Science. 1981 Aug 14;213(4509):780-2. doi: 10.1126/science.213.4509.780.
Male swamp sparrows reared in the laboratory and exposed to taped songs during infancy produce accurate imitations of the material following an 8-month interval with no rehearsal. When the first rehearsal occurs, at about 300 days of age, large numbers of syllables are perfected. They are developed through invention and improvisation as well as imitation. Most are discarded at the time of song crystallization. Hence, these songbirds learn more than they manifest in full adult song.
在实验室中饲养的雄性沼泽麻雀，在婴儿期接触录音歌曲后，在没有排练的情况下，经过 8 个月的时间就能准确模仿所听到的内容。当它们大约 300 天大，第一次进行排练时，大量的音节就会被完善。这些音节是通过发明和即兴创作以及模仿而发展起来的。大多数在歌曲定型时被丢弃。因此，这些鸣禽学习的内容比它们在完整的成年歌曲中表现出来的要多。
