Common cormorant (Phalacrocorax carbo (Linnaeus, 1758)) is a water bird of the Falacrocoracidae family widespread throughout Eurasia and Australasia, as well as in the north-eastern regions of North America and the northern parts of Africa. Cormorano comune Phalacrocorax carbo Great cormorant intotheblue.it
It measures 80-100 cm long, weighing 1810-2810 g (the females are smaller than the males); the wingspan is 130-160 cm.
The common cormorant, a sort of crow of the seas, is a large-sized bird, with a dark head, neck and body and a robust hook-shaped beak.
The bronze-colored wing feathers are bordered in black and create a chromatic contrast with the rest of the body; the lower plumage is almost entirely black. The adult males and females are distinguished from the young, which, in the first year of life, have a belly covered with white feathers that form a large or more extensive patch. During the second year, this white band disappears, but they still remain recognizable by the brownish color of the plumage, which begins to resemble that of adults only during the third year of life.
The moult of adults takes place twice a year: from July (after the breeding season) to December for tail feathers and, before nesting, from January to April for feathers of the head, neck and body.
Well adapted to the aquatic environment (sea or fresh water) which provides most of its food, the cormorant has a good visual capacity both underwater and on the surface: in fact its eye is provided with a transparent nictitating membrane (one third eyelid that moves from the inner corner to the entire eye) which acts as a diving mask allowing an excellent vision. On the other hand, touch and smell are little developed in this species.
Distribution and habitat
Above all, an aquatic animal, mostly linked to the salty and fresh waters, the common cormorant lives on all continents except in South America. It nests in the extreme North-East of the United States, in Terranova and in Greenland; in Europe, from northern Norway to the Mediterranean basin. On the African continent, inhabits the Mediterranean and Atlantic coasts as far as Mauritania and is widespread in southern Africa. In Asia, it is present as far as India and China; in Japan, only the island of Honshu hosts its own subspecies. Elsewhere, it is found in East Africa and South-East Asia. Another subspecies lives in Australia, Tasmania, New Zealand and the Chatham Islands.
The northern populations (Europe, North America, Greenland, Iceland) are the least sedentary and migrate, to winter, up to over the 40th parallel. In the twentieth century this distribution has undergone great changes, above all in the inner lands, due, on the one hand, to the persecution of which these birds have been victims by fishermen and, on the other, by the transformation of some habitats. In western Europe, the common cormorant lives mainly on the coasts, while, more to the east and in the Netherlands, northern populations nest in the vicinity of large expanses of inland waters. The only large colony of common cormorants worthy of signaling in Germany is found in Western Pomerania.
In France, the populations reproduce on the islands and cliffs of Normandy, Picardy and Brittany, and more recently, but modestly, inside: on the lake of Grand-Lieu (Vendée), in Picardy and in the Cher. The only nesting colonies in Italy are found in Sardinia. The coastal ponds of Sardinia, the Orbetello lagoon and the Circeo National Park, in Tuscany, Lazio and along the Savena torrent, just south of Bologna, are places of passage and wintering.