The great cormorant | Facts & Information

Origin

The largest concentration of large Cormorant specimens is found in the delta. It is widespread throughout Europe but in restricted locations. There is also a subspecies, Phalacrocorax carbo sinensis, which is not known to live in Romania and which has as distinctive sign the white feathers on the head and neck.

The family of cormorants (Phalacrocoracidae) includes about 40 species, which are found all over the Earth. Cormorants are also known as batlans, they are large aquatic birds.

Currently the population of cormorants is declining due to the intervention of man who considers the Cormorant an extremely harmful bird from a fish point of view. They are puddles-breeders who have specially hired hunters to destroy Cormorant populations.

The name cormorants comes from Latin: "corvus marinus" meaning sea Raven. They live, raise their young in large colonies and produce a variety of vocalizations.

Phalacrocorax carbo is part of the Phalacrocoracidae family and occupies mainly the areas around the coast of Great Britain, but is completely absent in the north-eastern parts of Scotland. Globally, this species is very widespread, occupying the vast majority of temperate zones in the Old World.

Feeding Large Cormorant

They generally feed on fish, which they catch by dipping their long necks into the water. Cormorants are considered to be harmful birds because of the large amount of fish they consume.

Live, on average 10-15 years, large species, such as Phalacrocorax carbo, can even reach the age of 30 years.

The large Cormorant is a very greedy bird, generally consuming one kilogeam, and during the growth of chicks two or three kilograms of fish daily.

Think about how much fish a colony consumes. The large colonies that once existed were shrunk by shooting and destroying nests, and the ones that exist today are gradually being removed.

To catch the fish, it jumps slightly into the water, dives, then comes out to the shore, shakes its feathers, and on the branch of a tree or a stump stands in a straight position, drying its wings (which it keeps open).

Features Large Cormorant

The predominant color in the Great Cormorant is black. On the belly and chest the dense and small feathers have metallic blue reflections. White is found in the area of the cheeks and hips. On the back and wings the feathers are well differentiated like scales.

The beak is strong, curved white below and above with shades of yellow towards the base. It is of medium length, with the tip bent downwards resembling a hook. The nasal orifices are not very visible, and the nasal cavity is almost nonexistent.

Thus, due to this disposition, water is prevented from entering the respiratory apparatus when the bird sinks its beak into the water. The body length is 80 -100 cm, the wingspan is 1.3 – 1.6 m and the weight is 2 – 2.5 kg.

These birds live in the Danube floodplain and on the coasts of the Black Sea, they are also known as batlan mare or sea Raven.

It usually broods on tall trees, in colonies that reach thousands of pairs. Occasionally up to 50 nests are found on a tree. The nest is made of pieces of wood and branches, lined inside with reeds or grass. Both partners build the nest and Hatch.

Birds procure their nest materials by taking them out of the water by diving, breaking branches off trees, or gathering the land spread on foot. Both partners Moult in December and acquire a splendid plumage, but which moults again in the middle of summer. The plumage of the males resembles that of the females.

The Great Cormorant is a bird very common throughout the Danube region as well as on the shores of the Black Sea and in the lagoons. If the Danube and puddles freeze, the Great Cormorant retreats on the banks and from here in the harsh winters migrates south to the coasts of the Mediterranean Sea, but as soon as the time becomes warmer and the ice melts it appears again to us. In Romania live in the Danube delta three species of Cormorant:

Large Cormorant (Phalacrocorax carbo) (91 cm)

Small Cormorant (Phalacrocorax pygmaeus) (48 cm)

Motat Cormorant (Phalacrocorax aristotelis) (76 cm)

Breeding Large Cormorant

The large Cormorant nests in colonies in Willows or poplars. The female lays up to 4 blue eggs and the incubation period is 30 days. Chicks can fly 30 days after hatching. Colonies are specific by the indescribable noise they produce.

Cormorants make their nests on the rocky edges of the islands, using as raw material: twigs, gravel, twigs or guano (fossil fertilizer). Other cormorants nest in trees or on the ground. The faeces of cormorants are so acidic that the trees in which they nest die in about 3 years.

In the first days of life, the chicks will be fed with the regurgitated fluid from the laryngeal sac of mature birds, after which they will be able to eat solid food from their parents ' goiter. After 50 days the chicks, able to fly, will leave the nests, returning to the colony after reaching the age of 2-3 years. During the winter cormorants shelter together each evening in groups exceeding several hundred specimens.