Sleep Affects a Bird’s Singing

Young birds sing badly in the morning but do much better later in the day.

It’s easy to feel tongue-tied and forgetful when you’ve first woken up. After that slow start, though, your memory usually gets sharper and you’re ready to go. And now, scientists say, the same may be true for young birds—at least when it comes to learning how to sing.

This snoozing young male finch will probably flub his attempts at song for a few hours after he awakes.

T. Revesz

A male zebra finch learns to sing 30 to 90 days after hatching. The baby bird begins by copying the songs of adult males. At first, the little guy chirps in a nonsensical, baby-talk kind of way. Over several days, though, this babbling turns into beautiful birdsong.

Previous birdsong research had involved simply taping a few minutes of song at a time. For the new experiment, Sébastien Derégnaucourt of the City University of New York and his team spent 3 years creating a computer program that could record and analyze every sound a bird makes for weeks at a time.

The study involved 40 birds, and the researchers collected a total of 40 million musical fragments, or syllables. When they compared 100 versions of each syllable from the evening with 100 counterparts from the next morning, the scientists found that the birds sang well in the evenings, but performed badly in the mornings.

After being awake several hours, however, the young males regained their mastery of the material and then improved on the previous day’s accomplishments.

To see whether this dip in learning was caused by the same kind of pre-coffee fog that many people feel in the morning, the researchers prevented the birds from practicing first thing in the morning. They also tried keeping the birds from singing during the day, and they used a chemical called melatonin to make the birds nap at odd times.

None of these disturbances kept the birds from progressing steadily, with a dip in singing ability after waking up and a surge later on.

The researchers conclude that their study supports the idea that sleep helps birds learn. Studies of other animals have also suggested that sleep improve learning.

Other researchers argue that the same data could be used to argue that sleep gets in the way of learning. One way to know which it is would be to show that sleep-deprived birds fail to learn.—E. Sohn

Going Deeper:

Milius, Susan. 2005. Hour of babble: Young birds sing badly in the morning. Science News 167(Feb. 19):118. Available at http://www.sciencenews.org/articles/20050219/fob6.asp .

McDonagh, Sorcha. 2004. Sleep lessons from sparrows. Science News for Kids (July 28). Available at http://www.sciencenewsforkids.org/articles/20040728/Note3.asp .

Sohn, Emily. 2004. Sleep to remember places and routes. Science News for Kids (Nov. 10). Available at http://www.sciencenewsforkids.org/articles/20041110/Note3.asp .

______. 2003. Memories are made with sleep. Science News for Kids (Oct. 15). Available at http://www.sciencenewsforkids.org/articles/20031015/Note2.asp .

You can learn more about how zebra finches learn to sing at soma.npa.uiuc.edu/courses/physl490b/
models/birdsong_learning/bird_song.html
(University of Illinois at Urbana-Champaign).

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