Parrot Powers: What Makes These Birds Great Vocal Imitators
Parrots have long been hailed as the best imitators in the avian world. Capable of not only imitating tunes and chimes, but human speech as well, the parrot can appear deceptively intelligent. Now researchers have identified some key differences in parrot brain structure that sets them apart from other birds, explaining for their incredible talent.
"This finding opens up a huge avenue of research in parrots, in trying to understand how parrots are processing the information necessary to copy novel sounds and what are the mechanisms that underlie imitation of human speech sounds," Mukta Chakraborty, a researcher of neuroscience at Duke University explained in a recent statement.
Working under Howard Hughes Medical Institute Investigator Erich Jarvis, Chakraborty and his colleagues set out to learn just what it is about parrots and a select few other birds that makes them expert sound imitators, or 'vocal learners.'
They paid special attention to the gene expression patterns of parrot brains in particular, noting that their brains are structured very differently than those of songbirds and even hummingbirds, who exhibit much less refined forms of vocal learning. (Scroll to read on...)
The resulting study, which was recently published in the journal PLOS ONE, details how the team traced gene markers for specialized vocal activity in the brains of humans and song-learning birds. The compared results revealed that in addition to having defined centers in the brain that control vocal-learning called 'cores,' the brains of parrots also boast shell-like outer-rings seemingly dedicated to vocal activities.
"It takes significant brain power to process auditory information and produce the movements necessary for mimicking sounds of another species," Chakraborty said. "The question is, how specialized are these parrot brains, and in what ways? Is it just a select group of specialized genes, or is it some specific projections that we haven't discovered yet?"
According to Jarvis, the discovery also supports his team's theory that the ability to imitate arose in animals with brain pathway duplication. The pattern of the 'shell' activity boast mirrored copies, with the only difference being where in the brain they are located. Traditionally, vocal learning cores are primarily tucked away. However, with their outer 'shells' - seen even in the most ancient of the parrot species they studied, the Kea of New Zealand - parrots vocal learning activity can also be found parts of the brain associated with mobility. This, the researchers speculate, could be why many parrot species can learn to dance to music. (Scroll to read on...)
"When Mukta and I were looking at the new results [I thought] 'Wow, how did I miss this all these years? How did everybody else miss this all these years?'' Jarvis added. "The surprise to me was more about human psychology and what we look for and how biased we are in what we look for. Once you see it, it's obvious. I have these brain sections from 15 years ago, and now I can see it."
According to the researchers, the unique structure of vocal-learning activity in the parrot brain has gone unnoticed for the greater part of the last 34 years - something that may very-well be largely due to the fact that the budgerigar (common pet parakeet) was the only species of parrot whose brain had been investigated.
For this study, in addition to the budgerigar, researchers carefully analyzed brain tissue from conures, cockatiels, lovebirds, two species of Amazon parrots, a blue and gold macaw, a kea and an African Grey parrot. The resulting work remains part of a larger international effort to sequence the complete genomes of all 10,000 species of birds in the next five years, as part of the Bird 10K Project.
A larger "ark-like' 10K genome project for all species of animal is also underway.
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