Studies of avian vocal development without exposure to conspecific song have been conducted in many passerine species, and the resultant isolate song is often interpreted to represent an expression of the genetic code for conspecific song. There is wide recognition that vocal learning exists in oscine songbirds, but vocal learning has only been thoroughly investigated in a few model species, resulting in a narrow view of birdsong learning. By extracting acoustic signals from published spectrograms, we have reexamined the findings of isolate studies with a universally applicable semi‐automated quantitative analysis regimen. When song features were analyzed in light of three different production aspects (respiratory, syringeal, and central programming of sequence), all three show marked interspecific variability in how close isolate song features are to normal. This implies that song learning mechanisms are more variable than is commonly recognized. Our results suggest that the interspecific variation shows no readily observable pattern reflecting phylogeny, which has implications for understanding the mechanisms behind the evolution of avian vocal communication. We emphasize that song learning in passerines provides an excellent opportunity to investigate the evolution of a complex, plastic trait from a phylogenetic perspective.

中文翻译：

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独立歌曲的歌曲特征特定分析揭示了学习组件中的种间差异。

在许多雀形目物种中已经进行了不接触同种歌曲的鸟类声带发育的研究，并且所得的分离出的歌曲通常被解释为代表同种歌曲的遗传密码的表达。人们广泛认识到，在鱼鸣鸟中存在声乐学习，但是仅在少数几个模型物种中对声乐学习进行了彻底的研究，从而导致了对鸟叫学习的狭narrow视野。通过从已发布的频谱图中提取声音信号，我们使用通用的半自动化定量分析方案重新检查了分离研究的结果。当根据三个不同的生产方面（呼吸，注射和序列的中央编程）分析歌曲特征时，在孤立歌曲特征与正常歌曲之间的接近程度方面，这三者均显示出明显的种间差异。这意味着歌曲学习机制比通常公认的更具可变性。我们的结果表明，种间变异显示没有容易观察到的反映系统发育的模式，这对于理解禽声通信的背后机制具有启示意义。我们强调，在雀形耳科的歌曲学习为从系统发育的角度研究复杂的可塑性特征的发展提供了极好的机会。这对于理解禽声通信演变的机制具有启示。我们强调，在雀形耳科的歌曲学习为从系统发育的角度研究复杂的可塑性特征的发展提供了极好的机会。这对于理解禽声通信演变的机制具有启示。我们强调，在雀形耳科的歌曲学习为从系统发育的角度研究复杂的可塑性特征的发展提供了极好的机会。