Birds are oviposing living organisms with pronounced (almost always) sexual dimorphism, t.e. a significant difference between females and males.
The reproductive system
If we talk about the reproductive system of birds, then the reproductive function of females is represented by ovaries (and only the left, and the right one is reduced to facilitate the flight function), as well as the egg.
The absence of one ovary is due to several moments:
Before starting the propagation process, the ovary acquires an appearance similar to the grape bun, since a large number of follicles appear on it. It is the follicles that enter the ovary structure and consist of an oocyte covered with a layer of epithelium, and after the maturation process in the oocyte, the egg is formed, then entering the egg.
Bird’s sexual system
Bird females sexual system
For this function, the oviduct, which is a pipe of significant length, equipped with internal glands, departs from the ovary in the shape of a funnel, ending with a peculiar expansion (uterus) and a cloak out of the outside: the process of fertilization itself and the excretion of the egg itself occurs through it.
Males of birds in the field of the reproductive system are characterized by the presence of testes (paired formations), which through the seven pipelines end in a cloak; Interestingly, the external genitalia in most males of birds are not formed. The exception can be called ducks and some types of ostriches, geese, which are distinguished by the presence of a copulating organ: a spiral penis or an organ stretching from a cloak (its wall).
The structure of the egg
The vast majority of birds multiply by the formation of eggs and their hatching. All birds of birds in their structure and structures are distinguished by identical features, but they have differences, if we talk about the size and parameters of the component ratio.
Eggs are quite simple in their structure, but they have a very difficult structure, due to the need to form a suitable environment for the existence of a future chick. The egg is a certain capsule that ensures the development of a new organism: it should be maintained in strictly defined heat parameters and other conditions that are required for the successful formation of the embryo. A medium is formed inside this capsule, where natural conditions are imitated, in which almost all mammals usually develop.
In their structure, the eggs are capsules with a protective shell of a dense property formed in the process of passing the fertilized formation of. During the passage, the egg receives several shells (protein, fibrous and shell), which provide reliable protection.
The egg itself, first of all, is a yolk where the supply of nutrients necessary for the development of the embryo is stored, which at this stage is an embryo disk.
Thanks to protein flagella forming sparse, or cords, yolk and is fixed inside the egg. These halazes provide the yolk with the ability to hang in the egg, thus taking care of its safety from mechanical damage, I guarantee the necessary position in which the embryo disk is always in the upper position.
In addition to the yolk, in the protein for the stocking and protective function, the presence of protein is provided, which also provides water for the embryo. Also, in the egg, thanks to the shell, an air chamber is formed, where the gas exchange process occurs, without which the embryo can simply die from a lack of oxygen.
Time and reproduction factors
Each species of these animals multiplies in a strictly defined season, which is correlated with the growth of the chicks and the presence of a feed environment. This is usually due to the end of spring (for the northern territories), and the rainy season (for tropics); drought time is a great moment for the propagation of birds whose food is fish.
There is a whole range of factors that can affect the process of ripening of germ cells:
In monogamous species of birds, pairs are formed during the breeding period, and persist for many years, up to death (swans, eagles). Polygamous birds are characterized by mating only during fleeting meetings: for such birds, pairs are not formed at all (peacocks, grouse).
The current process can be manifested in different ways:
And thanks to the specificity of such marriage rituals, nature took care of the prevention of interspecific hybridization.
Table “Conditions necessary for the development of the embryo”
|The conditions necessary for the development of the embryo||Where does the embryo get everything necessary|
|Oxygen||From the environment through the pores of the shell.|
|Protection against microorganisms||Above the rush shell|
|Drying and damage protection||Shell, grinding, protein shells|
|Warm||The warmth of the body of the chicken during incubation|
The appearance and development of chicks
The process of propagation and development are closely interconnected, and one determines the other. This process is several stages of egg development:
All bird chicks are divided depending on the level of maturity when: