Comparative Studies of Vocal Learning

鸣禽的声乐学习是一种复杂的运动技能，年轻的雄鸟记住成年鸟的歌曲，然后用它们的记忆来控制自己的歌曲输出。鸟类声乐学习的一个结果是形成了声乐方言，在这种方言中，一个地方的雄鸟会唱出与其他地方的雄鸟不同的类似歌曲。直到最近，人们一直认为方言的形成涉及一个单一的过程：幼鸟在同一时间模仿一个或多个成年鸟，并将幼鸟安顿在繁殖区域。最近的证据表明，对在不同时间和地点全部或部分获得的大量曲目中的歌曲进行选择性消耗的独立过程也可能导致邻居之间的歌曲共享。本研究将探讨歌曲生产过剩和选择性流失在地方歌曲方言形成中的作用。PI将采取比较的方法，通过研究不同亚种的白冠麻雀（斑鸠）。野外观察、实验室和野外实验将进行比较，在一个亚种中形成当地方言的（Z. l. oriantha或Z. l. leucophrys）与另一个亚种中不形成当地方言的（Z. l. gambelii），声音发育的过程。在野外，PI将观察雄鸟在定居领地时的声音互动，并在早春确定它们的歌曲制作曲目的大小，并比较它们是否有选择地保留或拒绝与邻居匹配的歌曲。这将检验在进化多样化过程中发育途径是保守的这一假设，而变化通常发生在最终阶段。然后，PI将进行现场和实验室回放测试，对比两个亚种雄性的鸣声匹配行为。这些实验旨在揭示歌曲感知分类的差异，并确定歌曲类型感知可能存在的基于基因的差异。PI还将采用一种新的方法来测量歌曲学习，这种方法独立于模仿的产生，以检查歌曲在敏感阶段和随后的存储间隔期间是如何记忆的。最后，PI将进行一项歌曲学习实验，以评估与磁带辅导相比，现场导师是否会改变或延长歌曲习得的早期敏感阶段。

9513821 Nelson Vocal learning in song birds is a complex motor skill in which young males memorize the songs of adults, and then use their memory to control their own song output. One consequence of vocal learning in birds is the formation of vocal dialects in which males at one locality sing similar songs that differ from those of males at other localities. Until recently, it has been assumed that a single process is involved in the formation of dialects: the young bird imitates one or more adults at the time and place the youngster settles upon a breeding territory. Recent evidence suggests that an independent process of selective attrition of songs from a large repertoire acquired in whole or in part at a different time and place can also lead to song sharing between neighbors. The proposed research will examine the role of song overproduction and selective attrition in the formation of local song dialects. The PI will take a comparative approach by studying different subspecies of the white-crowned sparrow (Zonotrichia leucophrys). Field observations, and laboratory and field experiments will be conducted to compare processess of vocal development in one subspecies that does form local dialects (Z. l. oriantha or Z. l. leucophrys) with another that does not (Z. l. gambelii). In the field, the PI will observe vocal interactions between males as they settle upon territories, and determine the sizes of their song production repertoire early in Spring, and compare whether they selectively retain or reject songs that match their neighbors. This will test the hypothesis that developmental pathways are conserved during evolutionary diversification, and that changes often are made to terminal stages. The PI will then conduct field and laboratory playback tests contrasting the song matching behavior of males of two subspecies. These experiments are designed to reveal differences in the perceptural categorization of songs, and to identify possible genetically-based differences in song pe rception. The PI will also employ a new method for measuring song learning that is independent of the production of imitations to examine how songs are memorized during the sensitive phase and during the subsequent storage interval. Finally, the PI will conduct a song learning experiment to assess whether live tutors modiy or extend the early sensitive phase for song acquisition, as compared with tape tutoring.