Song, sexual selection, and a song control nucleus (HVc) in the brains of European sedge warblers

Female sedge warblers select males that have more complex songs as mates. T his study tests two predictions concerning HVc, a telencephalic nucleus tha t is essential for song learning and production: first, that males with mor e complex songs will have a larger HVc, and second that males who pair succ essfully will have a larger HVc than unpaired males. Data on song compositi on and pairing status were collected from wild sedge warblers breeding in H ungary. We found significant positive correlations between three song attri butes (repertoire size, song complexity, and song length) and the size of H Vc. Males that paired successfully also had more complex songs (repertoire size and song complexity, though not song length) than males that did not. However, we find no direct evidence that males who paired successfully had a larger HVc than unpaired males. These findings are discussed in relation to the possible functions of HVc and also to current views on sexual select ion and the evolution of the song control pathway. (C) 2000 John Wiley & So ns, Inc.