Brenowitz E A, Arnold A P
J Neurosci. 1986 Oct;6(10):2875-9. doi: 10.1523/JNEUROSCI.06-10-02875.1986.
Previous studies have demonstrated a correlation between song repertoire size and volume of song control regions (SCRs) in the brains of songbirds. In the present study we demonstrate that 2 congeneric species of tropical duetting wrens, the rufous-and-white wren (Thryothorus rufalbus) and the bay wren (T. nigricapillus), share the same relationship between SCR volume and vocal complexity. In each species, females sing in elaborate duets with males. Males of these species have similar song repertoire sizes; there is no significant difference between heterospecific males in the volumes of SCRs. Female rufous-and-white wrens have less than half as large a song repertoire as female bay wrens, and all of their SCRs measured are significantly smaller than those of bay wren females. This interspecific equivalence of the relationship between SCR volume and repertoire size suggests that the neural system regulating vocal behavior in songbirds is evolutionarily conservative in the manner in which it encodes song complexity.
先前的研究表明，鸣禽大脑中歌曲 repertoire 大小与歌曲控制区域（SCRs）的体积之间存在相关性。在本研究中，我们证明了两种同属的热带二重唱鹪鹩，棕白鹪鹩（Thryothorus rufalbus）和湾鹪鹩（T. nigricapillus），在 SCR 体积与发声复杂性之间具有相同的关系。在每个物种中，雌性与雄性进行精心编排的二重唱。这些物种的雄性具有相似的歌曲 repertoire 大小；不同物种雄性的 SCR 体积之间没有显著差异。棕白鹪鹩雌性的歌曲 repertoire 不到湾鹪鹩雌性的一半，并且它们所有测量的 SCR 都明显小于湾鹪鹩雌性的 SCR。SCR 体积与 repertoire 大小之间这种种间关系的等效性表明，调节鸣禽发声行为的神经系统在编码歌曲复杂性的方式上在进化上是保守的。
