Syllable chunking in Bengalese finches in a multi-tutor environment

Abstract

Experiments in birdsong learning have traditionally involved one tutor, usually the father, and the proportion and accuracy of note copying are discussed as indexes of song learning. But in the wild, there are several conspecific males around song-learning pupils. To test song learning under naturalistic situation, 11 male and ten female Bengalese finches were kept in a large flight cage containing ten pot-shaped nests. Seventy-eight chicks were born in this aviary over an 18-month period. We recorded the full songs of male birds after they had matured, and compared the songs between offspring and the original adult males. Most of them learned their songs from one or two tutors and some learned from three or four tutors. When a bird learned from multiple tutors, each of these tutor songs was copied in chunks and within a chunk the order of the song elements was the same as that observed in the tutor male. Furthermore, Bengalese finches change the order of chunks as they sing, and it was possible to express the rule using a finite-state syntax. Therefore, Bengalese finches have an innate universal grammar allowing them to construct a finite-state syntax from multiple sources. [Work supported by JSPS and JST.]