Beskylovye birds: representatives, features of anatomy and vital functions

Everyone has long known that birds are capable of flying. This feature distinguishes them from other animals. But here some of them do not know how to fly at all - these are ratless birds. Their structure has significant differences from other animals of this class. What are the characteristic features of ratless birds, whose representatives are widely distributed on the planet? Let's answer these questions together.

A subclass of ratless birds

One of the characteristics of birds, which determines their ability to fly, is the presence of the keel. It is a flat growth of the sternum, to which the muscles are attached, which move the wings. Beskylov birds, whose list is large enough, do not have such a part of the skeleton. Accordingly, they can not fly.

Beskylbirds move only on the ground, quickly running or stepping. Therefore, they all have powerful and long legs. Beskylovye birds have underdeveloped wings. The exception is only kiwi, in which they are completely absent. Their habitat is open spaces or thickets of evergreen shrubs. All of them are brood birds. Therefore, their chicks are born with their eyes open and covered with down. A small amount of time after birth, they leave a cozy nest and learn to look for food and live independently.

And now let's get acquainted with the species diversity of ratless birds, which are united into four orders.

Stricate

The largest of the now existing representatives of this class belongs to the ratites. Its weight can reach 90 kg, and height - 270 cm. This is none other than the African ostrich. It has another record property - to develop speed while running up to 70 km / h. The African ostrich has a long neck, a flattened head and only two fingers on each leg. This also contributes to fast running.

Another representative of this group of ratites is the nandu, which lives in the expanses of South America. It also feeds on plant food and small land animals, developing a considerable speed during hunting.

Nandoo-shaped

Beskylovye birds, whose representatives do not fly, have certain systematic features of the structure. For nandu this is the presence of three fingers on each leg and almost invisible wings. However, during a quick run, the bird raises one of them, like a sail, using as a navigator while moving. In addition, on the wings of these birds there are hard and sharp outgrowths - claws. Their nandoo is used during mating games to intimidate rivals. Running birds very quickly, they can even jump a moat several meters long. In comparison with ostriches, nandu is much smaller. Their height reaches one and a half meters. Birds live in small flocks, feeding on vegetable food.

Casuariformes

On the expanses of Australia and New Zealand, you can meet cassowaries. If you translate this name from the ancient Papuan language, it will mean "horned head". And indeed, on their head is a kind of helmet. It is formed by a connective spongy tissue covered with a horny substance from above. Scientists suggest that the bird uses this device to spread the branches of a bush, making its way through thickets of tropical forests. The neck of the cassowaries is devoid of plumage, while it is painted in very bright colors - from blue to orange. Surprising is the fact that the female, laying eggs, leaves its nest. And the male breeds them. Sami cassowaries of amazing saturated colors: from olive to almost black.

Kiwifruit

Beskylovyh birds, whose list we continue, can be of very small size. For example, the inhabitant of New Zealand kiwi weighs just over three kg at a height of 55 cm. They have almost no wings, four fingers are placed on their feet. Kiwi feeds on small invertebrates, which they find in the soil with a thin and long beak. These birds prefer to live in tropical forests, hiding from dangerous predators in the dense vegetation of evergreen shrubs.

The value of ratites

Of particular importance among all ratites are ostriches. So, on African ostriches long time hunted because of beautiful feathers of males and tasty dietary meat. Such illegal fishing has led to a significant decrease in the number of these birds. Now in many countries of the world ostriches are bred on special farms. Here these ratless birds are used to obtain several unique products. First, it is meat, which is recognized by nutritionists around the world to be most useful due to the low content of cholesterol and fats. The next valuable product is the skin. With its special treatment, lacquered leather is obtained, which is more valued in the market than crocodile and snake. Feathers of ostriches people began to use in the 18th century to decorate headgear, making fans of different sizes, cleaning various parts of equipment. The eggs of ostriches are also unique. They are the largest among all birds. Some specimens even reach a couple of kilograms with a shell thickness of up to half a centimeter. And thanks to the large size of birds in the US and Africa, they even arrange ostrich runs, harnessing them to real harnesses.

Cassowaries and emus also have great economic importance in the Americas, as well as in Australia. Here they are bred for obtaining meat, skin and fat, which is used in the manufacture of cosmetics, biological supplements and medicines.

Besikylov birds are deprived of the ability to fly. Their typical representatives are ostriches, kiwis, emus and cassowaries. These birds are united by the presence of rudimentary or underdeveloped wings, the absence of a keel and the ability to run fast.