Odom Karan J, Omland Kevin E, Price J Jordan
Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland, 21250.
Evolution. 2015 Mar;69(3):839-47. doi: 10.1111/evo.12588. Epub 2015 Jan 20.
Female bird song and combined vocal duets of mated pairs are both frequently associated with tropical, monogamous, sedentary natural histories. Little is known, however, about what selects for duetting behavior versus female song. Female song likely preceded duet evolution and could drive apparent relationships between duets and these natural histories. We compared the evolution of female song and male-female duets in the New World blackbirds (Icteridae) by investigating patterns of gains and losses of both traits and their relationships with breeding latitude, mating system, nesting pattern, and migratory behavior. We found that duets evolved only in lineages in which female song was likely ancestral. Both female song and duets were correlated with tropical breeding, social monogamy, territorial nesting, and sedentary behavior when all taxa were included; however, correlations between duets and these natural history traits disappeared when comparisons were limited to taxa with female song. Also, likelihood values supported stronger relationships between the natural history traits and female song than between these traits and duets. Our results suggest that the natural histories thought to favor the evolution of duetting may in fact be associated with female song and that additional selection pressures are responsible for the evolution of duets.
雌鸟鸣叫以及配偶之间的联合二重唱通常都与热带、一夫一妻制、定居性的自然生活史相关。然而，对于二重唱行为与雌鸟鸣叫的选择因素却知之甚少。雌鸟鸣叫可能先于二重唱的进化，并且可能推动了二重唱与这些自然生活史之间的明显关联。我们通过研究这两种特征的获得与丧失模式以及它们与繁殖纬度、交配系统、筑巢模式和迁徙行为的关系，比较了新大陆黑鹂（拟鹂科）中雌鸟鸣叫和雌雄二重唱的进化。我们发现，二重唱仅在雌鸟鸣叫可能为祖先特征的谱系中进化。当纳入所有分类群时，雌鸟鸣叫和二重唱都与热带繁殖、社会一夫一妻制、领地筑巢和定居行为相关；然而，当比较仅限于有雌鸟鸣叫的分类群时，二重唱与这些自然生活史特征之间的相关性消失了。此外，似然值表明，自然生活史特征与雌鸟鸣叫之间的关系比与二重唱之间的关系更强。我们的结果表明，那些被认为有利于二重唱进化的自然生活史实际上可能与雌鸟鸣叫有关，而二重唱的进化是由额外的选择压力导致的。
