How do cocks/roosters know that it is time to crow?

The rooster's morning cock-a-doodle-doo is driven by an internal clock, finds new research, suggesting the male chickens really know the time of day. The study, detailed today (March 18) in the journal Current Biology, found that roosters put under constant light conditions will still crow at the crack of dawn. read more

In the first experiment, roosters experienced 12 hours of light and 12 hours of dim light conditions for 14 days. The scientists found that the roosters would start to crow two hours before the onset of light—called anticipatory predawn crowing—consistent with observations in wild red jungle fowl. read more

Although roosters can occasionally crow at any time of day, the majority of their crowing was like clockwork, peaking in frequency at time intervals roughly 24 hours apart—the time their bodies knew to be morning based on the sunlight they’d last seen before entering the experiment. read more

While it's true that roosters can indeed crow at any time, in a recent paper anthropologist Kevin Birth discusses how avian chronobiology shapes a reliable relationship between cockcrow and the coming dawn that may help understand perceptions of time prior to the establishment of a standard global time. read more