birds free wallpaper 99: Black Tern

Tuesday, 29 May 2012

Black Tern

Black Tern Biography

A marsh-breeding bird, the Black Tern nests in freshwater wetlands in Eastern Washington, mostly east of the Okanogan and Columbia Rivers. For nesting, it requires habitat with extensive, cover-providing, vegetation as well as open water. During migration, it uses large lakes and coastlines. In winter, it can be found along productive marine coastlines, lagoons and estuaries, especially off the Pacific Coast of Panama.

Black Terns swoop to pluck food from the water's surface; they rarely plunge-dive under the water. They will also forage in flight, snatching flying insects out of the air. Highly social, they often forage in flocks.

In the breeding season, insects are the primary food source, although small fish and other aquatic creatures are also eaten. During migration and in winter, small fish make up the bulk of the diet.

Breeding in scattered colonies, often associated with Forster's Terns, Black Terns nest low in marshes, on floating vegetation mats, muskrat houses, or on the ground near water. Both parents help build a nest which ranges from a substantial mound of vegetation to a simple depression with a little bit of vegetation added. When mixed with Forster's Terns, the Black Tern nests tend to be lower, closer to the water. In fact, the eggs of Black Terns are adapted to get wet (but not for extended periods of time), and are often moist. Both parents incubate the 2-4 eggs for about three weeks. After 2-3 days they may leave the nest, but stay close by. In approximately three weeks the young are ready to fly, but they may be fed by their parents for up to 2 more weeks. Typically only one brood is raised each year.

Black Tern