Double-crested Cormorant
Double-crested Cormorant (Phalacrocorax auritus )
The double-crested cormorant (Phalacrocorax auritus ) is a species of bird in the family of cormorants. Ohrenscharben are the only cormorant, which are found in North America, both along the coast and inland, and the largest cormorant in North America. We distinguish four subspecies.
In Europe, the double-crested cormorant is a rare exception guest, with scattered evidence, especially in the UK and rare in the Azores and the Canary Islands.
Description
Full grown achieve Ohrenscharben that one counts generally to marine birds, a body length of 76-91 inches and then have a body weight of about 1.5 to 2 kilograms. The plumage is black and shimmers slightly greenish. Ohrenscharben have the typical cormorants torpedo-shaped body. The neck is very flexible; the big feet have webbed feet. Similar to the native to Europe Cormorant they have a hook-shaped and powerful beak. The iris is greenish, the featherless skin on the chin and on the basis beak is orange and in some individuals even orange-yellow. The beak is dark.
Area of distribution and habitat
The range of the double-crested cormorant ranges from Alaska to the Gulf of California and the East North America from Newfoundland to Cape Cod Stocks of this bird are very large. For the fish farms along the Mississippi River, these birds are a problem, as they hunt the fish drawn there.
The habitat is cool, subtropical shores in sheltered estuaries or bays and mangrove swamps, rocky shores and coastal islands. Inland, the species occurs in lakes, rivers, reservoirs and flood plains.
Way of life
The double-crested cormorant lives all year gregarious and nest in colonies. They are monogamous birds and go a long standing relationships. They show especially a large nest fidelity. In breeding colonies first come to the males, the opposite Nistplatzkonkurrenten defend each nest. Through the nest fidelity and annual nesting nests are very large and can reach a height of up to two meters. Both parents birds are involved in the annual construction and also to defend the nest, since under the Ohrenscharben theft of nest material is common.
Clutches may include between one to seven eggs. The usual clutch size is four eggs, however. These are pale blue. They are incubated by both parents birds for a period of 25 to 30 days. The chicks are brooded and fed by both parents birds. The young birds are fledged with twenty to thirty days and can fifteen to twenty days to fly. You are able to reproduce with two to three years.