Yellow warbler
Before singing, you need to warm up your voice. Everyone knows it, and apparently the birds do too.
The phenomenon of singing at dawn, carried out by birds from all over the world, may be very close to being explained.
A recent study, not yet peer-reviewed, investigated this behavior in zebra finches (Taeniopygia guttata) in captivity and suggests that the intensity of morning singing may be linked to the hours before sunrise.
In a very well-lit laboratory, males of the specimen spontaneously sang hundreds of songs. But when the researchers turned off all the lights, in total darkness, the birds did not make any sound.
But then, scientists wondered, how does the alternation between night and day influence the morning chorus?
When sunrise was artificially delayed by three hours by keeping the lights off, the birds increased their song frequency and began singing earlier compared to days without a delay, according to the study in bioRxiv.
Despite the long darkness, the finches slept no more; they remained active and moving, but silent. In a way, they were somewhat impatient.
But then researchers handed the reins — literally — to the birds. The team offered them a switch that emitted ten seconds of early light and noticed that birds with late sunrise repeatedly activated the light, something they did not do when dawn arrived at the usual time.
According to Ednei Barros dos Santos, from the Korea Brain Institute, cited by , birds wake up in the dark long before dawn, probably through hormonal mechanisms linked to melatoninand their intrinsic motivation to sing increases as spontaneous singing is suppressed by the darkness.
But then what is the reason for the morning singing? Researchers believe that singing in the morning may act as a vocal warm-up after a night’s rest, a way to improve performance and increase the chances of reproductive success throughout the day. The same reason may explain the morning chorus observed in wild birds.
