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Double-Crested Cormorant

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Double-Crested Cormorant - Non-Breeding Adult

Double-Crested Cormorant - Non-Breeding Adult

USFWS

The most widespread cormorant in North America, the double-crested cormorant is also the cormorant most likely to be seen at inland lakes and waterways. Though related to boobies and tropicbirds, this dark, chunky bird seems to have little in common with is sleeker, more colorful cousins.

Common Name:

Double-Crested Cormorant, Sea Crow

Scientific Name:

Phalacrocorax auritus

Scientific Family:

Phalacrocoracidae

Appearance:

  • Bill: Long, black or gray but paler at base, prominently hooked tip
  • Size: 28-32 inches long with 45-52-inch wingspan, long neck, heavy body, long tail less than half the body length
  • Colors: Black, white, blue, yellow, orange, gray-black, brown, green, buff
  • Markings: Genders are similar with overall black plumage that tends toward brownish-black on the upperparts with scaly edging to the feathers. The plumage can show a green gloss in bright sunlight. Bare facial skin at the base of the bill and across the lores is a bright yellow or orange, and the eyes are bright blue. During the breeding season, adults grow ear tufts above the eyes that are white in western birds but are shorter and darker in eastern birds, though the color, length and thickness of the tufts varies widely. The legs and feet are black.

    Juveniles have a brownish head and neck, and the breast can be brown, buff or whitish. The tail is black, and they may show paler yellow on the face.

Foods:

Fish, crustaceans, insects (See: Piscivorous)

Habitat and Migration:

These birds are always found near open water sources such as lakes, bays, large rivers or coasts, particularly where brushy or rocky islands are available for roosts and nesting. Their year-round range extends along the Pacific coast from the Aleutian Islands south to the tip of the Baja Peninsula, though they are often absent from the northern coast of British Columbia. Additional year-round populations are found along the western coast of mainland Mexico and from the central Texas Gulf coast through the southeast, including all of Florida, to Connecticut. During the summer, the breeding population of double-crested cormorants spreads out to include much of the Midwest and northern Great Plains regions as far as northern Utah and southern Idaho where suitable habitat can found, and as far as the southern and central portions of Alberta, Saskatchewan and Manitoba. In winter, these birds are found along the northern coast of British Columbia and extend their range to much of the interior southeastern United States as far as western Texas, Arkansas and western Tennessee.

Vocalizations:

Away from the nest the double-crested cormorant is usually silent, but when caring for chicks a variety of deep grunts, moans and squeaks can be heard. Young birds have a squeaky begging call. Combined in large colonial nesting flocks, the noises of double-crested cormorants can be overwhelming.

Behavior:

These birds seem clumsy and heavy in flight and often fly in ragged V formations while holding their necks in a slight kink. When swimming they ride low in the water, and dive headfirst to fish. Their plumage is not as strongly waterproofed as other waterfowl, and they are often seen sunning themselves with their wings spread to dry off. These are gregarious birds and can gather in large flocks where food sources or roosting spots are plentiful.

Reproduction:

These are monogamous birds that mate after a male has successfully impressed a female by puffing out his yellow gular skin and showing off his bright blue eyes. Double-crested cormorants are colonial nesting birds, and both parents work together to build a shallow platform nest of sticks lined with twigs or grasses. Many different types of garbage and other debris may also be used as nesting material, and the nests are typically built very low over water or rocks.

The long eggs are bluish-white but may be stained with reddish or brown splotches from the nesting material. There are 2-4 eggs in a typical brood, and only one brood is laid per year. Both parents share incubation duties for 28-30 days, and after hatching, both parents continue to care for the altricial young. The juvenile birds will remain under their parents care for 60-70 days until they are fully independent, though they will leave the nest far earlier and return to be fed.

Attracting Double-Crested Cormorants:

These are not typical backyard birds, but in the appropriate habitat they can be attracted to specific areas with abundant fish and suitable perches for sunning. Protecting water supplies to ensure a healthy, vigorous fish population is essential to protect double-crested cormorants.

Conservation:

Double-crested cormorants experienced sharp population declines due to DDT poisoning in the 1960s and 1970s. Today, these birds are common and widespread, though they are occasionally still persecuted by fishermen who believe them to be competitors for popular sport fish (which has been studied and disproven). In severe cases, authorized culls of double-crested cormorants may be planned to protect fishing areas. Nesting birds are also threatened by fishing line that might be incorporated into nests but could injure chicks.

Similar Birds:

  • Brandt's Cormorant (Phalacrocorax penicillatus)
  • Neotropic Cormorant (Phalacrocorax brasilianus)
  • Great Cormorant (Phalacrocorax carbo)
  • Pelagic Cormorant (Phalacrocorax pelagicus)
  • Little Black Cormorant (Phalacrocorax sulcirostris)
  • European Shag (Leucocarbo aristotelis)
  • Anhinga (Anhinga anhinga)

Photo – Double-Crested Cormorant – Non-Breeding Adult © USFWS
Photo – Double-Crested Cormorant – Breeding Adult © Mike Baird, flickr.bairdphotos.com
Photo – Double-Crested Cormorant – Juvenile © Ian Sane

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