Phalacrocorax auritus

Description

This large water bird has a wingspan of 45 to 48 inches, a body length of 28 to 35 inches, and a weight of 2½ to 5½ pounds. It often sits with its wings extended. Both sexes are similar in plumage and size. Adults are all black with greenish gloss. During the breeding season they have small white, black or mottled plumes over their eyes. Juveniles are much lighter in color.

Distribution and Habitat

Double-crested cormorants are widely distributed across North America. They breed locally along all coasts, with dense concentrations being found in Florida, the Great Plains region, and along the Great Lakes and St. Lawrence Seaway corridor. Their wintering range extends along the Pacific Coast from Alaska to Mexico, along the Atlantic Coast from North Carolina to Florida, and along the Gulf Coast from Florida to Belize; they can also be seen in smaller numbers at inland sites along large rivers and lakes as far north as Indiana.

These cormorants are found in a wide variety of aquatic habitats, including ponds, lakes, rivers, lagoons, estuaries, and open coastline.

Reproduction

The nest is a large, flat platform built from sticks, seaweed, and flotsam. It is not uncommon to find pieces of rope, deflated balloons, fishnetting, plastic debris, and other trash among the materials used to construct the nest. The nest may be located in a tree, on a cliff, or on the ground.

A typical clutch contains 3 or 4 pale blue eggs. Chicks are naked and helpless at hatching.

In breeding colonies where the nests are placed on the ground, young cormorants (creches) leave their nests and congregate into groups with other youngsters, returning to their own nests to be fed.

Diet

Fish make up the majority of the cormorant's diet, with aquatic insects and amphibians also being taken on occasion. The cormorant dives from the surface of the water and chases its prey underwater, grabbing the prey in its bill.

Scientific Classification

phylum Chordata
subphylum Vertebrata
class Aves
order Pelecaniformes
family Phalacrocoracidae
genus & species Phalacrocorax auritus

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