Rooster clucking in the morning seems to be a natural phenomenon for most people. In many countries, the rooster’s cry is used as a symbol of dawn. But “why does the rooster croak in the morning”? This problem is not simple, and even stumps scientists.
Maybe you won’t believe that it wasn’t until 2013 that a scientist answered this question seriously and published a paper.
First of all, we have to know that roosters call at any time of the day, not only in the morning. Sometimes, the rooster will crow as a warning because of the invasion of other animals, the declaration of territory or the threat of other roosters. However, when it’s okay, they do call the most in the morning.
For many years, scientists believed that the reason why the rooster croaked in the morning was because the light rose from dark to bright after the sun rose, and the rooster responded to the stimulation of the light. However, some people think that the rooster is not stimulated by light, but only knows that it will come in the morning before crowing. That is to say, the rooster has the concept of time, and in the morning it sounds like an alarm clock.
Scientists at Nagoya University in Japan decided to do an experiment to see which one is right.
Scientists first found a group of roosters and observed how often they croaked. It turned out that after a day, the rooster would not only bark in the morning, but also chirp during feeding. And those who shout at the front always want more food.
In a formal experiment, the scientists controlled the lighting in the enclosed room where the rooster is located: lighting for 12 hours, then turning off the lights for 12 hours, and repeating for two weeks. It was found that under regular light, the rooster will start to croak about two hours before the light comes.
Scientists also have an interesting finding: chickens with obvious status advantages are called earlier than other chickens, and the cocks with the highest status have the highest priority for dawn. Then crow one by one in order, and the lowest position can only silently make a bottom after other chickens are called. Another study also confirmed that the lower the rooster’s status, the lower the frequency of crowing. The above findings indicate that crowing is indeed a way for cocks to promote their status.
Why the rooster croaks in the morning
As the status decreases, the frequency of crowing gradually decreases
In the next two weeks, the rooster in this room will enter the full “dark age”, that is, 24 hours without light. Scientists found that during the first week of the “dark age”, these roosters still seem to remember the approximate time in the previous 12-hour regular light experiment and began to croak when there was light.
However, with the passage of time, the roosters seem to be slowly deviating. For them, the original cycle was once a daybreak and croaked every 24 hours. After all black, it became 23.8 hours, a difference of 0.2 hours. In the dark environment, the rooster’s perception of time is problematic. The regularity of this kind of crowing is gradually broken, they no longer croak relatively fixedly, which shows that the lighting does affect the roar of the rooster.
Why the rooster croaks in the morning
In the completely black state, the roaring time of the cock fluctuated
In dark conditions, scientists tried to trick the roosters by lighting them at random times and playing the roars of the roosters. It was found that although these stimuli did cause some tweets, if the stimuli were around the time before the light was turned on, then they would crow more frequently than other time points.
Therefore, scientists have concluded that rooster crowing is mainly regulated by the internal circadian clock, and at the same time will be affected by the external environment. In addition, because the rooster does not cry as strongly as before and after the light (dawn) at other times of the day, the researchers believe that the rooster’s “internal clock has priority over external signals.”
So, what is a biological clock?
The 2017 Nobel Prize in Physiology’s research by three recipients answered this question, and it was they who discovered the molecular mechanism of the organism’s circadian rhythm.
Simply put, the circadian clock of humans and other animals is a 24-hour rhythmic behavior formed by a series of genes and proteins, which affects physiological changes at different time periods, such as body temperature, pulse, blood pressure, hormone secretion, etc. .
As for why the rooster crows most in the morning, scientists have not fully figured it out. However, considering that crowing is a way for the cock to promote its status, perhaps the cock understands the truth that “one day’s plan lies in the morning”. In the morning, determining one’s status by crowing can not be messed up early in the morning.