The 'contraceptive' way of hens

Hens can excrete sperm immediately after mating, and when they do, an average of over 80% of sperm of the male will be excreted, a new study at Oxford University, UK revealed. .

According to Physyorg , in non-penile birds (except for ducks), they mate in the way biologists call 'cloacal kiss', ie quick contact. a hole in both males and females - this hole has both a secretory function and a means to release eggs and sperm.

Hens can excrete 80% of their offspring right after mating if they do not want the male to be the father of the chicks. (Photo: Ox.ac).

Biologists at Oxford University observed hens secrete sperm directly after mating, so that little sperm can conceive eggs, minimizing the chance of fatherhood. of the male .

The team also found that the females treated differently with the males. Hens often " remove " sperm after conducting several consecutive mating, and in this case it is usually preferred to the first partner. The relationship in the flock of the males also determines the criteria for selecting or kicking the sperm of the female, the females prioritize the dominant male in the herd.

' Sperm clearance is an effective way for females to deceive the chance of successful fertilization of males, ' explains Rebecca Dean, of the Department of Zoology at Oxford University.

These results show that the offspring have a great position in the battle for fathers of different male rivals . Even in animals like chickens and males that force females to fertilize, females still have a way to control who will be the fathers of its chicks.

This way of dealing with hens is also found in worms, insects and even primates. The race for reproduction in chickens is like the race for breeding in ducks, only different in methods.

In ducks, male ducks have large twisted-shaped penis, which can allow it to have a maximum length of more than 20 centimeters in 1/3 second. In order to avoid fertilization by a male duck, the female ducks also evolved many long and amputated vaginal bags in the vaginal canal. If the male duck penis has been inserted into that penguin, it is blocked and cannot reach the egg-containing uterus.