Marler P, Peters S
Dev Psychobiol. 1982 Jul;15(4):369-78. doi: 10.1002/dev.420150409.
All phases of song development from infancy to adulthood were studied intensively in a group of laboratory-reared birds. Male swamp sparrows, Melospiza georgiana, trained with tape-recorded songs in infancy, developed song some 8 months later, averaging 2.2 song types per bird. Analysis of the intermediate stage of plastic song revealed that the birds generated 4 to 5 times more song material than was needed for the species-specific song repertoire. The excess was discarded at the time of full song crystallization. Indications that the attrition process is selective include tendencies to retain imitated rather than nonimitated elements, and the rejection of heterospecific elements. Attrition may also be influenced by vocal stimulation at the time of song crystallization, providing an opportunity for behavioral adjustment even though new themes can no longer be learned. Attrition has been described in the transition in human infants from babbling to speech.
在一组实验室饲养的鸟类中，对从幼年期到成年期歌曲发展的各个阶段进行了深入研究。雄性沼泽带鹀（Melospiza georgiana）在幼年期用录制的歌曲进行训练，大约8个月后开始唱歌，每只鸟平均有2.2种歌曲类型。对可塑性歌曲中间阶段的分析表明，这些鸟类产生的歌曲素材比特定物种歌曲库所需的多4到5倍。多余的部分在完整歌曲定型时被舍弃。有迹象表明，这种删减过程是有选择性的，包括保留模仿元素而非非模仿元素的倾向，以及对异种元素的排斥。删减也可能受到歌曲定型时声音刺激的影响，即使新的主题不再能被学习，这也为行为调整提供了机会。人类婴儿从咿呀学语到说话的转变过程中也有删减现象。
