Back in 2000, a study of brain activity found that zebra finches practice their singing while they sleep. In a follow-up study published in New Scientist in 2018, researchers discovered that the songbirds' vocal muscles actually twitch during these silent “sleep singing” episodes. These twitches coincide with the movements of the zebra finches' vocal muscles when they are singing during the day.
To sleep, perchance to sing:
- Researchers at the University of Buenos Aires attached electrodes to the vocal muscles of 10 zebra finches. They suspected that the birds were practicing different versions of the same song.
- The only reason that these nocturnal muscle movements don’t produce an audible song is the lack of air, the research team explained.
- In the original October 2000 study, scientists discovered that if a bird's sleep is unbroken, it will practice its daytime songs, trying out different variations such as changes to notes or tempo.