The cormorant family
includes about thirty species of birds. Representatives of six species of these birds can be found on the territory of Russia. This is a large cormorant, small cormorant, Cormorant Bering, Ussuri cormorant, red-faced cormorant and crested cormorant. These birds are marine and freshwater, in connection with which nature endowed them with an elongated body.
Cormorants have a thin and long beak, which at the end forms a large pointed hook. Such adaptation is necessary for cormorants to search for food – for successful catching. The cormorant’s neck is long. Cormorants are endowed with membranous paws, which are located far behind.
Color of plumage of cormorants is black, for him, there is a metallic tint. Cormorants – birds are silent, but their voice can be heard in the nesting colonies formed on the ground (as a rule, cormorants nest together with other birds). When building a nest, cormorants use grass and branches. Masonry contains four to six eggs, which have a matte surface.
Twice a year, these birds are replaced by feathering – incomplete moulting at the beginning of the year and complete molting, which begins with the arrival of summer and continues until the end of autumn. Incomplete molting is also called premarital, and complete molting is post-mortem.
Nestlings are born naked and blind, over time their body becomes covered with down. The newly born cormorants begin to fly in a seven-week or eight-week-old age. Sexual dimorphism in cormorants usually reduces only to the difference in size between females and males. The latter are larger.
Cormorants are widespread.
Representatives of this family in both cold and temperate latitudes are migratory species. They are also found in hot countries – these are sedentary species. Cormorants inhabit almost all major rivers and seas, they are often seen in many lakes of our planet. Some cormorants live in wetlands. Thus, cormorants are widely distributed around the globe. The greatest biological diversity is observed in temperate and tropical climates. Representatives of six species of these birds can be found on the territory of Russia. It is a large cormorant, small cormorant (dwells in the Caspian), Bering cormorant, Ussuri cormorant, red-faced cormorant and crested cormorant (inhabits the Kola Peninsula). The most common of them is a large cormorant. It inhabits the territory of Eurasia – from the Atlantic to the Pacific coast. Rare species are the crested and small cormorants. They are listed in the red book of Russia.
Cormorants are characterized by black color of plumage.
True, it has a metallic luster. Some species of cormorants have a different color. For example, in the case of the red-legged cormorant, it is gray, and the belly of the variegated cormorant is white (like several other species of these birds). On the obverse of the head of cormorants there is a small patch of bare skin. In different species of these birds it can be black, red, blue or yellow. In addition, younger cormorants have a lighter plumage. Color plumage, they are light brown.
Cormorants are medium to large birds.
The weight of large individuals can reach four kilograms. The wingspan of the cormorants can reach one hundred and sixty centimeters, and the length of the body is one meter.
Cormorants are excellent divers.
These birds swim with the use of only their feet, while they simultaneously perform non-weak jolts with both paws. The steering function is performed by the hard tail of these birds, and also, to some extent, their half-opened wings. Cormorants can be under water for one or two minutes. At the same time they are able to dive to a depth of up to twenty-five meters. After diving and underwater hunting, the plumage of these birds is substantially wet (which, in principle, is an amazing fact). Therefore, cormorants are forced to dry it for a long time. At the same time they rest either in the trees, or just on the shore, spreading their wings.
Cormorants are difficult to take off from the earth’s surface.
These birds can not practically do this, it is much easier for them to take off from rocks or trees. Cormorants can take off from the water, but for this they need a long takeoff. These birds fly a specific system for them – this is the line. The flight of cormorants is not only straightforward, but also very fast. The profile of the flying cormorant resembles a flat cross.
Cormorants nest colonically.
And one settlement often includes not even thousands, but millions of individuals. Cormorants are by nature considered silent birds. However, gathering in huge colonies, they practically all the time give a croaking rattling voice. As a rule, cormorants nest together with other birds. And even with animals (for example, seals). As for birds, it could be colonial birds like penguins and seagulls.
Cormorants are nomadic birds.
Many species do, in fact, not only seasonal migrations, but also significant daily flights. But not all cormorants are migratory birds. For example, the species of cormorants (the Galapagos cormorant) inhabiting the Galapagos Islands completely lost its ability to fly. This bird, of course, has wings. However, they are very short, so the Galapagos cormorant can not physically lift itself into the air. The reason for this loss is that on those small islands where these birds live, they have no enemies at all. Until the nineteenth century there was one more flightless cormorant on the Commander Islands, the cormorant stoller, but he died out.
A variety of conditions are suitable for the construction of a nest for cormorants.
These birds can equip their nests both in reeds and on level ground, both on trees and on rocks. When building a nest, cormorants use grass and branches. Masonry contains four to six eggs. Eggs have a matte surface. They have a bluish background, which is varied by white smudges.
Cormorant chicks are absolutely helpless.
They are born naked – plumage absent. Its appearance in different chicks is commemorated at different times. The period before the feathering can range from thirty-five to eighty days. Often parents feed their chicks and after they fledge, and this can continue for 2-4 months. As for adult plumage, it appears in young cormorants from one year to four years (depending on the species). It is interesting that the size of the hatched chicks differs from each other. This is due to the fact that eggs are not deposited simultaneously, but alternately. The incubation period lasts for twenty-four to thirty-one days.
In the diet mainly includes fish.
Freshwater cormorants diversify it with frogs as well as crayfish. Many cormorants are characterized by collective hunting, not only within the species, but also jointly, for example, with pelicans. When catching fish, they drive it to shallow water. On average, the cormorant consumes three hundred to four hundred grams of fish per day.
For many centuries, the Chinese and Japanese used cormorants for fishing.
And although at present it does not have any practical significance in Japan, it still remains as a tourist attraction. It is possible to observe the centuries-old tradition and take part in its incarnation in reality in two places – on the rivers Tamagwa and Nagara. By the light of torches from a raft or boat at night and carried out fishing – the fish rises to the light. At some point, they release prepared cormorants. This means that on their necks put on the ring and attached a short cord. Cormorant dives for prey and with it floats to the surface. The ring is necessary just so that the bird does not immediately swallow the caught fish. With the help of five to ten cormorants, it is possible to catch a whole basket of fish in just a few hours, while still having great fun.
Cormorants are useful not only to people due to fishing.
For example, the cormorant of Bougainville is the main “producer” of guano. Guano is a bird droppings, which is considered to be a very valuable fertilizer. This cormorant populates the coast of Peru in large numbers, and in some places the layer of guano reaches fifty meters. It is worth noting the fact that the Guano deposits began to be developed industrially only in the middle of the nineteenth century. At the same time, they were developed in the distant past by the ancient Incas.
The Great Cormorant inhabiting the territory of Russia is a large bird.
The length of the wing of the Great Cormorant varies from thirty-three to thirty-eight centimeters, and the weight on the average is three kilograms. The size of males is somewhat larger than females. Large cormorant is characterized by the presence of a large white semicircle on the underside of the head, and the bare parts of the head are yellow.
The Great Cormorant is a bird with a wide distribution area.
The Great Cormorant is found in vast areas of both Europe and Asia, while the nesting area continues to New Zealand, Tasmania and Australia, and captures many areas of the African continent. It is interesting that only the territory of Greenland is now the breeding site for this bird in the entire western hemisphere. Individuals nesting in the southernmost parts of the range, as well as in the northern parts, are migratory – wintering takes place in North Africa and the Mediterranean. The Great Cormorant is a sedentary bird, if the territory of warm latitudes becomes a nesting place. On the nesting sites in Russia, these birds fly with the first spring warming. For example, in February they can be in the Volga delta. If the winter cold returns, the cormorants may well go back.
Large cormorants are monogamous.
These birds are already in close pairs arriving at the nesting places. Probably, the cormorant pairs form for life. A significant number of cormorants at the age of three begin to nest for the first time. For some individuals, this happens at the age of four or even happens so that five, years. Cormorants of two years old, who are not yet sexually mature, arrive in their native colony. Here they keep close to adult cormorants.
Sometimes cormorants use nests of herons, while dragging them into trees.
But this happens rarely – as a rule, these birds self-equip their nests. Construction begins with the construction of the nest base. It is formed from large and thick branches. Above cormorants lay branches thinner. Often the branches are so fresh that they retain green leaves. Cormorant groups go to collect nesting material in the early morning, usually at a time the bird brings only one branch. The result of such construction (in which both the male and the female participate, and completely on an equal footing), the turret becomes the height of which can range from fifty to one hundred centimeters. Often such turrets are located very close to each other – almost closely.
The period from April to June is the time of cormorant egg laying.
In Western European territory, it happens that this period drags on until September. During the year there is only one masonry. The exception is the fact that the masonry is ruined. In this case, additional masonry is possible. Typically, a full masonry contains five eggs. They have a pale brownish-green color (although it is very difficult to recognize, due to the contamination of their surface with a droppipe) and an oval-elongated shape. On average, the size of cormorant eggs is as follows: 64 x 39.5 mm. However, in all eggs they vary in one direction or another. In some colonies of cormorants, a circumstance was discovered in which one of the eggs was rendered unfertilized in the clutch. This was especially true of those clutches that contained five or six eggs. Both female and male participate in hatching.In the Volga delta, the incubation period for cormorants is equal to either twenty-eight or twenty-nine days. As for the cormorants nesting in the territory of Western Europe, the individuals incubate here eggs for twenty-three or twenty-four days. The start of incubation may depend on local conditions. The newly born chicks are helpless – they are blind (eyes open on the third or fourth day of life) and bare (the fluff will cover their body only after a two-week period). Young individuals leave the parent’s nest seven weeks after birth, although the first sorties from the nest are beginning to be made much earlier than this time. Cormorants are considered independent after reaching the age of twelve to thirteen weeks, after which these birds are flocked into flocks. First flocks are small. In such a composition, young individuals wander near the nesting sites. Over time, the number of birds in the flocks increases significantly. As soon as this happened, the flight of cormorants begins.
Cormorant is easy to “loop around.”
This is often a gray crow. When the cormorant incubates eggs, in the immediate vicinity of it appears a crow. By nature, the crow is weaker than the cormorant, so he tries to hit it with his beak. True, it does not reach. The obsession with the gray raven leads to the fact that the cormorant, determined to inflict a crushing blow, rises to his feet. It turns out that the crow actually needs it – she flies unperturbed to the side. But behind the cormorant, indeed, during all this time there was a danger. As soon as the cormorant rises from the eggs, the raven’s partner grabs an egg with which it flies.
Small cormorant is the smallest cormorant inhabiting the territory of Europe.
The length of his body is on average about forty-eight centimeters, and the weight barely reaches eight hundred grams. Thus, the size of the small cormorant is at least half the size of the large cormorant. Small cormorant has a short beak. The European population of this species is about one thousand pairs. In the diet of small cormorant includes small fish, which the bird catches in shallow water.
Small cormorants are confined to internal freshwater reservoirs.
Often these are water bodies that are located in areas characterized by a warm climate. They prefer ponds overgrown with vegetation. Small cormorants build nests either in thickets of reeds, or in trees. Small cormorant is a colonial bird. In this case, the number of individuals in the colonies can be huge – one colony can contain from tens to hundreds of nests. If a small cormorant equips a nest on a standing tree, then it is often a neighbor of herons and ibises. Young individuals leave the parent’s nest even before they can fly. Cormorants rise on the wing at about ten weeks of age.
Small cormorants are migratory birds.
They go to the south in large flocks immediately after the nesting period is over. Wintering places for these birds are found in the Mediterranean. In winter, they can be found on water with salt water. At the nest sites small cormorants arrive in early March. Small cormorant cage contains three or four eggs. Their length is forty-seven millimeters. In early May, as a rule, small cormorants already finish egg laying and start hatching, which lasts from twenty-seven to twenty-nine days. Young cormorants become independent around the age of forty. If they are in danger, the cormorant chicks can jump out of the nest early enough. In this case, many of them are able to even swim.
Motley cormorant has a motley color.
The coloring of representatives of this species is much lighter than the rest. The upper part of the body is black, but the lower part (down to the cheeks) is white. A spot of yellowish color adorns the gap between the beak and eyes, and the area around the eyes has a blue color. Chin at motley cormorant reddish.Here is such a variety of colors and gave the name to this species of birds. Variegated cormorants inhabit the territories of New Zealand and Australia.
Motley cormorants live along the coasts of the seas.
They really give them preference. However, not infrequently variegated cormorants are found on the coasts of rivers and lakes, although if the water level in them is constant. Motley cormorants are colonial birds. Within one colony there may be several thousand nests. Most nests are built on bushes and trees.
Masonry of crooked cormorant contains three eggs.
The incubation continues for four weeks, with the participation of both the female and the male. The chicks are born helpless and feed their parents in the nest for seven or eight weeks. At the end of this period, care for the offspring is not completed, but lasts about eleven more weeks.
Crested cormorant is a rare species.
In Russia, the crested cormorant (aka long-nosed cormorant) is found only on the territory of the Kola Peninsula. In addition, crested cormorant can be found on the north-west African coast, the Mediterranean Sea, along the European Atlantic coast, and also in Iceland. On the territory of Russia, under watchful surveillance and protection are all nests of these birds.
Crested cormorant is a sea bird.
And over the sea waters (not far from the coast), the crested cormorant spends a significant part of the time. On land, this bird can be seen only during nesting. In the diet of the crested cormorant enters only the fish.
At the nest sites, crested cormorants form colonies.
Most often it is just like that. However, there are cases when these birds nest in separate pairs. At the same time, they build a nest in rather inaccessible places. It can be, for example, rocks or a mound of stones. As construction materials cormorants use dry grass or algae. In this regard, they can approach and branches of juniper or willow. One nest, crested cormorants are used for several years. Masonry contains from two to five white eggs. In hatching, both partners participate.
Eared cormorants – large birds.
The length of their body is from seventy to ninety centimeters, the weight reaches two and a half kilograms. They have a long beak. Female eared cormorants are somewhat smaller than males. The average life span of eared cormorants is six years. To be more precise, it is 6.1 years. However, life expectancy at 17 years and 9 months is fixed – this is how much it was in the oldest known cormorant.