In our article we want to talk about the extraordinary variety of birds on Earth. Depending on the classification, there are from 9, 800 to 10, 050 modern species of birds. If you think about it, this is an impressive figure.
Origin of birds
Modern science believes that birds evolved from ancient reptiles. This is indicated by some common features of the structure with reptiles: dry skin, feathers, like reptile scales, similarity of embryos, eggs.
I must say that already in the Jurassic period there was an intermediate form between birds and reptiles under the name Archeopteryx. And at the end of the Mesozoic, real birds appeared. Modern birds have characteristic progressive features that distinguish them from reptiles. These are developed organs of hearing, vision, coordination of movements with certain centers in the cerebral cortex, the appearance of warm-bloodedness as a result of changes in the nervous and respiratory systems, the presence of a four-chamber heart and spongy lungs.
Variety of birds
Now the bird world is very diverse. It is customary to divide all birds into three superorders:
- Forceless. Most of the representatives of this group have poorly developed wings. Such birds do not fly, but they can run fast and well. A striking example is the African ostrich that lives in the savannahs, semi-deserts and steppes of Africa, in Australia and South America.
- Penguins. This group is very small. Its representatives live mainly in the southern hemisphere on the shores of Antarctica. These birds also do not know how to fly, but they swim beautifully. Their forelimbs are modified into flippers. On the ice, penguins move in an upright position, sliding and leaning on their tail. An interesting fact is that they do not build nests. They store the egg on the membranes of the limbs, hiding them under the folds of fat on the tummy. In general, a large fat layer protects penguins from the cold.
- Keel. This group is very numerous. It includes more than twenty units. These are passerines, chicken, anseriformes, falcons, woodpeckers, etc.
In the framework of the article, we want to show the diversity of birds on specific examples of some representatives of the feathered world, since it is simply impossible to talk about everyone.
Ostrich
African ostrich is the largest bird on Earth. Previously, they included other related species, Rhea and Emu. However, modern researchers classify them as separate units. Therefore, now, from a scientific point of view, there is only one real ostrich - African.
The first thing that surprises a bird is its enormous size. In height, it is no less than a large horse. The height of the ostrich ranges from 1.8 to 2.7 meters, and the weight reaches 75 kg. There are also such large males that weigh up to 131 kilograms. Naturally, most of the growth falls on the neck and legs. And the bird’s head, on the contrary, is very small, the ostrich’s brain is even smaller, which affects the intelligence of the birds.
Feathers in birds grow evenly throughout the body, but in most birds they are located on special lines called pterillia. African ostriches lack keel, and therefore they are generally not adapted to flight. But their legs do a great job of running. The bird has very long paws and highly developed leg muscles. Only two toes are present on each leg. One huge claw, the other smaller. The second finger helps maintain balance while running.
There are many feathers on the body, tail and wings of the bird, but the head, neck and legs have only short fluffs, it seems that they are naked. Females and males of African ostrich differ in the color of their plumage. In addition, various species may have different coloration of the legs and beak.
African ostrich habitat
African ostrich lives almost all over Africa, it can not be found only in the Sahara and North Africa. There was a time when this bird lived on the lands adjacent to the African continent, in Syria and on the Arabian Peninsula.
In general, ostriches prefer open plains. They inhabit dry woodlands, grassy savannahs, semi-deserts. But the dense thickets, marshland, quicksand deserts they do not like. This is due to the fact that there they cannot develop greater speed while running. They lead a sedentary lifestyle, uniting in small groups. Very rarely, a flock can include up to 50 individuals, and they can graze along with antelopes and zebras. There is no constancy in the pack, but a clear hierarchy reigns. High-ranking individuals hold their tail and neck vertically, while weaker representatives - obliquely. The birds show activity at dusk, and rest at night and during the heat of the day.
Ostriches are stupid on the one hand and extremely cautious on the other. During meals, they constantly look around, looking around. Having noticed the enemy, they quickly leave, not wanting to collide with a predator. They have very good eyesight. They can spot an enemy per kilometer. Many animals monitor the behavior of the ostrich, if they themselves do not have such a good vision. An ostrich is capable of speeds up to 70 kilometers per hour, and in very rare cases up to 90 kilometers per hour.
Sparrow
Speaking about the diversity of birds on the planet, we will pass from the largest representative to one of the smallest - to the sparrow. For us, such a bird has been familiar since childhood. Sparrow is a bird that is widespread in cities and towns. It is small in size, weighing from 20 to 35 grams. The bird is part of a squadron, in which, in addition to it, there are more than 5000 species. The largest representative of this group is the raven, and the smallest is the king.
Sparrow - a bird that got its name in ancient times. And it is due to the fact that birds love to raid farm fields. Driving them away, people shouted "thief bang."
Two species of sparrows live in Russia: brownie (urban) and rural. An interesting fact is that this species of birds has a special eye structure, and these birds see the whole world in pink. A sparrow consumes a significant amount of energy per day, and therefore can not starve for more than two days.
House Sparrow
Birds have brown plumage with longitudinal black stripes. In length do not exceed seventeen centimeters, and weigh no more than 35 grams. Imagine the bird world is so diverse and rich that there are more than 16 species of house sparrow alone. Once this bird lived only in Northern Europe. But then gradually sparrows settled on almost all the continents except the Arctic. Now they can be seen even in South Africa, America, Australia, where they were brought at the beginning of the twentieth century.
It should be noted that sparrows always settle near a person, and lead a sedentary existence. And only birds living in the more northern regions fly away to the warmer regions for the winter.
Sparrows are the eternal companions of man. They are very fertile. The basis of their nutrition is plant food. But birds catch insects for their chicks. In villages, birds fly to the fields to pick up grains there. Sometimes sparrows peck fruits and berries in orchards, thereby causing damage to people.
In one summer, two or even three generations of offspring can be bred.
Stork
Stork - an unusual bird. It has long become a symbol of peace on earth. The white bird is so beautiful and graceful that many songs and poems are composed about it. The family of storks is represented by twelve species. These are quite large individuals. In adulthood, they reach a meter in height, and the wingspan is two meters. All storks have long legs, a neck and a beak.
They are distributed on almost all continents. They live not only in the tropics, but also in temperate latitudes. Those individuals that live in a warm climate do not fly away for the winter, while the rest make flights to Africa and India. Birds live up to twenty years.
The most famous species is the white stork. Birds live on Earth since ancient times, as evidenced by the findings of archaeologists. This species is considered almost dumb, because it has completely undeveloped vocal cords.
Storks are famous for their endurance, because they are able to make very long flights.
The lifestyle and nutrition of the bird depends on the habitat. White stork prefers low places with meadows and swamps. Sometimes they settle on the roofs of houses, making nests there. They feed on food of animal origin: lizards, frogs, insects, small mice. A stork is a beautiful and noble bird.
Swans
A swan is a white bird that conquered everyone with its beauty and grandeur. A small group of famous birds includes 7 species. In general, swans belong to the family of ducks, and their closest relatives are geese and geese.
Swans are the largest waterfowl wild birds. Weight reaches eight kilograms. Birds have a very long and flexible neck, and each species is characterized by its special setting. Paws in birds are quite short and equipped with special swimming membranes. On land, their gait seems very awkward. The coccygeal gland of birds emits a special lubricant, thanks to which the feathers do not get wet in the water.
All swans have the same coloring - white, and only the black swan is different from them.
They live in South and North America, Eurasia and Australia. Usually settle on the shores of water bodies, and it can be small lakes, and huge water spaces, like estuaries or bays.
All swans can be conditionally divided into southern and northern. The south lead a settled life, and the north have to fly away for the winter. Eurasian individuals winter in South and Central Asia, and American winter time is spent in California and Florida.
Birds usually live in pairs. They have a quiet and calm disposition. The voices of the birds are quite sonorous, but they rarely make sounds, but the mute swan can only hiss in case of danger.
As food birds use the kidneys, seeds, roots of aquatic plants, grass and small aquatic invertebrates. They find food in water, deeply plunging their heads. But the birds do not know how to dive.
Hummingbird Bee
We talked about the fact that the African ostrich is the largest bird. And the smallest is a hummingbird. This Cuban bird is not only the smallest in the world, but also the smallest warm-blooded creature on Earth. The male has a length of not more than five centimeters, and by weight is not heavier than two paper clips. But the females are slightly larger. The name itself suggests that these birds themselves are no more than bees.
The smallest bird is a very fast and powerful creature. Glittering wings make her look like a gem. However, its multi-colored color is not always visible, it all depends on the viewing angle.
Despite its tiny size, the bird plays an important role in the reproduction of plants. She flies from flower to flower and collects nectar with her thin proboscis, while transferring pollen from flower to flower. In one day, a little bee visits up to one and a half thousand flowers.
Hummingbirds build for themselves cup-shaped nests of no more than 2.5 centimeters in diameter. They are woven from bark, lichens and cobwebs. In them, the bird lays two small pea-sized eggs.
Forest birds
This is where you can appreciate the true diversity of birds, so it's in the forest. After all, it is home to many birds. At any time of the year you can meet an extraordinary number of them. Here, wild birds make their nests, find food and hatch their chicks. Thick greens reliably protects birds from enemies and bad weather. Walking through the forest, you can hear a variety of voices of birds, we don’t see them, but we hear their beautiful singing or “cuckoo”, familiar from childhood.
What birds live in our forests? The world of birds in them is so rich that it is difficult to count all species. We recall only the most famous: hazel grouse, woodpeckers, pine forests, swifts, owls, nightingales, black grouse, eagle owls, cuckoos, golden eagles, lentils, pine cedars, kings, flytraps, tits, hawks, crossbills, siskins and many others. Birds of the forest have adapted to living in forest thickets. Each of the species lives in certain areas of the country, in characteristic places. An interesting fact is that absolutely all the birds of the forest coexist in one territory, and among them there are formidable predators, and completely harmless, and very small birds. Just an amazing combination.
