The crow of a rooster is shorthand for waking up. Roosters tend to start making a racket around the break of dawn, cementing their role in popular culture as a living alarm clock (albeit an unreliable one). But how does a group of roosters decide when to start crowing?
It’s all about cock-a-doodle-dominance, according to a new study in the journal Scientific Reports. A group of Japanese researchers found that when chickens live together in groups, the top-ranked rooster always crows first, followed by social subordinates, even when the subordinates’ internal clocks would otherwise tell them to start making noise.
Chickens are the reason we have the term “pecking order,” and they follow it to the letter. The most dominant member of the group pecks at its compatriots, and those of lesser rank accept the punishment. Though roosters are typically inclined to crow according to their circadian rhythm, beginning in the early morning, the researchers found that the top-ranking rooster in a group always kicked off the chorus of crows, even when measurements of body temperature would indicate that the subordinate roosters were at the point in their day when they would otherwise normally crow. While they were physically able to crow, they didn’t—out of deference, it seems.
“These results indicate that in a group situation, the top-ranking rooster has priority to announce the break of dawn, and that subordinate roosters are patient enough to wait for the top-ranking rooster’s first crow every morning and thus compromise their circadian clock for social reasons,” the researchers write. Who knew chickens were so polite?