A team of researchers has discovered how young songbirds come to learn their species-specific songs. Baby birds normally learn from imitating their parents. However, young birds seem to be able to recognize when an adult is singing the song of their species. The team found that some aspects of this skill are innate. The findings are in a paper that was just published in the journal Science.
Young birds learn songs and other communication skills from their parents. In previous studies, researchers found that juvenile songbirds could learn these songs even when the environment was noisy and crowded. This has led scientists to wonder how exactly the birds can pick out the song of their own species even when other adult birds are singing.
Researchers from the Okinawa Institute of Science and Technology Graduate University in Japan designed an experiment that used finches as models. The team studied juvenile zebra finches (Taeniopygia guttata), common experimental models in songbird research, that were still in the learning stages. The birds had been raised by Bengalese finches (Lonchura striata domestica), also known as society finches. Interestingly, the zebra finches did learn from their foster parents but also retained zebra finch song traits. For example, the young zebra finches learned to sing the Bengalese finch song but sang it with a zebra finch “accent” and song structure. Zebra finch songs have specific gaps of silence, song syllables, and structures; the fostered birds followed these rules while superficially singing the Bengalese finch song. This suggests that some aspects of song learning are taught while the overall structures are known innately.
The team also measured neural responses and found that certain neurons fired up when the young zebra finches heard their own species’ song. If the songs were edited to have improper structures and incorrect silent gaps, these neurons did not fire. This happened with both the fostered birds and finches that had been raised in complete isolation. In other words, a zebra finch has the innate ability to pick out their species’ song but learns some singing techniques from adult birds.
The findings provide new insights into how songbirds learn their species-specific songs. Even when fostered by parents of a different species, zebra finches can still pick out songs sung by other zebra finches. They base this on song structures and gaps of silence. Then they fill in the blanks based on what they’re taught by adults, usually their parents. This allows young birds to recognize their own species even in crowded, loud environments.
Bandi et al. Mind the gap: Neural coding of species identity in birdsong prosody. Science (2016).