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Cranes

Cranes

Cranes are united in the bird family of the cranes order; this family belongs to the ancients. Their closest relatives are trumpeters and shepherd cranes.

The crane family includes fifteen species, combined into four genera. Seven species of cranes nest on the territory of Russia, which belong to two genera. The largest crane is the Australian crane, and the smallest is the belladonna.

Cranes have a small head. The beak is straight and sharp. Mostly all types of cranes have unfeathered areas of skin on their heads, which are brightly colored. The plumage color of cranes is usually white or gray. If we compare cranes with herons, the former have longer legs and an elongated neck. If we compare cranes with storks, then the legs of the cranes are longer, and the body is more graceful.

Cranes flock to flocks only during the dry season (and migratory birds also during migrations). During the nesting period, these birds keep in pairs. The diet of cranes, which in principle is quite diverse, is dominated by food of plant origin. These are roots, shoots and seeds of plants. From animal food, the diet of cranes includes a variety of insects, much less often small rodents and frogs. These birds feed, as a rule, in the morning or afternoon.

Insects are the main food for crane chicks. This food is rich in protein, which they need for normal development. A significant number of adult cranes molt at least once a year (after the end of the breeding season), and during this period, ten out of fifteen individuals cannot fly. The reason for the latter is the fact of loss of all flight feathers during molting.

The activity of cranes occurs mainly in the daytime. Cranes devote a lot of time to looking after feathers. The lifespan of cranes is quite long - in natural habitat it exceeds twenty years, in captivity, cranes can live up to eighty years.

The birds that make up the cranes order are similar to the crane. This is a delusion that goes back to pictures in children's books. Furthermore. The Crane-like order is so diverse that it is rather difficult to find a similar one. This detachment also includes bustards - the largest of the living flying birds (their weight reaches twenty kilograms), and small birds like shepherds (the weight of these individuals can be equal to only thirty grams). Representatives of the detachment differ not only in size, but also in general in appearance. Some individuals are endowed with long legs, some short ones; and there is no need to talk about the variety of plumage color and beak shape.

Cranes are widespread birds. They are found everywhere except South America and Antarctica. And man knew about cranes from very ancient times. This is proved by rock paintings with images of these birds found in Europe, Australia and Africa.

Cranes are large birds. They have a long neck and long legs. The height of cranes, as a rule, ranges from ninety to one hundred and fifty-five centimeters. For example, the height of some Australian cranes reaches one hundred and seventy-five centimeters. Thanks to this, this subspecies of the Australian crane (by the way, it lives in India) has become the tallest bird in the world that can fly. The wingspan ranges from one hundred and fifty to two hundred and forty centimeters. The weight of cranes varies from two to eleven kilograms (the Japanese crane often has a weight of eleven kilograms).

Cranes never land on trees. Unlike, for example, storks. Visually, when the cranes are on the ground, their tail seems lush and long. This feeling is given by the somewhat elongated tertiary flight feathers of the crane wings.

Different species of the cranes family have unique characteristics. These features depend on the ecological niche occupied by the cranes. For example, crowned cranes have the ability to stay on tree branches. This possibility is due to the presence of a hind grasping toe in these cranes. The African belladonna is able to move quite quickly on grassy terrain, which is associated with the short length of the fingers. A significant proportion of crane species are much better adapted to aquatic habitats. Having adapted to it, these cranes have long legs, beak and an elongated neck. In addition, they tend to have wider toes. The Siberian Crane is the most adapted to life in water. The structure of its legs allows this bird to move without any difficulty on the silty soil. Moreover, the Siberian Crane has the longest beak. The Australian crane, which lives in salt marshes, has specific salt glands near the eyes.

Sexual dimorphism is characteristic of cranes. In practice, this is not the case. Visible differences (in size, plumage color) between the female and the male are minimized. Still, female cranes are slightly smaller than males.

Cranes are sedentary. All species except those that breed in the north. The latter fly to more southern regions in winter. During migrations, cranes fly at an altitude of nine hundred meters to one and a half kilometers. When flying, these birds try to catch warm updrafts. If the wind has a direction unfavorable for the cranes, then only in this case they line up in a wedge. An interesting fact is that during the seasonal flight, the cranes make one or two stops. These stops can last for several weeks. Their goal is to recuperate for further covering the required distance. Juveniles during seasonal migrations, as well as at the site of the first wintering, are in close proximity to their parents. But already with the onset of spring, young cranes can fly to the nesting site before their parents. All other species of cranes, indeed, are sedentary.

During breeding, cranes resolutely protect their territory. The territory that cranes adhere to during breeding can be quite large. Its area can reach several square kilometers.

Cranes are monogamous birds. However, the popular judgment, the essence of which is that crane pairs do not fall apart throughout their lives, are not entirely true. Recent studies by ornithologists have shown that pairs of cranes do change from time to time. In particular, if a female or male dies, then with a high degree of probability another bird will find another pair for itself.

The rainy season coincides with the breeding season for cranes. We are talking about sedentary species. This feature is due to the fact that it is during the rainy season that food for cranes is abundant. In those species that migrate, pairs are formed at the wintering site. Near the future nest, the cranes arrange specific dances, which may include a prancing gait, flapping their wings, and also jumping. Dances are necessarily accompanied by singing. The diameter of a crane's nest can reach several meters.

The nest settles on the edge of the swamp or not far from it. There are times when cranes hide their nests in dense vegetation near the shore. These can be reeds or reeds. To build a nest, cranes use various parts of plants, as well as sticks that are intertwined with dry grass. An interesting fact is that young individuals are able to equip several nests in the first year of their life. However, young cranes do not lay eggs in the first year. In the second year, the cranes again build more than one nest, but choose the only one for use. As a rule, a clutch of cranes contains two eggs, and their size depends on the size of the crane (that is, on whether it belongs to one or another species). In large species of cranes, the egg length can exceed eleven centimeters. In a significant number of crane species, the eggs are abundantly covered with special pigment spots (the color of the spots, again, depends on the type of crane, as well as on the geographical habitat). In most cases, only one chick survives. Cranes have the opportunity to feed both chicks only in a very productive year. Both the female and the male take part in hatching eggs. The incubation period usually ranges from twenty seven to thirty six days. Chicks can leave the nest in a few days after birth. Chicks are born covered with down. Full plumage can be observed after fifty-five to one hundred and fifty days after the birth of the chicks (the period depends on the specific species). Crane chicks grow very quickly. Three months after birth, their growth can reach one and a half meters. Cranes become sexually mature at the age of four to five years (in captivity, at the age of three years).

The gray crane is a symbol of Russia. In fact, it is (one of the symbols). Probably everyone knows the cranes' chirping that is heard in the sky during the flights of cranes to the wintering place. The common crane is a rather large bird. Distribution area - Europe and Asia. In terms of numbers, the gray crane is considered the third species of the crane family. The plumage of a significant part of the body of the common crane has a characteristic bluish-gray color. This helps the cranes to camouflage themselves in wooded areas from natural enemies. The tail and back of the common crane is darker in color, while the belly and wings are somewhat lighter (although the wing tips are black). Under the eyes of these birds, a wide strip of white begins, which goes down along the neck. The beak is light.

The common crane is a large bird. The height of individuals of this species is approximately equal to one hundred and fifteen centimeters, while the wingspan varies from one hundred and eighty to two hundred centimeters. The weight of an adult male gray crane is on average 5.1-6 kilograms, and that of a female - 4.5-5.9 kilograms.

The Common Crane nests in swampy areas. This is mostly true. To arrange the nest, gray cranes find a more or less dry area, and thickets of sedges, reeds, that is, dense vegetation, become directly place for the nest. Immediately after the future parents have decided on a place for the nest, they together begin to announce this event in a drawn-out and complex voice. This measure allows the gray cranes to mark their territory. In springtime, mating dances of these birds can be observed in marshy meadows and swamps proper. They include a wide variety of movements - from a graceful step to running in a circle, which is also accompanied by flapping wings. At the same time, stops are necessarily associated with pirouettes and all kinds of bows. During mating dances, the gray cranes either jump up, or begin tossing bunches of grass or branches. Common cranes prefer isolated wetlands. However, in case of a lack of such territories, these birds can equip a nest in small areas located near agricultural land. The breeding season starts in April and ends in July. The pair is formed even before the flight to the nesting meta. The nest is large. Its diameter is more than one meter. Common cranes build nests using a wide variety of plant materials.

A clutch of gray cranes contains two eggs. This is usually the case. As soon as the chicks are born, they immediately leave their native nest. The responsibilities of the parents are to take care of the newly born chicks - the female takes care of one, the male takes care of the other. The incubation period for the common crane is on average thirty days. Both the female and the male take part in incubation.

The diet of common cranes includes both food of plant and animal origin. These birds feed on young shoots of herbs, seeds, flowers, berries, plant rhizomes. Invertebrates and small vertebrates are also eaten. Thus, gray cranes are not at all opposed to feasting on shellfish, insects, worms, and even fish and rodents. The choice of a particular food is largely determined by the availability of a particular product at a certain time and in a particular area. The diet of the common crane may also include grain, if there are sown fields near the nest of this bird. In this case, the gray crane can even threaten the safety of the crop. This kind of situation, for example, is not uncommon in Ethiopia, Germany and Israel. Gray cranes are migratory birds. For the winter, they go to China, India, Iran, Israel, Syria, Asia Minor and Africa; when flying, gray cranes develop speeds exceeding fifty kilometers per hour. For wintering, these birds prefer hills, which are almost completely covered with dense herbaceous vegetation. They often hibernate near pastures and agricultural land. The number of individuals of the common crane is gradually decreasing. This is mainly due to the fact that the areas used by the common crane as breeding grounds are decreasing. This problem is most relevant in the European part of Russia (and in Europe as a whole), as well as in Central Asia. Drainage and drying up of bogs is a threatening factor for the preservation of the population of the common crane unchanged. Many countries, despite the fact that at the moment the common cranes are not endangered, have banned hunting for representatives of this species. In Russia, the gray crane is still the most widespread representative of the cranes order.

The crowned crane inhabits the African continent. This bird is sedentary and can be found in East and West Africa. The number of crowned cranes is approximately forty thousand individuals. However, despite the fact that the number of representatives of this species is still quite large, the crowned crane is listed in the International Red Book. The status of the crowned crane in the Red Book is assessed as a species requiring international protection. The crowned crane species includes two subspecies.

The crowned crane is a large bird. The height of these birds varies from ninety-one to one hundred and four centimeters. The wingspan of the crowned crane reaches two meters. The weight of individuals ranges from 3.9 to 5.2 kilograms. Crowned cranes are endowed with a long hind toe, which most other members of the family lack. This finger serves the cranes in order to easily linger on the branches of a bush or tree.

The plumage color of the crowned crane is dark gray. Or black. We are talking about the plumage of a significant part of the body of these birds. But the coverts of the elytra and underwing of crowned cranes have a white color. The main characteristic feature of crowned cranes is the possession of a large tuft that adorns its head. This tuft consists of tough golden feathers. It is thanks to the tuft that this species got its name.White and red spots are visible on the cheeks of crowned cranes.

The crowned crane is a resident bird. Despite this, representatives of this species can still roam within the natural range. This type of migration largely depends on the season, and seasonal migrations (in principle, like daily migrations) may well cover a significant distance (even several tens of kilometers). Individuals of this species are active in the daytime. Crowned cranes during the period not related to the breeding time can gather in rather large flocks. But as soon as the rainy season comes, the cranes immediately split into pairs (although in a particularly unfavorable year, the pair may well remain in the flock). At the same time, individuals try to keep apart from each other and strictly guard their territory from all kinds of encroachments on it.

The arrival of the rainy season coincides with the breeding season for crowned cranes. The male can groom the female, for example, as follows. By releasing air from the throat sac, the male crowned crane makes specific clapping sounds, this measure is accompanied by bowing of the head first forward, and then tipping it back. In addition, crowned cranes can make peculiar trumpet sounds. The latter differ significantly from the sounds made by other types of cranes. The nesting area of ​​crowned cranes occupies a relatively small area, which ranges from ten to forty hectares. True, this territory is strictly guarded by crowned cranes from invasion by other birds. The nest settles either directly in the water among dense vegetation, or very close to it in the grass. Sedge is usually used as a building material for the nest. The clutch contains two to five eggs. The eggs are pinkish or blue in color and free from spots. The incubation period ranges from twenty-eight to thirty-one days. Although both parents take part in incubating eggs, the female devotes much more time to this than the male crowned crane. Brood-type chicks (like other cranes) - this means that immediately after birth, they are able to leave the nest. Soon after the appearance of offspring, the crane family moves to higher grassy areas. Here birds eat the tops of the shoots and insects.

Man is the main threat to populations of crowned cranes. As you know, the number of representatives of this species tends to decrease (it was this circumstance that caused the cranes to be included in the Red Book lists). A person catches crowned cranes for the purpose of their subsequent trade; this trade has grown substantially over the past thirty years. In addition, some West African countries (for example, Mali) maintain the tradition of keeping crowned cranes at home. Another factor limiting the development of the species is human economic activity, aimed, in particular, at reducing the area of ​​bogs.

Sterkh is endemic to the northern territories of Russia. This means that the Siberian Crane (aka the White Crane) lives in almost a limited range. This bird nests only on the territory of our country. For quite a long period of time, the biology of the white crane has been almost unexplored. However, after the foundation of the International Fund for the Conservation of Cranes in 1973, the Siberian Crane received very close attention from bird watchers. The threat of extinction hangs over the white cranes; at the moment the number of this species is on average three thousand birds. This circumstance caused the Siberian Crane to be included in the lists of the International Red Book, as well as the Red Book of Russia. The Siberian Crane is a fairly large bird. Its height is approximately equal to one hundred and forty centimeters, the wingspan can reach 230 centimeters. The weight of the white crane, as a rule, varies from five to eight kilograms (and may even exceed this number). The voice of white cranes is significantly different from the voice of other species of these birds. In Siberian Cranes, it is clean and tall.

The two populations of the white crane are isolated from each other. The western population of the Siberian Crane nests in the Yamalo-Nenets Autonomous Okrug, the Komi Republic and the Arkhangelsk Region (bogs surrounded by forests become nesting places), it can be conventionally called "Obskaya". The eastern population of the Siberian Crane nests in the north of Yakutia (these are hard-to-reach areas of the tundra). In winter, the Obskoy cranes migrate to the wetlands of northern Iran and India, while the eastern cranes migrate to China.

White cranes are the most demanding in terms of habitat. Compared to other types of cranes, this is indeed the case. This circumstance makes it very difficult to preserve the number of this species. The lifestyle of the Siberian Crane is much more closely related to the aquatic lifestyle than that of other cranes. Due to this, the white cranes have a special structure of legs and a longer beak. The special structure of the legs allows the Siberian Cranes to move freely on the viscous soil.

White cranes avoid humans. Even if a person appears far from the nesting site of these cranes, they can leave the nest. The latter poses a threat to the safety of the chicks of white cranes.

The number of the Australian crane is not known. This is due to the fact that for a long period of time the Australian cranes have not been distinguished as a separate species. The reason for this was the striking resemblance of the Australian and Indian cranes. The number of this species of cranes can vary from twenty thousand to one hundred thousand individuals. The Australian crane is a resident bird. Despite this feature, Australian cranes can migrate within their distribution range, and it covers the northern and eastern parts of Australia, as well as a small area of ​​New Guinea. It is worth noting the fact that earlier the distribution area of ​​this species was wider. During dry times, Australian cranes congregate near coastal freshwater marshes. Here birds eat the tubers of the Chinese water nut. During the wetter season, Australian cranes disperse to their nesting sites. The Indian crane is the largest species of the crane family. His approximate height is one hundred and seventy-six centimeters, and his weight exceeds six kilograms. The wingspan of the Indian crane is on average two meters forty centimeters. The population of the Indian crane can reach twenty thousand individuals. In general, it can be characterized as stable.

Belladonna is the smallest species of the crane family. However, in terms of prevalence, this crane takes the second place (second only to the Canadian crane). The belladonna population ranges from 200,000 to 240,000 birds. The height of representatives of this species is about eighty-nine centimeters, and the weight is two to three kilograms. Belladonna does not form subspecies.

Demoiselles are migratory birds. In winter, they migrate to the territory of India, Pakistan, as well as to the regions of Northeast Africa. Already in the period from August to September, these birds rally in flocks for a joint flight. Bellados fly relatively low. However, when flying over the Himalayas, these cranes are able to rise to a height of up to eight thousand meters. At wintering grounds, Demoiselles can be seen in some flocks with gray cranes. Interestingly, when flying to nesting sites, bellados are already kept in small groups of four to ten birds each.

Watch the video: Mega Cranes. Exceptional Engineering. Free Documentary (October 2020).