The Double-crested Cormorant is the most numerous and widespread North American cormorant. This large, dark waterbird is the only cormorant that occurs in large numbers inland, near fresh water, as well as on the coast. Cormorants (from the Latin for “sea crow”) are often seen floating low in the water, neck and bill raised, or perching upright near water to dry their outstretched wings.

Growing in numbers throughout its range, the Double-crested Cormorant is widely distributed across North America. It breeds locally along all coasts and extensively in Florida, the center of continent, and along the Great Lakes and the St. Lawrence Seaway, as well as in Mexico, Belize, the Bahamas, and Cuba. Most cormorants winter along the Pacific Coast from Alaska to Mexico, along the Atlantic and Gulf coasts from North Carolina to Belize, and inland on ice-free areas along large rivers and lakes.

Double-crested Cormorant populations decreased in the 19th and early 20th centuries due to human persecution at nesting colonies. Protective legislation led to population recovery in the 1920s, until the impacts of pesticide use in the 1950s and 1960s caused numbers to drop once again. The National Audubon Society listed the cormorant as a species of special concern in 1972, the same year DDT was banned. Since then, cormorant numbers and ranges have both been on the rise, particularly in eastern and central North America, as shown by BBS and CBC data.

Double-crested Cormorants have a long history of being persecuted by humans. Recent increases in their numbers have spurred renewed controversy. These increases have been most notable in the northern and eastern parts of the breeding range, and in southern states where these birds winter, causing conflicts with local catfish farms. Double-crested cormorants are perceived to be detrimental to such fish farms, as well as to sport fisheries.

 

In natural environments, fish species of direct interest to fishermen rarely make up a large part of the cormorants’ diet. However, cormorants feed opportunistically on readily available fish, often congregating where these fish are easily caught, such as after fish-stocking releases, downstream of fish hatcheries, or at aquaculture facilities. The extent of the economic impact is difficult to establish. The United States Fish and Wildlife Service recently extended cormorant control options to other government entities in the central and eastern U.S., although not to the public (i.e., there is no hunting season). To reduce cormorant impacts, both lethal and non-lethal programs (the latter include egg oiling, pyrotechnics, and improved aquaculture practices) have been carried out in various locations. Many government agencies in the U.S. and Canada are exploring how best to address this situation.

 

On East Sand Island in the Pacific Northwest, researchers are studying how social attraction techniques, such as decoys, audio playbacks of cormorant colony calls, and artificial stick nests) can help to restore or relocate Double-crested Cormorant colonies. Their studies have proven successful, with cormorants attempting to nest on eight of nine social attraction plots.

Join beach cleanups in your area. Properly discarding of debris, particularly plastic, will prevent cormorants and other waterbirds from eating it.

 

Don’t discard used oil into city sewers or municipal water supplies. It can end up in the ocean where cormorant rest and feed.

 

Dispose of monofilament lines, hooks, and fishing lures properly; cormorants can become entangled in this gear.

 

Don’t disturb nesting cormorants when hiking or boating; prevent dogs and children from disturbing them. Cormorants are very sensitive to disturbance near the nest; when scared from their nests, gulls will frequently feed on their eggs and young.

 

Make environmentally-friendly seafood choices, which helps protect fish that cormorants and other waterbirds depend upon. Learn more at http://seafood.audubon.org or http://www.mbayaq.org/cr/seafoodwatch.asp

 

Learn about ocean conservation at http://www.livingoceans.org/index.shtml

 

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.

 

Kaufman, Kenn. 1996. Lives of North American Birds. Houghton Mifflin Company, New York.

 

Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, Inc., New York, 2000