Great Cormorant

Belongs to a group of large, dark-plumaged waterbirds, with Phalacrocorax carbo being a robust taxon characterized by a substantial body mass ranging from 1.5 to 5.3 kilograms and a wingspan of 121 to 160 centimeters. The adult plumage is predominantly glistening black with subtle bronze and greenish reflections on the mantle and wings. It features a moderately long, wedge-shaped tail and a sturdy, hook-tipped grayish bill. A prominent diagnostic field mark is the bright yellow gular pouch, bordered by white feathers, which becomes intensely colored during the breeding season. During this period, breeding adults also exhibit conspicuous white patches on the thighs and fine, hair-like white plumes across the head and neck. Immature individuals are distinguished by their drab brownish upperparts and contrasting pale grayish or white underparts.

Belongs to a group of large, dark-plumaged waterbirds, characterized by a substantial body mass ranging from 1.5 to 5.3 kilograms and a wingspan of 121 to 160 centimeters. The adult plumage is predominantly glistening black with subtle bronze and greenish reflections on the mantle and wings. It features a moderately long, wedge-shaped tail and a sturdy, hook-tipped grayish bill. A prominent diagnostic field mark is the bright yellow gular pouch, bordered by white feathers, which becomes intensely colored during the breeding season. During this period, breeding adults also exhibit conspicuous white patches on the thighs and fine, hair-like white plumes across the head and neck. Immature individuals are distinguished by their drab brownish upperparts and contrasting pale grayish or white underparts.

Geographical distribution: Boasts an exceptionally wide cosmopolitan range, extending across Eurasia, Africa, Australasia, and the Atlantic coast of North America. It is highly abundant throughout the Palearctic, nesting from the coastal cliffs of the British Isles and Scandinavia to the Far East in Japan and China. In the Southern Hemisphere, stable breeding populations are widely distributed across Australia, Tasmania, and New Zealand, alongside localized colonies throughout sub-Saharan Africa. Conversely, this taxon is conspicuously absent from South America and polar zones.

Habitat: Utilizes an extensive array of aquatic environments, seamlessly transitioning between marine and inland freshwater systems. Common habitats include estuaries, sheltered coastal bays, large interior lakes, deep reservoirs, major river channels, and brackish marshes. It heavily relies on elevated, undisturbed perching sites for roosting and thermoregulation, favoring rocky cliffs, dead coastal trees, sandbars, and artificial structures such as utility poles and piers. Shallow, fish-rich waters are crucial ecological prerequisites for sustaining its foraging activities.

Feeding: Functions as an opportunistic and highly efficient piscivore, specialized in capturing prey via active pursuit diving. The diet consists primarily of a wide variety of bottom-dwelling and pelagic fish, including eels, flatfish, cod, and various cyprinids, adapting fluidly to local abundance. When hunting, it propels itself underwater using its powerful totipalmate feet, regularly reaching depths of 10 meters, with exceptional dives recorded up to 30 meters. On rare occasions, it supplements its diet with crustaceans, amphibians, and benthic invertebrates when fish populations dwindle.

Behavior: Frequently observed in its iconic wing-drying posture, standing erect on a perch with its wings widely spread. This behavior is an adaptation to its partially permeable plumage, which minimizes buoyancy to enhance diving efficiency but requires subsequent air-drying to prevent heat loss. It is a highly gregarious taxon, roosting, foraging, and migrating in large, organized flocks. Its flight is strong and direct, characterized by steady wingbeats, often forming distinct "V" shapes or long diagonal lines when commuting between communal roosts and foraging grounds.

Nesting: Occurs in dense colonial aggregations, sometimes comprising thousands of breeding pairs. Nest sites are selectively established on precipitous marine cliffs, isolated rocky islets, or within the upper canopies of mature trees situated near water. The bulky nests are constructed from twigs, sticks, reeds, and marine algae, consolidated over time with accumulating guano. The female typically deposits 3 to 5 pale blue or greenish eggs coated with a chalky layer. Both parents share incubation duties for 28 to 31 days and cooperatively provision the semi-altricial chicks through regurgitation.

Conservation status: Categorized globally as Least Concern (LC) on the IUCN Red List. Population trends in many regions, particularly across Europe, have shown substantial increases over recent decades due to targeted legal protections and habitat management. Despite this overall stability, local populations face conflict and persecution from commercial fisheries and aquaculture facilities, and remain vulnerable to drowning in gillnets, oil spills, and heavy metal bioaccumulation within aquatic food webs.