General Overview
Cormorants and shags (Phalacrocoracidae) are a family of medium to large aquatic birds widely distributed across coastal regions, lakes, and rivers worldwide. Known for their exceptional diving ability, they pursue fish and other prey underwater with powerful strokes of their feet. The family includes more than 40 species, some of which are important in traditional fishing practices where they have been trained by humans to catch fish.
Appearance
Cormorants have long necks, hooked bills, and strong, streamlined bodies built for diving. Their plumage is typically dark; black, brown, or gray. Sometimes with iridescent green or blue gloss, and a few species show white patches or ornamental crests during the breeding season. Unlike many aquatic birds, their feathers are not fully waterproof, which allows them to reduce buoyancy and dive more effectively. After feeding, they are often seen perched with wings spread to dry.
Diet
Cormorants are primarily piscivorous, feeding mainly on fish, though they also consume crustaceans, amphibians, and other aquatic prey when available. They hunt by diving from the surface, using their webbed feet for propulsion and their sharp, hooked bills to seize slippery prey. Their efficient hunting style makes them highly effective predators in both freshwater and marine ecosystems.
Habitat
Members of the Phalacrocoracidae family inhabit a wide variety of aquatic environments, including coastal seas, estuaries, large rivers, lakes, and reservoirs. They prefer areas with abundant fish populations and require perches such as rocks, trees, or man-made structures for roosting and drying their wings. Many species nest colonially on cliffs, islands, or in trees near water.
Behavior
Cormorants are highly social birds, often seen foraging, roosting, and nesting in large groups. They are skilled divers, sometimes hunting cooperatively to herd fish into tighter schools. After feeding, they characteristically perch with wings outstretched to dry. Courtship displays involve bowing, wing fluttering, and the showing of brightly colored facial skin or throat patches. Colonies can number in the thousands, with noisy gatherings during breeding season. Most species are sedentary or dispersive, though some populations migrate seasonally in response to food availability.
