Former President of the United States Lincoln once said: The hen is the smartest animal, because she only shows off loudly after laying eggs. According to Lincoln, the reason why hens cackle after laying eggs is because they are eager to show off their achievements to their owners. However, scientists believe that the truth may not be that simple. Why do hens crow?

In our eyes, chicken is fresh and tender, has high protein yield, and is one of the best sources of energy. In fact, not only humans think so, many animals in nature regard chickens as delicacies, which means that in the wild environment, chickens have many natural enemies.

For chickens with little attack power, the best way to survive is to remain silent and prevent natural enemies from discovering them. If a hen cackles for a while after laying an egg, it is likely to attract the attention of predators and they can easily be captured.

In this case, why does the chicken still crow?

At first, people thought that the reason why hens crow after laying eggs is because of pain. Hens have only one cloaca. As the name implies: one cavity is used for both excretion and reproduction, and their excretions are liquid and very easy to discharge. The eggs are not only solid, but also large in size, which may cause the hens to cry out in pain during reproduction.

However, scientists do not think so. The reason is very simple. If hens crow due to pain during evolution, then in the wild environment, the cries of hens are to alert the surrounding natural enemies that the hens are giving birth again. When laying an egg, it is very easy to capture the hen or swallow the egg.

Furthermore, scientists have observed that in pheasant flocks, most hens do not cluck and scream after laying eggs, but leave as if nothing happened to avoid attracting natural enemies.

Only artificially raised hens will cluck and scream after laying eggs, so what is going on? The mystery of the hen's cry

In the last century, some scientists once proposed a hypothesis that hens crow after laying eggs to show off their reproductive capabilities. In this way, you can attract better roosters to mate with you, so that your offspring will have stronger genes.

In order to test this hypothesis, animal researchers from the University of Sheffield in the UK once studied a group of Javanese chickens. The results showed that even if the hens did not cluck after laying eggs, the number of matings and the number of hens that clucked after laying eggs were significantly lower. There is not much difference between hens, so it can be seen that the crow of chickens is not to show off their reproductive capabilities.

Furthermore, this experiment also proved that hens that do not crow after laying eggs can also exist in nature, but in human breeding environments, there are more chickens that can crow.

It was not until recent years that scientists finally figured out that the hens cackling after laying eggs was neither to show off nor to attract the opposite sex, but to reject sexual harassment from the opposite sex. At that time, they had just spent a lot of energy laying eggs and had no intention of mating. They just wanted to eat. After they have calmed down for a while, they will continue to mate and reproduce.

However, the reason why human-raised hens cluck more is probably because in primitive societies, when hens clucked, they would attract human attention or catch them. Live hens eat or scavenge their eggs, so the chickens that squawk are eliminated by natural selection.

In the process of human domestication of animals, the living environment of hens has changed. In the past, hens were raised with other animals. If a hen did not make a sound after laying an egg, its eggs might be kicked to pieces or eaten by other animals. Hens that make sounds after laying eggs can remind humans to collect their eggs in time.

Over time, humans have inadvertently selected chickens that make sounds after laying eggs. Chickens that don’t like to make sounds after laying eggs will lay eggs that are easy to be eaten by other animals, so the survival rate is lower. It's relatively low, so hens who don't like to make sounds are eliminated by natural selection.

From the clucking of hens after laying eggs, we can see that sometimes inadvertent human behavior will replace the natural selection of animals, and animals that can meet human requirements can leave as many offspring as possible. , otherwise it may be eliminated. Summary

In the wild, some hens will occasionally cluck in order to avoid sexual harassment from roosters after laying eggs, but the frequency is not high.

But in the process of domesticating chickens, humans inadvertently selected hens that would cluck after laying eggs, so that in artificial breeding environments, most hens will cluck. The cry.

In fact, humans do not only choose chickens in this way, but also the frequency of chickens laying eggs. In the past, chickens only laid eggs during the mating season, but now they want to lay eggs every year. The reason is that humans tend to choose chickens with higher egg production.