Double-crested Cormorant

 

 

Photo Credit: Don Getty
http://www.dongettyphoto.com/

 

 
 
OTHER NAMES: water turkey, crow-duck, shag
 
DESCRIPTION: The double-crested cormorant is a large black bird that varies in length from 29 to 36 inches with a wingspan up to 52 inches. They can appear to have a green sheen color under certain sunlight. A yellow throat-patch is a distinguishing characteristic on mature birds. Juveniles are brown with a white face and breast. Males and females cannot be separated by viewing. Cormorants make a sound similar to a deep grunt.
 
DISTRIBUTION: The range of the cormorant extends from Mexico to southern Alaska on the west coast, and from the Bahamas to New England on the east coast. 
 
HABITAT: Rivers, lakes, inland bays, and ocean areas.
 
FEEDING HABITS: Cormorants mainly eat fish, but will also feed on amphibians and crustaceans. Using its feet for propulsion, cormorants can dive up to 25 ft. and remain underwater for 30 to 70 seconds while searching for food.  Unlike many other diving birds, their feathers are not completely waterproof. Cormorants spend long periods of time with their wings outstretched to dry after diving for food. They feed in rivers, freshwater lakes, inland bays, and ocean areas. Many consider these birds to be pests because large numbers can wipe out local fish populations in small farm ponds and commercial catfish operations. Accumulated fecal matter can devastate areas where they roost by killing trees and other shrubs and plants.
 
LIFE HISTORY AND ECOLOGY: Breeding occurs in coastal areas as well as inland rivers and lakes. Nests are constructed of sticks, pieces of rope, plastic debris, and are commonly found in trees and on cliff edges. Breeding colonies are generally large consisting of several hundred birds. Large pebbles, treated like eggs, are sometimes found in their nests.  
 
The double-crested cormorant’s numbers were reduced dramatically in the 1960’s due to negative effects from DDT. However, populations have been increasing over the past few years. In an effort to alleviate problems associated with their growing numbers, the United States Fish and Wildlife Service recently extended control options to some government entities. There is not a hunting season open to the general public.
 
REFERENCES:
 
Alsop, Fred J. III; Birds of Texas. Smithsonian Handbooks: DK Publishing, Inc.,
New York, NY (2002)
 
US Fish & Wildlife Service
(http://migratory birds.fws.gov/issues/cormorant/cormorant.html)
 
 
AUTHOR: Frank Allen, Wildlife Biologist, Division of Wildlife and Freshwater Fisheries, May 2006
SCIENTIFIC NAME:  Phalacrocorax auritus


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