Fooling the experts: accurate vocal mimicry in the song of the superb lyrebird, Menura novaehollandiae
- 作者：Anastasia H. Dalziell ; Anastasia.Dalziell@anu.edu.au ; Robert D. Magrath
- 关键词：birdsong ; Menura novaehollandiae ; mimicry ; repertoire ; rejection threshold ; sexual signal ; signal design ; song learning ; vocal accuracy ; vocal mimicry
- 刊名：Animal Behaviour
- 出版年：2012
- 期刊代码：77_00033472
- 类别：psy
- 出版时间：June, 2012
- 卷：83
- 期：6
- 页码：1401-1410
- 文件大小：418 K
摘要
The degree of resemblance between mimics and models provides valuable insight into the evolutionary dynamics of mimicry signalling systems, but for many systems mimetic resemblance has not been quantified. Superb lyrebirds have a reputation for accurately imitating an astonishing variety of sounds that they incorporate into their sexual displays. We assessed the accuracy with which males imitate the complex song of the grey shrike-thrush, Colluricincla harmonica. We measured vocal accuracy by (1) using playback experiments as a bioassay, to determine whether and how shrike-thrushes distinguish between their own song and imitations of shrike-thrush songs by lyrebirds and (2) comparing acoustic properties of mimicked and model songs. Shrike-thrushes reacted just as strongly towards mimetic song as to their own when songs were presented alone. When mimetic song was accompanied by lyrebird song sequences (emulating the lyrebird's natural singing style), shrike-thrushes still usually approached the speaker but less often than when mimetic song was presented alone or when model songs were broadcast. Acoustic analyses showed that imitations were remarkably similar to model songs. However, while lyrebirds maintained the structure and complexity of model songs, they sang fewer repetitions of individual element types. This 鈥榓bridging鈥?of model songs is consistent with a trade-off between demonstrating both mimetic accuracy and versatility. Overall, these results indicate strong selection on male lyrebirds to imitate accurately the complex vocalizations of other species, and show that species can integrate contextual information with the signal structure to distinguish between their own signals and imitations.