Like children learning to speak, little zebra finches learn songs from their elders. And like children, they have only a short time period for singing lessons, starting about a month after they have hatched and lasting for about two months. Now researchers from the Rockefeller University and Bell Laboratories have studied how male zebra finches master the perfect song during that time.
The scientists looked at birds on day 43 after hatching, when they had already started to utter untutored sound bites. They let the animals peck at a key, which caused a plastic father finch to "sing" them a recorded song, up to 28 seconds per day. The scientists then measured how the youngsters slowly approached perfect imitation. As reported in last week's Science Express, the scientists found the largest leap in learning occurred on the second day, when the birds had a good night's sleep. They developed a number of soundseven quite dissimilar onesfrom the same prototype sound they already knew. Sometimes they got the pitch too high at first, but instead of lowering it, they kept singing higher and higher for a few days and then suddenly halved the frequency to achieve a perfect match with the model.
These more or less direct ways to reach the goalthe model songprobably reflect some constraints on the vocal apparatus and the brain. Ultimately, understanding how a bird learns a song might shed some light on how humans learn a language or a skill by imitation.