Note on Taxonomy
1 Learning and the Ontogeny of Sound Signals in Birds
II. Vocal Development That Is Independent of Audition
III. World Survey of Vocal Learning in Birds
IV. What Is Actually Learned?
V. Timing of Vocal Learning
VI. Concluding Remarks
2 Subsong and Plastic Song: Their Role in the Vocal Learning Process
II. Subsong of the Song Sparrow
III. Subsong and Plastic Song in the Chaffinch
IV. Song Ontogeny in the Swamp Sparrow
V. When Do the Characteristics of Crystallized Song First Appear?
VI. Learning to Sing from Memory
VII. The Role of Improvisation
VIII. The Role of Invention
IX. Conclusions on the Functional Significance of Subsong and Plastic Song
3 Avian Vocal Mimicry: Its Function and Evolution
II. Some Conceptual Issues
III. A Survey of Mimics
IV. Possible Functions of Vocal Mimicry
V. The Evolution of Vocal Mimicry
4 The Ecological and Social Significance of Duetting
II. What Is a Duet?
III. What Are Duetting Species Like?
IV. Functional Significance of Duetting
V. Multiple Functions of Duets and Duet Structure
5 Song Repertoires: Problems in Their Definition and Use
II. Repertoire Size
III. Organization and Use of Song-Type Repertoires
IV. Concluding Remarks