It is defined as the “dawn chorus”: the singing performance of many birds, which have a “peak” in song at the first light of day. Now a team of scientists has studied what triggers these vocalizations
Although birds sing all day, at first light their vocalizations peak: this is what is called the “dawn chorus”. What triggers it? Scientists have put forward at least a dozen explanations: that the explosion of song serves as a warm-up for the subsequent songs of the day, that the sound spreads better in the humid morning air and is not distorted thanks to the absence of wind, that people sing more when there is too little light to search for food anyway…
EXERCISE. Satoshi Kojima, of the Korea Brain Research Institute (South Korea), and colleagues proposed a new mechanism by observing the morning song of zebra finches, which we can hear above. The theory? In the dark their singing is inhibited, even if they are already awake; while they are in the darkness, their motivation to sing increases and therefore as soon as the very first light appears they explode into vocalizations. An in-depth study has been dedicated to the study Evidence Network n° 400: in the laboratory, the researchers manipulated the arrival of light after night and saw that when the artificial dawn was delayed by three hours the birds sang with greater intensity. However, when it was anticipated, the opposite effect was noticed in mandarin diamonds. Furthermore, the researchers hypothesize that the dawn chorus serves as intense exercise to compensate for the inactivity of the night.
