Birds of Ocracoke Series

Birds of Ocracoke: the Double-crested Cormorant

Double Crested Cormorant in flight PS IMG_6071

To see more profiles in the Birds of Ocracoke series, click here 

Phalacrocorax auritus

Text and photos by Peter Vankevich

Perhaps the signature seabird of Ocracoke during the fall and winter, these birds are present in the thousands.  All throughout the day, one may see lines of them flying just above the  water numbering in the hundreds. When flying higher in the air, they will use a V-formation.

These cormorants  float low in the water and in flight, are easily identified by a long neck and body with black or dark-brown plumage with orange-yellow

Carol Pahl estimating the great number of Double-crested Cormorants on Ocracoke on a Christmas Bird Count.

Carol Pahl estimating the great number of Double-crested Cormorants on Ocracoke on a Christmas Bird Count.

skin of the face and throat. Breeding plumage will have a dull greenish or bronze gloss that fades out over time.   The underparts of a juvenile are lighter than the back with a pale throat and breast that darkens towards the belly.

The “double crest” is a poor field mark; apparent for only a brief time during courtship.

Cormorants dive from the surface to forage on schooling fish,  bottom-dwelling fish and invertebrates. They may be seen perched with their wings spread to dry.

Generally silent on Ocracoke, though the sound of their wings can be delightful.

 

 

Listen

(audio provided courtesy of OhioLINK Digital Resource Commons)

When to see: Possible year around, a few nonbreeders in summer. Abundant by mid-fall till early spring.

Where: Both Ocracoke and Hatteras inlets. In flight over ocean, island and sound. Look for long straight lines of flocks. Dawn arisings from roosts can be spectacular.

Click here for the Birds of the Outer Banks checklist

 

Notes:

The Double-crested Cormorant is the most numerous and most widely distributed species of the 6 North American cormorants and is the only cormorant to occur in large numbers in the interior as well as on the coasts. Their wintering grounds in North Carolina have increased substantially throughout the state to include many lakes, reservoirs and rivers.

There are just a couple of known breeding sites in North Carolina.Cormorant_onbeach_IMG_3882

There have been extensive studies on the levels and effects of contaminants on this species. Cormorants acquire contaminants from the fish they eat and high levels can signify environmental problems.

A similar species is the Great Cormorant which may be seen on occasion on and around the island. It is somewhat larger and thicker overall; breeding adults have prominent white flank patches and a less-obvious white patch around the bill. Juvenile Great Cormorants have a white belly. Great Cormorants tend to perch on pilings.

Perceived as a threat to fish populations, both recreational and  commercial aquaculture facilities (primarily catfish),  permits have been issued to control their numbers. This is a controversial measure with some questioning its effectiveness.

Gannets Cormorants PS IMG_6904

Double-crested Cormorants and Northern Gannets off breakers of Ocracoke beach.

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