Why do roosters crow at dawn?

The rooster's crow at dawn has long been considered nature's alarm clock, but it crows early in the morning not out of duty or tradition.

Roosters crow at dawn based on their biological clock - Photo: DISCOVERMAGAZINE

On April 15, the IFLScience website cited a number of scientific studies saying that roosters crow at dawn to show their dominance and also to show their "social status" with other chickens in the flock.

Chicken societies are much more complex than we might think. They are clearly hierarchical and have their own status. Much of their behavior, from who eats first, who gets to mate, to how they claim territory, is governed by the status of these chickens in their social structure. Understanding their position (rank) is essential to maintaining harmony within the flock.

In roosters, dominance is established by aggression and certain signals, such as comb size and crowing ability. Testosterone levels (the crucial male hormone) influence all of these signals.

Therefore, the timing of rooster crowing provides insight into their social hierarchy.

According to a 2015 study by the National Institute of Basic Biology in Japan, the highest-ranking roosters get priority in crowing first. The research team observed a group of four roosters and noticed a systematic pattern in the order in which they crowed each morning.

The group said the highest-ranking rooster always crowed first, followed by the second, third, and fourth roosters. If a lower-ranking rooster dared to crow first, it could be pecked and chased away.

The researchers concluded that this was because crowing was closely linked to social status, hierarchy, and dominance.

Another study, from the Central Experimental Farm in the Canadian province of Ontario and published by researchers in the United States in 1995, had similar findings. They concluded that "rooster crowing is likely to function as a status signal."

Additionally, brighter crowing is not necessarily due to sunlight. Another study in 2013 by the National Institute of Basic Biology in Japan found that roosters crow mainly due to their internal clocks, or circadian rhythms, rather than external factors such as sunrise.

Although sunlight can affect the circadian rhythms of animals, including humans, roosters still show a hierarchy in crowing even after dark.

Interestingly, when the dominant rooster is removed from the group, the second-ranking rooster crows first and “behaves as if it were the dominant rooster,” according to the Japanese researchers. This suggests that the highest-ranking rooster gets to “decide” when crowing should begin, based on its own biological rhythm. The others simply follow the leader or face the consequences.

In short, there is a lot behind the crowing of roosters. They use crowing to assert their dominance and social status in the flock.

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ANH THU

Source: https://tuoitre.vn/vi-sao-ga-gay-luc-binh-minh-20250416124907481.htm