for National Geographic News
Hummingbirds are well known for their ability to flap their wings at an eye-blurring 75 beats or more per second. Less known, perhaps, is the fact that they can learn to sing the hummingbird equivalent of "Supercalifragilisticexpialidocious."
Like parrots and sparrows, whales and dolphins, and bats and humans, hummingbirds are part of a select group of animals that possess the ability to imitate and learn soundsa process known as vocal learning.
Erich Jarvis, a neurobiologist at Duke University in Durham, North Carolina, studies the vocal-learning ability of birds like hummingbirds and zebra finches. His aim: to understand how the brain pathways for vocal learning evolved and work.
Most recently, Jarvis collaborated with two international teams of scientists who share this research interest. The scientists found that vocal-learning birds carry a gene called FoxP2, which becomes active when the birds are learning a new song.
The researchers note that a mutation in a nearly identical gene in humans causes an inherited language deficit.
The findings led the scientists to conclude that FoxP2 "is an important component to the circuitry of vocal learning," Jarvis said. "We can't say it is required, but we can say it is being used."
The teams described their findings in two papers published in the Journal of Neuroscience in 2004.
Jarvis and his lab colleagues led one of the studies with co-author Constance Scharff of the Max Planck Institute for Molecular Genetics in Germany. Stephanie White, a professor of psychological science at the University of California, Los Angeles, led the other study.
In future work, Jarvis said, he hopes to breed songbirds without FoxP2 to determine whether or not the gene is required for vocal learning. That finding may have implications for better understanding human speech and language.
Marc Schmidt is a neurobiologist at the University of Pennsylvania in Philadelphia. He said Jarvis's work pushes scientists to see parallels in the underlying organization of neural circuits involved in vocal learning between songbirds and humans. The two animals sit on two distinct branches of the evolutionary tree.
Schmidt said, "[Jarvis] is bold enough to cross disciplines and make people realize that these systems are organized in very similar ways."
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