Vocal learning and cultural evolution in temperate and tropical animals

在地球上的八种动物中，包括人类和鸣禽，幼崽通过倾听成年人的声音来学习交流。发声学习对行为生态学有着重要的影响——例如，学习发声对于保卫领土和吸引配偶至关重要——以及对进化生物学——例如，学习促进地理变异，从而影响种群分化和物种形成。鸟类为研究声音学习提供了一个杰出的模型系统，因为它们产生不同的声音信号，因为它们的生成时间短，因为它们对实验回放的反应强烈，使得操纵学习过程成为可能。传统的研究主要集中在雄性、温带动物和圈养个体的学习上，而我建议对雄性和雌性发声、温带和热带动物以及自然环境中的野生动物进行高度创新的研究。我将与一个由学生和博士后组成的团队，对两个模型系统进行研究：一个是温带麻雀种群，它的高回报率使我们能够跟踪鸟类从出生到成年；还有一群热带鹪鹩，两性都唱独唱和协调的二重唱。我们将使用定制设计的扬声器阵列来模拟教师参与现实的声音互动，教雏鸟唱歌。在本研究的A部分，我们将通过实验研究关于声乐学习的新观点。我们将测试这样的假设：幼小的动物更倾向于学习在互动中听到的歌曲，而不是单独的广播；动物早期的声音环境和它们繁殖前的社会环境都会改变声音学习；幼小的动物会优先学习难以演奏的高性能歌曲；热带鸟类通过听成年鸟唱歌来学习二重唱。在第二部分，我们将进行纵向分析来研究热带鹪鹩的声乐学习。我们将测试热带鸟类表现出性别特异性声音谱系的假设，以及热带鸟类通过遵循“二重奏代码”来学习从它们复杂的声乐曲目中组合特定的歌曲的假设。在C部分，我们将研究温带和热带鸟类的文化进化，记录声音随时间和空间的变化模式，以更好地理解模仿、创新、选择和漂变。独特的是，我们将通过量化我们使用模拟声乐导师引入的歌曲的演变来测试和完善文化进化的理论模型。这项研究将为动物的行为、生态学和进化生物学提供开创性的见解，并回答有关声乐学习和文化进化的新问题。这项研究可以让我培养许多年轻的加拿大科学家，并开发研究野生动物的创新技术。

In eight groups of animals on Earth, including humans and songbirds, juveniles learn to communicate by listening to adults. Vocal learning has important consequences for behavioural ecology – for example, learned vocalizations are critical for defending territories and attracting mates – and for evolutionary biology – for example, learning promotes geographic variation and thereby influences population divergence and speciation. Birds provide an outstanding model system for studying vocal learning because they produce diverse vocal signals, because they have short generation times, and because they respond strongly to experimental playback, making it possible to manipulate the learning process. Whereas traditional studies have focused on learning in males, temperate animals, and captive individuals, I propose highly innovative studies on both male and female vocalizations, on both temperate and tropical animals, and on wild animals in their natural environment. With a team of students and postdocs, I will conduct research on two model systems: a population of temperate sparrows where an unusually high return-rate allows us to track birds from birth to adulthood; and a population of tropical wrens where both sexes sing solo songs and coordinated vocal duets. We will teach songs to young birds using arrays of custom-designed loudspeakers that simulate tutors engaged in realistic vocal interactions. In part A of this investigation, we will experimentally investigate new ideas about vocal learning. We will test hypotheses that young animals preferentially learn songs overheard during interactions rather than solo broadcasts; that both an animal’s early acoustic environment and their pre-breeding social environment modifies vocal learning; that young animals preferentially learn high performance songs that are difficult to perform; and that tropical birds learn to perform duets by listening to adults. In part B, we will conduct longitudinal analyses to study vocal learning in tropical wrens. We will test hypotheses that tropical birds exhibit sex-specific vocal lineages, and that tropical birds learn to combine particular songs from their complex vocal repertoires by following “duet codes”. In part C, we will study cultural evolution in both temperate and tropical birds, documenting patterns of acoustic changes through time and space to better understand imitation, innovation, selection, and drift. Uniquely, we will test and refine theoretical models of cultural evolution by quantifying the evolution of songs we introduce using simulated vocal tutors. This body of research will provide groundbreaking insight into the behaviour, ecology, and evolutionary biology of animals, and answer novel questions about vocal learning and cultural evolution. This research will allow me to train many young Canadian scientists, and develop innovative technologies for studying wild animals.