Brittan-Powell E F, Dooling R J, Farabaugh S M
Department of Psychology, University of Maryland College Park 20742-4411, USA.
J Comp Psychol. 1997 Sep;111(3):226-41. doi: 10.1037/0735-7036.111.3.226.
Budgerigars have a complex vocal repertoire, some of which develops through learning. The authors examined the course of vocal development in budgerigars from hatching to about 4 weeks postfledging (approximately 85 days old). Food-begging calls showed changes in duration, peak frequency, bandwidth, and frequency modulation with age. Within a week of fledging, each bird produced a contact call bearing a strong resemblance to a shortened version of its patterned food-begging call. By 4 weeks postfledging, budgerigar contact call repertoires often contained more than one call type, and there was clear evidence of sharing and imitation among the calls of parents, fledglings, and other social companions. Perceptual testing showed that whereas acoustic variation in the structure of developing calls decreased both within and between nestling birds, the discrimination of these calls was easier for adult birds as young birds matured. These results suggest parallels with certain aspects of language development in humans.
虎皮鹦鹉拥有一套复杂的发声指令系统，其中一些是通过学习发展而来的。作者研究了虎皮鹦鹉从孵化到出飞后约4周（约85日龄）的发声发育过程。乞食叫声的时长、峰值频率、带宽和频率调制随年龄变化。出飞一周内，每只鸟发出的联络叫声与它有规律的乞食叫声的缩短版极为相似。到出飞后4周时，虎皮鹦鹉的联络叫声指令系统通常包含不止一种叫声类型，并且有明确证据表明亲鸟、雏鸟和其他社交同伴的叫声之间存在共享和模仿现象。感知测试表明，虽然雏鸟之间以及雏鸟自身发育过程中叫声结构的声学变化减少了，但随着幼鸟成熟，成年鸟对这些叫声的辨别更容易。这些结果表明与人类语言发展的某些方面存在相似之处。
