The Great cormorant is a large black bird, but there is a wide variation in size in the species' wide range. Males are typically larger and heavier than females. It has a longish tail and yellow throat patch. Adults have white patches on the thighs and on the throat in the breeding season. In European waters, the Great cormorant can be distinguished from the Common shag by its larger size, heavier build, thicker bill, lack of a crest, and plumage without any green tinge. In eastern North America, it is similarly larger and bulkier than the Double-crested cormorant, and the latter species has more yellow on the throat and bill and lack the white thigh patches frequently seen on great cormorants.
Great cormorants occur throughout Europe, Asia, Australia, Africa, and northeastern coastal North America. They may be both resident and migratory. Throughout the year in some areas, large groups remain within the breeding range. Greta cormorants frequent open marine environments and inland waters. They inhabit sandy or rocky sheltered coasts and estuaries and are rarely seen any distance from the coast. This species breeds on cliffs and inshore islands, among boulders and man-made structures. Birds that nest inland will breed on trees, bushes, and reedbeds, and even on bare ground.
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