The Great Cormorant

The Great Cormorant – Phalacrocorax carbo


  • Kingdom: Animalia
  • Class: Aves
  • Order: Suliformes
  • Family: Phalacrocoracidae
  • Genre: Phalacrocorax
  • Species: Phalacrocorax carbo

Identification characters

It is a large waterfowl with a body length of 77-94 cm and a wingspan of 121-149 cm. Weighs 1810-2810 g. The Great Cormorant can often be seen on rocks or other supports, with its wings spread out, like the Little Cormorant, to dry them in the sun, having no uropygial gland. The throat is long and thick. Compared to the Little Cormorant, it has a more elongated, triangular head profile with a strong beak. No sexual dimorphism. When swimming, the body is largely submerged, with the neck and raised beak visible at the surface. Adults have black plumage with blue and green iridescence. The wings have a bronze tinge with black scales. The skin at the base of the lower mandible is yellow, surrounded by white. A white patch on the thigh can be seen during the breeding season, but this disappears by July. In the colony it makes high, guttural sounds.


With the exception of South America and Antarctica, the Great Cormorant nests on all continents. Europe accounts for less than half of the species’ global nesting area. It is found all along the Atlantic Ocean, the Mediterranean and Black Sea coasts. Europe’s breeding population of 401 000-512 000 breeding pairs is increasing. Migratory in northern areas, sedentary in the rest of its range.
In Romania, the Great Cormorant is a partly migratory species. In winter it stays mainly on still, inland, unfrozen waters or even on large rivers. The number of individuals wintering in our country averages between 2 815 and 14 153.
In summer, the cormorant can be found in most aquatic habitats, both coastal and inland wetlands. The breeding population in Romania is 12 000-20 000 pairs, mostly found in inland waters and in the Danube Delta.

Living environment and biology of the species

In the marine environment, the Great Cormorant is found in protected coastal areas such as estuaries, brackish lakes, lagoons, floodplain forests, deltas and bays.
Freshwater habitats are represented by lakes, rivers, floodplains, meshed marshes
ponds, fish ponds, etc.
The Great Cormorant is a very good swimmer and diver. It floats with its body above the surface, and if it feels in danger, it submerges, leaving only its head and neck out. In the wild it can live for up to 23 years. It reaches sexual maturity at the age of three.
Food consists of fish up to 30-40 cm long. Among freshwater species, it mainly eats carp, carp, pike, pike-perch or perch. The most commonly eaten marine species are zander, mullet, barbel, sprat and anchovy. To feed, they dive with their feet or wings. It can dive up to 8 m deep and stay underwater for up to 2 minutes. Depending on its size, prey can be eaten either while diving or at the surface.
Mating is monogamous. Pairs usually form for one breeding season. Sometimes a pair can last longer, especially if they use the same territory and have the opportunity to return to their old nest. The nest can be set up on trees on islets, in floodplain forests, on the ground or even in reeds.
It usually nests in mixed colonies of up to 400 nests, together with other bird species such as little cormorants and various species of lizards.
Nuptial play takes place on the nest, even when the nest has not been completed. The nest is made of various organic materials such as twigs, plants and dried grasses, cemented with bird droppings. There can be up to 15 nests on the same tree. In May-June, the great cormorant lays 4-7 eggs. Incubation is 23-30 days. Both partners hatch and protect the nest. The chicks are fed 3-5 times a day, first with digested fish, then with regurgitated fish. At the age of 35 days, chicks begin to climb branches at 35 days of age, at 42 days they can already swim and jump into the water, and at 44 days after hatching they are able to fly. At 56 days after hatching, the chicks leave the nest for good.

Threats and conservation measures

The Great Cormorant can be threatened by habitat loss and alteration, pollution and poor water management, hunting and poaching. Mortality can also be caused by fishing gear.
To conserve cormorant populations, it is recommended to respect building restrictions in riparian areas, maintain wetland vegetation at an optimal level for the species, proper waste and sewage management around wetlands. Management of water levels in aquatic ecosystems should be consistent with the ecological needs of the species. It is recommended to limit the use of fishing nets to prevent accidental catching of birds. In areas of high importance for the species, tourist activities should be regulated, especially during the breeding and rearing period, and in some cases even banned. To increase the visibility of power lines, certain devices can be installed. To minimise the risk of collisions, it is recommended to plan the installation of wind turbines.
Hunting legislation must be respected, with cooperation between environmental protection organisations, hunting organisations, the gendarmerie and the Environmental Guard against poaching.
It is essential to give importance to research to assess the impact of waterfowl on commercially exploited resources and to establish measures to harmonise species conservation objectives with the activities of the affected sectors. Breeding, migration, feeding and aggregation areas should be inventoried. Studies on various aspects of the biology of the species, including demographic parameters, should be encouraged.


  • Fântână Ciprian, Kovács Istvan, Benkő Zoltán, Daròczi Szilárd, Domșa Cristian, Veres-Szászka Judit (editors), 2022, Atlas of bird species of community interest in Romania, 2nd edition – Love birds, save nature!, Project financed by the European Regional Development Fund through the Large Infrastructure Operational Programme 2014-2020, Ministry of Environment, Water and Forests – Biodiversity Directorate, scientific coordination Romanian Ornithological Society and Association for the Protection of Birds and Nature Milvus Group, produced by EXCLUS PROD SRL, p. 92;
    Svensson (text and maps), 2017, Guide to bird identification. Europe and the Mediterranean area, translation and adaptation into Romanian: Romanian Ornithological Society, Emanuel Ștefan Baltag, Sebastian Bugariu, Alida Barbu, p.78;
    Radu Dimitrie, 1983, Small Ornithological Atlas – Birds of the World, Albatros Publishing House, Bucharest, p. 57; Ornitodata | Great Cormorant (
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