Gardner Timothy J, Naef Felix, Nottebohm Fernando
Laboratory of Animal Behavior, Rockefeller University, New York, NY 10021, USA.
Science. 2005 May 13;308(5724):1046-9. doi: 10.1126/science.1108214.
Canary song is hierarchically structured: Short stereotyped syllables are repeated to form phrases, which in turn are arranged to form songs. This structure occurs even in the songs of young isolates, which suggests that innate rules govern canary song development. However, juveniles that had never heard normal song imitated abnormal synthetic songs with great accuracy, even when the tutor songs lacked phrasing. As the birds matured, imitated songs were reprogrammed to form typical canary phrasing. Thus, imitation and innate song constraints are separate processes that can be segregated in time: freedom in youth, rules in adulthood.
简短的固定音节重复形成乐句，乐句再组合形成歌曲。即使是单独饲养的幼鸟的歌声也有这种结构，这表明先天规则支配着金丝雀歌声的发展。然而，那些从未听过正常歌声的幼鸟却能极其准确地模仿异常的合成歌曲，即使示范歌曲缺乏乐句结构。随着鸟儿逐渐成熟，模仿的歌曲会被重新编排以形成典型的金丝雀乐句。因此，模仿和先天的歌声限制是可以在时间上分开的不同过程：幼年时自由，成年后遵循规则。
