The Great Cormorant (Phalacrocorax carbo): The Expert Diver of Our Waters
The Great Cormorant, an iconic silhouette on coasts and waterways, drying its less-waterproof plumage.
An Unmistakable Silhouette
The Great Cormorant (Phalacrocorax carbo) is one of those unforgettable birds that leaves a lasting impression once you spot it – standing tall and proud with its striking dark silhouette. You might have seen one resting on a dock post or a rocky ledge, wings spread wide as if it's putting on a show. Many folks assume it's just trying to warm up, but here’s the intriguing part: it’s actually drying its feathers! Unlike other seabirds that boast super waterproof feathers, the cormorant’s plumage gets completely soaked – and that’s by design. This smart adaptation allows it to glide through the water like a torpedo, diving deeper than most birds could ever imagine to catch fish.
Identification: Black Cormorant, White, or Juvenile?
One of the main questions when identifying a cormorant is its plumage color. Is it black, white, or black and white? The answer depends on its age and the season.
The Adult: The "Black Cormorant"
Outside the breeding season, the adult is an almost entirely black cormorant, with metallic green and blue sheens. Its powerful bill is hooked at the tip. There is no visible difference between the male and female.
The Breeding Plumage: The Appearance of White
During the breeding season (from winter to spring), the adult dons a spectacular breeding plumage. A distinctive white patch appears on each flank, and its head and neck become covered with fine white feathers, giving it a grizzled look. This is the black and white cormorant often seen early in the year.
The Juvenile: The "White-Bellied Cormorant"
The juvenile Great Cormorant looks very different from the adult. Its plumage is much duller, dark brown on the back and wings, while its belly, breast, and the front of its neck are whitish. This young bird is often mistakenly called a "white cormorant" or "white-bellied cormorant." It will take several years for the juvenile to acquire its full dark adult plumage.
The juvenile cormorant's plumage, with its white belly, is often a source of confusion.
Calls and Vocalizations
The Great Cormorant is generally a silent bird away from its colonies. At nesting sites, it emits a variety of deep, guttural croaks and grunts. Its calls are not melodious and are rather functional, used for communication between partners and with their young.
Habitat & Distribution
Originally a coastal bird, the Great Cormorant has undergone a remarkable expansion inland. It is now found along all coastlines but also on major rivers, lakes, ponds, and reservoirs. It settles wherever fish resources are sufficient. Its presence is particularly notable in winter when northern populations supplement local numbers.
Diet: A Master Fisher
The Great Cormorant is a formidably efficient piscivorous predator. It fishes by diving underwater, propelling itself with its large webbed feet. It can remain submerged for over a minute and reach depths of several meters to pursue and capture medium-sized fish. After fishing, it swallows its prey headfirst before returning to a perch to digest and dry its wings.
Nesting & Reproduction
Cormorants nest in colonies, often located on coastal cliffs, in trees near water, or on rocky islets. The nest is a large structure made of branches and seaweed, consolidated with droppings. The female lays 3 to 4 chalky, bluish-white eggs. Both parents take turns incubating and feeding the altricial chicks, which are entirely dependent on them.
Conservation Status
Once threatened, the Great Cormorant has benefited from protection measures that have allowed its populations to recover spectacularly in Europe and North America. It is now listed as "Least Concern" (LC) by the IUCN. However, this success has led to conflicts with professional and recreational fishers who accuse it of taking significant quantities of fish from rivers and fish farms.
