Why Do Roosters Crow?

With morning's first light, a musical chorus of chirps and tweets erupt from birds as they rise to start the day. The rooster's crow joins the chorus in rural settings, but welcoming a new day isn't the only reason a rooster crows. It's not unusual to hear him crow in the afternoon, evening or even in the dead of night, sometimes for reasons only a chicken can fathom.

In any barnyard, the dominant rooster does most of the crowing. He'll use his crow to let the females know he's on the job protecting the flock and that he's ready and willing to mate. A middle-of-the-night crow is often a response to a passing car or other disturbances, while an early evening crow usually summons straggling hens to the roost. Most of the rooster's crows come early in the morning, according to a study at Nagoya University in Japan. In light-controlled experiments, roosters consistently began crowing two hours before dawn even when kept in constant low light 24 hours a day.