背条螳臂树蛙鸣声的繁殖性状替代

Reproductive Character Displacement in the Call of Chiromantis doriae

繁殖性状替代(RCD)是指为减弱种间的繁殖干扰而产生的性状进化现象。重叠分布的物种通过繁殖性状的分化降低繁殖干扰,维持种间界线,是物种应对种间繁殖干扰的重要策略之一。无尾两栖类的求偶/择偶过程主要依赖声音通讯,本研究以声音通讯为手段研究背条螳臂树蛙Chiromantis doriae鸣声的RCD过程和机制。背条螳臂树蛙和侧条费树蛙Feihyla vittata分别属于树蛙科Rhacophoridae螳臂树蛙属Chiromantis和费树蛙属Feihyla,但二者形态特征相似、繁殖期重叠、鸣声频率接近、求偶信号彼此遮蔽,因此二者间存在一定程度的繁殖干扰。同域/异域背条螳臂树蛙的鸣声特征比较分析结果表明,背条螳臂树蛙的求偶鸣声包含4～8音节,对鸣声提取8项声音特征参数进行主成分分析,得到3个主成分。混合线性模型分析结果表明,反映时域特征及调频特征的主成分PC3在同域/异域分布的种群间的差异有统计学意义,而另2个主成分在同域/异域分布的种群间的差异无统计学意义。为比较同域/异域种群间的音节特征,对音节主频、音节时长和音节间隔3个参数进行混合线性模型分析,结果表明,音节主频和音节时长在同域/异域种群间的差异有统计学意义,音节间隔在同域/异域种群间的差异无统计学意义。总体而言,同域分布的背条螳臂树蛙鸣声频率更低、时长更长、调频更明显,有助于拉大与侧条费树蛙主频高、时长短的单音节鸣声间的差异。背条螳臂树蛙在鸣声特征上存在RCD现象,证明非近缘物种也可产生RCD,拓展了RCD的范围。

Reproductive character displacement (RCD) is a phenomenon of character evolution to reduce the reproductive interactions between species. It is one of the important strategies for sympatric species to deal with the interspecific repro- duction interference by using diverse reproductive traits to maintain the species boundary. Anuran species mainly rely on sound communication for breeding. In this research, we studied RCD by using the call of Chiromantis doriae. C. doriae and Feihyla vittata belong to different genus in Rhacophoridae. However, these 2 species have similar morphologies, male call spectral characteristics, breeding seasons and breeding micro-environments, which indicates the reproductive interference to some extent. We chose C. doriae as the research object, to compare the call parameters with the sympatric and allopatric C. dor/ae. We obtained 3 principal components from 8 call parameters. Mixed linear model analysis showed that only the PC3 which is related to the temporal cues and frequency modulation, was significantly different between the 2 sympatric and allopatric populations. In note parameters, the results of mixed linear model analysis showed that the main frequency and duration of note were significantly different between sympatric and al!opatric populations, and no significant difference was observed in note interval. In general, sympatric population had lower domain frequency, longer duration and more obvious frequency modulation than allopatric population, which helped the sympatric C. doriae to enlarge the discrepancy between conspecific sighal and monosyllabic call of F. vittata with high dominant frequency and short duration. Our results demon- strate that RCD exists in the sound communication of C. doriae, or even in unrelated species, which expands the range of RCD in nature.