When the subjects started singing the next spring, their repertoires were analyzed. The average was seven song types per subject. This does correspond with birds raised exclusively in the wild by their parents. Eight of the nine subjects learned songs from two or more of the tutors and later imitated these songs.
In similar experiments in which some birds are exposed to tutors and some are raised in isolation, those birds that were exposed to tutors almost always tend to imitate pieces and even complete songs. Those birds raised in isolation always sang isolate songs. These isolate songs were similar to each other and consist of much more structurally simpler songs than males raised with normal song exposure.
重点词汇:
song sparrows: 北美歌雀
broods:窝
aviary:鸟舍
subject:实验的对象
adjacent to:与…连接的
rotated:旋转的
repertoires:整段乐曲
correspond with:相符合,相一致
exclusively:专门的,排外的
isolation:孤立,隔离
(实习编辑:袁梅)