US: Young birds raised in isolation can learn a song that is not part of their repertoire. But once spring arrives, they instinctively switch to their mating song, even though they've never heard it before, a new study has found.
Scientists at Rockefeller University in Manhattan found that young male canaries raised in the laboratory had no trouble learning a computer-generated song that had no resemblance to the song their father would normally teach them.
But one morning the scientists arrived at the lab to discover that the birds, on the brink of adulthood, were chirping the song they were destined to sing even though they had never heard it before. The research appeared yesterday in the journal Science.
"This is something we didn't expect," said Timothy J Gardner, a former post-doctoral student at Rockefeller now working at the Massachusetts Institute of Technology.
"They can imitate things we never expected they could, but then the innate learning system must be so strong that the real song breaks through anyway."
Somehow, Gardner said, they do their own editing, splicing and rearranging of the computer-generated song so that they are singing the song, speaking the language, understood by songbirds.
Theorists have long debated whether language is innate or learned through experience. This study suggests it may be a bit of both.
Gardner and his colleagues, including Rockefeller neuroscientist Fernando Nottebohm, say that the mature birds in the experiment sing their species-specific song, yet every once in a while the old riff from their youth can be heard.
"It tells us there is freedom in the first year of life, freedom to imitate and experiment with song," Gardner said.
How the birds which lived in isolation converged on the normal canary song at the start of the breeding season is just not known. Gardner said he would attempt to repeat the studies and add a recording device to specific neurons in the brain to catch this process in action.