Song and the song control pathway in the brain can develop independently of exposure to song in the sedge warbler

Previous studies have shown that female sedge warblers choose to mate with males that have more complexsongs, and sexual selection has driven the evolution of both song complexity and the size of the majorsong control area (HVc) in the brain. In songbirds, learning from conspeci? cs plays a major role in songdevelopment and this study investigates the effects of isolation and exposure to song on song structureand the underlying song control system. Sibling pairs of hand-reared nestling sedge warblers were rearedto sexual maturity under two conditions. Siblings in one group were reared individually in acoustic isolationin separate soundproof chambers. In the other group, siblings were reared together in an aviarywith playback of recorded songs. The following spring, analysis of songs revealed that siblings reared inacoustic isolation produced normal song structures, including larger syllable repertoires than those exposedto song.

Stefan Leitner, Joanne Nicholson, Bernd Leisler, Timothy J. DeVoogd and Clive K. Catchpole, Proc. R. Soc. Lond. B (2002) 269, 2519-524