Any of various diving seabirds, mainly of the genus Phalacrocorax, order Pelecaniformes, about 90 cm/3 ft long, with webbed feet, a long neck, hooked beak, and glossy black plumage. Cormorants generally feed on fish and shellfish, which they catch by swimming and diving under water, sometimes to a considerable depth. They collect the food in a pouch formed by the dilatable skin at the front of the throat. Some species breed on inland lakes and rivers.
P. carbo has a bright shiny head and neck, with bluish-black feathers, speckled with white. The general colour above is a greenish black, the throat white, and the bill and feet are dark grey. It is found in all parts of the world in coastal regions.
There are about 30 species of cormorant worldwide, including a flightless form Nannopterum harrisi in the Galapagos Islands; the shag, or green cormorant, P. aristotelis; and the small European cormorant, Halietor pygmaeus, which is a freshwater bird. The guanay cormorantP. bougainvillei, of the Peruvian coast, is the main producer of the guano of those regions.
There are 8,000 breeding pairs in the UK (fewer than for the grey heron) according to a 1998 RSPB estimate.
The blue-eyed shag or king cormorantPhalacrocorax atriceps is the only Antarctic species to give birth to naked young, without fur; the chicks have to be brooded by the parents for the first three weeks, and are then fed by each parent in turn. The fledglings leave the nest after about seven weeks.