The bird class is a separate progressive branch of animals. They came from reptiles. Animals of this group, however, were able to adapt to flight.
Before moving on to the question of how birds mate, consider their biology.
General characteristics of the class
The progressive features of the organization are as follows.
- A high level of development of the nervous system and, consequently, a wide variety of adaptive behavior options.
- Constant high body temperature, which is due to intense metabolism.
- Compared to subclasses and classes of animals, birds have a more advanced breeding mechanism, which translates into hatched eggs and feeding offspring.
- The presence of adaptive organs for flight and at the same time the ability to move on the land surface, and in some species - the ability to swim and move on the water surface.
The above class features have allowed these animals to spread throughout the globe.
The genitals of males
Testes are a pair of bean-shaped bodies that are located above the upper part of the kidneys. They are suspended on the mesentery. The size of the testes varies throughout the year. During the breeding season, these organs increase. So, for a finch, for example, they can increase 1125 times, and for an ordinary starling, 1500 times.
Small appendages are attached to the inside of the testes. From them depart the vas deferens, extending parallel to the ureters and flowing into the cloaca. There are species of birds in which the vas deferens form small extensions - seminal vesicles, which serve as original reservoirs for sperm.
Not all species have a copulative organ. A functioning penis in birds is a protrusion of cesspools. It is present in ostriches, tinamu, goose. In bustards, storks and herons, the copulative organ is vestigial.
Answering the question of how birds mate, it is worth noting that in most species, fertilization occurs due to the maximum closeness of the openings of the female and male cloaca when the male ejaculates sperm.
Female genitals
A feature of the development of the reproductive system of females in birds is that it is sharply asymmetric in most species, i.e. consists of the left ovary and left oviduct. Only a few birds develop the right ovary: loons, owls, chicken, shepherds, parrots, and some daytime predators. But even a well-developed gland rarely functions in this case. It happens that a ripe egg in the right ovary is excreted through the left oviduct.
The reason for this asymmetry is that the female birds lay large eggs with a hard shell, which move along the oviduct for a sufficiently long time - about 2 days.
The ovary is a granular body of irregular shape. It is located in front of the kidney. The size of the ovary depends on the maturity of the eggs in it.
The oviduct is a long tube along which a ripened egg moves. It is connected at one end to the cesspool, and the other to the body cavity.
The oviduct consists of several sections. The first is rich in special glands that secrete protein. In this section, the egg is about 6 hours and is covered with the first protective layer. The second section is thinner, there the egg is covered with shell membranes. The next section of the oviduct is the uterus. The egg is in it for about 20 hours. Here, calcareous shells and various pigments are formed that color it. The last section is the vagina, from which the egg enters the cloaca, and then out.
The entire time the egg passes through the oviduct for a chicken is about 24 hours, for a pigeon - 41 hours.
