Data from: Immigrant song: males and females learn songs post-dispersal in a tropical bird

A fundamental hypothesis about vocal learning is that young animals learn vocalizations in their natal areas and, following post-natal dispersal, they may introduce new types of vocalizations into their breeding areas. We tested this hypothesis in a tropical bird, the Rufous-and-white Wren (Thryophilus rufalbus), a species in which both sexes produce learned songs. We collected blood samples and acoustic recordings from 146 adult wrens from three populations in northwestern Costa Rica. We genotyped individuals at 10 polymorphic microsatellite loci and identified first-generation migrants using partial Bayesian genotype assignment. We quantified acoustic variation by comparing fine-scale acoustic structure, song sharing, and repertoire novelty between residents and first-generation migrants. We found significant population-level differences in acoustic structure of songs among the three populations. Of the 146 individuals genotyped, 9 individuals were identified as first-generation migrants. In contrast to our predictions, however, we found that these first-generation migrants did not exhibit differences in the acoustic structure of their songs from resident individuals in their breeding population, either for males or females. We conclude that song learning in first-generation migrants must be behaviourly influenced by birds in their breeding populations, following post-natal dispersal. We observed population-level acoustic differences among the three study sites, which implies sustained divergent selection pressures at each site, possibly reflecting acoustic adaptation to different environments or social pressure to sing local songs. Understanding and quantifying patterns of cultural evolution at multiple scales provides insight into how behavioural barriers, such as acoustic signals, contribute to population differentiation and even speciation.关于鸣声学习的一项核心假说认为，幼年动物会在其出生区域习得鸣唱，在完成出生后扩散后，它们可将新型鸣唱引入自身的繁殖区域。我们以热带鸟类棕白苇鹪鹩（Rufous-and-white Wren，学名Thryophilus rufalbus）为研究对象验证该假说，该物种雌雄个体均能习得鸣唱。我们从哥斯达黎加西北部的三个种群中采集了146只成年个体的血液样本与鸣声录音。我们针对10个多态性微卫星位点（microsatellite loci）对个体开展基因分型，并通过部分贝叶斯基因型分配法（partial Bayesian genotype assignment）鉴定出第一代移民个体。我们通过对比留居个体与第一代移民个体的精细鸣声结构、鸣唱共享模式以及曲目新颖性，对鸣声变异程度进行了量化。研究发现，三个种群的鸣唱鸣声结构存在显著的种群水平差异。在完成基因分型的146只个体中，共鉴定出9只第一代移民个体。然而与预设相悖的是，无论雄性还是雌性，这些第一代移民个体的鸣唱鸣声结构与繁殖区域内的留居个体均无显著差异。据此我们推断，第一代移民个体在出生后扩散至繁殖区域后，其鸣唱学习必然受到当地种群个体的行为影响。我们在三个研究样地间观测到种群水平的鸣声差异，这表明各研究样地均存在持续的歧化选择压力，这可能反映了鸣声对不同环境的适应性，或是个体需遵循社会压力以演唱本地特有鸣唱。理解并量化多尺度下的文化进化模式，有助于揭示包括鸣声信号在内的行为障碍如何推动种群分化乃至物种形成。