Double-crested Cormorant

Phalacrocorax auritus

Order PELECANIFORMES - Family PHALACROCORACIDAE

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1. Cool Facts
2. Description
3. Similar Species
4. Sound
5. Range
6. Habitat
7. Food
8. Behavior
9. Reproduction
10. Conservation Status
11. Other Names

The Double-crested Cormorant is the most numerous and widespread North American cormorant. It's also the only one that occurs in large numbers inland as well as on the coast. Growing in numbers throughout its range, this cormorant is increasingly being blamed for declines in sport fisheries and for devastating fish farms.

Cool Facts

• The Double-crested Cormorant makes a bulky nest of sticks and other materials. It frequently picks up junk, such as rope, deflated balloons, fishnet, and plastic debris to incorporate into the nest. Parts of dead birds are commonly used too.

• Large pebbles are occasionally found in cormorant nests, and the cormorants treat them as eggs.

• Double-crested Cormorant nests often are exposed to direct sun. Adults shade the chicks and also bring them water, pouring it from their mouths into those of the chicks.

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

• Accumulated fecal matter below nests can kill the nest trees. When this happens, the cormorants may move to a new area or they may simply shift to nesting on the ground.

Description

• Size: 70-90 cm (28-35 in)
• Wingspan: 114-123 cm (45-48 in)
• Weight: 1200-2500 g (42.36-88.25 ounces)

• Large, dark water bird.
• Long body and long neck.
• Medium-sized bill is blunt or hooked at tip.

• Legs short and dark.
• Tail moderately long.
• Bare skin around face orange.
• Often sits with wings extended.
• Neck kinked during flight.
• Adult all black with greenish gloss.
• In breeding has small plumes over eyes; may be white, black, or mottled.
• Eye brilliant turquoise.

Sex Differences

Sexes alike.

Immature

Upper breast and throat pale. Chest variable from nearly whitish to dusky. Usually chest pale and belly dark, but may be uniform pale below.

Similar Species

• Great Cormorant bigger and blockier, has yellow facial skin bordered by white feathers; immature with belly paler than chest.
• Neotropic Cormorant slimmer; tail longer; facial skin smaller and pointed at rear, bordered white in breeding adult.
• Brandt's Cormorant has less conspicuous and dark facial skin, bordered with pale feathers.
• Red-faced and Pelagic cormorants smaller and slimmer, with much smaller bills and red facial skin.

Sound

Deep guttural grunts.

»listen to songs of this species

Range

Summer Range

Widely distributed across North America. Breeds locally along all coasts and extensively in Florida, the center of continent, and along the Great Lakes and the St. Lawrence Seaway. Also in Mexico, Belize, the Bahamas, and Cuba.

Winter Range

Winters along Pacific Coast from Alaska to Mexico; along the Atlantic and Gulf coasts from North Carolina to Belize, with smaller numbers northward to New Hampshire; and at inland sites along large rivers and lakes northward to Indiana.

Habitat

Found in diverse aquatic habitats, such as ponds, lakes, rivers, lagoons, estuaries, and open coastline; more widespread in winter.

Food

Predominantly fish. Also some other aquatic animals, insects, and amphibians.

Behavior

Foraging

Dives from the surface of the water and chases prey underwater. Grabs fish in bill, without spearing it.

Reproduction

Nest Type

Large, often flat nest of sticks and other bulky items, including seaweed and flotsam. Lined with grass or similar material. Placed in trees, on ground, or on cliffs. Nests in colonies.

Egg Description

Unmarked pale blue.

Clutch Size

Usually 3-4 eggs. Range: 1-7.

Condition at Hatching

Naked and helpless.

Conservation Status

Cormorant populations greatly decreased in the 19th and early 20th centuries from human persecution. They recovered after the 1920s, with an interruption in the recovery during the pesticide era of the 1950s and 1960s. The National Audubon Society considered it a species of special concern in 1972. Increases after the 1970s were explosive in some areas. Increasing cormorant populations have caused conflicts with people. Cormorants have been suggested as playing an important role in the collapse of some fisheries, although data to support these claims are sparse. Cormorants eat fish at fish farms, and recent legislation has been proposed to control cormorant numbers. For more information, click here.

Other Names

Cormoran à aigrettes (French)
Cormorán Orejudo, Cormorán Bicrestado, Corúa de Mar (Spanish)

Sources used to construct this page:

Hatch, J. J., and D. V. Weseloh. 1999. Double-crested Cormorant (Phalacrocorax auritus). In The Birds of North America, No. 441 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.