The Great Cormorant is a large, powerful fish-eating waterbird found across a remarkable range of the globe, from European coasts and lakes to Africa, Asia, Australasia and eastern North America. Almost entirely blackish, with an oily sheen and a hook-tipped bill, it is a familiar sight standing on rocks, posts and jetties with its wings held open to dry.
An expert underwater hunter, it dives from the surface and propels itself with its feet to chase fish, sometimes at considerable depth. Its success has at times brought it into conflict with anglers and fisheries, yet it remains one of the most widespread and adaptable of all waterbirds, equally at home on rugged sea cliffs and quiet inland reservoirs.
A big, heavy, dark waterbird sitting low in the water with its bill tilted slightly upward, or perched upright with wings spread to dry, is very likely a Great Cormorant. Breeding adults show white on the face and thigh, while the yellow skin at the base of the bill is a useful year-round feature.
| Size | 80-100 cm long with a 1.2-1.6 m wingspan; a large, bulky waterbird |
| Plumage | Blackish overall with a bronze-and-green sheen; breeding adults gain a white throat patch and a white thigh spot |
| Face | Bare yellow skin at the base of a strong, hook-tipped grey bill |
| Posture | Often perches upright with wings spread open to dry after diving |
| In water | Swims low with the body submerged and the bill angled slightly upward |
| Flight | Flies strongly with neck outstretched, often in lines or V-formations over water |
Away from the colony the Great Cormorant is largely silent. At breeding and roosting sites it becomes vocal, giving deep guttural croaks, grunts and cackling calls during displays and squabbles over nest sites. These low, rasping sounds carry across the noisy, crowded colony.
The Great Cormorant has one of the widest distributions of any waterbird, occurring across Europe, Africa, Asia, Australia, New Zealand and the Atlantic coast of North America. It uses an enormous variety of aquatic habitats, from rocky sea coasts, estuaries and harbours to freshwater lakes, rivers, reservoirs and gravel pits. Many populations are resident, while northern birds move south for winter.
The diet is made up almost entirely of fish, caught on underwater dives that can last up to a minute. The cormorant chases prey using powerful strokes of its webbed feet and seizes fish with its hooked bill, bringing larger catches to the surface to swallow. It takes whatever fish are locally common, which is why it sometimes clashes with fisheries and anglers.
Great Cormorants nest colonially, either on coastal cliffs and rocky islets or in trees beside inland waters. The nest is a bulky mound of sticks, seaweed and debris, often reused and enlarged each year. The female lays three or four pale eggs, and both parents incubate for around a month and then feed the young, which fledge at roughly seven to eight weeks.
- European Shag: Smaller and slimmer, greener glossed, with a peaked crest and no white face patch
- Double-crested Cormorant: North American relative with more orange facial skin and a slighter build
- Pygmy Cormorant: Much smaller with a shorter bill and longer tail, found on inland wetlands
Why do cormorants stand with their wings spread out?
Cormorant feathers are less waterproof than those of many waterbirds, which reduces buoyancy and helps them dive. After fishing they spread their wings to dry them out in the air and sun.
How is a Great Cormorant different from a Shag?
The Great Cormorant is larger and bulkier with yellow face skin and, when breeding, white on the face and thighs, while the European Shag is smaller, greener and shows a peaked crest and no white.
How deep can Great Cormorants dive?
They typically feed in shallow water but can dive well below the surface, sometimes to depths of several metres, using their feet to chase fish underwater.
Are Great Cormorants freshwater or saltwater birds?
Both. They are equally at home on the sea, in estuaries and on inland lakes, rivers and reservoirs, which is part of why they are so widespread.