Past studies have shown that a myriad of animal behaviors are generally driven by the internal clocks in the body that recognize time. Suppose that at night some animals duck themselves in swamps or puddles, even the fish in the cave use circadian clocks to tell time.
Then what about the behavior of chicken that always crows in the morning? Research in the journal Current Biology found that roosters kept crowing in the morning, despite being given constant light that leads to roosters.
"The sound of a rooster crowing is a symbol or a sign that the dawn has arrived in different countries, but this research has not been clear enough to prove whether a rooster actually crows because it has a time sensitivity in its body or just a response to stimulate its external stimuli," Takashi Yoshimura of Nagoya University.
Because all-day stimulation, such as lighting a car's headlights, will trigger a rooster to crow every time. It is also suspected to be the reason why the rooster continues to crow because of the light that leads to the rooster. To find out, Yoshimura and his colleagues conducted research and placed 40 roosters in a constant-light setting, then recorded as they crowed.
Sure enough, in fact the rooster crows not only at dawn. Rooster also crows because it responds to light and as a way to communicate with other chickens, but their crowing behavior is much stronger at dawn. These findings suggest that biological clocks affect the time of crowing of chickens.
As a follow up, the team hopes to determine the genetic basis of the sound of other animals. "We still do not know why dogs say 'woof' and cats say 'meow'," Yoshimura said. While the question of why the rooster crowed every morning has been studied also by Takashi Yoshimura with Jaanese scientist named Tsuyoshii Shimmura.
Experts from Nagoya University revealed that the most high-ranking rooster was the first to crow. The results of this research confirms that chicken is an animal that upholds differences in social levels and social levels of chicken can change every day.