The beautiful sounds of birds chirping is not inherent at birth, it is a learned behaviour. Baby birds babble, similar to young human children learning to speak. A behaviour much like play in children, babbling enables the learning process of a bird's particular song to take place.
It has already been studied and found that in the Zebra Finch, there are two areas of the brain used for song. One area is defined as the learning area and the other, called the motor circuit, is responsible for the production of the song.
Studies to the two areas found that damage to the learning circuit while a bird is young prevents the bird from further learning its "song", leaving it in a perpetual state of babbling.
Damage to the learning circuit of an adult showed to have no effect on the "song".
Therefore, scientists originally drew an assumption that the motor circuit was equally important in the development of a bird's "song", yet no studies on this assumption were accomplished.
A study on Zebra finches
out of McGovern Institute for Brain Research at MIT has found that the brains of these birds are much more complex with regards to their song than originally thought.
Michale Fee, Associate Professor at MIT's Department of Brain and Cognitive Sciences and his team were able to locate an area in the learning circuit of the brain called the LMAN and when they temporarily disabled the LMAN, the bird's ability to babble was ceased. When the temporarily disabled the HVC of the motor circuit, the babies still babbled.
This proved that LMAN in the learning circuit part of their brain had a significant role in baby bird babbling that led to their learning the "song".
More interestingly, the study found that HVC in the motor circuit part of the brain actually would cause an adult bird to revert to infant babbling, the opposite of what was originally believed.
These results, according to Fee
may apply more broadly to other forms of immature or exploratory behavior, in humans as well as birds. "In birds, the exploratory phase ends when learning is complete," he says. "But we humans can always call upon our equivalent of LMAN, the prefrontal cortex, to be innovative and learn new things."
The study details were released in the May 2 issue of Science