Almost everyone uses an alarm clock to wake up in the morning (whether they like it or not). People have been finding ways to make sure they wake up at the right time in the morning for a very long time, but for most of human history, people would know it is time to get up from nature.

The most iconic way that this was done was with the crow of a rooster. Farmers are still very familiar with this loud ‘Cock-a-doodle-doo’ every morning, and even people who live in cities know all about it from TV, movies, and visits to the country.

While everyone knows about the cock’s crow, most people don’t really know why they do it. Most people assume that the crowing is triggered by the rooster seeing the sunrise, but that is not actually the case.

A study published in 2013 found that the timing of the crowing is determined by the rooster’s circadian rhythm. While the circadian rhythm is certainly associated with the sunrise, it is not caused by it. The study looked at what roosters would do if they were in an environment without the solar cycles, and they found that they still crowed at around the same time each morning. Even if they made the lights come on or turn off at different times.

So, that helps to explain why roosters crow in the morning, but it doesn’t explain why they crow in general. This loud noise each day, after all, is a sure way to attract predators, so why would they do it?

Well, as with so many things in nature, it has to do with reproduction and dominance.

A study done in 1995 found that in a flock of chickens, the dominant rooster will always be the first one to crow in the morning. The second rooster in the pecking order (yes, that is where that phrase comes from) will crow next, and then the third, and so on.

Chickens have a very rigid hierarchy in their flocks, and the crowing of a rooster is one of the ways that they demonstrate that. The pecking order of the flock determines things like which roosters get to mate with the hens, which ones get to eat first, and much more.

If a lower-ranked rooster crows before a higher-ranked one, they will be chased around by the other roosters and pecked to put them in their place. If the top rooster is removed from the flock, the second-ranked one will move up and take its place. As with any animals, there can also be fights between the roosters to move up or down in the pecking order.

So, now you know why roosters crow. They aren’t just trying to wake you up, they are maintaining their dominance over the flock.

A rooster’s crow signals much more than the start of the day.

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