Date: December 12, 2016
Source: Okinawa Institute of Science and Technology (OIST) Graduate University
Like humans learning to speak, juvenile birds learn to sing by mimicking vocalizations of adults of the same species during development. Juvenile birds preferentially learn the song of their own species, even in noisy environments with a variety of different birdsongs. But how they can recognize their species' song has, until now, remained a mystery. In a collaborative study, neuroscientists and a physicist at the Okinawa Institute of Science and Technology Graduate University (OIST) have uncovered an innate mechanism for species identification based on the silent gaps between birdsong syllables.
"We co-designed an experiment that works within the constraints of neuroscience while satisfying the requirements of physics," says Professor Mahesh Bandi, head of the Collective Interactions Unit at OIST.
Dr. Makoto Araki and Professor Yoko Yazaki-Sugiyama of OIST's Neuronal Mechanism for Critical Period Unit and Professor Bandi performed a cross-fostering experiment in which juvenile zebra finches were raised by Bengalese finch foster parents to examine how their birdsong develops under the tutoring of a different species. Birdsong is comprised of stereotypical repeats of a few syllables, called 'song motifs', in which syllables are separated by silent gaps. The findings, published in Science, reveal that the fostered zebra finches learned morphologies of Bengalese finch syllables, including syllable duration, but transposed onto zebra finch silent gap patterns. This suggests that temporal gaps between syllables are innate, while syllable morphology can be learned.