanisms responsible for causing feathers to produce tonal sounds, and how a diversity of sounds can be produced with feathers of varying size and shape. These sounds are often produced during elaborate courtship displays, and understanding the mechanics of how feathers produce tonal sounds will provide insights into the evolution of signals. More broadly, this research will foster scientific development abroad through collaborations with scientists in Latin America. The results of this research will be disseminated through peer-reviewed scientific publications and to a broader public audience, such as through educational modules for middle school science students. Ultimately, this research may have technological applications, such as new types of sound production devices.