Bird father can teach his chicks to sing
Parental instruction starts even earlier than thought. A new video captures a zebra finch father giving singing lessons to his sons, revealing how important it can be to pay attention to dad.
Birds, humans and many other vocal animals appear to be more influenced by parental communications than previously thought, as new research finds that youngsters can start learning from a parent very early in life, with sounds of parental yammering imprinted in memory nearly for perpetuity.
"For young animals, the early sensory experiences are very important and strongly affect brain development," co-author Shin Yanagihara, a scientist at the Okinawa Institute of Science and Technology Graduate University's Neuronal Mechanism for Critical Period Unit, said in a press release. "This stage is called the 'critical period' where the brain circuits are very flexible and can be easily changed and modified."
For the study, published in the journal Nature Communications, Yanagihara and colleague Yoko Yazaki-Sugiyama studied zebra finch interactions as well as the brains of young zebra finches as the little birds listened to dad sing. They also monitored the neuronal activity in the young birds' brains as they listened to their own songs, as well as those of other zebra finches and the songs of different songbird species.
The researchers found that some "non-selective neurons" responded to all songs, but that other "selective neurons" responded exclusively to dad's tunes.
The scientists also found that about 5 percent of the neurons in the young birds' higher auditory cortex -- a part of the brain associated with hearing -- reacted to dad's songs. The researchers identified 27 neurons that selectively respond to dad's song.
The location in the brain that the scientists pinpointed could therefore be where early sound memories are located in the brains of birds and in many other animals, including humans.
As for why this is important, consider that for us, learning a first language is nearly effortless. That's because we start learning from our parents or early caregivers before we can even remember. Their words and sounds are imprinted into our memory at a very early age.
Learning a new language later in life, on the other hand, is much more difficult. It usually involves a lot of hard work and the speaker may never have the same fluency as with the first language.
The same is true of songbirds. Watch as, over time, two zebra finch sons learn a song from their dad:
At first the young birds sing as though they are babbling, not copying dad's songs very well. Over time their singing becomes more precise, until they can even develop their own song that is based on dad's, but is distinctive to the individual.
All of this is critical for the birds' future lives. Males are the singers in this species, and use their songs to attract mates. In short, a whole new generation of little birds relies upon such singing prowess.
The brain mechanisms during "the critical period" of learning vocalizations are still not very well understood, but the new findings could help show how the brain circuit is shaped during this early stage of development. They also shed light on how these neuronal circuits contribute to higher brain function in adulthood.
"This study gives some idea of how the brain acquires memories during the critical period," Yanagihara said. "This is a step in understanding how the neuronal mechanisms of memory and early sensory experiences form brain circuits in the early developmental stage, not only in birds, but also in humans and other species."