In the textbooks of zoology it is clearly written that all birds have a cloaca, that is, an extension of the back of the intestine, in which the excretory ducts and ducts of the reproductive system merge together. It was an axiom, but what was the surprise of those who, gutting the carcass of an indole, found an incomprehensible organ. Every curious person will want to know what it is. It turns out that some species of birds have copulative organs.
What it is?
Before moving on to birds, you need to understand what copulative organs are. The name itself comes from the Latin word "copula", which translates as connection. Such organs are only in representatives of the animal world with internal fertilization. Moreover, they have both males and females. Their second name is the copulatory organs. They are necessary for males to introduce sperm into the body of their chosen one.
Of the animals known to science, some worms, most mollusks, some arthropods and fish, amphibians, almost all reptiles and mammals, and some representatives of birds possess such organs.
Which birds do they have?
In most birds, the process of fertilization occurs when the male presses its cloaca to the cloaca of the female. Another such mating method is called a cloacal kiss. In this case, the birds do not have copulative organs. But there are a small number of species in which the cloaca plot is inverted, forming an unpaired copulative organ. In birds, it enters the body of a female during mating.
But in what species can this anatomical miracle be found? First of all, in ostriches, as well as in some species of ducks and geese, and also in tinamu. As for the size, the Argentinean white-headed duck is the record holder here, in which the organ's length exceeds the size of the duck itself and can reach 45 cm! Why so much? Just for bragging. And already the female herself chooses a suitable size for herself.
In geese, it is worm-shaped and twisted into a spiral. The length can vary from 7 to 15 cm. An erection occurs only from the influx of lymph, and not from the blood, as in mammals.
In roosters and turkeys, this organ is represented by an elevation called the folus, which bulges out only at the time of an erection. So there are exceptions in every rule, and not all birds have clown fertilization, as we are taught in school.