Chegrava - description, habitat, interesting facts

This type of tern as chegrava is the largest of the given family of birds, only slightly inferior in its size to the silver gull. It differs from this species of birds by a characteristic cap, which has a rich dark color, the same color with paws, a bright red beak and a tail ending in a cutout.

Rises into the air mainly to search for food, flies easily, the beak, like most terns, lowered down. For catching fish immersed in water with scattering. Chegrava has a peculiar low voice, making loud, grinding sounds or short sounds. The preferred resting place of this bird is the shore of the reservoir.

The average lifespan of a waterfowl in its natural habitat is about 7-8 years.

Natural habitat

Although the nesting area of ​​birds of this species is rather extensive, nevertheless, within it, the distribution of the species is sporadic.It prefers the temperate latitudes of Europe, the Baltic, the Caspian, the Black Sea, the African continent. Also the habitat is Asia, southwest of Siberia, North America, Australia, New Zealand. Wintering area - South Africa, mainly coastal zone, India, southeast China, the Mediterranean.

Preferred areas for living in birds are the pebble and sandy coast of water bodies (seas, lakes, rivers), rocky areas. As a rule, such habitats are selected for nesting. Note that when choosing a place of particular importance for this type of bird is the transparency of the water.

Outside the nesting period, Chergrava mainly keeps close to the seas, as well as close to large water bodies with a small current. As a rule, chegravs do not form large colonies, keep in small groups.

Dimensions and structure

Power Features

The main source of food is small fish and invertebrates. The main difference of this species from common terns is that sometimes the chegrava can eat eggs and nestlings of other birds.

During the hunt for fish, the bird flies, rises into the air above the surface of the water to a small height, seeing its prey, makes an abrupt stop, and then rushes down, while submerging not only its rather long beak, but also its head.

During the nesting period, such forage faults are carried out over short distances. For catching prey the bird chooses only reservoirs with clear and pure water.

Breeding species

Chegravy monogamous. The sexual maturity of the birds of this species of birds occurs upon reaching 3 years. In addition to pairs of birds, idlers are also found in the nesting colonies. Couples are created after the birds arrive at the nesting place.

One colony of birds can consist from 100 to 200 nests, as a rule, isolated from each other.In the colonial nesting places the bird behaves very noisy.

Directly the nest itself is a small hollow in the ground (sand, shell rock). Note that there is often no litter in such nests; if it exists, then small fish bones, stalks of dry plants are used as material for it.

The average number of eggs in a clutch is 2-3 pcs. Hatching eggs, birds (both females and males) are quite cautious and shy. The color of the eggshell varies from pale greenish to brownish. In this case, the eggs are covered with dark spots, thickening to the base.

Often, the clutch and the newly emerged offspring of the chegrava die as a result of raids by more predatory birds, including gulls. If the clutch is destroyed, the bird rushes repeatedly, but in this case the number of eggs laid does not exceed 1-2 pieces.

In the process of brooding, both parents take part, as a rule, the duration is about three weeks. Young offspring at the age of one and a half months get up on the wing and are ready for independent flights.

Features molting chegravy

The molt of this species of birds has its own sequence: the first one includes the chick-down, winter and mating. To the second: winter and marriage. In fact, the first mating dress of the bird is basic. Like most tern species, the adult chegrava sheds twice a year: before the mating season in the spring and after the mating season in the autumn.

1. The partial change of the plumage of young chaffra baby birds, as well as the period of molting, implying a shift to the first winter outfit, lasts from the beginning of autumn until January.
2. The premarital change of the plumage of adults lasts from January to March.
3. After marriage - from mid-summer to November.

Note that there may be deviations from the above dates of the beginning and end of molting birds, which is caused by violations in the normal course of the sexual cycle of individuals. As a rule, molt is late in those representatives of the species who were forced to re-lay eggs due to the death of offspring.

Bird Color

1. Downy outfit nestlings. The back of the body of the young individual has a grayish-ocher color, in some cases with characteristic brown markings. The neck is gray; the belly of the chick is white with a slight patina of ocher color.The color of the beak is pale red, the top is decorated with a dark spot.
2. Marital attire adults. Virtually the entire head of the bird is of a dark color, while the occipital feathers stand out a little due to their length, due to which a kind of tuft is formed. Virtually the entire back of the bird is a pale silvery color, the neck (its back), the nadkhvoste are white. Also silver gray and main primary feathers. The beak of an adult individual of the chegrava is bright red, the eyes are dark brown, the paws are black.
3. The winter outfit of adult birds differs in that the black cap characteristic of this species on the head becomes white with longitudinal marks scattered around it. On the ears and in front of the eyes of the bird there are small spots of dark color. Otherwise, this outfit completely coincides with the marriage.
4. Nesting outfit of young birds. The top of the head is white with a characteristic longitudinal pattern, which is more pronounced than that of adult birds in winter attire. Under the eyes and near the ears there are also black spots. The neck is white-gray with slight dark strokes. The lower part of the back is dark gray, decorated with a border of feathers of brown color. The beak of the bird is orange, its paws are black.
5. The first winter outfit, appearing after a partial molt, is similar to the plumage that adult birds get with their basic winter outfit. The only difference in this case is that almost all the flight and tail feathers remain from the nesting dress of young birds. Also, the overall gray tone of the color of the back becomes darker, and the plumage of the head has more dark strokes.
6. Changing the feathering of the chegrava after the first complete molt to the first nuptial attire implies that some birds get a darker color of the plumage of the back part.

Video: Chegrava (Hydroprogne caspia)