Dingle C, Halfwerk W, Slabbekoorn H
Bird Behavioural Ecology Group, Zoology Department, University of Cambridge, Cambridge, UK.
J Evol Biol. 2008 Jul;21(4):1079-89. doi: 10.1111/j.1420-9101.2008.01536.x. Epub 2008 Apr 25.
Song divergence among populations can theoretically lead to reproductive divergence and speciation. Despite many studies, this theory is still controversial. Habitat differences have been shown to shape songs, but few studies have looked for a link between ecologically driven acoustic and genetic divergence. We tested whether environmental selection has driven song divergence in two genetically distinct, but hybridizing, subspecies of the grey-breasted wood-wren (Henicorhina leucophrys) in Ecuador. Several acoustic features showed significant divergence between the subspecies. Spectral song divergence correlated with ambient noise profiles which differed significantly between the habitats of both subspecies. Temporal song divergence also corresponded as expected to vegetation density. However, in terms of quantified levels of reverberations, we found no significant differences in habitat-dependent sound transmission properties. We conclude that ecological niche segregation may explain acoustic divergence among the two wren subspecies. The resulting habitat-dependent song divergence may have contributed to reproductive divergence by guiding assortative mating in parapatric conditions or just currently contribute to maintenance of reproductive isolation upon secondary contact.
种群间的鸣声差异理论上可导致生殖差异和物种形成。尽管有许多研究，但该理论仍存在争议。已有研究表明栖息地差异会影响鸣声，但很少有研究探寻生态驱动的声学差异与遗传差异之间的联系。我们测试了环境选择是否推动了厄瓜多尔灰胸林鹩（Henicorhina leucophrys）两个遗传上不同但正在杂交的亚种之间的鸣声差异。几个声学特征在这两个亚种之间表现出显著差异。鸣声的频谱差异与环境噪声分布相关，这两个亚种的栖息地环境噪声分布存在显著差异。鸣声的时间差异也如预期的那样与植被密度相对应。然而，就混响的量化水平而言，我们发现与栖息地相关的声音传播特性没有显著差异。我们得出结论，生态位分离可能解释了这两种鹩亚种之间的声学差异。由此产生的与栖息地相关的鸣声差异可能通过在邻域条件下引导选型交配促进了生殖差异，或者目前仅在二次接触时有助于维持生殖隔离。
