Top cock: Roosters crow in pecking order

July 23, 2015
Crowing is thought to be a means for cockerels to advertise their territory
Crowing is thought to be a means for cockerels to advertise their territory

Roosters crow in order of seniority—the top cock announcing daybreak while juniors patiently wait their turn, said a study Thursday which revealed a long-guarded secret of chickendom.

We are all familiar with that first pre-dawn "cock-a-doodle-doo", quickly followed by others within hearing distance.

But how do cockerels decide who goes first?

They pull rank, according to a set of experiments with captive birds reported in the journal Scientific Reports.

"The top-ranking rooster always started to crow first, followed by its subordinates, in descending order of social rank," wrote the Japanese authors of the study.

"When the top-ranking rooster was physically removed from a group, the second-ranking rooster initiated crowing."

Crowing is thought to be a means for cockerels to advertise their territory—limiting the risk of surprise, potentially aggressive encounters.

Chickens are very social and hierarchical animals, and cockerels, when meeting each other for the first time, quickly settle their pecking order the old-fashioned way—with a fight.

The strongest, dominant birds subsequently enjoy priority access to food, hens and roosting places.

"Here, we show that the top-ranking rooster also has priority to determine the timing of predawn crowing, and that subordinates are obedient to the top-ranking rooster in a group situation," said the study paper.

The research team placed roosters in groups to establish their hierarchy from the number of sparring victories and losses, then separated them into individual cages to observe crowing behaviour.

Crowing order, they found, was strictly conserved even when the timing of the dominant rooster was earlier or later than the previous day.

Previous research had shown that the timing of crowing is controlled by an internal biological or "circadian" clock, which lower-ranking chickens also have.

The data suggests that subordinate roosters suppress their own natural rhythm, and "are patient enough to wait for the highest-ranking rooster's first crowing every morning," study co-author Tsuyoshi Shimmura told AFP by email.

"The subordinate roosters compromise their circadian clock for social reasons."

Explore further: Putting the clock in 'cock-a-doodle-doo'

Related Stories

Putting the clock in 'cock-a-doodle-doo'

March 18, 2013

Of course, roosters crow with the dawn. But are they simply reacting to the environment, or do they really know what time of day it is? Researchers reporting on March 18 in Current Biology have evidence that puts the clock ...

Old males win sex battle

June 25, 2010

(PhysOrg.com) -- Old roosters can still dominate the sexual pecking order even when their ability to fertilise eggs drastically declines, new Oxford University research has shown.

Baboons follow the majority

July 20, 2015

Baboons live together in hierarchical groups. However, important decisions are not dictated by the highest-ranking group members but are instead made democratically. This was discovered by a team of scientists including Iain ...

Recommended for you

Discovery could neutralize West Nile virus

November 20, 2018

Researchers at Vanderbilt University Medical Center and colleagues have isolated a human monoclonal antibody that can "neutralize" the West Nile virus and potentially prevent a leading cause of viral encephalitis (brain inflammation) ...

The taming of the dog, cow, horse, pig and rabbit

November 20, 2018

Research at the Earlham Institute into one of the 'genetic orchestra conductors', microRNAs, sheds light on our selectively guided evolution of domestic pets and farmyard animals such as dogs and cows.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.