The cormorant is a widespread aquatic bird found in marine and freshwater environments globally. These birds are highly adapted for diving and pursuing fish underwater, resulting in a unique set of physical characteristics and behaviors that aid in identification.
Overall Shape and Scale
The cormorant presents as a medium-to-large waterbird, comparable in size to a goose, with a thick, heavyset body. Its silhouette is dominated by a long, slender neck that can appear serpentine when alert. When perched on land, the bird often holds its body in a distinctly vertical, upright posture, which gives it a somewhat prehistoric appearance.
This body structure is optimized for diving, not for graceful movement on land. When swimming, the cormorant floats remarkably low in the water, a result of its dense bone structure and less buoyant plumage. Often, only the bird’s head and neck are visible above the surface. This low-slung profile aids its ability to quickly submerge and hunt prey beneath the surface.
Key Identifying Features
The cormorant’s plumage is predominantly dark, appearing black or brownish-black from a distance. In good light, especially during the breeding season, the feathers exhibit a striking metallic sheen, often displaying subtle iridescence in shades of green, purple, or bronze. The cormorant’s feathers have a unique microscopic structure that allows them to become waterlogged, which reduces buoyancy and helps the bird dive more effectively.
The head features a blocky shape and a long, thin bill with a distinct, sharply hooked tip. This hook is an adaptation used to grasp and secure slippery fish while underwater. At the base of the bill, the bird possesses a patch of bare skin known as the gular pouch.
The coloration of this gular pouch is a key field mark for identification, varying by species but frequently appearing in bright shades of yellow, orange, or red. Many cormorants also have vivid eyes, such as emerald or blue-green, which contrasts against their dark head feathers. Their feet are large, black, and fully totipalmate, meaning all four toes are connected by webbing.
Recognizable Habits and Posture
The most unmistakable visual trait of the cormorant is its distinctive wing-drying stance. After foraging, the bird will perch on a rock, log, or piling and spread its wings wide in a crucifix-like posture, holding them out for extended periods. This behavior is necessary because their specialized feathers are not fully waterproof and must be air-dried to allow the bird to fly again.
When actively swimming, cormorants move with a low profile, keeping their bodies submerged and only their heads and necks visible. This posture can create the illusion of a small, swimming snake as they patrol the water’s surface in search of prey. The act of fishing is a powerful visual cue, as the birds plunge beneath the surface with an agile, forward leap before pursuing fish deep underwater.