Behavioral Neurobiology Group, Department of Biology, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido, Japan.
Communication and Social Behaviour Group, Max Planck Institute for Ornithology, Eberhard-Gwinner-Straße, 82319, Seewiesen, Germany.
Biol Lett. 2020 Aug;16(8):20200399. doi: 10.1098/rsbl.2020.0399. Epub 2020 Aug 26.
The duets of birds have intrigued biologists for a long time, yet much remains unknown about the evolution of these striking collective displays. This is partly because previous studies on duet evolution have been biased to songbirds and neglected other bird groups. In songbirds, the absence of migration has been found to predict the occurrence of duetting, indirectlysupporting the idea that duet communication is linked with pair bonding. Here, we used phylogenetic comparative analyses in a sedentary clade of non-songbirds, the barbets (Capitonidae), to reveal new correlates of duet evolution. We found (i) that duets evolved several times independently in different barbet lineages and (ii) that duetting evolved in association with group living (i.e. the presence of helpers or non-breeding adults during the breeding period), but not with sexual monochromatism or habitat type. Our findings are consistent with a duet function in mate guarding and dominance against subordinate group members as well as joint territory defence. Altogether, the results highlight the importance of the social environment for the evolution of collective signalling.
鸟类的二重唱长期以来一直令生物学家着迷，但对于这些引人注目的集体展示的进化，仍有许多未知之处。这部分是因为以前关于二重唱进化的研究偏向于鸣禽，而忽略了其他鸟类群体。在鸣禽中，已经发现没有迁徙可以预测二重唱的发生，这间接支持了这样一种观点，即二重唱交流与配偶结合有关。在这里，我们在非鸣禽的一个定居的亲缘分支，伯劳科（Capitonidae）中使用系统发育比较分析，揭示了二重唱进化的新关联。我们发现 (i) 二重唱在不同的伯劳谱系中独立进化了多次，以及 (ii) 二重唱的进化与群体生活有关（即在繁殖期有帮手或非繁殖的成年个体），而与性单态性或栖息地类型无关。我们的发现与在配偶保护和对下属群体成员的支配方面以及共同领地防御方面的二重唱功能一致。总的来说，这些结果强调了社会环境对集体信号进化的重要性。
