Surprisingly little effort has been given to understanding how females perceive and make choices about song.  My study focused on how the type of song a female zebra finch (Taeniopygia guttata) hears as a juvenile affects her song preferences as an adult.

Male zebra finches copy their song from a tutor.  If they are raised without a tutor, they will make up their own song (untutored song), which is less complex than the song of normal males (tutored song).  Our study addressed several questions about how females perceive song:  Do females prefer tutored song over untutored song?  What features of song do they use to make that distinction?  How do they learn to make the distinction?

We raised female birds in three different conditions:  1) Hearing normal, tutored song from their fathers; 2) Father-deprived, so that females heard only their brothers making up untutored song; 3) Removing both the fathers and the brothers, so that females had no exposure to male song.  We then tested females’ song preferences in a series trials in which we measured the time that a female spent near each of two speakers that were broadcasting different song types.

If song preferences are learned from early auditory experience, then we would expect the normal females to prefer tutored song, the father-deprived females to prefer untutored song, and the song-isolated females to show no consistent preference between the two.  Normal and isolate females followed the predictions, but deprived females did not have a clear preference for either tutored or untutored song.  Perhaps the deprived females did not accept their brothers as being acceptable tutors, and therefore did not learn any song preference, or perhaps untutored song is not complex enough to trigger the neural mechanism for preference learning.  A replicate experiment raising females with fathers who sang untutored song would help to clarify this.

None of the three groups of females showed a clear preference for either forwards or backwards song, indicating that perhaps overall complexity is more important than specific note sequence in determining song quality.  All three groups of females also preferred zebra finch song over canary song (or perhaps found canary song aversive).  In any case, there appears to be some inborn mechanism for recognizing conspecific song.  It would be interesting to repeat this experiment, but to test innate discrimination between zebra finch song and the song of a more closely related species.

Part of the two-choice testing cage (speaker is behind the white sheet) and hand-painted male model used in female testing.

Begging Zebra Finch hatchling (2 days old).  Newly-hatched birds were painted with food coloring (in this case, yellow) so that they could be individually identified until they reached an appropriate size for leg bands.

All Photos © Nicole Gerlach 2002