The bird class is a separate progressive animal branch. They came from reptiles. The animals of this group, however, were able to adapt to flight.
Before we get into how birds mate, let's look at their biology.
General characteristics of the class
Progressive features of the organization are the following features.
- High level of development of the nervous system and, consequently, a wide variety of adaptive behaviors.
- Persistent high body temperature due to high metabolism.
- Compared to the lower subtypes and classes of animals, birds have a more advanced reproductive mechanism, which is expressed in incubation of eggs and rearing 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 features of the class allowed these animals to spread around the globe.
Male sex organs
The testicles are a pair of bean-shaped bodies that sit above the top of the kidneys. They are suspended on the mesentery. The size of the testes changes throughout the year. During the breeding season, these organs increase. So, in a finch, for example, they can increase by 1125 times, and in an ordinary starling by 1500 times.
Small appendages are attached to the inside of the testicles. The vas deferens depart from them, stretching parallel to the ureters and flowing into the cloaca. There are species of birds in which the vas deferens form small extensions - the seminal vesicles, which serve as a kind of reservoir for sperm.
The copulatory organ is not available in all species. A functioning penis in birds is a protrusion of the cloaca. It is present in ostriches, tinamou, goose. Bustards, storks and herons have a rudimentary copulatory organ.
Answering the question of how birds mate, it is worth noting that in most species, fertilization occurs due to the maximum convergence of the openings of the cloacae of the female and male, when the male spews sperm.
Genital organs of females
A feature of the development of the female reproductive system in birds is that it is sharply asymmetric in most species, i.e. consists of the left ovary and the left oviduct. The right ovary develops only in a few birds: loons, owls, chickens, shepherds, parrots, and some diurnal predators. But even a well-developed gland rarely functions in this case. It happens that a mature egg in the right ovary is excreted through the left oviduct.
The reason for this asymmetry is that female birds lay large eggs with hard shells that move along the oviduct for a 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 egg in it.
The oviduct is a long tube along which a mature egg moves. It is connected at one end to the cloaca, and at the other end to the body cavity.
The oviduct consists of several departments. The first is rich in special glands that secrete protein. In this section, the egg stays for about 6 hours and is covered with the first protective layer. The second section is thinner, where the egg is covered with shell membranes. The next section of the oviduct is the uterus. In it, the egg is about 20 hours. This is where the calcareous shell and the various pigments that color it are formed. The last section is the vagina, from which the egg enters the cloaca, and then out.
The whole time of passage of an egg through the oviduct in a chicken is about 24 hours, in a pigeon - 41 hours.
Features of bird breeding
Despite the general breeding pattern, each species of bird is individual.
When studying the question of how domestic birds, such as a chicken for example, mate, it is worth remembering that they can lay eggs without a male. This means that the released egg will be unfertilized.
The testes of males begin to function, increase in size - males are ready to start fertilization. Genetic transfer takes placematerial for females, who after a certain period begin to lay eggs. The number of them in different species of birds is not the same.
Bird breeding occurs at different times of the year. The biology of species is very diverse. If one species is ready for breeding in early spring, then the other - only in the middle of summer. Some birds are sedentary and nest in the same place, while others fly from distant countries precisely for the period of nesting and breeding.
To better understand how birds of a certain species mate, it is necessary to study the individual characteristics of the reproductive system of its representatives.
