Ritualization in ontogeny. II. Realization in the individual development of bird song

In my previous contribution, part I (pp. 311- 319) I discussed some of the general principles involved in considering ritualization in ontogeny and referred specifically to the case of ‘play’ in animals. I now propose to discuss what is perhaps the second most remarkable example of ritualization—namely, that which is displayed by the development of song in a few groups of birds. The main function of the full-song of many birds is to serve as a signal which is sufficiently stereotyped to function as a recognition mark characteristic of the species, and yet (within this overall fixity of pattern) capable of sufficient individual variation to differentiate one individual bird from another.