Theory predicts that allometric constraints on sound production should be stronger for the lower frequencies of vocalizations than for the higher frequencies, which could originate from an allometry for sound frequency bandwidth. Using song recordings of approximately 1,000 passerine species (from >75% passerine genera), we show a significantly steeper allometry for the lower song frequencies than for the higher song frequencies, resulting in a positive allometry of frequency bandwidth: larger species can use wider bandwidths than smaller species. The bandwidth allometry exists in songbirds (oscines) but not in nonoscine passerines, indicating that it emerges from a combination of constraints to sound frequency production or transmission and the evolved behavior of oscines: unlike the narrow bandwidths of most nonoscine songs, the learned songs of oscines often use wide bandwidths that can be limited by both lower and upper constraints to sound frequency. This bandwidth allometry has implications for several research topics in acoustic communication.

中文翻译：

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鸣禽声频带宽的异速生长

理论预测，对于发声的较低频率，对声音产生的异速生长限制应该比较高频率更强，这可能源于声音频率带宽的异速生长。使用大约 1,000 种雀形目物种（来自 >75% 雀形目属）的歌曲录音，我们显示较低歌曲频率比较高歌曲频率明显更陡峭的异速生长，导致频率带宽的正异速生长：较大的物种可以使用更宽的带宽比较小的物种。带宽异速生长存在于鸣禽（oscines）中，但不存在于 nonoscine 雀类中，这表明它是由对声音频率产生或传输的限制以及 oscines 进化行为的组合产生的：与大多数 nonoscine 歌曲的窄带宽不同，oscines 的学习歌曲通常使用很宽的带宽，这些带宽可能会受到声音频率的上下限的限制。这种带宽异速生长对声学通信的几个研究课题有影响。