The cormorant is a sea bird, whose habitat are the sea coast, banks of lakes and rivers, and wetlands belong to the family balanovich and unit pelecanoides.
The habitat of them is fairly common – inhabit the waters all over the world. They skillfully hunt fish often creating problems for people.
On the territory of our country, there are several types:
- Cormorant big.
- Crested or red-breasted.
- And pygmy cormorant.
Description of birds
These birds can be medium to large size, reaching lengths of one meter and a wingspan up to five feet. They have shiny black plumage, some specimens have the head and underbelly are parts of the feathers white, others have crests. In appearance they are somewhat similar to duck, dive and swim perfectly, as the legs they are quite powerful and have webbed feet.
The body of this bird is of an elongated shape with a long neck and beak. While fishing a wide open beak, the bird can easily swallow a rather large fish. The bird’s beak thin and long, with the tip tapering in the form of a hook. The voice of a bird-like cawing or muffled groans, raspy notes in his voice. On the head and around the eyes, birds of this species have bare areas of skin not covered by feathers, and the throat pouch.
In nature, there are several dozen species of waterfowl and cormorant is considered to be representative of this large family.
Birds live in a hot or cold climate zone, they can be found around the world. Mostly large birds hunt in the daytime, spending most of that time on the water or coast, getting food for themselves and their Chicks. Swim pretty fast, abruptly changing direction, aided by the tail, which he uses in the role of the keel. In search of food, they can dive very deeply, sometimes even to a depth of 10 meters, and can stay under water for up to two minutes. But leave the water, becoming rather clumsy animals, go waddling slowly moving across the sand.
Mostly cormorants, the birds of passage, only some of them lead a sedentary life.
Cormorant is gregarious birds live in large colonies that can include up to hundreds of thousands of couples unable to settle with other migratory birds such as terns and gulls. Fly away to winter in a warmer climate, however, for nesting and withdrawal of the Chicks come back. These birds are considered monogamous, because the generated steam does not leave never. Their nests cormorants build on the rocks, the trees, using branches and grass.
In nature there are several dozen species of cormorants:
- Crested cormorant and white, these two kinds are the most rare and appear infrequently, so they are listed in the Red book, and hunting them is forbidden.
- Large and other types of birds.
The most common is the cormorant is large, it is common practically all over the globe, he lives in the North Atlantic, on the Kola Peninsula, is found in Kazakhstan, in General, found everywhere on the banks of ponds, where there is a large number of fish. There are about three million individuals of this species.
The diet of great cormorant
The basis of the diet of this bird is fish, but can eat mollusks, echinoderms, crustaceans, and even amphibians. Any particular preference in food he does not, I think cormorants are very voracious fish, because his daily diet can be up to a pound, fresh fish. The photo shows the great cormorant during the meals.
Cormorant preys mostly on marine shallows, but with the form of production for her to dive into the water, his movements swift. So diving for prey in one place, on the surface it may appear far from it. After diving or swimming in the water, the cormorant be sure to dry the feathers widely spread its wings, so quite often you can see birds in this position.
Nesting and breeding great cormorants
As described above, the birds settle on the banks of ponds during their breeding, they are divided into several pairs, choosing hidden in the reeds of a small pond. The nest is a column height of one meter and a width of about three meters, built of branches and leaves of reeds, it covered litter, as if covered them well Packed inside.
Sometimes nests with other families cormorants are so close to each other that it is impossible to distinguish where one ends and begins another nest. It happens that the distance between them takes a few steps. One side have to be positioned close to the brush so the Chicks were for some time sheltered from the scorching rays of the sun, the other side directed towards the reservoir.
In the construction of the nest involves both parents. Nesting and laying eggs, falls on spring months from March to may. In clutch there are cormorants, there are up to five eggs that are greenish color. The time of incubation continues for months, this process involved both parents alternately. As eggs are laid at about the same time with such masonry, Chicks are obtained of different ages.
Fledglings appear clumsy, naked and blind, eyes open only a few days later. Pubescence appears only in two weeks, appear at the same time tubes flight and tail feathers. The feathers on the nestlings of a dark color. First week and a half, parents feed nestlings with half-digested food, belching from her stomach. After this period, they are already capable to swallow small fish.
On reaching a little more than two months, the Chicks independently selected from the nest, moving freely through the branches of trees or moving along the ground within the colony. They become fully independent only three, three and a half months. They reach reproductive maturity only after three years.
The species of these birds are considered to be long-lived, in the wild they can live up to twenty years.
Such large colonies of sea birds is very harmful to fishermen in areas of fishing and fish breeding areas. Because where they are located, significantly reduced the number of fish stocks, as one cormorant per day can eat over a pound of fresh fish.
One time they even were allowed to shoot, but currently it is prohibited by law.
Despite the fact that the bird is a great cormorant is a large species, they have enemies, and chief among them are the crows who try to steal from the nest eggs. Sometimes these invasions do gulls and starlings. But not only the walls exposed to the invasion of pests, a little helpless Chicks are also in danger from the attack of foxes, coyotes and other predators.